2,124 research outputs found
Estrutura de tamanho e fertilidade em uma população de Eriocnema fulva Naudin (Melastomataceae) no sudeste do Brasil
Eriocnema fulva Naudin is an endangered perennial herbaceous plant, endemic to Minas Gerais state, Brazil. This study was conducted in the Jambreiro Forest (19° 58' -59'S and 43° 52' -55' W, 800-1100 m altitude). In an attempt to describe the population size structure and its association with individual fertility, fifteen 1 x 1 m contiguous plots were set. We tagged, counted, and measured a total of 260 individuals in 1997, 1998 and 1999. Young individuals with leaf lamina lengths 10 cm in length did not reproduce was 2.69%. The highest survival probability of the large-sized individuals confirmed the strong correlation between size and survival. The data indicated that size is important for the fertility of E. fulva, and it may be one of the relevant aspects to be considered for analyses of survival probability. The intraspecific competition, which was indicated by negative correlation between fruit production per size unit and density, can affect fertility, as larger plants had higher fruit production.Eriocnema fulva Ă© endĂȘmica no estado de Minas Gerais e Ă© ameaçada de extinção. Este estudo foi realizado na Mata do Jambreiro (19° 58' -59' S e 43° 52'-55' W, 800-1100 m de altitude) Com o objetivo de descrever a estrutura de tamanho da população e suas relaçÔes com a fertilidade dos indivĂduos, foram instaladas 15 parcelas contĂguas de 1 x 1m. Marcamos, contamos e medimos um total de 260 indivĂduos em 1997, 1998 e 1999. Os indivĂduos jovens com o comprimento do limbo 10 cm nĂŁo se reproduzirem foi de 2,69%. A maior probabilidade de sobrevivĂȘncia dos indivĂduos de maior tamanho confirmou a forte correlação entre tamanho e sobrevivĂȘncia. Os dados mostraram que o tamanho Ă© importante para a fertilidade de Eriocnema fulva e pode ser relevante para anĂĄlises de probabilidade de sobrevivĂȘncia da espĂ©cie. A competição intra-especĂfica, indicada pela correlação negativa entre a produção de frutos por unidade de tamanho e a densidade, pode influir na fertilidade, pois plantas maiores apresentaram maior produção de frutos.685693Conselho Nacional de Desenvolvimento CientĂfico e TecnolĂłgico (CNPq
Incidence of accidental awareness during general anaesthesia in obstetrics: a multicentre, prospective cohort study
General anaesthesia for obstetric surgery has distinct characteristics that may contribute towards a higher risk of accidental awareness during general anaesthesia. The primary aim of this study was to investigate the incidence, experience and psychological implications of unintended conscious awareness during general anaesthesia in obstetric patients. From May 2017 to August 2018, 3115 consenting patients receiving general anaesthesia for obstetric surgery in 72 hospitals in England were recruited to the study. Patients received three repetitions of standardised questioning over 30 days, with responses indicating memories during general anaesthesia that were verified using interviews and record interrogation. A total of 12 patients had certain/probable or possible awareness, an incidence of 1 in 256 (95%CI 149â500) for all obstetric surgery. The incidence was 1 in 212 (95%CI 122â417) for caesarean section surgery. Distressing experiences were reported by seven (58.3%) patients, paralysis by five (41.7%) and paralysis with pain by two (16.7%). Accidental awareness occurred during induction and emergence in nine (75%) of the patients who reported awareness. Factors associated with accidental awareness during general anaesthesia were: high BMI (25â30 kg.m-2); low BMI (<18.5 kg.m-2); out-of-hours surgery; and use of ketamine or thiopental for induction. Standardised psychological impact scores at 30 days were significantly higher in awareness patients (median (IQR [range]) 15 (2.7â52.0 [2â56]) than in patients without awareness 3 (1â9 [0â64]), p = 0.010. Four patients had a provisional diagnosis of post-traumatic stress disorder. We conclude that direct postoperative questioning reveals high rates of accidental awareness during general anaesthesia for obstetric surgery, which has implications for anaesthetic practice, consent and follow-up
