169 research outputs found

    Phylogeny of the "orchid-like" bladderworts (gen. Utricularia sect. Orchidioides and Iperua : Lentibulariaceae) with remarks on the stolon-tuber system

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    Background and Aims The "orchid-like" bladderworts (Utricularia) comprise 15 species separated into two sections: Orchidioides and Iperua. These robust and mostly epiphytic species were originally grouped within the section Orchidioides by the first taxonomical systems. These species were later split into two sections when sect. Iperua was proposed. Due to the lack of strong evidence based on a robust phylogenetic perspective, this study presents a phylogenetic proposal based on four different DNA sequences (plastid and nuclear) and morphology to test the monophyly of the two sections. Methods In comparison with all previous phylogenetic studies, the largest number of species across the sections was covered: 11 species from sections Orchidioides and Iperua with 14 species as an external group. Maximum likelihood and Bayesian inferences were applied to DNA sequences of rps16, trnL-F, matK, the internal transcribed spacer (ITS) and three morphological characters: (1) the crest of the corolla; (2) the primary organs in the embryo; and (3) tubers. Additionally, a histochemical analysis of the stolons and tubers is presented from an evolutionary perspective. Key Results The analyses showed the paraphyly of sect. Iperua, since Utricularia humboldtii is more related to the clade of sect. Orchidioides. Utricularia cornigera is grouped in the sect. Iperua clade based on chloroplast DNA sequences, but it is nested to sect. Orchidioides according to ITS dataset. Morphological characters do not support the breaking up of the 'orchid-like' species into two sections, either. Moreover, the stolon-tuber systems of both sections serve exclusively for water storage, according to histological analyses. Conclusions This study provides strong evidence, based on DNA sequences from two genomic compartments (plastid and nucleus) and morphology to group the Utricularia sect. Orchidioides into the sect. Iperua. The tubers are important adaptations for water storage and have been derived from stolons at least twice in the phylogenetic history of 'orchid-like' bladderworts

    Theory of reactions between hydrogen and group-III acceptors in silicon

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    The thermodynamics of several reactions involving atomic and molecular hydrogen with group-III acceptors is investigated. The results provide a first-principles-level account of thermally- and carrier-activated processes involving these species. Acceptor-hydrogen pairing is revisited as well. We present a refined physicochemical picture of long-range migration, compensation effects, and short-range reactions, leading to fully passivated Si-HX\equiv\textrm{Si-H}\cdots X\equiv structures, where XX is a group-III acceptor element. The formation and dissociation of acceptor-H and acceptor-H2_{2} complexes is considered in the context of Light and elevated Temperature Induced Degradation (LeTID) of silicon-based solar cells. Besides explaining observed trends and answering several fundamental questions regarding the properties of acceptor-hydrogen pairing, we find that the BH2_{2} complex is a by-product along the reaction of H2_{2} molecules with boron toward the formation of BH pairs (along with subtraction of free holes). The calculated changes in Helmholtz free energies upon the considered defect reactions, as well as activation barriers for BH2_{2} formation/dissociation (close to 1\sim1 eV) are compatible with the experimentally determined activation energies of degradation/recovery rates of Si:B-based cells during LeTID. Dihydrogenated acceptors heavier than boron are anticipated to be effective-mass-like shallow donors, and therefore, unlikely to show similar non-radiative recombination activity

    Benefits associated with improving fatigue regulations for cargo pilots

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    This study investigated the potential business benefits of improving fatigue regulations for cargo pilots in Brazil. The research objectives were to compare fatigue levels between cargo and passenger operations, identify regulatory inefficiencies for cargo operators, simulate proposed changes, and analyze cost scenarios. The experimental design involved a review of fatigue regulations in Brazil and the USA, analyzing pilot scheduling data, and the creation of hypothetical flexible scheduling scenarios for 70 pilots flying 16,500 hours annually. We reviewed NTSB data on fatigue-related incidents in US cargo operations with flexible regulations and from the fatigue program of LATAM Cargo. Comparisons between the USA and the rest of the world showed that the rate of accidents per number of cargo flights in the USA is below average, with most accidents not attributed to fatigue. The results indicated that aligning with the US CFR 117 could improve cargo pilot availability in Brazil by 34.28%, with a potential cost savings of up to $3.6 million for an airline of that size. This research highlights the importance of flexibility and adaptation in fatigue management and mental health programs for pilots in the aviation industry, particularly cargo operations. Introducing more flexible fatigue regulations for cargo pilots could lead to operational efficiencies and potential cost savings without compromising safety. Further research needs to explore the impacts of these changes on passenger operations and to gather feedback from pilots and unions regarding extended pilot schedules. The proposed regulatory changes focused on maximum duty time, flight hours, rest periods, and monthly/annual limits

