Efeito do sistema plantio direto sobre a produtividade da mandioca (Manihot esculenta Crantz) em Sangão - SC.

A mandioca constitui parte fundamental da alimentação de mais de 500 milhões de pessoas no mundo, sendo também matéria-prima para uma série de produtos, sejam eles minimamente processados até quimicamente modificados (TAKAHASHI; CONÇALO, 2001). Para o cultivo da mandioca é recomendável que o solo tenha profundidade de 30 a 40 cm; ausência de camadas impermeáveis e material rochoso e; seja solto, poroso e friável para possibilitar o fácil crescimento das raízes (MONTALDO, 1979; SOUZA & SOUZA, 2000). Para propiciar estas condições, realiza-se o preparo do solo que, de acordo com HOWELER et al (1993), deve proporcionar um bom rompimento do solo para possibilitar melhor drenagem e aeração, reduzir a podridão de raízes e aumentar a produtividade, facilitar a colheita, reduzir os danos as raízes durante a colheita, proporcionando redução da deterioração durante o armazenamento. Entretanto, a associação de sistemas de preparo que resultam em pequena quantidade de palha remanescente sobre o solo com as características fitotécnicas da mandioca, a qual oferece reduzida proteção à superfície do solo no período inicial de desenvolvimento (HOWELER et al, 1993), agrava os problemas com erosão, compactação, oxidação da matéria orgânica, entre outros, resultando no empobrecimento crescente dos solos (SOUZA, SOUZA & GOMES, 2006). Nas regiões em que as áreas apresentam declividades mais acentuadas como é comum se observar no município de Sangão e regiões próximas, as perdas de solo por erosão são preocupantes. Em outras regiões, preocupados com estes aspectos, vários estudos foram realizados avaliando-se a produtividade de mandioca em diferentes sistemas de preparo, onde foi possível constatar que na maioria (OHIRI e EZUMAH, 1990; CADAVID et al, 1998; MATE, 2002; JONGRUAYSUP et al., 2003; FEY et al, 2007 e; OUSUBO et al, 2008) se obtiveram resultados de produtividade da mandioca equivalentes e até superiores em sistema plantio direto, enquanto OLIVEIRA et al (2001) e PEQUENO et al (2007), encontraram resultados equivalentes de produtividade em apenas um ano e, na média de todos os anos, o preparo mínimo e sistema plantio direto foram estatisticamente inferiores, apontado-se como possível causa destes resultados a maior densidade e menor macroporosidade encontrada nesses sistemas. Visando amenizar este problema que pode afetar o desenvolvimento, a produtividade e a colheita da mandioca, FEY (2009) desenvolveu um sulcador alado para a implantação da cultura da mandioca em sistema plantio direto, cujo objetivo é romper uma maior área de solo no sulco de plantio deixando-o solto para facilitar o desenvolvimento das raízes e melhorar a infiltração de água. Nos estudos realizados pelo autor não foram encontradas diferenças de produtividade na cultura da mandioca implantada em sistema de preparo convencional do solo e sistema plantio direto na região oeste do Paraná. Nesse contexto, o trabalho objetivou avaliar a produtividade da mandioca em sistema de preparo convencional e sistema plantio direto

Plantio direto de mandioca aspectos do manejo.

bitstream/item/186376/1/cartinha-plantiodireto-Rangel-2018-Ainfo.pd

Covariant and Heavy Quark Symmetric Quark Models

There exist relativistic quark models (potential or MIT-bag) which satisfy the heavy quark symmetry (HQS) relations among meson decay constants and form factors. Covariant construction of the momentum eigenstates, developed here, can correct for spurious center-of-mass motion contributions.Proton form factor and M1 transitions in quarkonia are calculated. Explicit expression for the Isgur-Wise function is found and model determined deviations from HQS are studied. All results depend on the model parameters only. No additional ad hoc assumptions are needed.Comment: 34 pages (2 figures not included but avaliable upon request), LATEX, (to be published in Phys.Rev.D

