Resultado preliminar da aplicação da poda mecânica num olival da variedade Arbequina conduzido em sebe

Nos olivais de elevada densidade conduzidos em sebe, a colheita da azeitona é efectuada com uma máquina automotriz cavalgadora, pelo que é fundamental adequar a dimensão das árvores às da máquina. A poda é a prática cultural que os olivicultores dispõem para controlar a dimensão das árvores. O ensaio iniciou-se em 2008 num olival foi instalado em 2000, com uma entrelinha de 3,5 m e com 1,35 m de afastamento entre as árvores na linha, tendo sido conduzido em eixo central. O ensaio foi delineado em blocos casualizados com três repetições, sendo cada talhão constituído por 3 linhas de 100 árvores cada. Foram definidos os seguintes tratamentos: T1 - poda manual efectuada por podadoras com motosserra e tesourões; T2 - poda mecânica que consistiu na realização de um corte horizontal na parte superior da copa das árvores, seguido de poda manual de complemento para controlar ramos excessivamente desenvolvidos nas faces laterais da copa das árvores; T3 - poda mecânica que consistiu na realização de um corte horizontal na parte superior da copa das árvores e de um corte vertical na face exposta a leste, seguido de poda manual complemento manual para controlar ramos excessivamente desenvolvidos na outra face lateral da copa das árvores; T4 - poda mecânica que consistiu na realização de um corte horizontal na parte superior da copa das árvores e de cortes verticais em cada uma das faces da copa das árvores. A utilização da máquina de podar permite controlar a altura das árvores com uma maior unifor midade do que a poda manual. Embora os resultados se refiram apenas ao primeiro ano de ensaio, as produções obtidas nos diferentes tratamentos foram similares. Será necessário assegurar a continuidade deste trabalho durante um maior período de tempo para definir a melhor estratégia de poda para este tipo de olival

Contribuição para definir a estratégia de poda num olival tradicional da região de Moura

A recente diminuição do preço do azeite levará a que os produtores tenham inevitavelmente que adoptar estratégias produtivas que permitam reduzir os custos de produção. A utilização da máquina de podar de discos é uma solução que permite reduzir os custos de poda, ao diminuir a dependência da mão-de-obra, nomeadamente nos olivais com densidades inferiores a 150 árvores por hectare (Peça et al., 2002; Dias, 2006, Dias et al., 2008). Neste trabalho pretende-se mostrar os resultados obtidos num ensaio de aplicação de poda mecânica iniciado em 2002 na região de Moura. O ensaio foi estabelecido num olival da variedade “Cordovil de Serpa”, com mais de 80 anos, cerca de 70 árvores por hectare e equipado com sistema de rega gota a gota. Estabeleceram-se os seguintes tratamentos: T0 – sem podar; T1 – poda manual com motosserra; T2 – poda mecânica, que consistiu na realização de um corte horizontal na parte superior da copa das árvores; T3 – poda mecânica realizada de forma análoga ao tratamento T2, complementada dois anos após (2004), com poda manual efectuada com motosserra. Os resultados obtidos mostram que, em média, a produção obtida nos diferentes tratamentos foi similar, confirmando que é possível manter as árvores a produzir sem necessidade de intervenções de poda. Apesar deste resultado, a ausência de poda dificulta a operação de colheita devido, quer à dimensão da copa, quer aos ramos excessivamente pendentes

Avaliação do efeito do corte horizontal da copa, com máquina de podar de discos, em pomares de pera “Rocha

