Ensemble variational assimilation as a probabilistic estimator – Part 2: The fully non-linear case

The method of ensemble variational assimilation (EnsVAR), also known as ensemble of data assimilations (EDA), is implemented in fully non-linear conditions on the Lorenz-96 chaotic 40-parameter model. In the case of strong-constraint assimilation, it requires association with the method of quasi-static variational assimilation (QSVA). It then produces ensembles which possess as much reliability and resolution as in the linear case, and its performance is at least as good as that of ensemble Kalman filter (EnKF) and particle filter (PF). On the other hand, ensembles consisting of solutions that correspond to the absolute minimum of the objective function (as identified from the minimizations without QSVA) are significantly biased. In the case of weak-constraint assimilation, EnsVAR is fully successful without need for QSVA.</p

The use of phosphinothricin resistance as selectable marker for genetic transformation of grapevine

A transformation procedure with the bar gene as a selectable marker was established via Agrobacterium-mediated transformation using strain LBA4404 harbouring the vector pPZP200-bar-gus-intron. Recreation of embryogenic cells from transformation stress in PPT free medium for four weeks improved viability and number of GUS expressing cells. Concentration of 2.5 mg·l-1 PPT yielded highest selection efficiency. Transgenicity of the regenerated grapevine plants was confirmed by histochemical GUS assay and bar specific PCR and RT/PCR. With the described procedure, 20 % of regenerated embryos could be converted into transgenic grapevines.

Construction of non-diagonal background error covariance matrices for global chemical data assimilation,

Abstract. Chemical data assimilation attempts to optimally use noisy observations along with imperfect model predictions to produce a better estimate of the chemical state of the atmosphere. It is widely accepted that a key ingredient for successful data assimilation is a realistic estimation of the background error distribution. Particularly important is the specification of the background error covariance matrix, which contains information about the magnitude of the background errors and about their correlations. As models evolve toward finer resolutions, the use of diagonal background covariance matrices is increasingly inaccurate, as they captures less of the spatial error correlations. This paper discusses an efficient computational procedure for constructing nondiagonal background error covariance matrices which account for the spatial correlations of errors. The correlation length scales are specified by the user; a correct choice of correlation lengths is important for a good performance of the data assimilation system. The benefits of using the nondiagonal covariance matrices for variational data assimilation with chemical transport models are illustrated

Construction of non-diagonal background error covariance matrices for global chemical data assimilation,

Abstract. Chemical data assimilation attempts to optimally use noisy observations along with imperfect model predictions to produce a better estimate of the chemical state of the atmosphere. It is widely accepted that a key ingredient for successful data assimilation is a realistic estimation of the background error distribution. Particularly important is the specification of the background error covariance matrix, which contains information about the magnitude of the background errors and about 5 their correlations. As models evolve toward finer resolutions, the use of diagonal background covariance matrices is increasingly inaccurate, as they captures less of the spatial error correlations. This paper discusses an efficient computational procedure for constructing non-diagonal background error covariance matrices which account for the spatial correlations of errors. The correlation length scales are specified by the user; a correct choice of correlation lengths is important for a good performance of 10 the data assimilation system. The benefits of using the non-diagonal covariance matrices for variational data assimilation with chemical transport models are illustrated

Egg parasitoids of the genus Trichogramma (Hymenoptera, Trichogrammatidae) in olive groves of the Mediterranean region

A survey of egg parasitoids of the genus Trichogramma (Hymenoptera, Trichogrammatidae) was carried out in olive groves in Portugal, Greece, Egypt, and Tunisia during the years 2002–2004. Parasitoids were obtained either by exposing sentinel eggs (Sitotroga cerealella Olivier or Ephestia kuehniella Zeller) on olive trees or by collecting eggs of lepidopterous olive pests. Parasitized egg samples were reared separately in the laboratory for emergence of parasitoids. These were further reared in separate lines and processed by morphological and molecular biology techniques for species characterization. The recorded fauna of Trichogramma parasitoids in olive groves was species poor and consisted of species mainly known from the Mediterranean region. Trichogramma bourarachae Pintureau and Babault was found in Tunisia and Egypt, T. cordubensis Vargas and Cabello, and T. euproctidis Girault in Egypt, Trichogramma cacoeciae Marchal in Portugal, Greece, Egypt, Tunisia and Trichogramma nerudai Pintureau and Gerding in Portugal. Apart from that, Trichogramma oleae Voegele´ and Pointel was collected in Tunisia. This species is probably not indigenous, but has established after several releases of a French strain were made in recent years. For selected strains, the sequence of the internal transcribed spacer 2 (ITS-2) region of rDNA was determined and deposited in the GenBank database. Differences in important biological attributes were found among collected strains of T. bourarachae, suggesting the existence of biotypes. The results contribute to the limited knowledge on distribution and biodiversity of the genus Trichogramma in the Mediterranean region. They can be helpful for the preservation and use of indigenous Trichogramma species in biological control of lepidopterous pests in olive and other local crops

