Antioxidant activity of Moringa oleifera tissue extracts

Moringa oleifera is an important source of antioxidants, tools in nutritional biochemistry that could be beneficial for human health; the leaves and flowers are used by the population with great nutritional importance. This work investigates the antioxidant activity of M. oleifera ethanolic (E1) and saline (E2) extracts from flowers (a), inflorescence rachis (b), seeds (c), leaf tissue (d), leaf rachis (e) and fundamental tissues of stem (f). The radical scavenging capacity (RSC) of extracts was determined using dot-blots on thin layer chromatography stained with a 0.4 mm 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) solution; spectrophotometric assays were recorded (515 nm). Antioxidant components were detected in all E1 and E2 from a, b and d. The best RSC was obtained with E1d; the antioxidants present in E2 reacted very slowly with DPPH. The chromatogram revealed by diphenylborinate-2-ethylamine methanolic solution showed that the ethanolic extract from the flowers, inflorescence rachis, fundamental tissue of stem and leaf tissue contained at least three flavonoids; the saline extract from the flowers and leaf tissue revealed at least two flavonoids. In conclusion, M. oleifera ethanolic and saline extracts contain antioxidants that support the use of the plant tissues as food sources.The authors acknowledge financial support from the Portuguese Fundacao para Ciencia e a Tecnologia (FCT) by the Post-doctoral grant SFRH/BPD/37349/2007. The Brazilian Programmes Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) for research grants and fellowships (PMGP and LCBBC) and the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES) are acknowledged for financial support

X-ray method to study temperature-dependent stripe domains in MnAs/GaAs(001)

MnAs films grown on GaAs (001) exhibit a progressive transition between hexagonal (ferromagnetic) and orthorhombic (paramagnetic) phases at wide temperature range instead of abrupt transition during the first-order phase transition. The coexistence of two phases is favored by the anisotropic strain arising from the constraint on the MnAs films imposed by the substrate. This phase coexistence occurs in ordered arrangement alternating periodic terrace steps. We present here a method to study the surface morphology throughout this transition by means of specular and diffuse scattering of soft x-rays, tuning the photon energy at the Mn 2p resonance. The results show the long-range arrangement of the periodic stripe-like structure during the phase coexistence and its period remains constant, in agreement with previous results using other techniques.Comment: 4 pages, 4 figures, submitted to Applied Physics Letter

Lissencephaly-pachygyria and cerebellar hypoplasia in a calf.

ABSTRACT: A case of lissencephaly-pachygyria and cerebellar hypoplasia diagnosed in a Charolais x Tabapuã calf is described. The calf presented since birth, clinical signs characterized by apathy, prolonged recumbency, tremors of the head and neck, ataxia, hypermetria, difficulty walking, blindness and swelling of the joints of the four limbs. Due to the unfavorable prognosis, the animal was euthanized and necropsied at 34 days of age. At necropsy, a rudimentary development of the brain folds (gyri) and grooves (sulci) was observed, and the cerebellum was hypoplastic. The cut surface of the brain exhibited thickening of the gray matter (pachygyria) in the frontal, parietal, temporal and occipital cortices and narrowing of the white matter. In the organs of the thoracic and abdominal cavities, no significant lesions were observed. Histologically, cerebral cortex was thick and exhibited neuronal disorganization of the gray matter. The cerebellum had a thin molecular layer, and neuronal disorganization with ectopia of the Purkinje neurons in the region of the granular and molecular layers. There were no bacterial growths in cultures of joint swabs. This was the only case on the property, which suggests that this malformation, which has not previously been described in cattle, was a sporadic case, and it was not possible to determine its cause. Neurological lesions and clinical sings presented here should be considered in the differential diagnosis of congenital diseases of the central nervous systems of cattle

Ages, metallicities and α\alpha-element enhancement for galaxies in Hickson compact groups

Central velocity dispersions and eight line-strength Lick indices have been determined from 1.3${\rm \AA}$ resolution long-slit spectra of 16 elliptical galaxies in Hickson compact groups. These data were used to determine galaxy properties (ages, metallicities and $\alpha$-element enhancements) and allowed a comparison with the parameters determined for a sample of galaxies in lower density environments, studied by Gonz\'alez (1993). The stellar population parameters were derived by comparison to single stellar population models of Thomas et al. (2003) and to a new set of SSP models for the indices Mg$_2$, Fe5270 and Fe5335 based on synthetic spetra. These models, based on an update version of the fitting functions presented in Barbuy et al. (2003), are fully described here. Our main results are: (1) the two samples have similar mean values for the metallicities and [$\alpha$/Fe] ratios, (2) the majority of the galaxies in compact groups seem to be old (median age of 14 Gyr for eight galaxies for which ages could be derived), in agreement with recent work by Proctor et al. (2004). These findings support two possible scenarios: compact groups are either young systems whose members have recently assembled and had not enough time to experience any merging yet or, instead, they are old systems that have avoided merging since their time of formation.Comment: Accepted for publication in A

Cryopreservation of Coffea canephora Pierre ex A. Froehner seeds: importance of drying rate and moisture content.

