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Search Results: 1 - 10 of 543108 matches for " L.V.B.D.; "
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Fotossíntese de biótipos de azevém sob condi??o de competi??o
Concen?o, G.;Ferreira, E.A.;Silva, A.A.;Ferreira, F.A.;Galon, L.;Reis, M.R.;d'Antonino, L.;Vargas, L.;Silva, L.V.B.D.;
Planta Daninha , 2008, DOI: 10.1590/S0100-83582008000300015
Abstract: characteristics associated with photosynthetic activity of ryegrass biotypes, susceptible and resistant to glyphosate, were evaluated under different competition levels. the experiment was installed in a factorial design, with two ryegrass biotypes, susceptible and resistant to glyphosate, growing in the plot center, surrounded by 0, 1, 2, 3, and 4 plants of the opposite biotype. fifty days after emergence, stomatal gas flow rate (u μmol s 1), sub-stomatal co2 concentration (ci - μmol mol-1) and photosynthetic rate (a μmol m-2 s-1 ) were evaluated, with the co2 used in photosynthesis (δc - μmol mol-1) being calculated as the difference between the reference co2 and the co2 in the evaluation chamber. data were collected using an infrared gas analyzer (irga), model lca4 (adc company), followed by building a correlation matrix between the variables. the ryegrass biotypes susceptible and resistant to glyphosate did not differ in relation to the photosynthetic activity in absence of competition. however, the photosynthetic rate was reduced in function of increasing competition with plants of the opposite biotype for both the resistant and susceptible biotypes, and for the resistant biotype when in competition with plants of the same biotype. this behavior was attributed to reciprocal shading and light competition.
A review of techniques for spatial modeling in geographical, conservation and landscape genetics
Diniz-Filho, José Alexandre Felizola;Nabout, Jo?o Carlos;Telles, Mariana Pires de Campos;Soares, Thannya Nascimento;Rangel, Thiago Fernando L.V.B.;
Genetics and Molecular Biology , 2009, DOI: 10.1590/S1415-47572009000200001
Abstract: most evolutionary processes occur in a spatial context and several spatial analysis techniques have been employed in an exploratory context. however, the existence of autocorrelation can also perturb significance tests when data is analyzed using standard correlation and regression techniques on modeling genetic data as a function of explanatory variables. in this case, more complex models incorporating the effects of autocorrelation must be used. here we review those models and compared their relative performances in a simple simulation, in which spatial patterns in allele frequencies were generated by a balance between random variation within populations and spatially-structured gene flow. notwithstanding the somewhat idiosyncratic behavior of the techniques evaluated, it is clear that spatial autocorrelation affects type i errors and that standard linear regression does not provide minimum variance estimators. due to its flexibility, we stress that principal coordinate of neighbor matrices (pcnm) and related eigenvector mapping techniques seem to be the best approaches to spatial regression. in general, we hope that our review of commonly used spatial regression techniques in biology and ecology may aid population geneticists towards providing better explanations for population structures dealing with more complex regression problems throughout geographic space.