Current pear pruning making use of pneumatic shears still is a very labour intensive operation. The Proder project “Avaliação da poda mecânica em pomares de pera” was designed to contribute to solutions that would reduce the present dependence in labour and therefore to promote a reduction in pruning costs. This paper shows the results of a trial made to evaluate the influence of mechanical topping in manual pruning complement field work and pear yield. Topping was performed using a Reynolds 6DT 3.0m cutting bar with six hydraulic-driven circular disc-saws mounted in the three point tractor linkage system. The field trial was performed in a commercial orchard with 20 years, planted in an array of 4m x 2m with tree lines oriented in North-South direction. Trees were trained as the central leader system. In this trial, in a randomised complete block design with four replications, two treatments are being compared leading to 8 plots with one line of 14 trees per plot. The treatments tests were: T1 - manual pruning performed by workers using pneumatic shears, in each year; T2 - Topping the canopy parallel to the ground, using a discs-saw pruning machine mounted in a front loader of an agricultural tractor, followed by manual pruning complement performed by workers with pneumatic shears. Tree height and width was measured, before and after pruning. Work was timed and pear yields evaluated. Mechanical topping seems to be effective in the control of tree height, which can contribute to increase 14% of work rates on manual pruning complement. No significant differences in pear yield were found between treatments

Production of Secondaries in High Energy d+Au Collisions

In the framework of Quark-Gluon String Model we calculate the inclusive spectra of secondaries produced in d+Au collisions at intermediate (CERN SPS) and at much higher (RHIC) energies. The results of numerical calculations at intermediate energies are in reasonable agreement with the data. At RHIC energies numerically large inelastic screening corrections (percolation effects) should be accounted for in calculations. We extract these effects from the existing RHIC experimental data on minimum bias and central d+Au collisions. The predictions for p+Au interactions at LHC energy are also given.Comment: 18 pages and 10 figure

Prediction of lamb body composition using in vivo bioimpedance analysis

The objective of this study was to evaluate the potential of in vivo bioimpedance analysis (BIA) as a method to estimate body composition in lambs. Thirty-one Texel x Ile de France crossbreed ram lambs were slaughtered at pre-determined intervals of average weights of 20, 26, 32, and 38 kg. Before the slaughter of the animals, their body weight (BW) and body length (BL) were measured. The values for resistance (Rs) and reactance (Xc) were collected using a single-frequency BIA equipment (Model RJL Quantum II Bioelectrical Body Composition Analyzer). The BIA main variables such as body bioelectrical volume (V), phase angle (PA), resistive density (RsD), and reactive density (XcD) were then calculated. The soft tissue mass of the right-half cold carcass was analyzed in order to determine its chemical composition. Multiple regression analyses were performed using the lamb body composition as dependent variables and the measurements related to bioimpedance as independent variables. The best regression models were evaluated by cross-validation. The predictive model of moisture mass, which was developed by using XcD and V, accounted for 84% of its variation. Resulting models of percentage moisture (R2 = 0.79), percentage lean mass (R2 = 0.79), percentage fat (R2 = 0.79), and fat mass (R2 = 0.87) were obtained using RsD and V. Furthermore, the values of RsD regarding V, and PA in the prediction models accounted for 91% and 89% of variation in protein mass and lean mass, respectively. Bioimpedance analysis proved to be an efficient method to estimate the body composition of lambs slaughtered at different body mass stages

Production of secondaries in soft p+pb collisions at LHC

We calculate the inclusive spectra of secondaries produced in soft (minimum bias) p+Pb collisions in the framework of Quark-Gluon String Model at LHC energy, and by taking into account the inelastic screening corrections (percolation effects). The role of these effects is expected to be very large at very high energies, and they should decrease the spectra about 3 times in the midrapidity region and increase them about 2 times in the fragmentation region at the energy of LHC.Comment: 18 pages and 10 figures. arXiv admin note: text overlap with arXiv:0802.219

Regularization Independent Analysis of the Origin of Two Loop Contributions to N=1 Super Yang-Mills Beta Function

We present a both ultraviolet and infrared regularization independent analysis in a symmetry preserving framework for the N=1 Super Yang-Mills beta function to two loop order. We show explicitly that off-shell infrared divergences as well as the overall two loop ultraviolet divergence cancel out whilst the beta function receives contributions of infrared modes.Comment: 7 pages, 2 figures, typos correcte

Static quantities of the W boson in the SU_L(3) X U_X(1) model with right-handed neutrinos

