Influence of aluminum on root growth and of anatomy Stenocalyx dysentericus (DC.) O. Berg

This study aimed to evaluate the effect of aluminum (Al) on root growth and root anatomical structure of Stenocalyx dysentericus seedlings. Newly emerged plants were grown in simple solution composed of 0.1 μM of CaCl2.2H2O and five Al concentrations of 0, 150, 300, 600, and 1200 μM for 37 days in a hydroponic system. Subsequently, the seedlings were evaluated for root growth, relative root elongation, and anatomical studies using bright-field and fluorescence microscopy techniques. The results showed tolerance by S. dysentericus, with more root relative elongation in treatments with 150, 300, and 600 μM of Al. The anatomical studies revealed the presence of Al in root tissue, through the morin reagent, mainly in the 1200 μM treatment, characterizing some internal detoxification mechanism. S. dysentericus demonstrated tolerance in the tests with Al, principally at lower doses. These results may be entirely linked to its wide distribution in the cerrado domain, demonstrating to be a species  adapted to soils with higher Al concentration. S. dysentericus, when subjected to treatment with Al, showed a stimulating effect on root growth; for this species, low concentrations of Al may be essential for better root growth.Keywords: Cerrado, acidic soils, plant toxicity, toleranc

A note on a problem due to Zelmanowitz

In this paper we consider a problem due to Zelmanowitz. Specifically, we study under what conditions a uniform compressible module whose nonzero endomorphisms are monomorphisms is critically compressible. We give a positive answer to this problem for the class of nonsingular modules, quasi-projective modules and for modules over rings which are in a certain class of rings which contains at least the commutative rings and the left duo rings

Relief evolution of the Quadrilatero Ferrifero (Minas Gerais, Brazil) by means of (Be-10) cosmogenic nuclei

This paper investigates the evolution of the relief within the so-called Iron Quadrangle (Quadrilatero Ferrifero) in Minas Gerais, Brazil, by means of quantification of erosion processes, which affected the principal rock types of the region. The method used is based on measurement of in-situ produced cosmogenic Be-10 concentration in fluvial sediments. The results indicate that the regional landscape evolution is controlled by lithotypes: the most resistant areas correspond to substrates developed on itabirites and quartzites (long-term erosion rates between 0.29 to 2.35 m/My), whereas the most fragile ones developed on schistphyllitcs (long-term erosion rates between 7.95 to 11.82 m/My) and granite-gneisses (long-term erosion rate at 12.92 m/My)

Influence Of A Cobalt-chromium Metal Framework On Surface Roughness And Knoop Hardness Of Visible Light-polymerized Acrylic Resins

