Atributos anatômicos de lâminas foliares de Paspalum spp.

Gramíneas do gênero Paspalum spp. apresentam alto potencial para o melhoramento genético, devido à sua grande variabilidade genética. Este estudo, conduzido na Universidade Federal da Grande Dourados, teve como objetivo avaliar atributos anatômicos de lâminas foliares de Paspalum spp. (P. malacophyllum - P30, P. guenoarum - P65, P. glaucescens - P114, P. spp.- Pl16, P. spp. - P127, P. guenoarum - P148, P. regnellii - P191 e uma cultivar comercial- P. alralum cv. Pojuca). Utilizou-se o delineamento de blocos ao acaso, oito genótipos e quatro repetições. Os fragmentos das lâminas foram fixados em F AA e após efetuou-se o preparo histológico. Alta variabilidade entre os genótipos foi observada quanto à proporção e arranjo de tecidos, e presença de tanino condensado na epiderme. Dos caracteres avaliados a presença de estrutura girder, foi a que mais discriminou os genótipos quanto ao potencial qualitativo das lâminas. Estudos devem ser conduzidos para verificar o efeito do tanino condensado, presente na epiderme, no potencial qualitativo dos genótipos

Partial Ion Yield Sspectroscopy around the Cl 2p and C 1s Ionization Thresholds in CF3Cl

We present a partial ion yield experiment on freon 13, CF3Cl, excited in the vicinity of the C 1s and Cl 2p ionization thresholds. We have collected a large amount of cationic fragments and a few anionic fragments at both edges. We have observed a strong intensity dependence of Rydberg transitions with ion fragment size for the CFnCl+ and CFn+/F+ (n=0–3) series at both the Cl 2p and C 1s ionization edges. Selectivity in the fragmentation processes involving the C–Cl and C–F bonds are highlighted by the intensities of the C 1s to lowest unoccupied molecular orbital (LUMO) and LUMO+1 transitions measured on the CFnCl+ and CFn+ yields. Equally, by comparison with their cation counterpart, we discuss possible bond-length dependence for the anion formation at the carbon 1s edge

Free electron lifetime achievements in Liquid Argon Imaging TPC

A key feature for the success of the liquid Argon imaging TPC (LAr-TPC) technology is the industrial purification against electro-negative impurities, especially Oxygen and Nitrogen remnants, which have to be continuously kept at an exceptionally low level by filtering and recirculating liquid Argon. Improved purification techniques have been applied to a 120 liters LAr-TPC test facility in the INFN-LNL laboratory. Through-going muon tracks have been used to determine the free electron lifetime in liquid Argon against electro-negative impurities. The short path length here observed (30 cm) is compensated by the high accuracy in the observation of the specific ionization of cosmic ray muons at sea level as a function of the drift distance. A free electron lifetime of (21.4+7.3-4.3) ms, namely > 15.8 ms at 90 % C.L. has been observed over several weeks under stable conditions, corresponding to a residual Oxygen equivalent of about 15 ppt (part per trillion). At 500 V/cm, the free electron speed is 1.5 m/ms. In a LAr-TPC a free electron lifetime in excess of 15 ms corresponds for instance to an attenuation of less than 15 % after a drift path of 5 m, opening the way to the operation of the LAr-TPC with exceptionally long drift distances.Comment: 15 pages, 10 figures; Accepted for publication in JINS

Fragmentation of Methyl Chloride Studied by Partial Positive and Negative Ion Yield Spectroscopy

The authors present partial-ion-yield experiments on the methyl chloride molecule excited in the vicinity of the Cl2p and C1s inner shells. A large number of fragments, cations produced by dissociation or recombination processes, as well as anionic species, have been detected. Although the spectra exhibit different intensity distributions depending on the core-excited atom, general observations include strong site-selective fragmentation along the C–Cl bond axis and a strong intensity dependence of transitions involving Rydberg series on fragment size

Velocidade de embebição de sementes de soja submetidas a diferentes recobrimentos.

