La chloritisation supergène zincifère des phlogopites de Canoas (PR, Brésil)

Dans l'altération superficielle de la mine de Pb-Zn-Ba de Canoas, les chlorites apparaissent en pseudomorphose des phlogopites avec un faciès et une composition tout à fait particuliers et sont très fortement zincifères (de 15 à 20% ZnO). Cette chlorite se substitue aux phlogopites du gisement. La chloritisation supergène est transitoire, avec une altération de la chlorite en smithsonite. La chlorite zincifère, (Zn3,48Mg5,11Fe3,71Al0,48Ti0,08)(Si5,67Al2,33)O26(OH)16, est de genèse et de compostion différentes de celles de la baileychlore. (Résumé d'auteur

Jarosita e plumbojarosita nos gossans do distrito mineiro de Canoas (PR)

Jarosites and plumbojarosites in gossans related to Pb-Zn mineralization in the Canoas District are described. They are always associated with goethite and in minor extent with hematite. Some crystals show zoning with a core of jarosite and a rim of plumjarosite. Others are rather homogeneous with intermediate composition. In the general formula AB3(SO4)2(OH)6, A sites are occupied by K and Pb and B sites by Fe, Al and Zn. A and B sites are often incompletely filled. A sites generally show excess of charge. B sites show deficiency. Jarosites and plumbojarosites are secondary minerals formed by sulfur, iron and lead derived from the weathering of sulphides, and potassium from the gangue mineral orthoclase. The jarosite-goethite association in gossans percolated by meteoric waters is thermodynamically unstable. It persists due to the sluggishness of the transformation of the jarosite into goethite. Thus, the Canoas jarosites are transitory Pb bearing phases. In the mature gossans Pb is associated only with the oxyhydroxides. (Résumé d'auteur

The lateritic ore deposits of Brazil

Au Brésil, les mécanismes d'altération supergène ont conduit à la formation d'un épais recouvrement latéritique sur environ 65 % de la surface totale; dans des conditions particulières, l'accumulation de certains métaux dans ce manteau peut atteindre le stade économique. La latéritisation des diverses roches mères, tout à fait spécifiques de chaque type de gisement, est intervenue pour l'essentiel au Tertiaire, pendant des épisodes de stabilité tectonique auxquels correspondent des surfaces d'aplanissement généralisées. Le rôle des facteurs lithologiques, climatiques et morpho-tectoniques dans le mécanisme de genèse des gisements latéritiques est discut

Full field electrorretinogram standartization in dogs

Eletrorretinograma (ERG) é o meio diagnóstico objetivo e não-invasivo para avaliar a função retiniana e detectar precocemente, em várias espécies, lesões nas suas camadas mais externas. As indicações mais comuns para ERG em cães são: avaliação pré-cirúrgica de pacientes com catarata, caracterização de distúrbios que causam cegueira, além de servir como importante modelo para o estudo da distrofia retiniana que acomete o homem. Vários são os fatores que podem alterar o ERG tais como: eletrorretinógrafo, fonte de estimulação luminosa, tipo do eletrodo, tempo de adaptação ao escuro, tamanho pupilar, opacidade de meios e protocolo de sedação ou anestesia; além da espécie, raça e idade. Objetivou-se com este estudo padronizar o ERG para cães submetidos à sedação, seguindo o protocolo da International Society for Clinical Electrophysiology of Vision (ISCEV), utilizando Ganzfeld e eletrodos Burian Allen. Foram realizados 233 eletrorretinogramas em cães, 147 fêmeas e 86 machos, com idades entre um e 14 anos. Dos 233 cães examinados, 100 apresentavam catarata em diferentes estágios de maturação, 72 eram diabéticos e apresentavam catarata madura ou hipermadura, 26 apresentaram eletrorretinograma compatível com degeneração retiniana progressiva, três apresentaram eletrorretinograma compatível com síndrome da degeneração retiniana adquirida subitamente e 32 não apresentaram lesão retiniana capaz de atenuar as respostas do ERG, sendo considerados normais quanto à função retiniana. A sedação foi capaz de produzir boa imobilização do paciente sem rotacionar o bulbo ocular, permitindo adequada estimulação retiniana bilateralmente, com auxílio do Ganzfeld. O sistema eletrodiagnóstico Veris registrou com sucesso e simultaneamente de ambos os olhos, as cinco respostas preconizadas pela ISCEV. Como o ERG de campo total tornou-se exame fundamental na rotina oftalmológica, sua padronização é indispensável quando se objetiva comparar resultados de laboratórios distintos. A confiabilidade e reprodutibilidade deste protocolo foi demonstrada com a obtenção de registros de ótima qualidade utilizando protocolo padrão da ISCEV, eletrorretinógrafo Veris, Ganzfeld e eletrodos Burian Allen nos cães submetidos à sedação.Electroretinogram (ERG) is an objective non invasive diagnostic method to evaluate retinal function which permits the early detection of lesions at retinal external layers, even before the appearance of clinical signs. In dogs, ERG is mostly utilized for preoperative evaluation in patients presenting cataracts; characterization of disturbances causing blindness, among the utilization of dogs as animal models in scientific research. Several factors interfere in ERG responses, such as the ERG machine, light stimulation, electrode, time spent on dark adaptation, pupil size, means opacity, sedation or anesthetization, species, breed and age. The purpose of this study was to standardize the full field ERG in sedated dogs, according to the International Society for Clinical Electrophysiology of Vision (ISCEV) protocol, using Ganzfeld and bipolar electrodes. Two hundred thirty threes ERGs were performed in 147 female and 86 male with ages from 1 to 14 years old. Among those 233 dogs, 100 presented cataracts in different stages of maturation, 72 were diabetic and presented mature or hypermature cataracts, 26 presented ERG compatible to progressive retinal degeneration, 3 presented ERG compatible to sudden acquired retinal degeneration syndrome; for 32 dogs no abnormal ERG was registered and they were considered as having normal retinal function. Sedation was capable to induce a good immobilization with no bulb rotation, resulting uniform retinal stimulation, using Ganzfeld. Veris system successfully registered all 5 ISCEV responses, simultaneously from both eyes, at the same time. Full field ERG became a fundamental ophthalmic exam, then, its standardization is mandatory to allow comparison between ERGs from different laboratories. The reliability and reproducibility of this protocol has shown very good responses, using ISCEV protocol, Veris system, Ganzfeld and Burian Allen electrodes in sedated dogs.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