Although visible light-polymerized acrylic resins have been used in removable partial dentures, it is not clear whether the presence of a metal framework could interfere with their polymerization, by possibly reflecting the light and affecting important properties, such as roughness and hardness, which would consequently increase biofilm accumulation. The aim of this study was to compare the roughness and Knoop hardness of a visible light-polymerized acrylic resin and to compare these values to those of water-bath- and microwave-polymerized resins, in the presence of a metal framework. Thirty-six specimens measuring 30.0 x 4.0 ± 0.5 mm of a microwave- (Onda Cryl), a visible light- (Triad) and a water-bath-polymerized (Clássico) (control) acrylic resins containing a cobalt-chromium metal bar were prepared. After processing, specimens were ground with 360 to 1000-grit abrasive papers in a polishing machine, followed by polishing with cloths and 1-μm diamond particle suspension. Roughness was evaluated using a profilometer (Surfcorder SE 1700) and Knoop hardness (Kg/mm 2) was assayed using a microhardness tester (Shimadzu HMV 2000) at distances of 50, 100, 200, 400 and 800 μm from the metal bar. Roughness and Knoop hardness means were submitted to two-way ANOVA and compared by Tukey and Kruskal Wallis tests at a 5% significance level Statistically significant differences were found (p<0.05) for roughness and Knoop hardness, with light-polymerized resin presenting the highest values (Ra = 0.11 μm and hardness between 20.2 and 21.4 Kg/mm 2). Knoop values at different distances from the metal bar did not differ statistically (p>0.05). Within the limitations of this in vitro study, it was concluded that the presence of metal did not influence roughness and hardness values of any of the tested acrylic resins.143208212Anusavice, K.J., (2003) Philip's Science of Dental Materials. 11 th Ed., p. 96. , 11 St. Louis: Elsevier ScienceBollen, C.M.L., Lambrechts, P., Quirynen, M., Comparison of surface roughness of oral hard materials to the threshold surface roughness for bacterial plaque retention: A review of the literature (1997) Dent Mater, 13 (4), pp. 258-269Borchers, L., Tavassol, F., Tschernitschek, H., Surface quality achieved by polishing and by varnishing of temporary crown and fixed partial denture resins (1999) J Prosthet Dent, 82 (5), pp. 550-556Braun, K.O., Del Bel Cury, A.A., Cury, J.A., Use of microwave energy for processing acrylic resin near metal (1998) Braz Oral Res, 12 (2), pp. 173-180Curtis, D.A., Eggleston, T.L., Marshall, S.J., Watanabe, L.G., Shear bond strength of visible-light-cured resin relative to heat-cured resin (1989) Dental Mater, 5 (7), pp. 314-318De Clerck, J.P., Microwave polymerization of acrylic resins used in dental prosthesis (1987) J Prosthet Dent, 57 (5), pp. 650-658Khan, Z., Von Fraunhofer, J.A., Razavi, R., The staining characteristics, transverse strength, and microhardness of a visible light-cured denture base material (1987) J Prosthet Dent, 57 (3), pp. 384-386Levin, B., Sanders, J.L., Reitz, P.V., The use of microwave energy for processing acrylic resins (1989) J Prosthet Dent, 61 (3), pp. 381-383Ogle, R.E., Sorensen, S.E., Lewis, E.A., A new visible light-cured resin system applied to removable prosthodontics (1986) J Prosthet Dent, 56 (4), pp. 497-506Quirynen, M., Cml, B., Willems, G., Van Steenberghe, D., Comparison of surface characteristics of six commercially pure titanium abutments (1994) JOMI, 9 (1), pp. 71-76Reitz, P.V., Sanders, J.L., Levin, B., The curing of denture acrylic resins by microwave energy. Physical properties (1985) Quintessence Int, 6 (8), pp. 547-551Rodrigues Garcia, R.C.M., Souza Jr., J.A., Rached, R.N., Del Bel Cury, A.A., Effect of denture cleansers on the surface roughness and hardness of a microwave-cured acrylic resin and dental alloys (2004) J Prosthodont, 13 (3), pp. 1-6Rueggeberg, F.A., Goughman, W.F., Curtis Jr., J.W., Effect of light intensity and exposure duration on cure of resin composite (1994) Oper Dent, 19 (1), pp. 26-32Truong, V.T., Thomasz, F.G., Comparison of denture acrylic resins cured by boiling water and microwave energy (1988) Aust Dent J, 33 (3), pp. 201-204Ulusoy, M., Ulusoy, N., Aydin, A.K., An evaluation of polishing technique on surface roughness of acrylic rsins (1986) J Prosthetic Dent, 56 (1), pp. 107-11

Avaliação experimental do comportamento fora do plano de paredes de alvenaria de adobe

