A methodology for parameter estimation in seaweed productivity modelling

This paper presents a combined approach for parameter estimation in models of primary production. The focus is on gross primary production and nutrient assimilation by seaweeds. A database of productivity determinations, biomass and mortality measurements and nutrient uptake rates obtained over one year for Gelidium sesquipedale in the Atlantic Ocean off Portugal has been used. Annual productivity was estimated by harvesting methods, and empirical relationships using mortality/ wave energy and respiration rates have been derived to correct for losses and to convert the estimates to gross production. In situ determinations of productivity have been combined with data on the light climate (radiation periods, intensity, mean turbidity) to give daily and annual productivity estimates. The theoretical nutrient uptake calculated using a 'Redfield ratio' approach and determinations of in situ N and P consumption by the algae during incubation periods have also been compared. The results of the biomass difference and incubation approaches are discussed in order to assess the utility of coefficients determined in situ for parameter estimation in seaweed production models

The C-Terminal Domain of the Arabinosyltransferase Mycobacterium tuberculosis EmbC Is a Lectin-Like Carbohydrate Binding Module

The D-arabinan-containing polymers arabinogalactan (AG) and lipoarabinomannan (LAM) are essential components of the unique cell envelope of the pathogen Mycobacterium tuberculosis. Biosynthesis of AG and LAM involves a series of membrane-embedded arabinofuranosyl (Araf) transferases whose structures are largely uncharacterised, despite the fact that several of them are pharmacological targets of ethambutol, a frontline drug in tuberculosis therapy. Herein, we present the crystal structure of the C-terminal hydrophilic domain of the ethambutol-sensitive Araf transferase M. tuberculosis EmbC, which is essential for LAM synthesis. The structure of the C-terminal domain of EmbC (EmbCCT) encompasses two sub-domains of different folds, of which subdomain II shows distinct similarity to lectin-like carbohydrate-binding modules (CBM). Co-crystallisation with a cell wall-derived di-arabinoside acceptor analogue and structural comparison with ligand-bound CBMs suggest that EmbCCT contains two separate carbohydrate binding sites, associated with subdomains I and II, respectively. Single-residue substitution of conserved tryptophan residues (Trp868, Trp985) at these respective sites inhibited EmbC-catalysed extension of LAM. The same substitutions differentially abrogated binding of di- and penta-arabinofuranoside acceptor analogues to EmbCCT, linking the loss of activity to compromised acceptor substrate binding, indicating the presence of two separate carbohydrate binding sites, and demonstrating that subdomain II indeed functions as a carbohydrate-binding module. This work provides the first step towards unravelling the structure and function of a GT-C-type glycosyltransferase that is essential in M. tuberculosis. Author Summary Top Tuberculosis (TB), an infectious disease caused by the bacillus Mycobacterium tuberculosis, burdens large swaths of the world population. Treatment of active TB typically requires administration of an antibiotic cocktail over several months that includes the drug ethambutol. This front line compound inhibits a set of arabinosyltransferase enzymes, called EmbA, EmbB and EmbC, which are critical for the synthesis of arabinan, a vital polysaccharide in the pathogen's unique cell envelope. How precisely ethambutol inhibits arabinosyltransferase activity is not clear, in part because structural information of its pharmacological targets has been elusive. Here, we report the high-resolution structure of the C-terminal domain of the ethambutol-target EmbC, a 390-amino acid fragment responsible for acceptor substrate recognition. Combining the X-ray crystallographic analysis with structural comparisons, site-directed mutagenesis, activity and ligand binding assays, we identified two regions in the C-terminal domain of EmbC that are capable of binding acceptor substrate mimics and are critical for activity of the full-length enzyme. Our results begin to define structure-function relationships in a family of structurally uncharacterised membrane-embedded glycosyltransferases, which are an important target for tuberculosis therapy

Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector

The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV

Gestor de Enfermagem em unidades de saúde mental: das atividades à utilização do tempo

