Base-base interactions in nucleic acids containing A-T base pairs: Structure of poly[d(A-T)]

The Watson-Crick type of base pairing is considered to be mandatory for the formation of duplex DNA. However, conformational calculations carried out in our laboratory, have shown that some combinations of backbone torsion angles and sugar pucker lead to duplexes with Hoogsteen type of base pairing also. Here we present the results of energy calculations performed on A-T containing doublet sequences in the D-form with both Hoogsteen and Watson-Crick type of base pairing and the 3 viable models for the A-T containing polynucleotide duplex poly[d(A-T)].

Neutron diffraction evidence for oxygen dimers in Bi-Ca-Sr-Cu-O superconductors

A comparative neutron diffraction study of Bi2CaSr2Cu2O8+δ, Bi2Ca2SrCu2O8+δ and Bi2Ca1.5Y0.5SrCu2O8+δ has not only shown the presence of considerable oxygen excess in the Bi layers, but also evidence for oxygen pairing giving rise to O1−2 or O2−2 type species, probably the latter. The proportion of the paired species increases when Y partly replaces Ca. Furthermore, the Tc decreases with an increase in paired species.

Raman spectral studies of borate glasses

Raman spectroscopic measurements in borate glasses have been reviewe. The review shows that the technique is useful in identifying the structural groups present in the borate on the basis of the Krogh-Moe hypothesis. Vitreous B2O3 and alkali borates are extensvvely studied and a satisfactory assignment of bands is possible by a careful consideration of the literature. A cation effect on the borate netwoork is observed. Availaable measurements on binary borates other than alkali borates and on ternary borates are limited and more work is required to identify the structural modifications that take place with composition. Mixed alkali effect is reported only lithium-caesium borade and shows the formation of non-bridging oxygens, destroying the six-membered rings when Li2O is replaced by Cs2O. Fast ionic glasses (alkali borates containing alkali halides) yield the same Raman spectra as the alkali borates, except when the alkali is a fluoride.

Transfer of resistance training to enhance rapid coordinated force production by older adults

The purpose of this study was to examine the capacity of resistance training to enhance the rapid and coordinated production of force by older people. Thirty adults (greater than or equal to 60 years) completed a visually guided aiming task that required the generation of isometric torque in 2 df about the elbow prior to and following a 4-week training period. Groups of six participants were allocated to two progressive ( 40 - 100% maximal voluntary contraction (MVC)) resistance-training (PRT) groups, to two constant low-load (10% MVC) training groups (CLO) and to one no-training control group. Training movements required the generation of either combined flexion and supination (FLESUP), or combined extension and supination (EXTSUP). In response to training, target acquisition times in the aiming task decreased for all groups; however, both the nature of the training load and the training movement influenced the pattern and magnitude of improvements (EXTSUP_ CLO: 36%, FLESUP_ PRT 26%, EXTSUP_ PRT 22%, FLESUP_ CLO 20%, CONTROL 15%). For one group that trained with progressively increasing loads, there arose a subsequent decrease in performance in one condition of the transfer task. For each group, these adaptations were accompanied by systematic changes in the coordination of muscles about the elbow joint, particularly the biceps brachii.

Relative activity of triclabendazole metabolites against the liver fluke, Fasciola hepatica

A study has been carried Out to determine the relative activity Of triclabendazole (TCBZ) and its sulphoxide (TCBZ(center dot)SO) and sulphone (TCBZ(center dot)SO(2)) metabolites against the adult stage of the liver fluke, Fasciola hepatica. Flukes were incubated for 24 h in vitro in 15 mu g/ml of each of the compounds and prepared for scanning and transmission electron microscopy.

Vie des Pères et Passion de Jésus-Christ, en vers, Roman des Sept Sages, en prose, etc.

