957 research outputs found

    Better late than never, but never late is better: risk assessment of nuclear power construction projects

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    This work seeks to evaluate overnight construction costs (OCC) and lead-time escalation of nuclear power construction projects from 1955 to 2016. To this end, a comprehensive database of commercial Light Water Reactors (LWR) was developed and a statistical analysis was conducted. Findings reveal a significant delay in lead-time, especially for the last generation reactors constructed from 2010s, with 3/4 of the sample showing significant construction delays. This results in an escalation of capital costs rather than in a decline. Average OCC of newer reactors is 60% higher than the ones implemented in the earlier stages of the nuclear era. This suggests a discontinuity of the learning curve for both OCC and lead-time, which threats the market and financial sustainability of current and future nuclear energy projects. Although this is a general trend, this discontinuity is country specific and, thus, induced by national policies and regulatory frameworks. Therefore, the role of nuclear technology as an alternative to cope with the need for a decarbonisation of the power sector must be better evaluated, taking into account the real cost impacts of nuclear technology implementation.- This work was funded by the Brazilian National Council for Scientific and Technological Development agency (CNPq) (166074/2015-2) and the Marie Curie International Research Staff Exchange Scheme Fellowship within the 7th European Union Framework Programme, under the project NETEP- European Brazilian Network on Energy Planning (PIRSES-GA-2013-612263). Authors would like to acknowledge Rafael Garaffa for his helpful advices about processing data with R statistical software and data analysis. Authors are also thankful to the comments of anonymous reviewers. Special thanks to the Grantham Institute and Imperial College London media office for assisting in publicising the findings of the paper

    Polissacarídeos da biodiversidade brasileira: uma oportunidade de transformar conhecimento em valor econômico

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    A brief comment about general characteristics of polysaccharide was presented. Brazilian trade of polysaccharides was obtained from the "Ministério de Desenvolvimento, Indústria e Comércio Exterior" - Brazil. A list of these products was prepared and their price and amount analyzed in the period of 1998-2007. Some chemical properties and application of polysaccharides from our biodiversity was described. In this review they were classified by origin, in vegetal (exudate, seed, fruit, seaweed), animal and bacteria source. There is a trade deficit that can be reverted if part of the accumulated scientific knowledge was used to promote the national economic development in the field

    Smoking-induced aggravation of experimental arthritis is dependent of aryl hydrocarbon receptor activation in Th17 cells.

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    Background: Epidemiologic studies have highlighted the association of environmental factors with the development and progression of autoimmune and chronic inflammatory diseases. Among the environmental factors, smoking has been associated with increased susceptibility and poor prognosis in rheumatoid arthritis (RA). However, the immune and molecular mechanism of smoking-induced arthritis aggravation remains unclear. The transcription factor aryl hydrocarbon receptor (AHR) regulates the generation of Th17 cells, CD4 T cells linked the development of autoimmune diseases. AHR is activated by organic compounds including polycyclic aromatic hydrocarbons (PAHs), which are environmental pollutants that are also present in cigarette smoke. In this study, we investigated the role of AHR activation in the aggravation of experiment arthritis induced by exposure to cigarette smoke. Methods: Mice were exposed to cigarette smoke during the developmental phase of antigen-induced arthritis and collagen-induced arthritis to evaluate the effects of smoking on disease development. Aggravation of articular inflammation was assessed by measuring neutrophil migration to the joints, increase in articular hyperalgesia and changes in the frequencies of Th17 cells. In vitro studies were performed to evaluate the direct effects of cigarette smoke and PAH on Th17 differentiation. We also used mice genetically deficient for AHR (Ahr KO) and IL-17Ra (Il17ra KO) to determine the in vivo mechanism of smoking-induced arthritis aggravation. Results: We found that smoking induces arthritis aggravation and increase in the frequencies of Th17 cells. The absence of IL-17 signaling (Il17ra KO) conferred protection to smoking-induced arthritis aggravation. Moreover, in vitro experiments showed that cigarette smoke can directly increase Th17 differentiation of T cells by inducing AHR activation. Indeed, Ahr KO mice were protected from cigarette smoke-induced arthritis aggravation and did not display increase in TH17 frequencies, suggesting that AHR activation is an important mechanism for cigarette smoke effects on arthritis. Finally, we demonstrate that PAHs are also able to induce arthritis aggravation. Conclusions: Our data demonstrate that the disease-exacerbating effects of cigarette smoking are AHR dependent and environmental pollutants with AHR agonist activity can induce arthritis aggravation by directly enhancing Th17 cell development

