Changes in the activities of enzymes involved in nitrogen and sulphur assimilation during leaf and berry development of Vitis vinifera

The changes in the activities of 0-acetylserine sulphydrylase, ATP sulphurylase, glutamate dehydrogenase, glutamine synthetase and nitrate reductase in extracts from leaves and berries of Vitis vinifera L. cv. Merlot were studied at weekly intervals prior to anthesis up to grape harvest. Total nitrogen, amino nitrogen and protein contents were also determined.The total nitrogen content decreased from the beginning of the determinations either in leaves or in berries. Protein and amino nitrogen increments in berries matched their decreases in leaves.Nitrate reductase activity was not detectable either in leaves or berries. On the contrary, all the other examined enzymes showed at least three maxima of activity: one at anthesis and the others between the beginning of berry development and grape harvest.The ATP sulphurylase, 0-acetylserine sulphydrylase and glutamate dehydrogenase activities of berries were always higher than those observed in leaves, whereas glutamine synthetase activitywas similar in the two organs.Our results indicate that sulphur and nitrogen assimilation occur either in leavesor berries of grapevine.Changements des activités enzymatiques de l'assimilation de l'azote et du soufre pendant le développement de la feuille et du grain de Vitis viniferaSur des extraits de feuilles et de grains de raisins de Vitis vinifera L. cv. Merlot, prélevés chaque semaine dans la période entre la floraison et la vendange, les changements des activités enzymatiques de 1'0-acétylsérine sulfhydrilase, ATP sulfurylase, glutamate déshydrogénase, glutamine synthétase et de la nitrate réductase ont été étudiés.La teneur en azote total diminuait dans les feuilles aussi bien que dans les grains. L'accroissement des protéines et de l'amino-azote dans les grains était lié à leur décroissement dans les feuilles. L'activité enzymatique de la nitrate réductase n'a été retrouvée ni dans les grains ni dans les feuilles; toutes les autres activités enzymatiques analysées présentaient au moins trois pointes d'activités: la première à la floraison, les autres dans la période comprise entre le début du développement du grain et la vendange.Les activités de l'ATP sulfurylase, 0-acétylsérine sulfhydrilase et de la glutamate déshydrogénase étaient plus élevées dans les grains que dans les feuilles, tandis que l'activité de la glutamine synthétase était pareille dans les deux organes.Ces résultas indiquent que l'assimilation du soufre et de l'azote se fait dans les feuilles aussi bien que dans les grains de la vigne

De uma subjetivação forçada:

O objetivo deste artigo é discutir em que medida a releitura lacaniana do conceito psicanalítico da sublimação é realizada tendo-se os fundamentos da estética de Kant como pano de fundo. No curso de nossa exposição, pretendemos descrever como a sublimação se caracteriza eminentemente como procedimento crítico frente a uma determinada realidade social. Diferentemente de Freud, que pensava a sublimação nos quadros do desvio da meta sexual em direção a objetos reconhecidos e valorizados pela cultura, Lacan propõe um deslocamento da problemática da sublimação para fora do horizonte normativo da história e da cultura, mobilizando categorias como transgressão e disrupção. Tomaremos a tragédia de Antígona como exemplo, buscando enfatizar como essa função encontra nos recursos estéticos um meio de formalização privilegiado para ser desempenhada. As noções kantianas do belo e do sublime, tal como relidas por Lacan, subsidiarão o exame dessa formalização a que tende a sublimação. A hipótese central é que a sublimação lacaniana pressupõe - e aprofunda - uma espécie de fusão do belo com o sublime, e não sua separação.

