952 resultados para M2-m3 Loop
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The super-Poincaré covariant formalism for the superstring is used to compute massless four-point two-loop amplitudes in ten-dimensional superspace. The computations are much simpler than in the RNS formalism and include both external bosons and fermions. © SISSA 2006.
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The massless 4-point one-loop amplitude computation in the pure spinor formalism is shown to agree with the computation in the RNS formalism. © SISSA 2006.
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Uncoupling proteins (UCPs) are specialized mitochondrial transporter proteins that uncouple respiration from ATP synthesis. In this study, cDNA encoding maize uncoupling protein (ZmPUMP) was expressed in Escherichia coli and recombinant ZmPUMP reconstituted in liposomes. ZmPUMP activity was associated with a linoleic acid (LA)-mediated H+ efflux with Km of 56.36 ± 0.27 μM and Vmax of 66.9 μmol H+ min-1 (mg prot)-1. LA-mediated H+ fluxes were sensitive to ATP inhibition with Ki of 2.61 ± 0.36 mM (at pH 7.2), a value similar to those for dicot UCPs. ZmPUMP was also used to investigate the importance of a histidine pair present in the second matrix loop of mammalian UCP1 and absent in plant UCPs. ZmPUMP with introduced His pair (Lys155His and Ala157His) displayed a 1.55-fold increase in LA-affinity while its activity remained unchanged. Our data indicate conserved properties of plant UCPs and suggest an enhancing but not essential role of the histidine pair in proton transport mechanism. © 2006 Elsevier Inc. All rights reserved.
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To stimulate the bone callus development process from distal third of radius, 24 adult mongrel dogs used were from both sexes. These dogs were separated in two experimental groups of 12 animals each, named control and treated, divided in 4 moments (M1=15 days; M2=30 days; M3=45 days; M4=60 days), who underwent were performed surgical fractures. In treated group, it was performed bone perforations on proximal and distal edges, craniolateral and mediolateral to the fracture site. At the end of each moment, control and treated animals were evaluated by radiography, histology, and bone mineral densitometry (BMD) was determined on fracture site. According to the radiographic data of treated dogs, it was verified on days 15 and 30 more intense bone regeneration than control group. During M3 and M4, it wasn't detected any difference in bone reparation process betweencontrol and treated groups. In densitometric study, BMD values were greater in treated animals than in control dogs. Histological studies revealed at 15 and 30 days chondrocyte hyperplasia and initial endochondral ossification on drilled limbs; control group showed sustainment connective tissue and initial chondrocyte hiperplasia. At M3 and M4 of the treated group, were verified development and remodeling of periosteal callus in more advanced phases when comparing with limbs from control group. It can be concluded that using perforations enhances blood flow supply and activation of osteogenic cells on fracture site, stimulating the beginning of fracture consolidation process.
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We examined the variation in mitochondrial DNA by sequencing the D-loop region in wild and domestic (large-white breed) pigs, in hybrids between domestic and wild pigs, and in Monteiro pigs. A D-loop fragment of approximately 330 bp was amplified by PCR. Sequencing of DNA amplicons identified haplotypes previously described as European and Asian types. Monteiro pigs and wild pigs had European haplotypes and domestic pigs had both European and Asian haplotypes. ©FUNPEC-RP.
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We compute the one-loop beta functions for the Type II superstring using the pure spinor formalism in a generic supergravity background. It is known that the classical pure spinor BRST symmetry puts the background fields on-shell. In this paper we show that the one-loop beta functions vanish as a consequence of the classical BRST symmetry of the action. © SISSA 2007.
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The aim of this work was to evaluate the effect of a millet-soybean rotation, during the implantation phase of no-tillage system on the physical properties of a Nitossolo Vermelho distroférrico and the dry mass production of millet and the productivity of soybean. The experimental design used was a randomized blocks, in a split splot arrangement, with four replications. The parcels was constituted by three sowings (E1, E2 and E3) and the subparcels was constituted by harvests, where each harvest handling was: M1 - harvest each blooming and covering withdrawal; M2 - harvest each blooming and covering permanency; M3 - only in the first harvest on blooming and covering withdrawal; M4 - only in the first harvest on blooming and covering permanency, and M5-free growing, with no harvest. Samples were collected from three soil layers: 0-0,05, 0,05-0,10 and 0,10-0,20 m. The E2 showed smaller values of soil density and larger values of total porosity. The E3 resulted in smaller values of flocculation degree and mean weight diameter of the aggregates. The E3 showed smaller production of dry mass.