Objective: to understand the use of time by nurse managers in psychiatry and mental health units, as they carry out their daily tasks. Methods: cross-sectional study, carried out by 48 managers from public psychiatric units and from the social sector. Data collection was made through an online questionnaire that is part of the Scale of Perception of Nurse Manager Work, including 43 items separated in five functional domains of nurse managers. The responses were in a Likert scale: does not take time, takes little time, takes some time, takes much time. Results: the activities inherent to ethical and legal professional practices and to the management of care and of human resources required more time from the manager when compared to policy interventions, and consulting and professional development. Conclusion: the managers recognize that managing time implies organization, planning work, and establishing priorities in the tasks to be developed.Objetivo: compreender a utilização do tempo dos gestores de enfermagem em unidades de Saúde Mental e Psiquiatria no desempenho das atividades diárias. Métodos: estudo transversal, constituído por 48 gestores de unidades psiquiátricas públicas e do setor social. Coleta de dados por meio de questionário online que integrava a Escala de Percepção do Trabalho dos Gestores em Enfermagem, inclui 43 itens, distribuídos por cinco domínios funcionais dos enfermeiros gestores. Respostas cotadas em escala tipo Likert: não ocupa tempo; ocupa pouco tempo; ocupa algum tempo; ocupa muito tempo. Resultados: as atividades inerentes às competências prática profissional ética e legal, e gestão de cuidados e de recursos humanos consumiam mais tempo ao gestor comparativamente com intervenção política e assessoria e desenvolvimento profissional. Conclusão: os gestores reconhecem que gerir o tempo implica organização, planejamento do trabalho e estabelecer prioridades nas tarefas a desempenhar.info:eu-repo/semantics/publishedVersio

Uncovering trophic interactions in arthropod predators through DNA shotgun-sequencing of gut contents

Characterizing trophic networks is fundamental to many questions in ecology, but this typically requires painstaking efforts, especially to identify the diet of small generalist predators. Several attempts have been devoted to develop suitable molecular tools to determine predatory trophic interactions through gut content analysis, and the challenge has been to achieve simultaneously high taxonomic breadth and resolution. General and practical methods are still needed, preferably independent of PCR amplification of barcodes, to recover a broader range of interactions. Here we applied shotgun-sequencing of the DNA from arthropod predator gut contents, extracted from four common coccinellid and dermapteran predators co-occurring in an agroecosystem in Brazil. By matching unassembled reads against six DNA reference databases obtained from public databases and newly assembled mitogenomes, and filtering for high overlap length and identity, we identified prey and other foreign DNA in the predator guts. Good taxonomic breadth and resolution was achieved (93% of prey identified to species or genus), but with low recovery of matching reads. Two to nine trophic interactions were found for these predators, some of which were only inferred by the presence of parasitoids and components of the microbiome known to be associated with aphid prey. Intraguild predation was also found, including among closely related ladybird species. Uncertainty arises from the lack of comprehensive reference databases and reliance on low numbers of matching reads accentuating the risk of false positives. We discuss caveats and some future prospects that could improve the use of direct DNA shotgun-sequencing to characterize arthropod trophic networks

Identification of critical paralog groups with indispensable roles in the regulation of signaling flow

Extensive cross-talk between signaling pathways is required to integrate the myriad of extracellular signal combinations at the cellular level. Gene duplication events may lead to the emergence of novel functions, leaving groups of similar genes - termed paralogs - in the genome. To distinguish critical paralog groups (CPGs) from other paralogs in human signaling networks, we developed a signaling network-based method using cross-talk annotation and tissue-specific signaling flow analysis. 75 CPGs were found with higher degree, betweenness centrality, closeness, and ‘bowtieness’ when compared to other paralogs or other proteins in the signaling network. CPGs had higher diversity in all these measures, with more varied biological functions and more specific post-transcriptional regulation than non-critical paralog groups (non-CPG). Using TGF-beta, Notch and MAPK pathways as examples, SMAD2/3, NOTCH1/2/3 and MEK3/6-p38 CPGs were found to regulate the signaling flow of their respective pathways. Additionally, CPGs showed a higher mutation rate in both inherited diseases and cancer, and were enriched in drug targets. In conclusion, the results revealed two distinct types of paralog groups in the signaling network: CPGs and non-CPGs. Thus highlighting the importance of CPGs as compared to non-CPGs in drug discovery and disease pathogenesis

Do hypoxia/normoxia culturing conditions change the neuroregulatory profile of Wharton Jelly mesenchymal stem cells secretome?