    Evaluation of acute oral toxicity and diuretic activity of Rudgea viburnoides (Cham.) Benth. (congonha-de-bugre)

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    Rudgea viburnoides é utilizada popularmente como diurética, hipotensora, antirreumática, antissifilítica, depurativa do sangue e tratamento da dispepsia. Este trabalho teve como objetivos avaliar a toxicidade aguda e a atividade diurética do extrato etanólico bruto (EEBFRV) das folhas da R. viburnoides. Na toxicidade aguda empregou-se o teste de Classe, nas doses de 2000 e 5000 mg/kg, dose única, gavage, em camundongos Swiss e ratos Wistar (ambos os sexos). Na atividade diurética administrou-se em ratas Wistar o extrato bruto (40, 80 e 160 mg/kg, furosemida 20 mg/kg (controle +) e solução salina 0,9% (controle -). Não houve letalidade ou sinais de intoxicação, indicando baixa toxicidade desse extrato. O efeito diurético foi dose-dependente nas 24 h, com aumento dos parâmetros: volume de urina 24 h, excreção dos eletrólitos sódio, potássio e cloreto, uréia e creatinina. Os resultados até o momento, podem justificar a sua utilização popular como diurética.Rudgea viburnoides is popularly used as anti-hypertensive, anti-rheumatic, antissifilitic, blood depurative and for treatment of dyspepsia (leaves, bark, tea). The acute toxicity of ethanolic extract (EEBFRV) in single dose was performed by gavage of doses of 2000 and 5000 mg/kg in Swiss mice and Wistar rats, both sexes, by the class test. To diuretic activity in Wistar rats, it was used the EEBFRV at the doses of 40, 80 and 160 mg/kg, furosemide 20 mg/kg (control +), and saline solution 0.9 % (control -). Regarding acute toxicity, no mortality and no toxicity signs at the dose levels were observed, indicating low toxicity of the extract. The EEBFRV showed statistically significant dose-dependent diuretic effect in 24 h, increasing all parameters evaluated (24h urine volume, excretion of Na+, K+ and Cl- electrolytes, urea (BUN) and creatinine). Thus, the results so far may justify the popular use of Rudgea viburnoides as diuretic.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Enhanced role of adenosine A2A receptors in the modulation of LTP in the rat hippocampus upon ageing

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    Adenosine neuromodulation depends on a balanced activation of inhibitory A1 (A1R) and facilitatory A2A receptors (A2AR). Both A1R and A2AR modulate hippocampal glutamate release and NMDA-dependent long-term potentiation (LTP) but ageing affects the density of both A1R and A2AR. We tested the effects of selective A1R and A2AR antagonists in the modulation of synaptic transmission and plasticity in rat hippocampal slices from three age groups (young adults, 2–3 month; middle-aged adults, 6–8 months; aged, 18–20 months). The selective A2AR antagonist SCH58261 (50 nm) attenuated LTP in all age groups, with a larger effect in aged ()63 ± 7%) than in middle-aged adults ()36 ± 9%) or young adult rats ()36 ± 9%). In contrast, the selective A1R antagonist DPCPX (50 nm) increased LTP magnitude in young adult rats (+42 ± 6%), but failed to affect LTP magnitude in the other age groups. Finally, in the continuous presence of DPCPX, SCH58261 caused a significantly larger inhibition of LTP amplitude in aged ()71 ± 45%) than middle-aged ()28 ± 9%) or young rats ()11 ± 2%). Accordingly, aged rats displayed an increased expression of A2AR mRNA in the hippocampus and a higher number of glutamatergic nerve terminals equipped with A2AR in aged (67 ± 6%) compared with middle-aged (34 ± 7%) and young rats (25 ± 5%). The results show an enhanced A2AR-mediated modulation of LTP in aged rats, in accordance with the age-associated increased expression and density of A2AR in glutamatergic terminals. This age-associated gain of function of A2AR modulating synaptic plasticity may underlie the ability of A2AR antagonists to prevent memory dysfunction in aged animals

    Reactivation of latent HIV-1 in vitro using an ethanolic extract from Euphorbia umbellata (Euphorbiaceae) latex