麦类作物学报 , 1984, DOI: 10.7606/j.issn.1009-1041.1984.04.085
Abstract: 1引言决定一种植物适应性和分布区域的重要因素之一是它们对低温的忍耐力。它的生存依赖于冷驯化或锻炼过程。冬小麦的冷驯化是在遗传系统的控制下受低温诱导的。这个锻炼过程所需的能量不是来自种子的贮藏物,就是来自光合产物。任何形式的胁迫,例如含盐量,营
Cytokine production profile of heart-infiltrating T cells in Chagas' disease cardiomyopathy
Cunha-Neto, E.;Rizzo, L.V.;Albuquerque, F.;Abel, L.;Guilherme, L.;Bocchi, E.;Bacal, F.;Carrara, D.;Ianni, B.;Mady, C.;Kalil, J.;
Brazilian Journal of Medical and Biological Research , 1998, DOI: 10.1590/S0100-879X1998000100018
Abstract: the hallmark of chronic chagas' disease cardiomyopathy (ccc) is the finding of a t cell-rich inflammatory mononuclear cell infiltrate in the presence of extremely few parasites in the heart lesions. the scarcity of parasites in affected heart tissue casts doubt on the direct participation of trypanosoma cruzi in ccc heart tissue lesions, and suggests the possible involvement of autoimmunity. the cells in the infiltrate are presumably the ultimate effectors of tissue damage, and there is evidence that such cells recognize cardiac myosin in molecular mimicry with t. cruzi proteins rather than primary reactivity to t. cruzi antigens (cunha-neto et al. (1996) journal of clinical investigation, 98: 1709-1712). recently, we have studied heart-infiltrating t cells at the functional level. in this short review we summarize the studies about the role of cytokines in human and experimental t. cruzi infection, along with our data on heart-infiltrating t cells in human chagas' cardiomyopathy. the bulk of evidence points to a significant production of ifn-g and tnf-a which may be linked to t. cruzi-induced il-12 production
Biocontrol of aflaroot and dry root rot of groundnut by transgenic Rhizobium
Indian Phytopathology , 2011,
Abstract: Aflaroot (Aspergillus flavus) and dry root rot (Aspergillus niger) are known to cause considerable loss of groundnut (Arachis hypogea L.). Rhizobial isolates were obtained from the nodules of groundnut and wild legumes such as Indigofera linifolia, I. duthiei, Alysicarpus tetraganolobus and Tephrotia pumila. Pseudomonas fluorescens was isolated from rhizosphere of groundnut and noted to be antagonistic to A. flavus and A. niger. This was also confirmed by plasmid analysis. The horizontal gene transfer from P. fluorescens to Rhizobium was obtained. The transconjugants were used for biocontrol of aflaroot and dry root rot. The percentage control efficacy (PCE) was better due to application of transconjugants.
A UPFC damping control scheme using Lead-Lag and ANN based Adaptive controllers
D. Ramesh,L.V.MaheshBabu
International Journal of Computer Technology and Applications , 2012,
Abstract: Low Frequency Oscillations (LFO) occur inpower systems because of lack of the damping torque inorder to dominance to power system disturbances aschange in mechanical input power. In the recent pastPower System Stabilizer (PSS) was used to damp LFO.FACTs devices, such as Unified Power Flow Controller(UPFC), can control power flow and increase transientstability. So UPFC may be used to damp LFO instead ofPSS. UPFC damps LFO through direct control of voltageand power. In this research the linearized model ofsynchronous machine (Heffron-Philips) connected toinfinite bus (Single Machine-Infinite Bus: SMIB) withUPFC is used and also in order to damp LFO, adaptiveANN damping controller for UPFC is designed andsimulated. Simulation is performed for various types ofloads and for different disturbances. Simulation resultsdemonstrate that the developed ANN damping controllerwould be more effective in damping electromechanicaloscillations in comparison with the conventional lead-lagcontroller.
Biomarcadores histológicos: toxicidade cr?nica pelo Roundup em piau?u (Leporinus macrocephalus)
Albinati, A.C.L.;Moreira, E.L.T.;Albinati, R.C.B.;Carvalho, J.V.;Lira, A.D. de;Santos, G.B.;Vidal, L.V.O.;
Arquivo Brasileiro de Medicina Veterinária e Zootecnia , 2009, DOI: 10.1590/S0102-09352009000300015
Abstract: the use of gills, liver, and kidneys as histological biomarkers was evaluated in a chronic toxicity analysis with herbicide roundup? in piau?u (leporinus macrocephalus). the animals were exposed to 1/10 of lc50 (1.58mg/l), during a period of 14 and 28 days. five animals were used for treatment (days 0, 14, and 28). hepatic hemorrhage and necrosis and renal congestion were the alterations that presented differences between exposed and non-exposed animals. among the organs used as histological biomarkers, the liver presented the best results, followed by the kidneys.
