3,032 research outputs found

    Recomendação de diferentes épocas de colheita para cultivares de mandioca tipo Indústria em Alagoas.

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    Assessing binary mixture effects from genotoxic and endocrine disrupting environmental contaminants using infrared spectroscopy

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    Benzo[a]pyrene (B[a]P), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) are persistent contaminants and concern has arisen over co-exposure of organisms when the chemicals exist in mixtures. Herein, attenuated total reflection Fouriertransform infrared (ATR-FTIR) spectroscopy was used to identify biochemical alterations induced in cells by single and binary mixtures of these environmental chemicals. It was also investigated as a method to identify if interactions are occurring in mixtures and as a possible tool to predict mixture effects. Mallard fibroblasts were treated with single and binary mixtures of B[a]P, PCB126, PCB153, BDE47 and BDE209. Comparison of observed spectra from cells treated with binary mixtures with expected additive spectra, which were created from individual exposure spectra, indicated that in many areas of the spectrum, less-than-additive binary mixture effects may occur. However, possible greater-than-additive alterations were identified in the 1650-1750 cm-1 lipid region and may demonstrate a common mechanism of B[a]P and PCBs or PBDEs, which can enhance toxicity in mixtures

    Comparison of 120Sn(6He,6He)120Sn and 120Sn(alpha,alpha)120Sn elastic scattering and signatures of the 6He neutron halo in the optical potential

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    Cross sections of 120^{120}Sn(α\alpha,α\alpha)120^{120}Sn elastic scattering have been extracted from the α\alpha particle beam contamination of a recent 120^{120}Sn(6^6He,6^6He)120^{120}Sn experiment. Both reactions are analyzed using systematic double folding potentials in the real part and smoothly varying Woods-Saxon potentials in the imaginary part. The potential extracted from the 120^{120}Sn(6^6He,6^6He)120^{120}Sn data may be used as the basis for the construction of a simple global 6^6He optical potential. The comparison of the 6^6He and α\alpha data shows that the halo nature of the 6^6He nucleus leads to a clear signature in the reflexion coefficients ηL\eta_L: the relevant angular momenta LL with ηL0\eta_L \gg 0 and ηL1\eta_L \ll 1 are shifted to larger LL with a broader distribution. This signature is not present in the α\alpha scattering data and can thus be used as a new criterion for the definition of a halo nucleus.Comment: 13 pages, 7 figures, accepted for publication in Phys. Rev.

    Topological phase transitions between chiral and helical spin textures in a lattice with spin-orbit coupling and a magnetic field

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    We consider the combined effects of large spin-orbit couplings and a perpendicular magnetic field in a 2D honeycomb fermionic lattice. This system provides an elegant setup to generate versatile spin textures propagating along the edge of a sample. The spin-orbit coupling is shown to induce topological phase transitions between a helical quantum spin Hall phase and a chiral spin-imbalanced quantum Hall state. Besides, we find that the spin orientation of a single topological edge state can be tuned by a Rashba spin-orbit coupling, opening an interesting route towards quantum spin manipulation. We discuss the possible realization of our results using cold atoms trapped in optical lattices, where large synthetic magnetic fields and spin-orbit couplings can be engineered and finely tuned. In particular, this system would lead to the observation of a time-reversal-symmetry-broken quantum spin Hall phase.Comment: 8 pages, 3 figures, Accepted in Europhys. Lett. (Dec 2011

    Dominance and G×E interaction effects improvegenomic prediction and genetic gain inintermediate wheatgrass (Thinopyrumintermedium)

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    Genomic selection (GS) based recurrent selection methods were developed to accelerate the domestication of intermediate wheatgrass [IWG, Thinopyrum intermedium (Host) Barkworth & D.R. Dewey]. A subset of the breeding population phenotyped at multiple environments is used to train GS models and then predict trait values of the breeding population. In this study, we implemented several GS models that investigated the use of additive and dominance effects and G×E interaction effects to understand how they affected trait predictions in intermediate wheatgrass. We evaluated 451 genotypes from the University of Minnesota IWG breeding program for nine agronomic and domestication traits at two Minnesota locations during 2017–2018. Genet-mean based heritabilities for these traits ranged from 0.34 to 0.77. Using fourfold cross validation, we observed the highest predictive abilities (correlation of 0.67) in models that considered G×E effects. When G×E effects were fitted in GS models, trait predictions improved by 18%, 15%, 20%, and 23% for yield, spike weight, spike length, and free threshing, respectively. Genomic selection models with dominance effects showed only modest increases of up to 3% and were trait-dependent. Crossenvironment predictions were better for high heritability traits such as spike length, shatter resistance, free threshing, grain weight, and seed length than traits with low heritability and large environmental variance such as spike weight, grain yield, and seed width. Our results confirm that GS can accelerate IWG domestication by increasing genetic gain per breeding cycle and assist in selection of genotypes with promise of better performance in diverse environments

    Low-dietary fiber intake as a risk factor for recurrent abdominal pain in children

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    Objective: To evaluate dietary fiber intake in children with recurrent abdominal pain.Design: Cross-sectional study with control group.Setting: Outpatients of the Pediatric Gastroenterology public health clinic of the Darcy Vargas Children's Hospital, Brazil.Subjects: Forty-one patients with recurrent abdominal pain were evaluated and 41 children, as a control group.Interventions: Macronutrients and fiber intake evaluation by the Daily Food Intake method. Two tables of fiber composition in foods were used.Results: According to the Brazilian table the mean intake of fiber ( g/day) by the children of the recurrent abdominal pain groups with chronic constipation or not, and the control group was, respectively, 18.2, 16.6 and 23.7 for total fiber ( P 0.001), 7.5, 6.9 and 9.5 for soluble fiber ( P 0.001) and 10.7, 9.7 and 14.1 for insoluble fiber ( P 0.002). According to the AOAC table, the recurrent abdominal pain group with chronic constipation or not ( 10.6 and 9.9 g/day) also had lower intake of total fiber than the control group ( 13.4 g/day) ( P 0.008). the intake of fiber was lower than the minimum recommended value ( age+5g) and statistically associated ( P 0.021) with the recurrent abdominal pain group ( 78%) in comparison with the control one ( 51.2%). the odds ratio was 3.39 ( 95% CI, 1.18 - 9.95).Conclusion: fiber intake below the minimum recommended value is a risk factor for recurrent abdominal pain in children.Universidade Federal de São Paulo, Dept Pediat, Paulista Sch Med, BR-04023062 São Paulo, BrazilDarcy Vargas Childrens Hosp, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Pediat, Paulista Sch Med, BR-04023062 São Paulo, BrazilWeb of Scienc
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