Contient : Vie des Pères, en vers ; Passion de Jésus-Christ, en vers ; Les Quinze signes du jugement dernier ; Roman des Sept Sages, en prose ; Fragment de comput, en vers français, chapitre « des Bissextes ». « Mais quant antrés suis en matire... » Cf. art. de M. P. Meyer, Bulletin des anciens textes, 1883, t. IX, p. 108-109 ; Poème moral sur la cité divine et les sept péchés capitaux, par « HENRIS » ; Chastie Musart ; « Aucunnes parties notaules a plusors maladies, estraites de fysique des quatre complexions. Li maistre dient que quatre complexions sont... — ... trop cras et li coulor blanche » ; « L'espistre qu'Aristotes envoia au roi Alixandre. Après mont de paroles qu'Aristotes dist au roi Alixandre il li dist cest ansignement. Dans rois, dist-il... — (Recettes diverses.) — ... Por savoir si le vins aigrez est bons metez en un pou sor .I. fer froit ou sor la terre, se il est bon il bondra » ; « Si comme dit freres Bertholomeis Anglois, de l'Ordre des Freres Menors, en livre des Proprietés, qu'il meismes fist, li cors d'umaine nature... — ... et premierement de sanc pur » ; Sermon, en français. « Omnis qui se exaltat humiliabitur, etc. Ces paroles sunt escrites en l'Esvangile et les dist nostres sires là où il preschoit... — ... et pour ce sormonta elle les apostres en fait et en hardiece »

Le Roman de la Rose, par Guillaume de Lorris et Jean de Meun.

Contient : Testament de Jean de Meun ; Dit des tribulations

Excepcionalidad de la prisión preventiva en el Ecuador

La excepcionalidad de la prisión preventiva se encuentra vigente con la nueva Constitución de la República del Ecuador en el Art. 77 numerales 1 y 11, guarda relación con la Declaración Universal de los Derechos Humanos, Convención Americana Sobre Derechos Humanos, Pacto Internacional de Derechos Civiles y Políticos, en atención a lo dispuesto en el Art. 424 inciso 2º., de la Ley Fundamental, está regulada por el Art. 159, inciso 2º., del Código de Procedimiento Penal. En el capitulo primero he orientado la investigación a la libertad personal como derecho fundamental, y su relación con otros derechos; la limitación de la libertad personal y los derechos de los privados de la libertad, en base a la Constitución, la Ley y pronunciamientos doctrinarios. En el capítulo segundo lo dedico al análisis de las medidas privativas de libertad ambulatoria, como son: la detención y la prisión preventiva, la presunción de inocencia, la responsabilidad del Estado frente a estas medidas, el plazo razonable, concluyendo con la audiencia de formulación de cargos, acudiendo a estudios de autores que tratan sobre la materia. En el capítulo tercero se ha investigado la excepcionalidad de la prisión preventiva, con sus características especiales, su revocatoria, y, análisis de la doctrina jurisprudencial de la Corte Interamericana de Derechos Humanos. En el capítulo cuarto analizo las medidas alternativas a la prisión preventiva, como el arresto domiciliario, la obligación de presentarse periódicamente ante el juez y la prohibición de salida del país, finalizo realizando conclusiones y recomendaciones sobre el tema investigado, que a mi juicio son pertinentes.

Non-lignified parenchyma in Cactaceae and Portulacaceae

This work describes the occurrence and distribution pattern of non-lignified parenchyma in species of Cactaceae and Portulacaceae, of which samples of roots and stems of six species of Cactaceae and four species of Portulacaceae were analysed. The first records of non-lignified parenchyma in Portulacaceae were obtained and, in the case of Cactaceae, an in-depth discussion is given on the characterization of this tissue by various authors, as well as new information on the occurrence and distribution pattern of the non-lignified parenchyma. The terminology used to characterize the non-lignified parenchyma cells in the wood of Cactaceae is extremely diversified and often not very descriptive, which makes it difficult to establish homologies and better characterize this tissue. Non-lignified parenchyma cells in the secondary xylem in Cactaceae and Portulacaceae occur in association with the fibrous phase of the wood, often forming true continuous bands. This resembles what some authors call parenchyma wood. The proposal of this study is to demonstrate that, independent of the distribution pattern of the non-lignified parenchyma cells, the terminology used should follow that of the International Association of Wood Anatomists (IAWA) Committee as non-lignified parenchyma and not refer to a parenchymous phase of the wood. (C) 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159, 322-329.