Introduction: The use of human umbilical cord Wharton Jelly-derived mesenchymal stem cells (hWJ-MSCs) has been considered a new potential source for future safe applications in regenerative medicine. Indeed, the application of hWJ-MSCs into different animal models of disease, including those from the central nervous system, has shown remarkable therapeutic benefits mostly associated with their secretome. Conventionally, hWJ-MSCs are cultured and characterized under normoxic conditions (21 % oxygen tension), although the oxygen levels within tissues are typically much lower (hypoxic) than these standard culture conditions. Therefore, oxygen tension represents an important environmental factor that may affect the performance of mesenchymal stem cells in vivo. However, the impact of hypoxic conditions on distinct mesenchymal stem cell characteristics, such as the secretome, still remains unclear. Methods: In the present study, we have examined the effects of normoxic (21 % O2) and hypoxic (5 % O2) conditions on the hWJ-MSC secretome. Subsequently, we address the impact of the distinct secretome in the neuronal cell survival and differentiation of human neural progenitor cells. Results: The present data indicate that the hWJ-MSC secretome collected from normoxic and hypoxic conditions displayed similar effects in supporting neuronal differentiation of human neural progenitor cells in vitro. However, proteomic analysis revealed that the use of hypoxic preconditioning led to the upregulation of several proteins within the hWJ-MSC secretome. Conclusions: Our results suggest that the optimization of parameters such as hypoxia may lead to the development of strategies that enhance the therapeutic effects of the secretome for future regenerative medicine studies and applications. © 2015 Teixeira et al.Portuguese Foundation for Science and Technology (FCT) (Ciência 2007 program and IF Development Grant (AJS); and pre-doctoral fellowships to FGT (SFRH/69637/ 2010) and SIA (SFRH/BD/81495/2011); Canada Research Chairs (LAB) and a SSE Postdoctoral Fellowship (KMP); The National Mass Spectrometry Network (RNEM) (REDE/1506/REM/2005); co-funded by Programa Operacional Regional do Norte (ON.2 – O Novo Norte), ao abrigo do Quadro de Referência Estratégico Nacional (QREN), através do Fundo Europeu de Desenvolvimento Regional (FEDER).info:eu-repo/semantics/publishedVersio

Challenges faced by nurse-managers at work in brazilian and portuguese hospitals: A mixed-methods study

Objetivo: analisar os desafios presentes no trabalho de enfermeiros gestores no contexto hospitalar, no Brasil e em Portugal. Método: pesquisa de métodos mistos, abordagem explanatório sequencial, realizada com enfermeiros gestores de quatro hospitais, entre março de 2019 e março de 2020. O estudo iniciou com a etapa quantitativa, aplicando um survey a 143 participantes e dados analisados por estatística analítica e inferencial. A etapa qualitativa foi realizada com 71 destes participantes utilizando entrevistas, para compreender os desafios deste trabalho, e os dados foram submetidos à análise de conteúdo. A integração dos achados foi realizada por meio de conexão de dados. Resultados: na etapa quantitativa os resultados evidenciaram que as atividades de gestão realizadas pelos enfermeiros por cenário, incluíram planejamento, gestão de pessoas, de processos assistenciais, de materiais, da qualidade e liderança, com maiores médias para os quatro primeiros. A qualitativa permitiu aprofundar os achados anteriores, contrastando a invisibilidade do planejamento, confirmando a gestão de pessoas como o desafio comum às realidades, explicando as médias nas realidades nacional e portuguesa. A integração dos achados detalhou na gestão de pessoas e liderança a relevância dos conflitos e do déficit de profissionais. Conclusão: gerenciar pessoas, processos assistenciais e materiais se mostram desafios dos enfermeiros na gestão hospitalar nos dois países. Os enfermeiros carecem de suporte estrutural e formação continuada para melhor gestão e aprimoramento do planejamento e liderança.Objective: to analyze the challenges found in nurse-managers' work in the Brazilian and Portuguese hospital contexts. Method: a mixed-methods research study with a sequential explanatory approach, carried out between March 2019 and March 2020 with nurse-managers from four hospitals. The study was initiated with the quantitative stage, applying a survey to 143 participants and analyzing the data by means of analytical and inferential statistics. The qualitative stage was carried out with 71 of these participants using interviews, in order to understand the challenges inherent to this job, and the data were submitted to content analysis. Integration of the findings was performed through data connection. Results: in the quantitative stage, the results evidenced that the managerial activities carried out by nurses by scenario included planning, people management, management of care processes, management of materials, quality management and leadership, with higher mean values for the first four. The qualitative stage allowed deepening the previous findings, contrasting invisibility of the planning, confirming people management as the common challenge to the realities, explaining the mean values in the national and Portuguese scopes. Integration of the findings detailed the relevance of the conflicts and the deficit of professionals in people management and leadership. Conclusion: managing people, care processes and materials are challenges for nurses in hospital management in both countries. Nurses lack structural support and ongoing training for better management and improvement of planning and leadership.info:eu-repo/semantics/publishedVersio