Adubação nitrogenada em milho e capim-xaraés sob plantio direto e preparo convencional em sistema agrossilvipastoril.

O objetivo deste trabalho foi avaliar o desempenho agronômico das culturas do milho e do capim-xaraés (Urochloa brizantha 'Xaraés') em consórcio, cultivadas em plantio direto e convencional, em sistema agrossilvipastoril, com a aplicação de diferentes doses de nitrogênio em cobertura. O experimento foi conduzido em área de cultivo de milho com a espécie florestal mulateiro (Calycophyllum spruceanum). Utilizou-se o delineamento experimental de blocos ao acaso, com arranjo em parcelas subdivididas, com dois sistemas de manejo do solo (plantio direto e convencional com grade pesada) alocados nas parcelas e com cinco doses de adubação nitrogenada em cobertura (0, 50, 100, 150 e 200 kg ha-1 de N), nas subparcelas, o que totalizou dez tratamentos. A produtividade de grãos de milho respondeu linearmente à aplicação de N em área de plantio convencional. Em área de plantio direto, a dose de 165 kg ha-1 de N em cobertura foi necessária para a obtenção de produtividades satisfatórias. A adubação nitrogenada em cobertura na cultura do milho, até a dose de 200 kg ha-1 de N, não influencia o rendimento do capim-xaraés em consórcio nas entrelinhas, após a colheita do milho

Rendimento de milho e braquiaria com diferentes doses de nitrogênio em cobertura em sistema agrossilvipastoril no Acre.

O objetivo deste trabalho foi avaliar o rendimento produtivo das culturas do milho e Brachiaria brizantha cv. Xaraés consorciadas, cultivadas a diferentes distâncias de árvores nativas de mulateiro (Calycophyllum spruceanum Benth) e com aplicação de diferentes doses de nitrogênio em cobertura, em um sistema agrossilvipastoril no Acre. O delineamento experimental utilizado foi de blocos ao acaso, arranjado em parcelas subdivididas, com duas posições de amostragem (Perto da Linha e Distante da Linha do mulateiro) nas parcelas e cinco doses de adubação nitrogenada em cobertura (0; 50; 100; 150; 200 kg ha) nas subparcelas, totalizando dez tratamentos. Foram avaliados na cultura do milho a altura de plantas, teor de clorofila foliar e a produtividade de grãos e para forragem o acúmulo de matéria seca. Constatou-se que a produtividade do milho não é afetada pelo mulateiro aos quatro anos de idade e a adubação nitrogenada em cobertura até a dose de 200 Kg ha de N aumenta linearmente a produtividade de grãos. A pastagem formada apresentou acúmulo de matéria seca da forragem estatisticamente igual para todos os tratamentos, aos 90 dias após a colheita do milho

The Influence of Train Leakage Currents on the LEP Dipole Field

The determination of the mass and the width of the Z boson at CERN's LEP accelerator, an e+e- storage ring with a circumference of approximately 27 kilometres, imposes heavy demands on the knowledge of the LEP counter-rotating electron and positron beam energies. The precision required is of the order of 1 MeV or »20 ppm frequency. Due to its size the LEP collider is influenced by various macroscopic and regional factors such as the position of the moon or seasonal changes of the rainfall in the area, as reported earlier. A new and not less surprising effect of the LEP energy was observed in 1995: railroad trains in the Geneva region perturb the dipole field. A parasitic flow of electricity, originating from the trains, travels along the LEP ground cable and the vacuum chamber, interacting with the dipole field. An account of the phenomenon with its explanation substantiated by dedicated measurements is presented

Optical diffraction radiation for position monitoring of charged particle beams

In the framework of the future linear collider collaboration (CLIC, ILC), non-intercepting beam monitoring instruments are under development for very low emittance and high charge density beams. Optical diffraction radiation (ODR) was studied and developed during the last years focussing on beam size measurements. We propose in the paper to consider the use of diffraction radiation for ultra relativistic beams as position monitors with applications for the centering of scrapers, collimators and targets with high resolution. We present the experimental results obtained using small aperture slits on the ATF2 extraction beam line at KEK and on the Cornell Electron Storage Ring with 1.2 GeV and 2.1 GeV electrons respectively

High contrast microstructural visualization of natural acellular matrices by means of phase-based x-ray tomography

Acellular scaffolds obtained via decellularization are a key instrument in regenerative medicine both per se and to drive the development of future-generation synthetic scaffolds that could become available off-the-shelf. In this framework, imaging is key to the understanding of the scaffolds\u2019 internal structure as well as their interaction with cells and other organs, including ideally post-implantation. Scaffolds of a wide range of intricate organs (esophagus, lung, liver and small intestine) were imaged with x-ray phase contrast computed tomography (PC-CT). Image quality was sufficiently high to visualize scaffold microarchitecture and to detect major anatomical features, such as the esophageal mucosal-submucosal separation, pulmonary alveoli and intestinal villi. These results are a long-sought step for the field of regenerative medicine; until now, histology and scanning electron microscopy have been the gold standard to study the scaffold structure. However, they are both destructive: hence, they are not suitable for imaging scaffolds prior to transplantation, and have no prospect for post-transplantation use. PC-CT, on the other hand, is non-destructive, 3D and fully quantitative. Importantly, not only do we demonstrate achievement of high image quality at two different synchrotron facilities, but also with commercial x-ray equipment, which makes the method available to any research laboratory