Biochemical and biophysical properties of a highly active recombinant arginase from Leishmania (Leishmania) amazonensis and subcellular localization of native enzyme

Arginase (L-arginine amidinohydrolase, E.C. 3.5.3.1) is a metalloenzyme that catalyses the hydrolysis Of L-arginine to L-ornithine and urea. In Leishmania spp., the biological role of the enzyme may be involved in modulating NO production upon macrophage infection. Previously, we cloned and characterized the arginase gene from Leishmania (Leishmania) amazonensis. In the present work, we successfully expressed the recombinant enzyme in E. coli and performed biochemical and biophysical characterization of both the native and recombinant enzymes. We obtained K-M and V-max. values of 23.9(+/- 0.96) mM and 192.3 mu mol/min mg protein (+/- 14.3), respectively, for the native enzyme. For the recombinant counterpart, K-M was 21.5(+/- 0.90) mM and V-max was 144.9(+/- 8.9) mu mol/min mg. Antibody against the recombinant protein confirmed a glycosomal cellular localization of the enzyme in promastigotes. Data from light scattering and small angle X-ray scattering showed that a trimeric state is the active form of the protein. We determined empirically that a manganese wash at room temperature is the best condition to purify active enzyme. The interaction of the recombinant protein with the immobilized nickel also allowed us to confirm the structural disposition of histidine at positions 3 and 324. The determined structural parameters provide substantial data to facilitate the search for selective inhibitors of parasitic sources of arginase, which could subsequently point to a candidate for leishmaniasis therapy. (c) 2008 Elsevier B.V. All rights reserved.

Pigeons (Columba livia) are a suitable experimental model for Neospora caninum infection in birds

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Spatial Distribution of Seropositive Dogs to Leptospira spp. and Evaluation of Leptospirosis Risk Factors Using a Decision Tree

Background: Leptospirosis is an important zoonotic disease associated with poor areas of urban settings of developing countries and early diagnosis and prompt treatment may prevent disease. Although rodents are reportedly considered the main reservoirs of leptospirosis, dogs may develop the disease, may become asymptomatic carriers and may be used as sentinels for disease epidemiology. The use of Geographical Information Systems (GIS) combined with spatial analysis techniques allows the mapping of the disease and the identification and assessment of health risk factors. Besides the use of GIS and spatial analysis, the technique of data mining, decision tree, can provide a great potential to find a pattern in the behavior of the variables that determine the occurrence of leptospirosis. The objective of the present study was to apply Geographical Information Systems and data prospection (decision tree) to evaluate the risk factors for canine leptospirosis in an area of Curitiba, PR.Materials, Methods & Results: The present study was performed on the Vila Pantanal, a urban poor community in the city of Curitiba. A total of 287 dog blood samples were randomly obtained house-by-house in a two-day sampling on January 2010. In addition, a questionnaire was applied to owners at the time of sampling. Geographical coordinates related to each household of tested dog were obtained using a Global Positioning System (GPS) for mapping the spatial distribution of reagent and non-reagent dogs to leptospirosis. For the decision tree, risk factors included results of microagglutination test (MAT) from the serum of dogs, previous disease on the household, contact with rats or other dogs, dog breed, outdoors access, feeding, trash around house or backyard, open sewer proximity and flooding. A total of 189 samples (about 2/3 of overall samples) were randomly selected for the training file and consequent decision rules. The remained 98 samples were used for the testing file. The seroprevalence showed a pattern of spatial distribution that involved all the Pantanal area, without agglomeration of reagent animals. In relation to data mining, from 189 samples used in decision tree, a total of 165 (87.3%) animal samples were correctly classified, generating a Kappa index of 0.413. A total of 154 out of 159 (96.8%) samples were considered non-reagent and were correctly classified and only 5/159 (3.2%) were wrongly identified. on the other hand, only 11 (36.7%) reagent samples were correctly classified, with 19 (63.3%) samples failing diagnosis.Discussion: The spatial distribution that involved all the Pantanal area showed that all the animals in the area are at risk of contamination by Leptospira spp. Although most samples had been classified correctly by the decision tree, a degree of difficulty of separability related to seropositive animals was observed, with only 36.7% of the samples classified correctly. This can occur due to the fact of seronegative animals number is superior to the number of seropositive ones, taking the differences in the pattern of variable behavior. The data mining helped to evaluate the most important risk factors for leptospirosis in an urban poor community of Curitiba. The variables selected by decision tree reflected the important factors about the existence of the disease (default of sewer, presence of rats and rubbish and dogs with free access to street). The analyses showed the multifactorial character of the epidemiology of canine leptospirosis.

Optimization Strategies Based on Sequential Quadratic Programming Applied for a Fermentation Process for Butanol Production

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)