Seeds of the Coffea canephora species are considered more recalcitrant than those of the Coffea arabica species. They tolerate partial dehydration and they cannot be stored in conventional seed banks at -18ºC because they are sensitive to freezing temperatures. Cryopreservation is a reliable method for storing seeds with these characteristics for long periods. However, preliminary studies are necessary to determine ideal storage conditions. The aim of this study was to investigate the ideal physical and physiological conditions for cryopreservation of Coffea canephora seeds to reduce seed mortality caused by the formation of intracellular ice crystals and to avoid cell damage caused by excessive desiccation. Seeds were subjected to rapid drying in silica gel and slow drying in saturated NaCl solution to moisture contents of 0.20, 0.25, and 0.28 g.g-¹ (dry basis), followed by direct immersion in liquid nitrogen for rapid freezing. Physiological and biochemical analyses were performed to evaluate seed quality before and after cryopreservation. Rapid drying of Coffea canephora seeds to values near 0.20 g.g-1 (db) does not cause reduction in physiological quality. Moisture content of 0.25 g.g-¹ brings about greater survival of Coffea canephora seeds after cryopreservation. Drying rate affects the physiological quality of cryopreserved Coffea canephora seeds, and rapid drying in silica gel is more favorable than slow drying in a saturated NaCl solution. The activity of the enzymes catalase, esterase, glutamic oxaloacetic transaminase, and polyphenol oxidase are indicators of seed quality for Coffea canephora seeds subjected to cryopreservation

Magnetic reconfiguration of MnAs/GaAs(001) observed by Magnetic Force Microscopy and Resonant Soft X-ray Scattering

We investigated the thermal evolution of the magnetic properties of MnAs epitaxial films grown on GaAs(001) during the coexistence of hexagonal/orthorhombic phases using polarized resonant (magnetic) soft X-ray scattering and magnetic force microscopy. The results of the diffuse satellite X-ray peaks were compared to those obtained by magnetic force microscopy and suggest a reorientation of ferromagnetic terraces as temperature rises. By measuring hysteresis loops at these peaks we show that this reorientation is common to all ferromagnetic terraces. The reorientation is explained by a simple model based on the shape anisotropy energy. Demagnetizing factors were calculated for different configurations suggested by the magnetic images. We noted that the magnetic moments flip from an in-plane mono-domain orientation at lower temperatures to a three-domain out-of-plane configuration at higher temperatures. The transition was observed when the ferromagnetic stripe width L is equal to 2.9 times the film thickness d. This is in good agreement with the expected theoretical value of L = 2.6d.Comment: 16 pages in PD

Aplicação de ácido húmico via fertirrigação na produtividade da bananeira BRS Tropical.

Os ácidos húmicos constituem a maior fração da matéria orgânica do solo. A parte mais estável do carbono presente na matéria orgânica do solo e são cruciais no conceito de desenvolvimento sustentável, devido à sua influência na manutenção da qualidade do solo

PH e condutividade elétrica do solo sob lâminas de irrigação e doses de adubação nitrogenada em bananeira.

O nitrogênio é um dos nutrientes mais necessários ao bom desenvolvimento e produção da bananeira. A adubação nitrogenada pode ser preparada por fontes de sais inorgânicos rapidamente disponíveis como o amônio, o nitrato e a uréia. A utilização da uréia pelos produtores se traduz pelo menor custo que esses fertilizantes possuem, porém, a possibilidade de aumento da acidez do solo, ou seja, a redução do pH e da saturação de base se tornam aspectos indesejados na aplicação desse fertilizante. Nas condições irrigadas, pode haver interações entre os níveis de água aplicados e as dosagens de adubos, fazendo com que o pH do solo e os níveis de condutividade elétrica (CE) do solo apresentem diferentes comportamentos em relação as condição de sequeiro. Além disso, a CE está relacionada ao conteúdo de água presente no solo, sendo que sua alteração está relacionada à diluição dos sais da solução. O objetivo do trabalho foi avaliar o comportamento do pH do solo e da CE do extrato de saturação ao longo do segundo ciclo da bananeira BRS Tropical com três doses de uréia sob quatro lâminas de irrigação nas condições edafoclimáticas do projeto Gorutuba, Norte de Minas.PDF. 097