Nonfactorizable contributions in B decays to charmonium: the case of B−→K−hcB^- \to K^- h_c

Nonleptonic $B$ to charmonium decays generally show deviations from the factorization predictions. For example, the mode $B^- \to K^- \chi_{c0}$ has been experimentally observed with sizeable branching fraction while its factorized amplitude vanishes. We investigate the role of rescattering effects mediated by intermediate charmed meson production in this class of decay modes, and consider $B^- \to K^- h_c$ with $h_c$ the $J^{PC}=1^{+-}$ $\bar c c$ meson. Using an effective lagrangian describing interactions of pairs of heavy-light $Q{\bar q}$ mesons with a quarkonium state, we relate this mode to the analogous mode with $\chi_{c0}$ in the final state. We find ${\cal B}(B^- \to K^- h_c)$ large enough to be measured at the $B$ factories, so that this decay mode could be used to study the poorly known $h_c$.Comment: RevTex, 16 pages, 2 eps figure

Landau model for uniaxial systems with complex order parameter

We study the Landau model for uniaxial incommensurate-commensurate systems of the I class by keeping Umklapp terms of third and fourth order in the expansion of the free energy. It applies to systems in which the soft mode minimum lies between the corresponding commensurate wave numbers. The minimization of the Landau functional leads to the sine-Gordon equation with two nonlinear terms, equivalent to the equation of motion for the well-known classical mechanical problem of two mixing resonances. We calculate the average free energies for periodic, quasiperiodic and chaotic solutions of this equation, and show that in the regime of finite strengths of Umklapp terms only periodic solutions are absolute minima of the free energy, so that the phase diagram contains only commensurate configurations. The phase transitions between neighboring configurations are of the first order, and the wave number of ordering goes through harmless staircase with a finite number of steps. These results are the basis for the interpretation of phase diagrams for some materials from the I class of incommensurate-commensurate systems, in particular of those for A$_2$BX$_4$ and BCCD compounds. Also, we argue that chaotic barriers which separate metastable periodic solutions represent an intrinsic mechanism for observed memory effects and thermal hystereses.Comment: 12 pages, 14 figures, LaTeX, to be published in Phys. Rev.

Heavy Baryon Specroscopy from the Lattice

The results of an exploratory lattice study of heavy baryon spectroscopy are presented. We have computed the full spectrum of the eight baryons containing a single heavy quark, on a $24^3\times 48$ lattice at $\beta=6.2$, using an $O(a)$-improved fermion action. We discuss the lattice baryon operators and give a method for isolating the contributions of the spin doublets $(\Sigma,\Sigma^*)$, $(\Xi',\Xi^*)$ and $(\Omega,\Omega^*)$ to the correlation function of the relevant operator. We compare our results with the available experimental data and find good agreement in both the charm and the beauty sectors, despite the long extrapolation in the heavy quark mass needed in the latter case. We also predict the masses of several undiscovered baryons. We compute the \Lambda-\mbox{pseudoscalar meson} and $\Sigma-\Lambda$ mass splittings. Our results, which have errors in the range $10-30\%$, are in good agreement with the experimental numbers. For the $\Sigma^*-\Sigma$ mass splitting, we find results considerably smaller than the experimental values for both the charm and the beauty baryons, although in the latter case the experimental results are still preliminary. This is also the case for the lattice results for the hyperfine splitting for the heavy mesons.Comment: 31 pages LaTex, with postscript figures include

Two-proton small-angle correlations in central heavy-ion collisions: a beam-energy and system-size dependent study

Small-angle correlations of pairs of protons emitted in central collisions of Ca + Ca, Ru + Ru and Au + Au at beam energies from 400 to 1500 MeV per nucleon are investigated with the FOPI detector system at SIS/GSI Darmstadt. Dependences on system size and beam energy are presented which extend the experimental data basis of pp correlations in the SIS energy range substantially. The size of the proton-emitting source is estimated by comparing the experimental data with the output of a final-state interaction model which utilizes either static Gaussian sources or the one-body phase-space distribution of protons provided by the BUU transport approach. The trends in the experimental data, i.e. system-size and beam energy dependences, are well reproduced by this hybrid model. However, the pp correlation function is found rather insensitive to the stiffness of the equation of state entering the transport model calculations.Comment: 9 pages, 8 figures, accepted at Eur. Phys. Journ.