Crescimento foliar de Eriocnema fulva Naudin (Melastomataceae) em um fragmento florestal no Brasil sudeste
Eriocnema fulva Naudin is an endangered herbaceous, perennial, iteroparous, evergreen species geographically restricted to southeastern-center Minas Gerais State, SE Brazil. The individuals occur as patches on rocky riverbanks shaded by seasonal semideciduous Atlantic forest; they are fixed by roots and have a pending stem. Aiming to investigate leaf development and its importance for individual survival, fifteen contiguous plots (1 x 1 m) were set down in Jambreiro Forest (19° 58?-59? S and 43° 52?-55? W, 800-1100 m altitude), in the municipality of Nova Lima. A total of 260 individuals with the largest leaf blade length > 1 cm was tagged and measured in 1997, 1998, and 1999. Leaf expansion was recorded each month during 26 months until April 2000. Plant size was measured through leaf blade length, petiole length, stem length, and number of leaves. Significant changes were detected only after two years, thus indicating that plant growth is slow. The proportion of surviving leaves after two years was 60%. Total blade expansion took over 14 months, a slow growth rate when compared to leaves of other tropical forest canopy and understory species. Long leaf lifespans are to be found in plants exhibiting slow growth, and we observed that some leaves lived longer than three years. Petiole growth can help to better position the leaf in the search for light, thus contributing to the growth and survival of the plant. The relationships among size measures were significant, reinforcing the great contribution of leaf size for plant size. The age of the largest individual was estimated as 36 years based on the median annual leaf production rate.Eriocnema fulva Ă© uma espĂ©cie herbĂĄcea, perene, iteropĂĄrica, com distribuição geogrĂĄfica restrita ao centro-sudeste do Estado de Minas Gerais, Brasil, e ameaçada de extinção. Os indivĂduos ocorrem agrupados em paredĂ”es rochosos, na beira de riachos sombreados pela Mata AtlĂąntica estacional semidecĂdua e tĂȘm caule que pendem do barranco. Com o objetivo de investigar o desenvolvimento da folha e sua importĂąncia para a sobrevivĂȘncia dos indivĂduos, foram instaladas 15 parcelas contĂguas de 1 x 1 m na Mata do Jambreiro (19° 58?-59?S, 43° 52?-55? W, 800-1100 m de altitude), municĂpio de Nova Lima. Todos os indivĂduos cuja maior folha tivesse comprimento do limbo maior ou igual a 1 cm foram marcados, sendo medidos em 1997, 1998 e 1999. O tempo de expansĂŁo da folha foi registrado mensalmente durante 26 meses atĂ© abril de 2000. Na ĂĄrea amostrada foram marcados 260 indivĂduos cujo limbo foliar tinha comprimento > 1cm. O tamanho das plantas, medido atravĂ©s do comprimento do limbo e do pecĂolo e do nĂșmero de folhas, apresentou mudanças significativas somente apĂłs dois anos, indicando que o crescimento Ă© lento. A proporção das folhas sobreviventes apĂłs dois anos foi de 60%. O tempo necessĂĄrio para a expansĂŁo da folha foi superior a 14 meses e Ă© lento quando comparado com o de outras espĂ©cies do dossel ou do sub-bosque da floresta tropical. Maior longevidade foliar tende a ser encontrada em plantas de crescimento lento. Observamos que algumas folhas tiveram maior longevidade que 3 anos. O crescimento do pecĂolo pode ajudar no melhor posicionamento da folha na busca de luz no sub-bosque, contribuindo para o crescimento e sobrevivĂȘncia da planta. As relaçÔes entre a folha e demais medidas de tamanho foram significativas, indicando sua grande importĂąncia para o tamanho de cada planta. A idade do indivĂduo de maior tamanho foi estimada em 36 anos atravĂ©s da taxa mediana de produção anual de folhas.110Conselho Nacional de Desenvolvimento CientĂfico e TecnolĂłgico (CNPq
Somatic Embryogenesis as a tool for forest tree improvement: a case- study in Eucalyptus globulus
Functionalized Cyclopentenones with Low Electrophilic Character as Anticancer Agents
