Benefícios da aplicação de azoto, potássio e boro na fisiologia da oliveira em condições de sequeiro

O azoto, o potássio e o boro são nutrientes que frequentemente condicionam a fisiologia da oliveira (Olea europaea L.). O azoto apresenta um papel primordial por ser constituinte de vários compostos orgânicos, em especial proteínas, ácidos nucleicos, hormonas e clorofila. O boro influencia directamente a produção por proporcionar maior desenvolvimento radicular, maximizando o aproveitamento da água e dos fertilizantes, bem como por estar directamente envolvido na formação da parede celular, contribuindo para aumento da resistência geral da planta. Relativamente ao potássio, para além do efeito directo na produção, existem evidências que as árvores bem nutridas com este elemento toleram melhor a seca. Neste trabalho apresentam-se resultados de um ensaio de campo com duas modalidades de azoto, duas modalidades de potássio e duas modalidades de boto, conduzidos em olival de sequeiro de Verdeal Transmontana em Mirandela, desde o início de 2004

Multidimensional continued fractions, dynamical renormalization and KAM theory

The disadvantage of `traditional' multidimensional continued fraction algorithms is that it is not known whether they provide simultaneous rational approximations for generic vectors. Following ideas of Dani, Lagarias and Kleinbock-Margulis we describe a simple algorithm based on the dynamics of flows on the homogeneous space SL(2,Z)\SL(2,R) (the space of lattices of covolume one) that indeed yields best possible approximations to any irrational vector. The algorithm is ideally suited for a number of dynamical applications that involve small divisor problems. We explicitely construct renormalization schemes for (a) the linearization of vector fields on tori of arbitrary dimension and (b) the construction of invariant tori for Hamiltonian systems.Comment: 51 page

Transforming growth factor-β (TGF-β) maintains follicular ultrastructure and stimulates preantral follicle growth in caprine ovarian tissue cultured in vitro

O objetivo desse estudo foi investigar se o TGF-β afeta a sobrevivência, ativação e crescimento de folículos primordiais caprinos inclusos no córtex ovariano após o cultivo in vitro. Ovários de cabras foram coletados em abatedouro e fragmentos de tecido ovariano foram cultivados por um e sete dias em meio essencial mínimo alfa (α-MEM+) sozinho ou suplementado com TGF-β (1, 5, 10 ou 50ng/mL). Fragmentos ovarianos não cultivados e cultivados foram processados para análise histológica e ultraestrutural. Os resultados mostraram que, comparado ao controle fresco, houve diminuição no percentual de folículos morfologicamente normais em todos os tratamentos somente após sete dias de cultivo. O TGF-β não afetou a ativação folicular independente da concentração testada, contudo, o diâmetro folicular foi superior (P<0.05) no tratamento com 10ng/mL de TGF-β quando comparado ao controle fresco e aos demais tratamentos. Além disso, essa mesma concentração manteve a ultraestrutura normal dos folículos após sete dias de cultivo. Em conclusão, o TGF-β apresentou efeito adicional no crescimento folicular e na manutenção da integridade ultraestrutural de folículos pré-antrais caprinos inclusos no tecido ovariano quando utilizado na concentração de 10ng/mL durante sete dias de cultivo.The objectives of this study were to investigate whether TGF-β affect the survival, activation and further growth of goat primordial follicles enclosed in ovarian cortex after in vitro culture. Goat ovaries were collected from an abattoir and pieces of ovarian tissues were cultured for one or seven days in a supplemented alpha Minimum Essential Medium, alone or containing TGF-β (1, 5, 10 or 50ng/mL). Ovarian tissues from the fresh control as well as those cultured were processed for histological and ultrastructural studies. The results showed that when compared with fresh control, there was decrease in the percentages of histologically normal follicles in all treatments only after seven days culture. TGF-β did not affect the activation of preantral follicles regardless of its concentration, however, larger follicles diameter (P<0.05) was observed using 10ng/mL TGF-β than in the fresh control and other treatments. Moreover, this concentration maintained the normal ultrastructure after seven days of culture. In conclusion, TGF-β showed additional effect on the follicle growth and the maintenance of ultrastructural integrity of goat preantral follicles enclosed in ovarian tissue when used at 10ng/mL during seven days of culture

β-amino alcohols and their respective 2-phenyl-N-alkyl aziridines as potential DNA minor groove binders

