909 research outputs found
Resposta de milhos híbridos e variedades de polinização livre a fertilização orgânica e mineral
Em condições de cultivo marginais, as variedades regionais de
polinização livre de milho podem ser alternativa aos híbridos comerciais.
Neste trabalho reportam-se resultados comparativos de duas variedades
regionais de milho, uma proveniente de Benguela ('Angola'), e outra
proveniente do norte de Portugal ('Montalegre'), e dois híbridos comerciais,
um recomendado para Benguela ('SC411SRT') e outro recomendado para o
norte de Portugal ('PR36Y03'). A experiência foi organizada num fatorial com
as quatro cultivares referidas e seis modalidades de fertilizaçao, 0, 50, 100 e
200 kg N ha' na forma de nitrato de amónio, estrume de bovino e um
composto orgânico comercial aplicados na dose de 100 kg N ha'. Os ensaios
decorreram em Bragança, NE Portugal. A variedade 'Angola' foi a que
apresentou maior altura média (3, 6 m), maior número de folhas (18) e menor
número de espigas por planta (0, 9). Na posição oposta esteve a variedade
'Montalegre' com a menor altura (2, 2 m), menor número de folhas (9) e
maior número de espigas por planta (1, 1). A produção de gao foi mais elevada
no híbrido 'SC411SRT' (9,8 Mg hal ), seguida do híbrido 'PR36Y03' (8,1 Mg ha
'), variedade 'Montalegre' (5, 7 Mg ha') e, por último, a variedade 'Angola' (0,8
Mg ha'). As modalidades de fertilizaçao orgânica, em particular o estrume de
bovino, mostraram baixa eficiência de uso do azoto e menor produtividade
que as modalidades de fertilizaçâo mineral. A variedade 'Montalegre', de ciclo
particularmente curto, produziu aproximadamente ao nível das cultivares
híbridas se os resultados tiverem em conta o tempo necessário até à colheita
e a soma de temperaturas associadas ao seu ciclo cultural.info:eu-repo/semantics/publishedVersio
Efeito de espécies vegetais em bordadura em cebola sobre a densidade populacional de tripes e sirfídeos predadores.
Analisou-se a relação entre o efeito do plantio de diferentes espécies vegetais, em bordadura, na cultura da cebola, Allium cepa L, na incidência de Thrips tabaci Lind. e sirfídeos predadores, Toxomerus spp. O experimento foi conduzido na Epagri, EE de Ituporanga, de agosto a dezembro de 1998. Os tratamentos foram cebola em monocultivo; cebola + trigo mourisco (Fagopyrum esculentum Moench); cebola + nabo forrageiro (Raphanus sativus L. var. oleiferus Metzg.); cebola + cenoura (Daucus carota L., cv. Nantes e cv. Brasília); cebola + milho (Zea mays L.); cebola + rúcula
(Eruca sativa L.) + vegetação espontânea. O plantio de diferentes espécies vegetais em bordadura não provocou diferenças significativas na incidência de tripes e sirfídeos predadores. A produtividade comercial de bulbos de cebola foi similar em sistema de monocultivo e diversificado, sugerindo ser possível adotar tais sistemas sem perdas em rendimento
Vlp-based vaccines as a suitable technology to target trypanosomatid diseases
Funding Information: This research was funded by Global Health and Tropical Medicine (Grant number IHMT UID/multi/04413/2013 and Grant number PTDC/CVT-CVT/28908/2017), Funda??o para Ci?ncia e Tecnologia (FCT), Portugal; Grant GIU18/172 Grupos de Investigaci?n de la UPV/EHU, and Grant from CSIC Programa I-COOP+2020 (ICOOPB20503), Spain.A.M.V.Q., J.W.d.F.O., and C.J.M. thanks to the financial support (PhD scholar-ships) provided by CNPq and CAPES, Brazil. M.S.S. thanks to CNPq for the Research Grant (Bolsa de Produtividade em Pesquisa). We are also grateful to Paulo Fanado and Laysa Ohanna for editing this manuscript. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Research on vaccines against trypanosomatids, a family of protozoa that cause neglected tropical diseases, such as Chagas disease, leishmaniasis, and sleeping sickness, is a current need. Today, according to modern vaccinology, virus-like particle (VLP) technology is involved in many vaccines, including those undergoing studies related to COVID-19. The potential use of VLPs as vaccine adjuvants opens an opportunity for the use of protozoan antigens for the development of vaccines against diseases caused by Trypanosoma cruzi, Leishmania spp., and Trypanosoma brucei. In this context, it is important to consider the evasion mechanisms of these protozoa in the host and the antigens involved in the mechanisms of the parasite–host interaction. Thus, the immunostimulatory properties of VLPs can be part of an important strategy for the development and evaluation of new vaccines. This work aims to highlight the potential of VLPs as vaccine adjuvants for the development of immunity in complex diseases, specifically in the context of tropical diseases caused by trypanosomatids.publishersversionpublishe
Debate sobre o artigo de Narvai et al.