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    Euphorbia umbellata (E. umbellata) belongs to Euphorbiaceae family, popularly known as Janauba, and its latex contains a combination of phorbol esters with biological activities described to different cellular protein kinase C (PKC) isoforms. Here, we identified deoxi-phorbol esters present in E. umbellata latex alcoholic extract that are able to increase HIV transcription and reactivate virus from latency models. This activity is probably mediated by NF-kB activation followed by nuclear translocation and binding to the HIV LTR promoter. In addition, E. umbellata latex extract induced the production of pro inflammatory cytokines in vitro in human PBMC cultures. This latex extract also activates latent virus in human PBMCs isolated from HIV positive patients as well as latent SIV in non-human primate primary CD4+ T lymphocytes. Together, these results indicate that the phorbol esters present in E. umbellata latex are promising candidate compounds for future clinical trials for shock and kill therapies to promote HIV cure and eradication.Research and experimental expenses were funded by the grant E26/2015064289 from FAPERJinfo:eu-repo/semantics/publishedVersio

    In-depth genome characterization of a Brazilian common bean core collection using DArTseq high-density SNP genotyping

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    Background: Common bean is a legume of social and nutritional importance as a food crop, cultivated worldwide especially in developing countries, accounting for an important source of income for small farmers. The availability of the complete sequences of the two common bean genomes has dramatically accelerated and has enabled new experimental strategies to be applied for genetic research. DArTseq has been widely used as a method of SNP genotyping allowing comprehensive genome coverage with genetic applications in common bean breeding programs. Results: Using this technology, 6286 SNPs (1 SNP/86.5 Kbp) were genotyped in genic (43.3%) and non-genic regions (56. 7%). Genetic subdivision associated to the common bean gene pools (K = 2) and related to grain types (K = 3 and K = 5) were reported. A total of 83% and 91% of all SNPs were polymorphic within the Andean and Mesoamerican gene pools, respectively, and 26% were able to differentiate the gene pools. Genetic diversity analysis revealed an average HE of 0.442 for the whole collection, 0.102 for Andean and 0.168 for Mesoamerican gene pools (FST = 0.747 between gene pools), 0. 440 for the group of cultivars and lines, and 0.448 for the group of landrace accessions (FST = 0.002 between cultivar/line and landrace groups). The SNP effects were predicted with predominance of impact on non-coding regions (77.8%). SNPs under selection were identified within gene pools comparing landrace and cultivar/line germplasm groups (Andean: 18; Mesoamerican: 69) and between the gene pools (59 SNPs), predominantly on chromosomes 1 and 9. The LD extension estimate corrected for population structure and relatedness (r2 SV) was~88 kbp, while for the Andean gene pool was~395 kbp, and for the Mesoamerican was ~ 130 kbp. Conclusions: For common bean, DArTseq provides an efficient and cost-effective strategy of generating SNPs for large-scale genome-wide studies. The DArTseq resulted in an operational panel of 560 polymorphic SNPs in linkage equilibrium, providing high genome coverage. This SNP set could be used in genotyping platforms with many applications, such as population genetics, phylogeny relation between common bean varieties and support to molecular breeding approaches

    DIMENSÕES QUALITATIVAS E QUANTITATIVAS DO TRABALHO HOSPITALAR: INTERFACE COM A CULTURA DE SEGURANÇA DO PACIENTE

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    Objetivou-se analisar a cultura de segurança do paciente entre a equipe multiprofissional hospitalar quanto às dimensões que tratam do qualitativo organizacional e o quantitativo de pessoal. Procedeu-se pesquisa descritiva, quantitativa, com a participação de 71 profissionais de um hospital de ensino público do interior do Paraná, que responderam ao questionário “Hospital Survey on Patient Safety Culture”. A análise estatística descritiva foi procedida às dimensões de aprendizado organizacional (qualitativa) e dimensão de pessoal (quantitativa) do referido instrumento. A maioria (67,6%) dos sujeitos legitimou percepção favorável ao aprendizado organizacional contínuo, contudo, 91,6% dos profissionais sinalizaram que o hospital empregador não propicia quantitativo adequado de pessoal para o atendimento seguro, além das pessoas estarem expostas à elevada carga de trabalho e continuamente atuarem sob tensão. Concluiu-se que, através desta dualidade na percepção dos participantes, fica evidente a maior e melhor atenção das lideranças à provisão de capital humano adequado no serviço. Descritores: Segurança do Paciente; Cultura Organizacional; Downsizing Organizacional; Gestão da Qualidade; Administração Hospitalar.
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