It is known that aziridines and nitrogen mustards exert their biological activities, especially in chemotherapy, via DNA alkylation. The studied scaffold, 2-phenyl-1-aziridine, provides a distinct conformation compared to commonly used aziridines, and therefore, leads to a change in high-strained ring reactivity towards biological nucleophiles, such as DNA. The above series of compounds was tested in three breast cell lines: MCF-10, a healthy cell; MCF-7, a hormone responsive cancer cell; and MDA-MB-231, a triple negative breast cancer cell. Both aziridines and their precursors, β-amino alcohols, showed activity towards these cells, and some of the compounds showed higher selectivity index than cisplatin, the drug used as control. When the type of cell death was investigated, the synthesized compounds demonstrated higher apoptosis and lower necrosis rates than cisplatin, and when the mechanism of action was studied, the compounds were shown to interact with DNA via its minor groove instead of alkylation or intercalation

Search for antihelium in cosmic rays

The Alpha Magnetic Spectrometer (AMS) was flown on the space shuttle Discovery during flight STS-91 in a 51.7 degree orbit at altitudes between 320 and 390 km. A total of 2.86 * 10^6 helium nuclei were observed in the rigidity range 1 to 140 GV. No antihelium nuclei were detected at any rigidity. An upper limit on the flux ratio of antihelium to helium of < 1.1 * 10^-6 is obtained.Comment: 18 pages, Latex, 9 .eps figure

Protons in near earth orbit

The proton spectrum in the kinetic energy range 0.1 to 200 GeV was measured by the Alpha Magnetic Spectrometer (AMS) during space shuttle flight STS-91 at an altitude of 380 km. Above the geomagnetic cutoff the observed spectrum is parameterized by a power law. Below the geomagnetic cutoff a substantial second spectrum was observed concentrated at equatorial latitudes with a flux ~ 70 m^-2 sec^-1 sr^-1. Most of these second spectrum protons follow a complicated trajectory and originate from a restricted geographic region.Comment: 19 pages, Latex, 7 .eps figure

A Study of Cosmic Ray Secondaries Induced by the Mir Space Station Using AMS-01

The Alpha Magnetic Spectrometer (AMS-02) is a high energy particle physics experiment that will study cosmic rays in the $\sim 100 \mathrm{MeV}$ to $1 \mathrm{TeV}$ range and will be installed on the International Space Station (ISS) for at least 3 years. A first version of AMS-02, AMS-01, flew aboard the space shuttle \emph{Discovery} from June 2 to June 12, 1998, and collected $10^8$ cosmic ray triggers. Part of the \emph{Mir} space station was within the AMS-01 field of view during the four day \emph{Mir} docking phase of this flight. We have reconstructed an image of this part of the \emph{Mir} space station using secondary $\pi^-$ and $\mu^-$ emissions from primary cosmic rays interacting with \emph{Mir}. This is the first time this reconstruction was performed in AMS-01, and it is important for understanding potential backgrounds during the 3 year AMS-02 mission.Comment: To be submitted to NIM B Added material requested by referee. Minor stylistic and grammer change

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

Measurement of D*+/- meson production in jets from pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

This paper reports a measurement of D*+/- meson production in jets from proton-proton collisions at a center-of-mass energy of sqrt(s) = 7 TeV at the CERN Large Hadron Collider. The measurement is based on a data sample recorded with the ATLAS detector with an integrated luminosity of 0.30 pb^-1 for jets with transverse momentum between 25 and 70 GeV in the pseudorapidity range |eta| < 2.5. D*+/- mesons found in jets are fully reconstructed in the decay chain: D*+ -> D0pi+, D0 -> K-pi+, and its charge conjugate. The production rate is found to be N(D*+/-)/N(jet) = 0.025 +/- 0.001(stat.) +/- 0.004(syst.) for D*+/- mesons that carry a fraction z of the jet momentum in the range 0.3 < z < 1. Monte Carlo predictions fail to describe the data at small values of z, and this is most marked at low jet transverse momentum.Comment: 10 pages plus author list (22 pages total), 5 figures, 1 table, matches published version in Physical Review

Using OpenStreetMap (OSM) to enhance the classification of local climate zones in the framework of WUDAPT

The World Urban Database and Access Portal Tools (WUDAPT) project has adopted the LocalClimate Zone (LCZ) scheme as a basic and consistent description of form and function of cities atneighbourhood scale. LCZs are classified using crowdsourced training samples, open data andopen source software but the quality of the maps still needs improvement. The aim of this paperis to investigate the use of data from OpenStreetMap (OSM) to enhance the development of LCZs,complement the existing data sources, and improve the accuracy of the maps. Various featureswere derived from the OSM database and combined with seasonal LCZ maps. Therefore amethodology was developed and tested for Hamburg, Germany, using a fuzzy approach and thena weighted combination method was applied to combine the inputs from OSM with each of theseasonal LCZ maps. The results showed that improvements can be achieved for certain classes,either in terms of accuracy, e.g. rectifying the misclassification of agricultural areas as heavyindustry, or representation on the map, e.g. a more detailed water network. The approach developedis flexible and allows for knowledge about which data sources are more reliable as inputsto the combination and weighting process