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Beetle luciferases emit a wide range of bioluminescence colors, ranging from green to red. Firefly luciferases can shift the spectrum to red in response to pH and temperature changes, whereas click beetle and railroadworm luciferases do not. Despite many studies on firefly luciferases, the origin of pH-sensitivity is far from being understood. Through comparative site-directed mutagenesis and modeling studies, using the pH-sensitive luciferases (Macrolampis and Cratomorphus distinctus fireflies) and the pH-insensitive luciferases (Pyrearinus termitilluminans, Phrixotrix viviani and Phrixotrix hirtus) cloned by our group, here we show that substitutions dramatically affecting bioluminescence colors in both groups of luciferases are clustered in the loop between residues 223-235 (Photinus pyralis sequence). The substitutions at positions 227, 228 and 229 (P. pyralis sequence) cause dramatic redshift and temporal shift in both groups of luciferases, indicating their involvement in labile interactions. Modeling studies showed that the residues Y227 and N229 are buried in the protein core, fixing the loop to other structural elements participating at the bottom of the luciferin binding site. Changes in pH and temperature (in firefly luciferases), as well as point mutations in this loop, may disrupt the interactions of these structural elements exposing the active site and modulating bioluminescence colors. © 2007 The Authors.
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The analysis of the physical medium in hydrographic basins requires knowledge of the processes involved and characteristics of variables at different geographic scales. Considering the principle that the micro-basins can be categorized, they are then considered territorial units of ideal work for the analysis of hydrologic conditions. The objective of this work was to compare water resources of four hydrographic basins' with different land use and occupation. Five sampling points along the drainage network of hydrographic basins of first order of magnitude and a sampling point in the river mouth of M1 and M4 micro-basins were established. The water collections occurred at monthly intervals from August, 2006 to August, 2007. Temperature (°C), turbidity (NTU), odor, pH, electric conductivity (μS cm-1), dissolved oxygen (mg/L), total dissolved solids (ppm) and total phosphorous (mg/L) were the variables evaluated in the study. The highest variability of the parameters was found in hydrographic basins M2 and M3. The characterization of the hydrologic conditions of the hydrographic micro-basins indicated that agricultural activities, including cultural practices of anthropic activities affect water resources.
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Using the results recently obtained for computing integrals over (non-minimal) pure spinor superspace, we compute the coefficient of the massless two-loop four-point amplitude from first principles. Contrasting with the mathematical difficulties in the RNS formalism where unknown normalizations of chiral determinant formulæ force the two-loop coefficient to be determined only indirectly through factorization, the computation in the pure spinor formalism can be smoothly carried out. © SISSA 2010.
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This work has evaluated the hematological and biochemical profile by the use of sodium diclofenac, meloxicam and firocoxib in Wistar rats. The rats were distributed in groups: G1 (control), G2 (diclofenac sodium: 15 mg/kg), G3 (meloxicam: 2.0 mg/ kg), G4 (meloxicam: 10.0 mg/ kg), G5 (firocoxib: 5.0 mg/ kg) e G6 (firocoxib: 25.0 mg/ kg). The drugs were administered intragastrically (gavage) once a day, during five days and evaluated in three moments: M1 (48 hours after the beginning of the treatment), M2 (96 hours after the beginning of the treatment) and M3 (72 hours after the ending of the treatment). In each moment of each group, five to seven animals were evaluated and laboratory exams were performed. There were no significant changes observed in the biochemical and hematological parameters by the use of meloxicam and firocoxib. One of the effects of the sodium diclofenac was eritrogram variation as hematocrit, erythrocytes, hemoglobin decrease during the treatment. In addition, the platelets and total white blood cells counts did not change except for basophil. There was no changes in AST, ALP, GGT, urea, creatinine, sodium, potassium values. However, the values of protein, globulin and albumin decreased. It was concluded that diclofenac sodium does not provide large variations in the hemogram and biochemical profile than the meloxicam and firocoxib do not provide delletery effects in laboratories tests.