English title: Debate on the paper by Narvai et al.Margareth Crisóstomo Portela & Mauricio Teixeira Leite de Vasconcello
Nascent markets: Understanding the success and failure of new stock markets
We study the success and failure of 59 newly established (“nascent”) stock markets since 1975 in their first 40 years of activity. Nascent markets differ markedly in their success, as measured by number of listings, market capitalization, and trading activity. Long-term success is in part determined by early success: a high initial number of listings and trading activity are necessary, though not sufficient, conditions for long-term success. Banking sector development at the time of establishment and development of national savings over the life of the stock market are the other two most reliable predictors of success. We find little evidence that structural factors such as country size or legal and political institutions matter. Rather, our results point to an important role of banks, demand factors, and initial success in fostering long-term stock market development
Model-based estimation of transmissibility and reinfection of SARS-CoV-2 P.1 variant
Acknowledgements We are grateful for the collaborative work of the reviewers and the entire group of the Observatório COVID-19 BR. In particular, we thank Verônica Coelho for critical inputs. We also thank the research funding agencies: the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brazil (Finance Code 001 to F.M.D.M., L.S.F. and T.P.P.), Conselho Nacional de Desenvolvimento Científico e Tecnológico—Brazil (grant number: 315854/2020-0 to M.E.B., 141698/2018-7 to R.L.P.S., 313055/2020-3 to P.I.P., 312559/2020-8 to M.A.S.M.V., 311832/2017-2 to R.A.K., 305703/2019-6 to A.A.M.S.) and Fundação de Amparo à Pesquisa do Estado de São Paulo—Brazil (grant number: 2019/26310-2 and 2017/26770-8 to C.F., 2018/26512-1 to O.C., 2018/24037-4 to S.P. and contract number: 2016/01343-7 to R.A.K.). The findings and conclusions in this article are those of the authors and do not necessarily represent the official position of the Centers of Disease Control and Prevention.Peer reviewe
Electronic structure of nuclear-spin-polarization-induced quantum dots
We study a system in which electrons in a two-dimensional electron gas are
confined by a nonhomogeneous nuclear spin polarization. The system consists of
a heterostructure that has non-zero nuclei spins. We show that in this system
electrons can be confined into a dot region through a local nuclear spin
polarization. The nuclear-spin-polarization-induced quantum dot has interesting
properties indicating that electron energy levels are time-dependent because of
the nuclear spin relaxation and diffusion processes. Electron confining
potential is a solution of diffusion equation with relaxation. Experimental
investigations of the time-dependence of electron energy levels will result in
more information about nuclear spin interactions in solids
Coronary flow velocity reserve after percutaneous interventions is predictive of periprocedural outcome
BACKGROUND: Because heterogeneous results have been reported, we assessed coronary flow velocity changes in individuals who underwent percutaneous transluminal coronary angioplasty (PTCA) and examined their impact on clinical outcome. METHODS AND RESULTS: As part of the Doppler Endpoints Balloon Angioplasty Trial Europe (DEBATE) II study, 379 patients underwent Doppler flow-guided angioplasty. All patients were evaluated according to their coronary flow velocity reserve (CFVR) results (> or =2.5 or < 2.5) at the end of the procedure. A CFVR < 2.5 after angioplasty was associated with an elevated baseline blood flow velocity in both the target artery and reference artery. CFVR before PTCA and CFVR in the reference artery were independent predictors of an optimal CFVR after balloon angioplasty (CFVR before PTCA: odds ratio [OR], 2.26; 95% confidence interval [CI], 1.57 to 3.24; CFVR in reference artery: OR, 1.90; 95% CI, 1.21 to 2.98; both P<0.001) and stent implantation (before PTCA: OR, 2.54; 95% CI, 1.47 to 4.36; reference artery: OR, 1.97; 95% CI, 1.07 to 3.87; both P<0.05). A low CFVR at the end of the procedure was an independent p
Vegetative development and content of calcium, potassium, and sodium in watermelon under salinity stress on organic substrates
Transitions from partial to complete generalized synchronizations in bidirectionally coupled chaotic oscillators
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