O tratamento de sementes de soja é uma prática utilizada para aumentar o desempenho das sementes, especialmente durante as fases iniciais do ciclo. A utilização do tratamento de sementes com polímeros tem sido uma alternativa para os agricultores por permitir melhor fi xação dos princípios ativos utilizados no tratamento químico. Entretanto, esses produtos não devem afetar as propriedades fisiológicas e físicas das sementes, como a velocidade de embebição. Assim, o objetivo do trabalho foi estudar o efeito de diferentes recobrimentos na velocidade de embebição das sementes de soja. Foram utilizados dois lotes de sementes de soja das cultivares SYN1263 RR e BMX Potência RR, as quais foram submetidas a seis diferentes recobrimentos: 1: Testemunha (ausência de fungicida, inseticida e polímero); 2: Fungicida + Inseticida; 3: Fungicida + Inseticida + Polímero A; 4: Fungicida + Inseticida + Polímero B; 5: Polímero A; 6: Polímero B. O fungicida e o inseticida utilizados foram Derosal Plus (carbendazim + thiram) e Cropstar FloRite 1197 (Nitral Urbana (imidacloprido + tiodicarbe), respectivamente, e os polímeros ) (A) e Laborsan (Laborsan) (B). Para a determinação da velocidade de embebição, as sementes foram dispostas sobre papel germitest umedecido 2,25 vezes o peso do papel seco e incubadas àtemperatura de 20°C, mensurando-se a massa das sementes em intervalos regularesde 1h, durante um período de 24h. De acordo com os resultados, o recobrimento das sementes de soja com os polímeros FloRite1197 (Nitral Urbana) e Laborsan (Laborsan) isolados ou em associação com o fungicida e inseticida não retardam a velocidade de absorção de água

Solar models and solar neutrino oscillations

We provide a summary of the current knowledge, theoretical and experimental, of solar neutrino fluxes and of the masses and mixing angles that characterize solar neutrino oscillations. We also summarize the principal reasons for doing new solar neutrino experiments and what we think may be learned from the future measurements.Comment: Submitted to the Neutrino Focus Issue of New Journal of Physics at http://www.njp.or

Non-Dipolar Electron Angular Distributions from Fixed-in-Space Molecules

The first indication of nondipole effects in the azimuthal dependence of photoelectron angular distributions emitted from fixed-in-space molecules is demonstrated in N2. Comparison of the results with angular distributions observed for randomly oriented molecules and theoretical derivations for the nondipole correction first order in photon momentum suggests that higher orders will be needed to describe distributions measured in the molecular frame

CPT violation and particle-antiparticle asymmetry in cosmology

General features of generation of the cosmological charge asymmetry in CPT non-invariant world are discussed. If the effects of CPT violation manifest themselves only in mass differences of particles and antiparticles, the baryon asymmetry of the universe hardly can be explained solely by breaking of CPT invariance. However, CPT non-invariant theories may lead to a new effect of distorting the usual equilibrium distributions. If this takes place, CPT violation may explain the baryon asymmetry of the universe.Comment: 7 pages, no figures. Submitted to a special issue of Yadernaya Fizika (Physics of Atomic Nuclei) dedicated to 80th birthday of L.B. Okun. Three references are adde

A new, very massive modular Liquid Argon Imaging Chamber to detect low energy off-axis neutrinos from the CNGS beam. (Project MODULAr)

The paper is considering an opportunity for the CERN/GranSasso (CNGS) neutrino complex, concurrent time-wise with T2K and NOvA, to search for theta_13 oscillations and CP violation. Compared with large water Cherenkov (T2K) and fine grained scintillators (NOvA), the LAr-TPC offers a higher detection efficiency and a lower backgrounds, since virtually all channels may be unambiguously recognized. The present proposal, called MODULAr, describes a 20 kt fiducial volume LAr-TPC, following very closely the technology developed for the ICARUS-T60o, and is focused on the following activities, for which we seek an extended international collaboration: (1) the neutrino beam from the CERN 400 GeV proton beam and an optimised horn focussing, eventually with an increased intensity in the framework of the LHC accelerator improvement program; (2) A new experimental area LNGS-B, of at least 50000 m3 at 10 km off-axis from the main Laboratory, eventually upgradable to larger sizes. A location is under consideration at about 1.2 km equivalent water depth; (3) A new LAr Imaging detector of at least 20 kt fiducial mass. Such an increase in the volume over the current ICARUS T600 needs to be carefully considered. It is concluded that a very large mass is best realised with a set of many identical, independent units, each of 5 kt, "cloning" the technology of the T600. Further phases may foresee extensions of MODULAr to meet future physics goals. The experiment might reasonably be operational in about 4/5 years, provided a new hall is excavated in the vicinity of the Gran Sasso Laboratory and adequate funding and participation are made available.Comment: Correspondig Author: C. Rubbia (E-mail: [email protected]), 33 pages, 11 figure

Four Zero Texture Fermion Mass Matrices in SO(10) GUT

We attempt the integration of the phenomenologically successful four zero texture of fermion mass matrices with the renormalizable SO(10) GUT. The resulting scenario is found to be highly predictive. Firstly, we examine the phenomenological implications of a class of the lepton mass matrices with parallel texture structures and obtain interesting constraints on the parameters of the charged lepton and the neutrino mass matrices. We combine these phenomenological constraints with the constraints obtained from SO(10) GUT to reduce the number of the free parameters and to further constrain the allowed ranges of the free parameters. The solar/atmospheric mixing angles obtained in this analysis are in fairly good agreement with the data.Comment: 14 pages, 3 figures, 1 tabl