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In this work it is proposed to validate an evolutionary tuning algorithm in plants composed by a grid connected inverter. The optimization aims the tuning of the slopes of P-Ω and Q-V curves so that the system is stable, damped and minimum settling time. Simulation and experimental results are presented to prove the feasibility of the proposed approach. However, experimental results demonstrate a compromising effect of grid frequency oscillations in the active power transferring. In addition, it was proposed an additional loop to compensate this effect ensuring a constant active power flow. © 2011 IEEE.
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This work evaluated the effect of triiodothyronine (T3) on larviculture of matrinxã, Brycon amazonicus. Oocytes of three females were pooled, fertilized with pooled semen of two males and separated in four batches that were immersed in triiodothyronine solutions as follows: M1 (control - water); M2 (0.01mg/L T3); M3 (0.05mg/L T3); and M4 (0.1mg/L T3). Triiodothyronine did not affect fertilization rate and number of hatched larvae. Weight of hatched larvae was significantly higher in treatments M3 and M4, as well as among larvae sampled at Day 12 in all treatments. After 12d of rearing, biomass gain was higher in the hormone treatments (M1 688±569mg; M2 2436±562mg; M3 3572±569mg; and M4 4129±770mg). In general, coefficients of variation of weight (CVw) and length (CVl) did not differ among treatments and cannibalism was registered between 36 and 72hours post-hatching (h.p.h.) without differences among treatments. Larval survival increased in the hormone treatments (M1 26.5%; M2 37.6%; M3 40.6%; and M4 40.8%). The results indicate that the immersion of matrinxã eggs in triiodothyronine can promote beneficial effects to its larviculture and indicate promising perspectives for culture of this tropical species. © by the World Aquaculture Society 2013.
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Mitochondrial DNA (mtDNA) analysis is usually a last resort in routine forensic DNA casework. However, it has become a powerful tool for the analysis of highly degraded samples or samples containing too little or no nuclear DNA, such as old bones and hair shafts. The gold standard methodology still constitutes the direct sequencing of polymerase chain reaction (PCR) products or cloned amplicons from the HVS-1 and HVS-2 (hypervariable segment) control region segments. Identifications using mtDNA are time consuming, expensive and can be very complex, depending on the amount and nature of the material being tested. The main goal of this work is to develop a less labour-intensive and less expensive screening method for mtDNA analysis, in order to aid in the exclusion of non-matching samples and as a presumptive test prior to final confirmatory DNA sequencing. We have selected 14 highly discriminatory single nucleotide polymorphisms (SNPs) based on simulations performed by Salas and Amigo (2010) [1] to be typed using SNaPShotTM (Applied Biosystems, Foster City, CA, USA). The assay was validated by typing more than 100 HVS-1/HVS-2 sequenced samples. No differences were observed between the SNP typing and DNA sequencing when results were compared, with the exception of allelic dropouts observed in a few haplotypes. Haplotype diversity simulations were performed using 172 mtDNA sequences representative of the Brazilian population and a score of 0.9794 was obtained when the 14 SNPs were used, showing that the theoretical prediction approach for the selection of highly discriminatory SNPs suggested by Salas and Amigo (2010) [1] was confirmed in the population studied. As the main goal of the work is to develop a screening assay to skip the sequencing of all samples in a particular case, a pair-wise comparison of the sequences was done using the selected SNPs. When both HVS-1/HVS-2 SNPs were used for simulations, at least two differences were observed in 93.2% of the comparisons performed. The assay was validated with casework samples. Results show that the method is straightforward and can be used for exclusionary purposes, saving time and laboratory resources. The assay confirms the theoretic prediction suggested by Salas and Amigo (2010) [1]. All forensic advantages, such as high sensitivity and power of discrimination, as also the disadvantages, such as the occurrence of allele dropouts, are discussed throughout the article. © 2013 Elsevier B.V.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)