10,180 research outputs found

    Summerfruit tοrtriχ, Adoxophyes orana: life cycle, warning system and control

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    Το Λεπιδόπτερο Adoxophyes orana F.v.R., είναι ένας εχθρός που προσαρμόσθηκε πρόσφατα στις εντατικές καλλιέργειες μηλιάς και αχλαδιάς. Οι προνύμφες αναπτύσσονται αρχικά επάνω σε νεαρά φύλλα και βλαστούς και ευκαιριακά προσβάλλουν την επιφάνεια του καρπού. Στην Ελβετία υπάρχουν δύο πτήσεις το χρόνο, ενώ στην Ελλάδα υπάρχουν τρεις πτήσεις με τη δεύτερη και τρίτη να επικαλύπτονται. Οι διαπαύουσες προνύμφες διαχειμάζουν όταν είναι στο τρίτο στάδιο (L?) και αρχίζουν πάλι να αναπτύσσονται την άνοιξη. Υπάρχουν τρεις περίοδοι που οι προνύμφες είναι δραστήριες. Οι μέθοδοι προειδοποίησης είναι: η οπτική εξέταση των λουλουδιών την άνοιξη, οι παγίδες με φορομόνες φύλου και η οπτική εξέταση των βλαστών και καρπών το καλοκαίρι. Ένα μοντέλο, που περιγράφει το βιολογικό κύκλο σε συνάρτηση με τη θερμοκρασία, επιτρέπει τον καθορισμό του καλύτερου χρόνου δειγματοληψίας ζημιών και εφαρμογής φαρμάκων σε σχέση με τον τρόπο δράσης τους. Μερικά κλασικά εντομοκτόνα προσφέρουν θεραπευτική καταπολέμηση αλλά η αποτελεσματικότητα τους πάντοτε μειώνεται εναντίον προνυμφών προχωρημένης ηλικίας. Τα καλύτερα αποτελέσματα επιτυγχάνονται κατά την εκκόλαψη των ωών της πρώτης γενεάς. Ο ρυθμιστής ανάπτυξης των εντόμων (IGR), fenoxycarb, είναι πολύ αποτελεσματικός όταν εφαρμόζεται την άνοιξη εναντίον του τελευταίου προνυμφικού σταδίου (Ls) της διαχειμάζουσας γενεάς. Ένας ειδικός ιός επίσης δίνει καλά αποτελέσματα εναντίον των διαχειμαζουσών προνυμφών. Τον καιρό αυτό μελετώνται η τεχνική της παρεμπόδισης των συζεύξεων και οι παρεμποδιστές ανάπτυξης των εντόμων (IGI) που εμποδίζουν τον σχηματισμό της χιτίνης. Για όλα τα προϊόντα που χρησιμοποιήθηκαν για την καταπολέμηση του Α. orana ο χρόνος που μεσολαβεί είναι πολύ σημαντικός για τη μέγιστη αποτελεσματικότητα.The summerfruit tortrix, Adoxophyes orana F.v.R., is a pest which has recently adapted to the intensive culture of apple and pear. The larvae develop primarily on the young leaves and shoots and occasionally feed on the surface of the fruit. Under Swiss conditions there are two flights per year though there are three in Greece with the second and third overlapping. The diapausing larvae hibernate in the third stage (L3) and begin development again in the spring. There are three periods in which the larvae are active. The methods used to sample populations for making management decisions are: visual examination of flower clusters in spring, sex pheromone traps, and visual examination of shoots and fruit in summer. A model describing the life cycle as a function of temperature allows for the determination of the best time to sample damage and to apply treatments with regard to their particular mode of action. Some classical insecticides provide control curatively but efficiency is always reduced against older larvae. The best results are obtained at egg eclosion following the first flight. The insect growth regulator (IGR), fenoxycarb, is very effective when applied in the spring against the last stage larvae (Ls) of the overwintering generation. A specific virus also gives good control in the spring against overwintering larvae. The mating disruption technique and insect growth inhibitors (ICI), which prevent the formation of chitin, are currently being studied. For all the products used to control A. orana, the timing of the application is extremely important in order to obtain the bes

    ICPL_ESIQuant – a Powerful Freeware Tool for Handling Proteomics LCESI- MS2 Experiments

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    Among the MS-based quantitative methods using stable isotope labelling, the Isotope-Coded Protein Label (ICPL) technique has emerged as a powerful tool to identify and relatively quantify thousands of proteins within complex protein mixtures. The ICPL_ESIQuant 3.0 software package is one of the key components of the ICPL-ESI workflow, covering data processing steps like LC-MS feature detection, ICPL doublet/triplet/quadruplet quantification as well as a merging step of LC-MS features and Mascot search results. As unique features, the software performs isotope pattern overlap corrections and utilizes additional chemical knowledge, e.g. the physico-chemical properties of the ICPL labels, to discard false positive isotope pattern, which significantly improves the quality of the final peptide and protein results. ICPL_ESIQuant is the first freeware tool on the market, which supports both the shotgun proteomics strategy using Data Dependent Acquisition (DDA) and the directed proteomics strategy using mass inclusion lists for precursor ion selection. ICPL_ESIQuant 3.0 (32 and 64 bit versions) can be downloaded from https://sourceforge.net/projects/icplquant/ files