Toxicity to sea urchin egg development of the quinone fraction obtained from Auxemma oncocalyx
Costa-Lotufo, L.V.;Ferreira, M.A.D.;Lemos, T.L.G.;Pessoa, O.D.L.;Viana, G.S.B.;Cunha, G.M.A.;
Brazilian Journal of Medical and Biological Research , 2002, DOI: 10.1590/S0100-879X2002000800010
Abstract: auxemma oncocalyx taub. belongs to the boraginaceae family and is native to the brazilian northeast where it is known as "pau-branco". we investigated the ability of the water soluble fraction isolated from the heartwood of a. oncocalyx to inhibit sea urchin egg development. this fraction contains about 80% oncocalyxone a (quinone fraction), a compound known to possess strong cytotoxic and antitumor activities. in fact, the quinone fraction inhibited cleavage in a dose-dependent manner [ic50 of 18.4 (12.4-27.2) μg/ml, n = 6], and destroyed the embryos in the blastula stage [ic50 of 16.2 (13.7-19.2) μg/ml, n = 6]. we suggest that this activity is due to the presence of oncocalyxone a. in fact, these quinones present in a. oncocalyx extract have strong toxicity related to their antimitotic activity.
Experimental Investigation of the Ferrum (III) Hydroxide Polymaltosate Preparation Influence Peculiarities on the Lipid Peroxidation Values
L.V. Lovtsova,V.B. Kuzin
Sovremennye Tehnologii v Medicine , 2010,
Abstract: Aim of investigation is a study of the ferrum (III) hydroxide polymaltosate preparation influence peculiarities on the lipid peroxidation and antioxidant protection values in blood of experimental animals at the background of a ferrodeficient anemia.Materials and methods. The experiment is made on 120 nonlinear male-rats. The values of induced biochemiluminescence, a content of malone dialdehyde, an activity of superoxidedismutase and catalase, a concentration of ceruloplasmin in blood of experimental animals at infusion of a preparation, containing a trivalent ferrum, — a ferrum (III) hydroxide polymaltosate (maltofer) — in equitherapeutic dose of 17.14 mg/kg a day (calculating the elementary ferrum) have been detected during investigation for 30 days.Results. A trivalent ferrum (III) hydroxide polymaltosate preparation (maltofer) stipulates at the early stages an insignificant, and at the later stages — expressed influence on the pointed process, which is confirmed by an increase of a free-radical oxidation process abatement rate in blood plasma of experimental animals, and also a decrease of a superoxidedismutase activity (in a day of its infusion), a decrease of a malone dialdehyde concentration (in 5 days), a decrease of the antioxidant and superoxidedismutase activity (in 10 days), an increase of a plasma free-radical activity and a free-radical oxidation process abatement rate (in 20 days), a decrease of a malone dialdehyde content (in 30 days).Conclusion. The investigating trivalent ferrum preparation activates a process of lipid peroxidation. Its distinctive feature is a more expressed influence on the pointed process at the late stages of its infusion.
Candidate gene linkage analysis indicates genetic heterogeneity in Marfan syndrome
Teixeira, L.V.S.;Mandelbaum, K.L.;Pereira, L.V.;Perez, A.B.A.;
Brazilian Journal of Medical and Biological Research , 2011, DOI: 10.1590/S0100-879X2011007500095
Abstract: marfan syndrome (mfs) is an autosomal dominant disease of the connective tissue that affects the ocular, skeletal and cardiovascular systems, with a wide clinical variability. although mutations in the fbn1 gene have been recognized as the cause of the disease, more recently other loci have been associated with mfs, indicating the genetic heterogeneity of this disease. we addressed the issue of genetic heterogeneity in mfs by performing linkage analysis of the fbn1 and tgfbr2 genes in 34 families (345 subjects) who met the clinical diagnostic criteria for the disease according to ghent. using a total of six microsatellite markers, we found that linkage with the fbn1 gene was observed or not excluded in 70.6% (24/34) of the families, and in 1 family the mfs phenotype segregated with the tgfbr2 gene. moreover, in 4 families linkage with the fbn1 and tgfbr2 genes was excluded, and no mutations were identified in the coding region of tgfbr1, indicating the existence of other genes involved in mfs. our results suggest that the genetic heterogeneity of mfs may be greater that previously reported.
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