Com vista a colmatar a escassez de informação acerca do comportamento e propriedades mecânicas das construções em alvenaria de adobe existentes na região de Aveiro, tem-se vindo a realizar várias campanhas experimentais. Procurando identificar aspectos tais como a rigidez, a capacidade resistente, a dissipação de energia e os mecanismos de colapso, essas campanhas têm incluído levantamentos dimensionais, estudos da composição granulométrica dos diferentes adobes da região, ensaios de caracterização do comportamento mecânico deste material (em tracção e compressão), ensaios cíclicos quase-estáticos em alvenaria (fora do plano e no plano), ensaios de caracterização dinâmica, etc. Neste artigo apresentam-se os principais resultados de um ensaio cíclico quase-estático para fora do plano, complementado com ensaios dinâmicos realizados sobre paredes de alvenaria de adobe de uma construção existente. Procura-se assim contribuir para uma melhor caracterização das construções já edificadas, tendo em vista a interpretação das patologias estruturais mais comuns, a calibração de modelos numéricos, a avaliação da segurança e o desenvolvimento de adequadas soluções de reforço

A atitude do utilizador das Bibliotecas do Ensino Superior Politécnico

Comunicação oral apresentada ao 7.º Congresso Nacional de Bibliotecários,Arquivistas e Documentalistas, no âmbito de um painel, coordenado pela Comissão Permanente do Grupo de Trabalho das Bibliotecas do Ensino Superior da BAD.Apresentam-se os resultados de um inquérito efectuado aos bibliotecários dos estabelecimentos de ensino superior politécnico portugueses com o intuito de perceber a sua perspectiva acerca dos utilizadores das bibliotecas. A amostra foi constituída pelos bibliotecários de todos os estabelecimentos de ensino superior politécnico existentes em 2001, em Portugal, tendo a taxa de resposta atingido os 65% do total. Obtiveram-se resultados acerca da utilização dos serviços e recursos disponibilizados pelas bibliotecas, tendo os bibliotecários identificado a necessidade de formação dos utilizadores como o maior obstáculo à utilização plena dos mesmos

Effects of motor imagery training of Parkinson's disease: a protocol for a randomized clinical trial

Background Gait disorders in individuals with Parkinson’s disease (PD) may be associated with alterations in the motor control system and aggravated by psychoemotional and cognitive issues. Therapeutic strategies aimed at self-perception and motor regulation seem to be promising. Motor imagery (MI) has been shown to be one of these strategies, but there is still no clear evidence of its applicability in this population. The aim of this trial is to determine the effects of motor-imagery training on the gait and electroencephalographic activity of individuals with PD. Methods/design The sample will consist of 40 individuals, aged between 45 and 75 years, in the mild and moderate phase of the disease, with the ability to generate voluntary mental images. They will be assessed for cognitive level, degree of physical disability, mental-image clarity, kinematic gait variables, electroencephalographic activity and mobility. Next, subjects will be randomly assigned to an experimental group (EG) and a control group (CG). The EG will perform motor imagery and gait, while the CG will only engage in gait exercises. Twelve training sessions will be conducted lasting up to 90 min each, three times a week, for 4 weeks. The subjects will be reassessed on the kinematic variables of gait, electroencephalographic activity and mobility at 1, 7 and 30 days after the final training session. Discussion The results may provide an important advance in neurological rehabilitation where an easy-access and low-cost intervention may help to improve gait, electroencephalographic activity and mobility in individuals with PD