    Robótica para a Inclusão Social (RISO): promovendo a robótica na comunidade e inserindo discentes no contexto social

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    Anais do 35º Seminário de Extensão Universitária da Região Sul - Área temática: EducaçãoO Grupo Estudantil de Robótica Móvel (GERM) promove iniciativas de ensino, pesquisa e extensão no âmbito da disseminação da robótica. Dentre as iniciativas centradas na extensão encontra-se o programa de extensão Robótica para a Inclusão Social (RISO), que tem por objetivo a aproximação da sociedade com a área da robótica, incentivando crianças e adolescentes do município de Joinville/SC a ingressarem no ensino superior. O programa é composto por três ações, que difundem a robótica na sociedade através de aulas ministradas com kits de robôs LEGO MINDSTORMS® em escolas da rede pública e instituições carentes, campeonatos e outros eventos relacionados a área. O RISO já alcançou uma quantidade expressiva de pessoas na comunidade interna e externa, tornando-se uma ação extensionista de referência na regiã

    Hydration with sodium bicarbonate does not prevent contrast nephropathy: a multicenter clinical trial

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    BACKGROUND: Radiographic contrast media exposition can cause acute renal function impairment. There is limited and conflicting evidence that hydration with sodium bicarbonate prevents contrast-induced nephropathy (CIN) in patients undergoing cardiac catheterization. OBJECTIVE: The present study was aimed at determining whether sodium bicarbonate is superior to hydration with saline to prevent nephropathy in patients at risk undergoing cardiac catheterization. METHODS: Three hundred and one patients undergoing coronary angiography or percutaneous coronary intervention with serum creatinine > 1.2mg/dL or glomerular filtration rate (GFR) 1,2 mg/dL ou Taxa de Filtração Glomerular (TFG) < 50 mL/min, foram randomizados para receber hidratação com bicarbonato de sódio a partir de 1 hora antes do procedimento, e 6 horas após o procedimento, ou hidratação com solução salina a 0,9%. A NIC foi definida como um aumento de 0,5 mg/dL na creatinina em 48h. RESULTADOS: Dezoito pacientes (5,9%) desenvolveram nefropatia induzida por contraste: 9 pacientes no grupo do bicarbonato (6,1%) e 9 pacientes no grupo da solução salina (6,0%), p = 0,97. A variação na creatinina sérica foi semelhante em ambos os grupos, 0,01 ± 0,26 mg/dL no grupo do bicarbonato, e 0,01 ± 0,35 mg/dL no grupo da solução salina, p = 0,9. Não foi observada diferença estatística entre a alteração na taxa de filtração glomerular (0,89 ± 9 mL/ min vs. 2,29 ± 10 mL/min, p = 0,2, grupo do bicarbonato e grupo da solução salina, respectivamente). CONCLUSÃO: A hidratação com bicarbonato de sódio não foi superior ao soro fisiológico na prevenção a nefropatia induzida pelo contraste, em pacientes de risco submetidos a cateterismo cardíaco.PUCRS Hospital São LucasUNIFESP Hospital São PauloHospital São CamiloHospital General de PueblaHospital da UnimedHospital Intercath MeridionalUFRGSUNIFESP, Hospital São PauloSciEL

    Metabolic Signatures of Lung Cancer in Biofluids: NMR-Based Metabonomics of Blood Plasma

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    In this work, the variations in the metabolic profile of blood plasma from lung cancer patients and healthy controls were investigated through NMR-based metabonomics, to assess the potential of this approach for lung cancer screening and diagnosis. PLS-DA modeling of CPMG spectra from plasma, subjected to Monte Carlo Cross Validation, allowed cancer patients to be discriminated from controls with sensitivity and specificity levels of about 90%. Relatively lower HDL and higher VLDL + LDL in the patients' plasma, together with increased lactate and pyruvate and decreased levels of glucose, citrate, formate, acetate, several amino acids (alanine, glutamine, histidine, tyrosine, valine), and methanol, could be detected. These changes were found to be present at initial disease stages and could be related to known cancer biochemical hallmarks, such as enhanced glycolysis, glutaminolysis, and gluconeogenesis, together with suppressed Krebs cycle and reduced lipid catabolism, thus supporting the hypothesis of a systemic metabolic signature for lung cancer. Despite the possible confounding influence of age, smoking habits, and other uncontrolled factors, these results indicate that NMR-based metabonomics of blood plasma can be useful as a screening tool to identify suspicious cases for subsequent, more specific radiological tests, thus contributing to improved disease management.ERDF - Competitive Factors Thematic Operational ProgrammeFCT/PTDC/ QUI/68017/2006FCOMP-01-0124-FEDER-007439SFRH/BD/ 63430/2009National UNESCO Committee - L'Oréal Medals of Honor for Women in Science 200Portuguese National NMR Network - RNRM
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