The static electromagnetic properties of the $W$ boson, $\Delta \kappa$ and $\Delta Q$, are calculated in the SU_L(3)} \times U_X(1) model with right-handed neutrinos. The new contributions from this model arise from the gauge and scalar sectors. In the gauge sector there is a new contribution from a complex neutral gauge boson $Y^0$ and a singly-charged gauge boson $Y^\pm$. The mass of these gauge bosons, called bileptons, is expected to be in the range of a few hundreds of GeV according to the current bounds from experimental data. If the bilepton masses are of the order of 200 GeV, the size of their contribution is similar to that obtained in other weakly coupled theories. However the contributions to both $\Delta Q$ and $\Delta \kappa$ are negligible for very heavy or degenerate bileptons. As for the scalar sector, an scenario is examined in which the contribution to the $W$ form factors is identical to that of a two-Higgs-doublet model. It is found that this sector would not give large corrections to $\Delta \kappa$ and $\Delta Q$.Comment: New material included. Final version to apppear in Physical Review

Finite-Temperature Transport in Finite-Size Hubbard Rings in the Strong-Coupling Limit

We study the current, the curvature of levels, and the finite temperature charge stiffness, D(T,L), in the strongly correlated limit, U>>t, for Hubbard rings of L sites, with U the on-site Coulomb repulsion and t the hopping integral. Our study is done for finite-size systems and any band filling. Up to order t we derive our results following two independent approaches, namely, using the solution provided by the Bethe ansatz and the solution provided by an algebraic method, where the electronic operators are represented in a slave-fermion picture. We find that, in the U=\infty case, the finite-temperature charge stiffness is finite for electronic densities, n, smaller than one. These results are essencially those of spinless fermions in a lattice of size L, apart from small corrections coming from a statistical flux, due to the spin degrees of freedom. Up to order t, the Mott-Hubbard gap is \Delta_{MH}=U-4t, and we find that D(T) is finite for n<1, but is zero at half-filling. This result comes from the effective flux felt by the holon excitations, which, due to the presence of doubly occupied sites, is renormalized to \Phi^{eff}=\phi(N_h-N_d)/(N_d+N_h), and which is zero at half-filling, with N_d and N_h being the number of doubly occupied and empty lattice sites, respectively. Further, for half-filling, the current transported by any eigenstate of the system is zero and, therefore, D(T) is also zero.Comment: 15 pages and 6 figures; accepted for PR

Invasive fungal diseases in haematopoietic cell transplant recipients and in patients with acute myeloid leukaemia or myelodysplasia in Brazil

AbstractInvasive fungal disease (IFD) shows distinct regional incidence patterns and epidemiological features depending on the geographic region. We conducted a prospective survey in eight centres in Brazil from May 2007 to July 2009. All haematopoietic cell transplant (HCT) recipients and patients with acute myeloid leukaemia (AML) or myelodysplasia (MDS) were followed from admission until 1 year (HCT) or end of consolidation therapy (AML/MDS). The 12-month cumulative incidence (CI) of proven or probable IFD was calculated, and curves were compared using the Grey test. Among 237 AML/MDS patients and 700 HCT recipients (378 allogeneic, 322 autologous), the 1-year CI of IFD in AML/MDS, allogeneic HCT and autologous HCT was 18.7%, 11.3% and 1.9% (p <0.001), respectively. Fusariosis (23 episodes), aspergillosis (20 episodes) and candidiasis (11 episodes) were the most frequent IFD. The 1-year CI of aspergillosis and fusariosis in AML/MDS, allogeneic HCT and autologous HCT were 13.4%, 2.3% and 0% (p <0.001), and 5.2%, 3.8% and 0.6% (p 0.01), respectively. The 6-week probability of survival was 53%, and was lower in cases of fusariosis (41%). We observed a high burden of IFD and a high incidence and mortality for fusariosis in this first multicentre epidemiological study of IFD in haematological patients in Brazil