Laser Wire Scanner Compton Scattering Techniques for the Measurement of the Transverse Beam Size of Particle Beams at Future Linear Colliders

This archive summarizes a working paper and conference proceedings related to laser wire scanner development for the Future Linear Collider (FLC) in the years 2001 to 2006. In particular the design, setup and data taking for the laser wire experiments at PETRA II and CT2 are described. The material is focused on the activities undertaken by Royal Holloway University of London (RHUL).Comment: 61 page

SUSY spectrum constraints on direct dark matter detection

We perform an investigation of the MSSM parameter space at the Fermi scale taking into account available accelerator, non-accelerator and cosmological constraints. Extra assumptions about upper bounds for some of the SUSY particles are also imposed. We show that a non-observation of the SUSY dark matter candidates with a high-accuracy dark matter detector, such as Ge-73, under above-mentioned assumptions can exclude large domains of the MSSM parameter space and, for instance, can make especially desirable collider search for light SUSY charged Higgs boson.Comment: latex, 13 pages, 6 figures, modified version to be published in Phys. Rev.

Effects of X-ray irradiation on haemocytes of Procambarus clarkii (Arthropoda: Decapoda) males

The red swamp crayfish Procambarus clarkii is an invasive alien species spreading worldwide. The sterile male release technique (SMRT) is among the methods used to contrast the growth of P. clarkii populations within invaded areas. In this study males underwent X-ray sterilisation with a dose of 40 Gy and their immunocompetence was analysed in comparison to untreated animals to ascertain whether radiation can affect welfare parameters other than reproductive organs. The present research investigated the immune function in P. clarkii males in term of (1) morphological haemocyte characterisation by transmission electron microscopy to identify the main phagocyting haemocyte after in vivo artificial non-self challenge with latex beads; (2) total and differential haemocyte counts; and (3) basal and total phenoloxidase activities as components of the humoral defence. Three types of circulating haemocytes were characterised via transmission electron microscopy: hyaline, semigranular and granular haemocytes. The ultrastructural features of haemocyte granules allowed the characterisation of a fourth type of haemocyte, the medium granule haemocyte. In vivo artificial non-self-challenge with latex beads identified the semigranular haemocytes as primarily involved in phagocyting activity. Circulating haemocytes of males irradiated with a dose of 40 Gy, after 20 days, showed a significantly lower diameter in the granules of hyaline and semigranular haemocytes, but no other evident ultrastructural alterations in comparison with un-irradiated animals were found. Irradiated males showed a significant decrease of about 80% of circulating haemocytes and an increase in frequency of semigranular and granular haemocytes. No significant differences in basal and total phenoloxidase activity were recorded and this could, in part, explain the good survival level of irradiated males despite the drastic decline of the haemocyte number. This study represents the basis to appraise whether SMRT affects important functions, such as those of the immune system, in addition to altering the gonad tissue

Target dark matter detection rates in models with a well-tempered neutralino

In the post-LEP2 era, and in light of recent measurements of the cosmic abundance of cold dark matter (CDM) in the universe from WMAP, many supersymmetric models tend to predict 1. an overabundance of CDM and 2. pessimistically low rates for direct detection of neutralino dark matter. However, in models with a ``well-tempered neutralino'', where the neutralino composition is adjusted to give the measured abundance of CDM, the neutralino is typically of the mixed bino-wino or mixed bino-higgsino state. Along with the necessary enhancement to neutralino annihilation rates, these models tend to give elevated direct detection scattering rates compared to predictions from SUSY models with universal soft breaking terms. We present neutralino direct detection cross sections from a variety of models containing a well-tempered neutralino, and find cross section asymptotes with detectable scattering rates. These asymptotic rates provide targets that various direct CDM detection experiments should aim for. In contrast, in models where the neutralino mass rather than its composition is varied to give the WMAP relic density via either resonance annihilation or co-annihilation, the neutralino remains essentially bino-like, and direct detection rates may be below the projected reaches of all proposed experiments.Comment: 13 pages including 1 EPS figur

Non-thermal dark matter via Affleck-Dine baryogenesis and its detection possibility

The formation and late time decays of Q-balls are generic consequences of the Affleck-Dine (AD) baryogenesis. A substantial amount of the lightest supersymmetry (SUSY) particles (LSPs) are produced non-thermally as the decay products of these Q-balls. This requires a significantly large annihilation cross section of the LSP so as not to overclose the universe, which predicts a higgsino- or wino-like LSP instead of the standard bino LSP. We have reexamined the AD baryogenesis with special attention to the late-time decays of the Q-balls, and then specified the parameter regions where the LSPs produced by the Q-ball decays result in a cosmologically interesting mass density of dark matter by adopting several SUSY breaking models. This reveals new cosmologically interesting parameter regions, which have not attracted much attention so far. We have also investigated the prospects of direct and indirect detection of these dark matter candidates, and found that there is an intriguing possibility to detect them in various next generation dark matter searches.Comment: 51 pages, 18 figures, version accepted for publication in Physical Review