45,601 research outputs found

    Some responses of Eryngium vesiculosum Labill to light intensity, daylength and nitrogen : a thesis presented in partial fulfilment of the requirements for the degree of Master of Horticultural Science in Plant Science at Massey University

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    Eryngium vesiculosum Labill. is a plant commonly found in sandy coastal flat in New Zealand. Some preliminary observations (pers comm. Veale) had suggested that flowering in this species might be controlled by the external environment especially with respect to daylength. Normally the mature plant has oblong and dissected leaves but in the shade the leaves tend to have less dissection and this change in leaf form serves as a useful feature for morphological investigations. Another interesting feature of the plant is that it produces runners like the strawberry plant. The plant also produces daughter plants on the runners and lateral branches. The production of these organs, which enables a large family of homogenous plants to be raised rapidly by vegetative propagation is another feature which would make this plant useful experimental material. The object of this study is to obtain some information on the effects of light intensity, daylength and nitrogen on flowering, leaf morphology and anatomy and plant growth. Much work has been carried out on the effects of the three external factors used in this study on many plant species but none on E. vesiculosum. Because of the absence of such information on this plant, the review of literature includes other plant species thus making it more voluminous than otherwise would be. For obvious reasons the review has been limited to present only the salient responses of some plant species to light intensity, daylength and nitrogen. [FROM INTRODUCTION

    Recent investigations of QCD at HERA

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    The latest results from the H1 and ZEUS collaborations which challenge the QCD description of high energy epep collisions are presented. Data from HERA continue to provide precision measurements and are compared to the latest theoretical predictions. Measurements of new processes are also presented as well as investigation of regions where perturbative QCD fails to describe the data. Four themes are presented here. Measurements of hard QCD processes, prompt photon and jet production, are used to compare to the latest theoretical predictions and, in the case of jet production, used to make high-precision extractions of the strong coupling constant up to next-next-to-leading order in QCD. All H1 and ZEUS charm and beauty cross sections in deep inelastic scattering have been combined and used to extract heavy-quark masses, including the running of the charm-quark mass with the scale of the process. Factorisation in diffraction has been investigated in charm production in deep inelastic scattering and prompt photon production in diffractive photoproduction has been measured for the first time. Finally, the inclusive data on deep inelastic scattering is presented in various forms in order to allow investigation of the underlying mechanism at very low photon virtuality Q2Q^2 and low Bjorken xx.Comment: 11 pages, 9 figures. submitted to the proceedings of the "DIS2017" Workshop, Birmingham, UK. Updated with some additional reference

    Heavy quark production at HERA and its relevance for the LHC

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    The import of HERA data on heavy quark production for LHC experiments is discussed. Knowlegde of all aspects of the beauty and charm production process, viz. the parton density functions of colliding hadrons, the hard scatter, and the fragmentation of the quarks into hadrons, can aid LHC experimentation. This short write-up concentrates on possible influences HERA data can have and on the current status (and history) of beauty production from both HERA and Tevatron experiments. In general, next-to-leading order QCD gives a reasonable description of beauty production although some regions of phase space such as low p_T show indications of differences.Comment: 4 pages, to appear in DIS2006 conference proceeding

    The Discreet Trader

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    This paper examines insider trading, specifically trades by corporate insiders around quarterly earnings announcements. Announcements were broken up into three categories: earnings above analyst expectations, earnings below expectations, and earnings in line with expectations. Trade data was collected from the thirty companies of the Dow Jones Industrial Average from 2012-’13. The trades were sorted by purchases and sales by date and analyzed with the earnings report of which the trades were made. Only trades in the interval from twenty days before the announcement date to twenty days after the announcement date were considered. The prediction was that corporate insiders would leverage their inside knowledge to delay trading until after the earnings announcement. They would benefit financially by trading after the announcement and draw less attention from the SEC, as they delayed trading until the announcement became public information. However, knowing how the market would react would allow them to make a meditated decision. For an announcement that was below analyst expectations, corporate insiders should buy stock after the market reaction causes the price to drop. Our findings were that corporate insiders did in fact wait until the announcement day and overall were net buyers. The study will give better insights into how corporate insiders trade and how restrictions can be made to stop this insider trading activity

    Cryptanalysis of SIGABA

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    SIGABA is a World War II cipher machine used by the United States. Both the United States Army and the United States Navy used it for tactical communication. In this paper, we consider an attack on SIGABA using the largest practical keyspace for the machine. This attack will highlight the strengths and weaknesses of the machine, as well as provide an insight into the strength of the security provided by the cipher
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