In this study were synthesized non-Michael acceptor cyclopentenones (CP) from biomass derivative furfural as anticancer agents. Cyclic enones, both from natural sources and synthetic analogues, have been described as cytotoxic agents. Most of these agents were unsuccessful in becoming valuable therapeutic agents due to toxicity problems derived from unselective critical biomacromolecule alkylation. This may be caused by Michael addition to the enone system. Ab initio studies revealed that 2,4-substituted CPs are less prone to Michael additions, and as such were tested three families of those derivatives. We prepare the new CPs from furfural through a tandem furan ring opening/nazarov electrocyclization and further functionalization. Experimentally the 2,4-substituted CPs exhibited no reactivity towards sulphur nucleophiles, while maintaining cytotoxicity against HT-29, MCF-7, NCI-H460, HCT-116 and MDA-MB 231 cells lines. Moreover, the selected CP are non-toxic against healthy HEK 293T cell lines and present proper calculated drug-like properties
Incidence of accidental awareness during general anaesthesia in obstetrics: a multi-centre, prospective cohort study
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Assessment of electrophoresis and electroosmosis in construction materials: effect of enhancing electrolytes and heavy metals contamination
Electrokinetic effects are those that take place by application of an electric field to porous materials, with the zeta potential as the key parameter. Specifically, in the case of contaminated construction materials, the generation of an electroosmotic flux, with the corresponding dragging due to water transport, is a crucial mechanism to succeed in the treatment of decontamination. Therefore, it is of great interest trying to optimize the treatment by the addition of specific electrolytes enhancing the electrokinetic phenomena. Most of the data of zeta potential found in literature for construction materials are based in micro-electrophoresis measurements, which are quite far of the real conditions of application of the remediation treatments. In this paper, electrophoretic and electroosmotic experiments, with monolithic and powdered material respectively, have been carried out for mortar, brick and granite clean and contaminated with Cs, Sr, Co, Cd, Cu and Pb. The electrolytes tested have been distilled water (DW), Na2âEDTA, oxalic acid, acetic acid and citric acid. The zeta potential values have been determined through the two different techniques and the results compared and critically analysed
A prĂĄtica do fonoaudiĂłlogo nos NĂșcleos de Apoio Ă SaĂșde da FamĂlia em municĂpios paraibanos
Toxic effects of Pb2+ on the growth and mineral nutrition of signal grass (Brachiaria decumbens) and Rhodes grass (Chloris gayana)
Although grasses are commonly used to revegetate sites contaminated with lead (Pb), little is known regarding the Pb-tolerance of many of these species. Using dilute solution culture to mimic the soil solution, the growth of signal grass (Brachiaria decumbens Stapf cv. Basilisk) and Rhodes grass (Chloris gayana Kunth cv. Pioneer) was related to the mean activity of Pb2+ {Pb2+} in solution. There was a 50% reduction in fresh mass of signal grass shoots at 5 mu M {Pb2+} and at 3 mu M {Pb2+} for the roots. Rhodes grass was considerably more sensitive to Pb in solution, with shoot and root fresh mass being reduced by 50% at 0.5 mu M {Pb2+}. The higher tolerance of signal grass to Pb appeared to result from the internal detoxification of Pb, rather than from the exclusion of Pb from the root. At toxic {Pb2+}, an interveinal chlorosis developed in the shoots of signal grass (possibly a Pb-induced Mn deficiency), whilst in Rhodes grass, Pb2+ caused a bending of the root tips and the formation of a swelling immediately behind some of the root apices. Root hair growth did not appear to be reduced by Pb2+ in solution, being prolific at all {Pb2+} in both species
Foliar growth of Eriocnema fulva Naudin (Melastomataceae) in a forest fragment in southeastern Brazil
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