Membrane-associated proteins of ejaculated sperm from Morada Nova rams

AbstractThe objective was to describe the profile of membrane proteins from sperm of tropically adapted Morada Nova rams (N = 5). Samples from protein-enriched fractions of ejaculated sperm (containing 400 μg of protein) were separated by two-dimensional electrophoresis and respective maps analyzed using PDQuest software (version 7.3.0; Bio-Rad). Proteins were identified using tandem mass spectrometry. Also, membrane proteins were incubated with antibodies against binder of sperm protein (BSP) 1 and bodhesin 2 (Bdh-2), components of vesicular gland secretion. For membrane proteins of ejaculated sperm, an average of 133 ± 4.6 spots were detected per gel, of which, 107 spots were consistently present on all gels. Sixty-eight spots and 37 proteins were identified using mass spectrometry, corresponding to 71.6% of the intensity of all spots detected. Three major spots identified as ram seminal vesicle protein (RSVP) 14 represented approximately 30% of the intensity of all spots. Two of the most intense spots in the gel reacted against anti-BSP1, at 14 kDa. In addition, four low molecular weight spots reacted with anti-Bdh-2 antibodies. Proteins RSVP and Bdh-2 belong to the BSP and spermadhesin families, respectively, and were previously reported as major components of ram seminal proteins. Additional proteins identified in the sperm membrane two-dimensional maps included alpha-2-heparan sulfate-glycoprotein, plasma glutamate carboxypeptidase, arylsulfatase A, cathelicidin, heat shock protein 70 kDa, angiotensin-converting enzyme, leucine aminopeptidase, and clusterin. Some proteins were present as multiple isoforms, such as tubulin (12), alpha-2-heparan sulfate-glycoprotein (5), ATP synthase (5), Bdh-2 (4) and RSVP14 (3). Based on gene ontology analysis, the most common biological processes associated with the membrane proteins were cellular processes (34%), response to stimulus (14%), and metabolic processes (11%). Binding (37%) and catalytic activity (32%) corresponded to the most frequent molecular functions for those proteins. In conclusion, we identified a diverse cohort of components of membrane proteins in ram sperm. Major proteins previously reported in seminal plasma, such as RSVP14 and Bdh-2, were also extracted from sperm membranes. Knowledge of sperm proteins is crucial for elucidating mechanisms underlying their association with sperm function

Efeito de níveis de nitrogênio e fósforo no desenvolvimento de mudas de guaranazeiro (Paullinia cupana (Mart.) Ducke), em condições de viveiro

The present work was done with the objective of verifying the effect of nitrogen (N) and phosphorus (P) levels on the development of five progenies of guaranazeiro (Paullinia cupana var. sorbilis (Mart.) Ducke) under nursery conditions. The experiment was carried out in an experimental area of EMBRAPA (Empresa Brasileira de Pesquisa Agropecuária -Porto Velho, RO. Brazil). The experimental design consisted of a completely randomized design with three replications and nine treatments. The results obtained allowed for the following conclusions: a) N1P2 treatment showed better results among those studied; b) Progenies 16 and 13 showed greater potential for development when compared with the others; progeny 29 was second best.Com objetivo de se estudar o efeito de níveis de nitrogênio e fósforo, no desenvolvimento de mudas de cinco progênies de guaranazeiros (Paullinia cupana var. sorbilis (Mart.) Ducke) em condições de viveiro, foi conduzido um ensaio, na área experimental da EMBRAPA (Empresa Brasileira de Pesquisa Agropecuária) localizada em Porto Velho, Rondônia. O delineamento utilizado foi inteiramente casualizado, constituído de 135 plantas úteis, com nove tratamentos e três repetições. Os resultados obtidos permitiram concluir que: a) o tratamento N1P2 correspondente a 2,92 gramas de uréia e 5,20 gramas de superfosfato triplo, aplicados por planta, foi o melhor para todos os parâmetros avaliados; b) as progênies 16 e 13 apresentaram um maior potencial de desenvolvimento, em relação as demais progênies testadas, vindo a seguir a progênie 29

Compatibility of a model for the QCD-Pomeron and chiral-symmetry breaking phenomenologies

The phenomenology of a QCD-Pomeron model based on the exchange of a pair of non-perturbative gluons, i.e. gluon fields with a finite correlation length in the vacuum, is studied in comparison with the phenomenology of QCD chiral symmetry breaking, based on non-perturbative solutions of Schwinger-Dyson equations for the quark propagator including these non-perturbative gluon effects. We show that these models are incompatible, and point out some possibles origins of this problem.Comment: 21 pages, uuencoded latex file, 3 postscript figures, uses epsf.sty and epsf.tex. To be published in Phys. Lett.