A cultura do lúpulo em Bragança. Aspetos agronómicos inovadores e potencial e expansão

O lúpulo foi uma cultura de elevada importância na economia Nacional, apesar de a produção estar restringida a duas pequenas zonas de cultivo no norte de Portugal. Na década de 1970, a produção chegou a ultrapassar as necessidades da indústria cervejeira Nacional, tendo-se exportado lúpulo. Razões de conjuntura internacional desfavoráveis e um sistema produtivo que terá demorado a adaptar-se às novas exigências dos mercados nacional e internacional conduziram a cultura a uma importância económica residual. No presente cultiva-se lúpulo em duas explorações, num total de 12 ha. No entanto, Portugal tem boas condições ecológicas para produzir lúpulo. Se for possível restruturar o setor e lançá-lo em bases tecnológicas mais competitivas, é possível voltar a ter um setor florescente em Portugal. Seria também importante intervir já, enquanto os dois produtores atuais pudessem partilhar os seus conhecimentos com novos produtores. Perdida esta fonte de conhecimento, a ilusão de voltar a haver em Portugal produção significativa de lúpulo reduz-se grandemente. Neste trabalho discutem-se alguns aspetos da adaptação ecológica do lúpulo à região norte de Portugal, avalia-se o potencial de expansão de cultura e os constrangimentos e lançam-se algumas ideias base sobre as quais deveria estar suportado o “novo” setor do lúpulo em Portugal.info:eu-repo/semantics/publishedVersio

Heavy meson semileptonic differential decay rate in two dimensions in the large Nc

We study QCD in 1+1 dimensions in the large $N_c$ limit using light-front Hamiltonian perturbation theory in the $1/N_c$ expansion. We use this formalism to exactly compute hadronic transition matrix elements for arbitrary currents at leading order in $1/N_c$. We compute the semileptonic differential decay rate of a heavy meson, $d\Gamma/dx$, and its moments, $M_N$, using the hadronic matrix elements obtained previously. We put some emphasis in trying to understand parity invariance. We also study with special care the kinematic region where the operator product expansion ($1/N \sim 1-x \sim 1$) or non-local effective field theories ($1/N \sim 1-x \sim \Lambda_{QCD}/m_Q$) can be applied. We then compare with the results obtained using an effective field theory approach based on perturbative factorization, with the focus to better understand quark-hadron duality. At the end of the day, using effective field theories, we have been able to obtain expressions for the moments with relative accuracy of $O(\Lambda_{QCD}^2/m_Q^2)$ in the kinematic region where the operator product expansion can be applied, and with relative accuracy of $O(\Lambda_{QCD}/m_Q)$ in the kinematic region where non-local effective field theories can be applied. These expressions agree, within this precision, with those obtained from the hadronic result using the layer-function approximation plus Euler-McLaurin expansion. Very good numerical agreement for the moments is obtained between the exact result and the result using effective field theories.Comment: 52 pages, 30 figures, references added, small modifications, some discussion of the four dimensional case changed, journal versio

O lúpulo: da cultura ao extrato. Técnica cultural tradicional

Este trabalho consiste numa breve revisão sobre a cultura do lúpulo em Portugal, com incidência na técnica cultural tradicional. Faz-se um breve apontamento histórico sobre a cultura do lúpulo, em particular do desenvolvimento inicial da cultura em Portugal. Segue-se uma descrição sumária dos principais aspetos botânicos da planta e da sua adaptação ecológica. Na descrição da técnica cultural tentam destacar-se aspetos importantes como instalação da cultura, fertilização, poda, rega, proteção sanitária e colheita.info:eu-repo/semantics/publishedVersio

Macrozonagem da Aptidão do Solo para a Cultura do Lúpulo no Distrito de Bragança

Existem em Portugal excelentes condições para o lúpulo, cuja cultura já teve uma dimensão importante nas regiões de Bragança e Braga. À presente data restam apenas cerca de 12 hectares pertencentes a 2 produtores de Bragança. O abandono desta cultura acompanhou o gradual abandono doutros sistemas tradicionais de agricultura, como os terrenos de regadio e pastagens permanentes. No contexto actual, podem existir possibilidades favoráveis para o regresso da cultura do lúpulo. Neste trabalho fez-se inicialmente uma revisão sobre os aspectos culturais do lúpulo e da sua adaptação ecológica. Foram consideradas as possibilidades de modernização desta cultura – instalação, fertilização, poda, rega, protecção sanitária e colheita, que permitam considerar o alargamento para outras áreas potenciais além das outrora ocupadas com lúpulo. Considerando as exigências edafoclimáticas desta cultura modelou-se a informação geográfica digital disponível através de Sistemas de Informação Geográfica (SIG) e pesquisaram-se as áreas de Bragança potencialmente mais favoráveis para a instalação do lúpulo. O conhecimento que venha a adquirir-se futuramente acerca da cultura do lúpulo na região poderá refinar esta análise. Foi produzida uma simulação da aptidão de uso do solo para a cultura do lúpulo.info:eu-repo/semantics/publishedVersio