RETINAL DEGENERATION IN A PIT BULL DOG: ELECTRORETINOGRAPHIC FINDINGS

Electroretinogram (ERG) is a non-invasive electrophysiologic test widely used in both human and veterinary ophthalmology to evaluate retinal function. Case report: due to recent cases of severe visual impairment in Pit Bull dogs in our clinic, we decided to evaluate the retinal function by full-field ERG in a 5-month-old male Pit Bull dog whose owner have noticed visual impairment since 40 days of age. Under general anesthesia, the dog was submitted to full-field ERG testing, according to ISCEV (International Society for Clinical Electrophysiology of Vision) standard protocol. ERG recordings were obtained in one eye after 30 minutes of dark adaptation from a fully dilated pupil, using a monopolar contact lens electrode. Non-detectable scotopic and photopic responses were found, confirming the devastating effect of the retinal degeneration. Conclusion: ERG was able to quantify the severity of retinal degeneration on retinal function. We believe that heredogram study of these animals may be helpful to better understand this new retinal condition affecting Pit Bull dogs.O eletrorretinograma (ERG) consiste em exame objetivo, não invasivo, capaz de avaliar a função retiniana tanto na oftalmologia humana como na veterinária. Caso Clínico: com o recente surgimento em São Paulo, de cães da raça Pit Bull apresentando déficit visual severo, optou-se por realizar ERG de campo total em um filhote macho, 5 meses de idade, com baixa de visão desde os 40 dias de idade, com intuito de avaliar sua função retiniana. O animal, sob anestesia geral, foi submetido ao ERG, segundo o protocolo padrão da ISCEV (International Society for Clinical Electrophysiology of Vision). Em um dos olhos foi adaptado eletrodo de lente de contato monopolar, após adaptação ao escuro por 30 minutos e dilatação completa da pupila. As respostas escotópicas e fotópicas mostraram-se não detectáveis, confirmando o efeito devastador da degeneração na função retiniana. Comentários conclusivos: o Erg foi capaz de detectar a severidade da degeneração retiniana e acredita-se que o estudo do heredograma destes animais possibilitará melhor compreensão desta nova doença

Condições de conservação pós-colheita de frutos de pimentão (Capsicum annum L.)