Entwicklung nachhaltiger Pflanzenschutzstrategien zur Bek_mpfung von Schadschmetterlingen im olivenanbau

Current olive growing practices range from the traditional Mediterranean olive grove to intensively managed olive plantations. Insecticides against major olive pests, like the olive moth (Prays oleae, Lep.: Yponomeutidae) and the jasmine moth, (Palpita unionalis, Lep.: Pyralidae) are still applied frequently. The European Union-funded international research project TRIPHELIO is aimed at the development of economically feasible and sustainable insecticide-free control methods for key Lepidopterous pests of olive. Main research activities focus on (1) the use of pheromones for mating disruption and improved monitoring of target pests, (2) habitat management strategies to enhance the activity of natural enemies in the olive grove, and (3) the use of inundative releases of mass-reared egg parasitoids of the genus Trichogramma. Moreover, tools for successful integration of the methods developed into an integrated pest management (IPM) strategy for olive pests were explored by optimising techniques for surveillance as well as considering potential side-effects of common pesticides on beneficial organisms. An intense exchange of scientific information and technology between European and North African countries was undertaken to create solutions for a wide range of olive growing regions. Key results and recommendations for further essential steps towards practical implementation are presented in this publication.Zusammenfassung Traditionelle, extensiv bearbeitete Olivenhaine, aber auch moderne Intensiv-Plantagen mit k_nstlicher Bew_sserung und hohem Einsatz von D_ngern bzw. chemischen Pflanzenschutzmitteln kennzeichnen die derzeitigen verschiedenen Anbauformen der Olive im Mittelmeerraum. Schadlepidopteren wie die Olivenmotte (Prays oleae, Lep.: Yponomeutidae) und die Jasminmotte (Palpita unionalis, Lep.: Pyralidae) werden durch regelm_ssigen Insektizideinsatz bek_mpft. Das von der EU gef_rderte internationale Forschungsprojekt TRIPHELIO zielte auf die Entwicklung insektizidfreier Alternativmethoden durch (1) die Optimierung der pheromongest _tzten _berwachung und Verwirrtechnik, (2) der Anwendung von Habitatmanagement-Strategien zur F_rderung nat_rlicher Gegenspieler, und (3) dem Einsatz von Trichogramma-Schlupfwespen. Zus_tzlich wurden Module f_r eine optimale Anwendung biotechnischer und biologischer Methoden bez_glich der Ph_nologie der Schadinsekten und m_glicher Nebenwirkungen von Pestiziden erarbeitet. Die intensive Kooperation zwischen Wissenschaftlern und Praktikern aus mehreren L_ndern Europas und Nordafrikas erlaubte den Entwurf m_glicher L_sungsans_tze f_r verschiedene Anbaubedingungen und klimatische Regionen des Mittelmeerraumes. Die wichtigsten Ergebnisse und Ausblicke f_r eine zuk_nftige praktische Umsetzung werden in dieser Ver_ffentlichung beschrieben

Triphelio – an international research project for sustainable control of lepidopterous pests in olive groves.

The olive moth (Prays oleae, Lepidoptera: Plutellidae) is known as one of the key pests in olive cultivation. In particular areas, also the jasmine moth (Pal pita zmionalis, Lepidoptera: Pyralidae) can cause serious damage to both leaves and fiuits of the olive tree. Both pests are mainly controlled by insecticide applications. In November 200 I, an international research project was started to promote biological and biotechnical methods for the control of these pests