Hop dry matter yield and cone quality responses to amino acid and potassium-rich foliar spray applications

The use of amino acid and K-rich foliar sprays was evaluated in a commercial hop field in North-eastern Portugal. Four applications of an amino acid-rich foliar spray were performed in place of a second side dress N application of “70 kg N ha−1, which is usually applied by the farmer. The K-rich foliar spray was applied once at the cone developing stage as a supplement to the farmer’s fertilization plan. The amino acid-enriched foliar spray maintained crop dry matter yield at the levels of the control treatment and increased cone alpha-acids concentration (41.8% in 2018 and 9.3% in 2019). Foliar K did not increase cone dry matter yield, cone size or bitter acid concentration. Tissue K concentration was not significantly affected by foliar treatments whereas the application of K seemed to increase N uptake, with leaves and stems being the predominant allocation tissues. Both foliar treatments increased leaf and stem Mg concentrations. The results seem to emphasize the importance of amino acids in the biosynthesis of bitter acids, while K and Zn seemed to play an important secondary role, maybe related to N metabolism and its reduction into amino acids. The concentrations of total phenols in cones and leaves were lower in the foliar treatments in comparison to the control, and the higher values registered in leaves. In this study, the use of amino acids as a foliar spray provided an interesting result, since they maintained cone dry matter yield and increased cone bitter acid concentration with reduced N use.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES to CIMO (UID/AGR/00690/2020) and Sandra Afonso doctoral scholarships (BD/116593/2016).info:eu-repo/semantics/publishedVersio

Response of rapeseed to nitrogen fertilisation in a mediterranean environment

Portugal needs urgently to increase the production of vegetable oils to be able to meet the mandatory 10% minimum target to be achieved by all member states for the share of biofuels in transport petrol and diesel consumption by 2020 (Directive 2009/28/EC). Rapeseed oils the main raw material used in Europe for the manufacture of biofuels. Portugal, however, does not produce rapeseed oil, in spite of some studies have indicated that there are favourable ecological conditions to do that around the country [I, 2]

1/N_c and 1/n preasymptotic corrections to Current-Current correlators

We obtain the corrections in $1/n$ and in $1/\ln n$ ($n$ is the principal quantum number of the bound state) of the decay constants of scalar and pseudoscalar currents in two and four dimensions in the large $N_c$. We obtain them from the operator product expansion provided a model for the large $n$ mass spectrum is given. In the two-dimensional case the spectrum is known and the corrections obtained in this paper are model independent. We confirm these results by confronting them with the numerical solution of the 't Hooft model. We also consider a model at finite $N_c$ and obtain the associated decay constants that are consistent with perturbation theory. This example shows that that the inclusion of perturbative corrections, or finite $N_c$ effects, to the OPE does not constrain the slope of the Regge trajectories, which remain a free parameter for each different channel.Comment: 29 pages, 11 figures. Two references adde

Are the helminth communities from unisexual and bisexual lizards different? Evidences from gastrointestinal parasites of Darevskia spp. in Turkey

Specimens of three species of parthenogenetic lizards (Darevskia uzzelli, D. bendimahiensis,and D. sapphirina) from northeastern Turkey were examined for gastrointestinal parasites. Only one species, the nematode Spauligodon saxicolae (Pharyngodonidae), was found. The extremely low infection and diversity parameters, falling among the lowest within the Palaearctic saurians, support depauperate helminth communities for these parthenogenetic lacertid lizards. Our results suggest that parthenogenetic Darevskia follow a pattern of parasitism similar to other unisexual lizards (i.e. Aspidocelis). The low rates of infection and diversity may be explained by the decreasing opportunities for interchanging helminths rather than factors of susceptibility of unisexual hosts

Dynamic Response of Wind Turbines to Theoretical 3D Seismic Motions Taking into Account the Rotational Component

We study the dynamic response of a wind turbine structure subjected to theoretical seismic motions, taking into account the rotational component of ground shaking. Models are generated for a shallow moderate crustal earthquake in the Madrid Region (Spain). Synthetic translational and rotational time histories are computed using the Discrete Wavenumber Method, assuming a point source and a horizontal layered earth structure. These are used to analyze the dynamic response of a wind turbine, represented by a simple finite element model. Von Mises stress values at different heights of the tower are used to study the dynamical structural response to a set of synthetic ground motion time historie