Two packing types and exponsure to ethylene, in room and refrigerator conditions, were studied for fruits of sweet pepper Agronomico 10G. After 5 day intervals the fruits were weighed. It was concluded that the best temperature range for sweet pepper preservation is 7 to 9°C; at these temperatures, the best packaging was aluminium trays covered with 0,0165 mm PVC film. Potassium permanganate in perforated capsules showed no evident effect as ethylene absorbent. After 30 days fruit losses were very high due to senescence and/or disease incidence.Com o objetivo de verificar a conservação de frutos de pimentão, foi estudada a utilização de dois tipos de embalagem e um seqüestrador de etileno, em condições ambientais e em geladeira. As avaliações foram realizadas a cada cinco dias, obtendo-se as seguintes conclusões: a melhor temperatura para conservação de pimentões situa-se entre 7 e 9°C; o armazenamento de pimentões em bandejas envolvidas com filme de PVC, constitui-se na melhor alternativa para sua conservação, naquela faixa de temperatura. O permanganato de potássio, colocado em cápsulas perfuradas no interior das embalagens, não apresentou efeito evidente como absorvente de etileno. Após 30 dias, foram verificadas perdas de frutos por senescência e/ou pela incidência de doenças

Carcass characteristics and meat quality of sheep fed buffelgrass silage to replace corn silage

The aim of the study was to evaluate the carcass characteristics, proximate composition, and sensorial attributes of meat from sheep fed diets in which buffelgrass silage replaced corn silage. Thirty-two intact male crossbred Santa Inês sheep with an average live weight of 20.09 ± 2.0 kg were housed in individual stalls and allotted at random to four treatments in which corn silage was replaced by buffelgrass silage at the levels of 0 (control), 33.3%, 66.6%, and 100%. After an adaption period of 10 days, the sheep were fed for an additional 61 days. Feed was offered ad libitum and corn silage comprised 60% of the diet for the control group. Carcass characteristics, non-carcass components and meat quality were evaluated. Hot carcass yield, cold carcass yield, true carcass yield, trimmings, fat weight, and mesenteric and omental fat weight were highest for the control group (P <0.05). Loin eye area had a quadratic response (P =0.02), with the largest areas being observed in animals fed the diet containing 66.6% buffelgrass silage. Liver weight (P <0.01), luminosity of the meat (P <0.05), and cooking loss (P <0.05) likewise had nonlinear responses to the concentration of buffelgrass silage in the diet. The treatments did not have significant negative influence on the nutritional and organoleptic characteristics of the meat

Raman spectroscopy of a single ion coupled to a high-finesse cavity

We describe an ion-based cavity-QED system in which the internal dynamics of an atom is coupled to the modes of an optical cavity by vacuum-stimulated Raman transitions. We observe Raman spectra for different excitation polarizations and find quantitative agreement with theoretical simulations. Residual motion of the ion introduces motional sidebands in the Raman spectrum and leads to ion delocalization. The system offers prospects for cavity-assisted resolved-sideband ground-state cooling and coherent manipulation of ions and photons.Comment: 8 pages, 6 figure

Chapter 7: Wetlands

Contains fulltext : 205862.pdf (publisher's version ) (Open Access

Flexural strengthening of RC continuous slab strips using NSM CFRP laminates

To assess the effectiveness of the near surface mounted (NSM) technique, in terms of load carrying and moment redistribution capacities, for the flexural strengthening of continuous reinforced concrete (RC) slabs, an experimental program was carried out. The experimental program is composed of three series of three slab strips of two equal span length, in order to verify the possibility of increasing the negative (at the intermediate support region) resisting bending moment in 25% and 50% and maintaining moment redistribution levels of 15%, 30% and 45%. Though the flexural resistance of the NSM strengthened sections has exceeded the target values, the moment redistribution was relatively low, and the increase of the load carrying capacity of the strengthened slabs did not exceed 25%. This experimental program is analyzed to highlight the possibilities of NSM technique for statically indeterminate RC slabs in terms of flexural strengthening effectiveness, moment redistribution and ductility performance. Using a FEM-based computer program, which predictive performance was appraised using the obtained experimental results, a high effective NSM flexural strengthening strategy is proposed, capable of enhancing the slab’s load carrying capacity and maintaining high levels of ductility.The study reported in this paper forms a part of the research program "CUTINEMO - Carbon fiber laminates applied according to the near surface mounted technique to increase the flexural resistance to negative moments of continuous reinforced concrete structures" supported by FCT, PTDC/ECM/73099/2006. The authors wish to acknowledge the support also provided by the S&P, Casais and Artecanter Companies. The first Author acknowledges the financial support of National Council for Scientific and Technological Development (CNPq) - Brazil, Ph.D. Grant no. 200953/2007-9. The second Author wishes to acknowledge the support provided by FCT, by means of the SFRH/BSAB/818/2008 and SFRH/BSAB/913/2009 sabbatical grants