QCD Sum Rule Analysis of the Decays B→Kℓ+ℓ−B \to K \ell^+ \ell^- and B→K∗ℓ+ℓ−B \to K^* \ell^+ \ell^-

We use QCD sum rules to calculate the hadronic matrix elements governing the rare decays $B \to K \ell^+ \ell^-$ and $B \to K^* \ell^+ \ell^-$ induced by the flavour changing neutral current $b \to s$ transition. We also study relations among semileptonic and rare $B \to K^{(*)}$ decay form factors. The analysis of the invariant mass distribution of the lepton pair in $B \to K^{(*)} \ell^+ \ell^-$ and of the angular asymmetry in $B \to K^* \ell^+ \ell^-$ provides us with interesting tests of the Standard Model and its extensions.Comment: 26 pages REVTEX + 7 figures. Some typos corrected, figure 5 and 7 modified. This version will appear on Physical Review

Gabapentin as add-on to morphine for severe neuropathic or mixed pain in children from age 3 months to 18 years - Evaluation of the safety, pharmacokinetics, and efficacy of a new gabapentin liquid formulation: Study protocol for a randomized controlled trial

Background: Gabapentin has shown efficacy in the treatment of chronic neuropathic or mixed pain in adults. Although pediatric pain specialists have extensive experience with gabapentin for the treatment of neuropathic pain, its use is off-label. Its efficacy and safety in this context have never been shown. The aim of this trial is to compare gabapentin with placebo as add-on to morphine for the treatment of severe chronic mixed or neuropathic pain in children. This trial is part of the European Union Seventh Framework Programme project Gabapentin in Paediatric Pain (GAPP) to develop a pediatric use marketing authorization for a new gabapentin suspension. Methods/design: The GAPP-2 study is a randomized, double-blind, placebo-controlled, multicenter superiority phase II study in children with severe chronic neuropathic or mixed pain. Its primary objective is to evaluate the efficacy of a gabapentin liquid formulation as adjunctive therapy to morphine. Sixty-six eligible children 3 months to 18 years of age with severe pain (pain scores ≥ 7), stratified in three age groups, will be randomized to receive gabapentin (to an accumulating dose of 45 to 63 mg/kg/day, dependent on age) or placebo, both in addition to morphine, for 12 weeks. Randomization will be preceded by a short washout period, and treatment will be initiated by a titration period of 3 weeks. After the treatment period, medication will be tapered during 4 weeks. The primary endpoint is the average pain scores in the two treatment groups (average of two measures each day for 3 days before the end-of-study visit [V10] assessed by age-appropriate pain scales (Face, Legs, Activity, Cry, Consolability scale; Faces Pain Scale-Revised; Numeric Rating Scale). Secondary outcomes include percentage responders to treatment (subjects with 30% reduction in pain scale), number of episodes of breakthrough pain, number of rescue interventions, number of pain-free days, participant dropouts, quality of life (Pediatric Quality of Life Inventory), and acceptability of treatment. Outcomes will be measured at the end-of-study visit after 12 weeks of treatment at the optimal gabapentin dose. Groups will be compared on an intention-to-treat basis. Discussion: We hope to provide evidence that the combination of morphine and gabapentin will provide better analgesia than morphine alone and will be safe. We also aim to obtain confirmation of the recommended pediatric dose. Trial registration: EudractCT, 2014-004897-40. Registered on 7 September 2017. ClinicalTrials.gov, NCT03275012. Registered on 7 September 2017