Analyses of Genetic Change in Grass-Clover Based Systems Over Time

Since the use of nitrogen fertilisers is reduced, swards based on grass-clover mixtures regain importance in grassland production. Management of these swards is more complicated than the management of pure grass swards. The population structure will develop in response to abiotic and biotic stresses. In this study we will test the genetic change in the clover components of grass-clover mixtures

Quantum secrecy in thermal states II

In this paper we consider a scheme for cryptographic key distribution based on a variation of continuous variable quantum key distribution called central broadcast. In the continuous variable central broadcast scheme, security arises from discord present in the Hanbury Brown and Twiss effect from a thermal source. The benefit of this scheme is that it expands the range of frequencies into the microwave regime. Longer wavelengths—where the thermal photon number is higher and correlations remain robust over long distances—may even be preferable to optical wavelengths. Assuming that Alice controls the source but not the distribution of the light (e.g. satellite broadcasts), then we demonstrate that the central broadcast scheme is robust to an entangling cloner attack. We establish the security of the protocol both experimentally and theoretically

AgapeZ1: a Large Amplification Microlensing Event or an Odd Variable Star Towards the Inner Bulge of M31

AgapeZ1 is the brightest and the shortest duration microlensing candidate event found in the Agape data. It occured only 42" from the center of M31. Our photometry shows that the half intensity duration of the event6 is 4.8 days and at maximum brightness we measure a stellar magnitude of R=18.0 with B-R=0.80 mag color. A search on HST archives produced a single resolved star within the projected event position error box. Its magnitude is R=22.Comment: 4 pages with 5 figure

Thermal state quantum key distribution

We analyse a central broadcast continuous variable quantum key distribution protocol in which a beam produced by a thermal source is used to create a secret key between two parties, Alice and Bob. A beam splitter divides the initial beam into a pair of output beams, which are sent to Alice and Bob, with Eve intercepting Bob's beam. We investigate the protocol in detail, calculating mutual informations through a pair of analytic methods and comparing the results to the outputs of a Monte Carlo simulation of the protocol. In a lossless system, we find that a lower bound on the key rate remains positive in the protocol under a beam splitter attack, provided Bob receives a nonzero proportion of the beam initially sent to him. This suggests that the thermal state protocol could be used experimentally to produce secure keys

Evaluation of rice cultivars for resistance to rice yellow mottle virus

Rice yellow mottle virus (RYMV), which is only found in Africa, threatens rice farming on the continent. A local Oryza sativa cultivar collected from Burkina Faso (named BM24), was evaluated with that of well known highly resistant and tolerant cultivars. Firstly, three RYMV isolates were used to characterise the differential interaction within the cultivars. Secondly, disease kinetics of symptom expression and virus titer on leaves at 21 days after inoculation were assessed using the BF1 isolate. Thirdly, the allelic profile of O. sativa varieties using SSR marker RM101 located on chromosome 12 was also assessed. IR64 showed susceptibility to all isolates; while Tog5681 was resistant to all isolates. Ng122 overcame the resistance of Gigante, with mild leaf symptoms at 42\ua0dpi. Azucena and BM24 had, therefore, different resistance level regarding the three isolates (Ng117b, Ng122 and Ng144). When infected with the isolate, BF1, BM24 and Azucena exhibited same resistance patterns in early growth stages with delayed of symptoms appearance, but BM24 outperformed Azucena at later stages. The virus content in the two accessions, at 14 days post inoculation, was statistically different with BM24, showing less virus compared to Azucena. However, the two accessions depicted an identical allelic profile at RM101 locus.Le virus de la panachure jaune du riz (RYMV) est end\ue9mique seulement en Afrique, et fait des ravages dans les rizi\ue8res du continent. Une vari\ue9t\ue9 de riz local (appel\ue9e BM24), r\ue9sistante au RYMV et collect\ue9e au Burkina Faso a \ue9t\ue9 compar\ue9e avec des cultivars bien connus qui sont r\ue9sistants ou tol\ue9rants au RYMV. Tout d\u2019abord, trois isolats ont \ue9t\ue9 utilis\ue9s pour caract\ue9riser les interactions diff\ue9rentielles au sein des cultivars. Ensuite, la cin\ue9tique de l\u2019expression des sympt\uf4mes de la maladie et le titre en virus sur les feuilles \ue0 21 jours apr\ue8s inoculation ont \ue9t\ue9 \ue9valu\ue9e avec l\u2019isolat BF1. Enfin, le profile all\ue9lique des vari\ue9t\ue9s de Oryza sativa a \ue9t\ue9 \ue9valu\ue9 au marqueur SSR RM101 situ\ue9 sur le chromosome 12. La vari\ue9t\ue9 IR64 s\u2019est av\ue9r\ue9e sensible \ue0 tous les isolats tandis que Tog5681 s\u2019est montr\ue9 r\ue9sistant \ue0 tous les isolats. L\u2019isolat Ng122 a surmont\ue9 la r\ue9sistance de Gigante avec la pr\ue9sence de sympt\uf4mes mod\ue9r\ue9s \ue0 42 jours apr\ue8s inoculation (JAI). Azucena et BM24 par contre ont eu diff\ue9rents niveaux de r\ue9sistance en pr\ue9sence des trois isolats (Ng117b, Ng122 and Ng144). Lorsqu\u2019ils sont infect\ue9s avec l\u2019isolat BF1, BM24 et Azucena expriment le m\ueame niveau de r\ue9sistance avec un retard de l\u2019apparition des sympt\uf4mes dans les premiers moments suivant l\u2019inoculation mais au-del\ue0 de 14 JAI, les sympt\uf4mes apparaissent plus rapidement chez Azucena compar\ue9 \ue0 BM24. A 14 JAI, le titre de virus contenu dans e cultivar Azucena est bien sup\ue9rieur statistiquement \ue0 celui de BM24. Cependant, les deux cultivars ont eu un profile all\ue9lique identique au locus RM101

Spectrum and Variability of Mrk501 as observed by the CAT Imaging Telescope

The CAT Imaging Telescope has observed the BL Lac object Markarian 501 between March and August 1997. We report here on the variability over this time including several large flares. We present also preliminary spectra for all these data, for the low emission state, and for the largest flare.Comment: 4 pages, 4 figures, Late

Detection of Vhe Gamma-Rays from MRK 501 with the Cat Imaging Telescope

The CAT imaging telescope on the site on the former solar plant Themis has been observing gamma-rays from Mrk501 above 220 GeV in March and April 1997. This source is shown to be highly variable and the light curve is presented. The detected gamma-ray rate for the most intense flare is in excess of 10 per minute.Comment: 5 pages, 4 figures, Tex, contribution to 25th ICRC Durba

Observation of the Crab Nebula Gamma-Ray Emission Above 220 Gev by the Cat Cherenkov Imaging Telescope

The CAT imaging telescope, recently built on the site of the former solar plant Themis (French Pyrenees), observed gamma-rays from the Crab nebula from October 1996 to March 1997. This steady source, often considered as the standard candle of very-high-energy gamma-ray astronomy, is used as a test-beam to probe the performances of the new telescope, particularly its energy threshold (220 GeV at 20 degrees zenith angle) and the stability of its response. Due to the fine-grain camera, an accurate analysis of the longitudinal profiles of shower images is performed, yielding the source position in two dimensions for each individual shower.Comment: 5 pages, 3 figures, Tex, contribution to 25th ICRC Durba