The variability of refractivity in the atmospheric boundary layer of a tropical island volcano measured by ground-based interferometric radar

For 24 h we measured continuously the variability of atmospheric refractivity over a volcano on the tropical island of Montserrat using a ground-based radar interferometer. We observed variations in phase that we interpret as due to changing water vapour on the propagation path between the radar and the volcano and we present them here in the context of the behaviour of the atmospheric boundary layer over the island. The water vapour behaviour was forced by diurnal processes, the passage of a synoptic-scale system and the presence of a plume of volcanic gas. The interferometer collected images of amplitude and phase every minute. From pairs of phase images, interferograms were calculated and analyzed every minute and averaged hourly, together with contemporaneous measurements of zenith delays estimated from a network of 14 GPS receivers. The standard deviation of phase at two sites on the volcano surface spanned a range of about 1–5 radians, the lowest values occurring at night on the lower slopes and the highest values during the day on the upper slopes. This was also reflected in spatial patterns of variability. Two-dimensional profiles of radar-measured delays were modelled using an atmosphere with water vapour content decreasing upwards and water vapour variability increasing upwards. Estimates of the effect of changing water vapour flux from the volcanic plume indicate that it should contribute only a few percent to this atmospheric variability. A diurnal cycle within the lower boundary layer producing a turbulence-dominated mixed layer during the day and stable layers at night is consistent with the observed refractivity

Intensidades da poda seca e do desbaste de cacho na composição da uva Cabernet Sauvignon.

A pesquisa foi realizada durante quatro anos, num vinhedo de Cabernet Sauvignon (Vitis vinifera L.), em Bento Gonçalves-RS. O objetivo foi determinar o efeito das intensidades da poda seca e do desbaste de cacho em variáveis relacionadas aos componentes de produção da videira e à composição do mosto de uva. Os tratamentos consistiram em dois níveis de poda seca - curta e longa - e quatro de desbaste de cacho (%) - 0; 25; 50 e 75 -; com cinco repetições. O delineamento experimental foi o em blocos casualizados, com os tratamentos em parcelas subdivididas. Os resultados mostram que a poda seca e o desbaste de cacho tiveram efeito altamente significativo na produtividade do vinhedo que, na média dos quatro anos, variou de 10.971 kg/ha ? poda curta, 75% de desbaste ? a 32.819 kg/ha ? poda longa, 0% de desbaste. Houve, também, efeito significativo na produtividade por gema, peso de ramos podados por gema e por hectare, área foliar/peso fresco do fruto e produtividade/peso de ramos podados. Entretanto, o efeito nas variáveis relacionadas a açúcar e acidez do mosto da uva foi pouco expressivo. O componente 1 da análise de componentes principais discriminou o tratamento poda curta a 75% de desbaste de cacho dos tratamentos poda longa-0% de desbaste e poda longa-25% de desbaste

Hepatic safety of antibiotics used in primary care

Antibiotics used by general practitioners frequently appear in adverse-event reports of drug-induced hepatotoxicity. Most cases are idiosyncratic (the adverse reaction cannot be predicted from the drug's pharmacological profile or from pre-clinical toxicology tests) and occur via an immunological reaction or in response to the presence of hepatotoxic metabolites. With the exception of trovafloxacin and telithromycin (now severely restricted), hepatotoxicity crude incidence remains globally low but variable. Thus, amoxicillin/clavulanate and co-trimoxazole, as well as flucloxacillin, cause hepatotoxic reactions at rates that make them visible in general practice (cases are often isolated, may have a delayed onset, sometimes appear only after cessation of therapy and can produce an array of hepatic lesions that mirror hepatobiliary disease, making causality often difficult to establish). Conversely, hepatotoxic reactions related to macrolides, tetracyclines and fluoroquinolones (in that order, from high to low) are much rarer, and are identifiable only through large-scale studies or worldwide pharmacovigilance reporting. For antibiotics specifically used for tuberculosis, adverse effects range from asymptomatic increases in liver enzymes to acute hepatitis and fulminant hepatic failure. Yet, it is difficult to single out individual drugs, as treatment always entails associations. Patients at risk are mainly those with previous experience of hepatotoxic reaction to antibiotics, the aged or those with impaired hepatic function in the absence of close monitoring, making it important to carefully balance potential risks with expected benefits in primary care. Pharmacogenetic testing using the new genome-wide association studies approach holds promise for better understanding the mechanism(s) underlying hepatotoxicity