    A Morphological and Multicolor Survey for Faint QSOs in the Groth-Westphal Strip

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    Quasars representative of the populous faint end of the luminosity function are frustratingly dim with m~24 at intermediate redshift; moreover groundbased surveys for such faint QSOs suffer substantial morphological contamination by compact galaxies having similar colors. In order to establish a more reliable ultrafaint QSO sample, we used the APO 3.5-m telescope to take deep groundbased U-band CCD images in fields previously imaged in V,I with WFPC2/HST. Our approach hence combines multicolor photometry with the 0.1" spatial resolution of HST, to establish a morphological and multicolor survey for QSOs extending about 2 magnitudes fainter than most extant groundbased surveys. We present results for the "Groth-Westphal Strip", in which we identify 10 high likelihood UV-excess candidates having stellar or stellar-nucleus+galaxy morphology in WFPC2. For m(606)<24.0 (roughly B<24.5) the surface density of such QSO candidates is 420 (+180,-130) per square degree, or a surface density of 290 (+160,-110) per square degree with an additional V-I cut that may further exclude compact emission line galaxies. Even pending confirming spectroscopy, the observed surface density of QSO candidates is already low enough to yield interesting comparisons: our measures agree extremely well with the predictions of several recent luminosity function models.Comment: 29 pages including 6 tables and 7 figures. As accepted for publication in The Astronomical Journal (minor revisions

    Higher-Order Angular Galaxy Correlations in the SDSS: Redshift and Color Dependence of non-Linear Bias

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    We present estimates of the N-point galaxy, area-averaged, angular correlation functions ωˉN\bar{\omega}_{N}(θ\theta) for NN = 2,...,7 for galaxies from the fifth data release of the Sloan Digital Sky Survey. Our parent sample is selected from galaxies with 18r<2118 \leq r < 21, and is the largest ever used to study higher-order correlations. We subdivide this parent sample into two volume limited samples using photometric redshifts, and these two samples are further subdivided by magnitude, redshift, and color (producing early- and late-type galaxy samples) to determine the dependence of ωˉN\bar{\omega}_{N}(θ\theta) on luminosity, redshift, and galaxy-type. We measure ωˉN\bar{\omega}_{N}(θ\theta) using oversampling techniques and use them to calculate the projected, sNs_{N}. Using models derived from theoretical power-spectra and perturbation theory, we measure the bias parameters b1b_1 and c2c_2, finding that the large differences in both bias parameters (b1b_1 and c2c_2) between early- and late-type galaxies are robust against changes in redshift, luminosity, and σ8\sigma_8, and that both terms are consistently smaller for late-type galaxies. By directly comparing their higher-order correlation measurements, we find large differences in the clustering of late-type galaxies at redshifts lower than 0.3 and those at redshifts higher than 0.3, both at large scales (c2c_2 is larger by 0.5\sim0.5 at z>0.3z > 0.3) and small scales (large amplitudes are measured at small scales only for z>0.3z > 0.3, suggesting much more merger driven star formation at z>0.3z > 0.3). Finally, our measurements of c2c_2 suggest both that σ8<0.8\sigma_8 < 0.8 and c2c_2 is negative.Comment: 46 pages, 19 figures, Accepted to Ap

    A portable platform for accelerated PIC codes and its application to GPUs using OpenACC

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    We present a portable platform, called PIC_ENGINE, for accelerating Particle-In-Cell (PIC) codes on heterogeneous many-core architectures such as Graphic Processing Units (GPUs). The aim of this development is efficient simulations on future exascale systems by allowing different parallelization strategies depending on the application problem and the specific architecture. To this end, this platform contains the basic steps of the PIC algorithm and has been designed as a test bed for different algorithmic options and data structures. Among the architectures that this engine can explore, particular attention is given here to systems equipped with GPUs. The study demonstrates that our portable PIC implementation based on the OpenACC programming model can achieve performance closely matching theoretical predictions. Using the Cray XC30 system, Piz Daint, at the Swiss National Supercomputing Centre (CSCS), we show that PIC_ENGINE running on an NVIDIA Kepler K20X GPU can outperform the one on an Intel Sandybridge 8-core CPU by a factor of 3.4

    MIMAC: MIcro-tpc MAtrix of Chambers for dark matter directional detection

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    Directional detection of non-baryonic Dark Matter is a promising search strategy for discriminating WIMP events from neutrons, the ultimate background for dark matter direct detection. This strategy requires both a precise measurement of the energy down to a few keV and 3D reconstruction of tracks down to a few mm. The MIMAC (MIcro-tpc MAtrix of Chambers) collaboration has developed in the last years an original prototype detector based on the direct coupling of large pixelized micromegas with a special developed fast self-triggered electronics showing the feasibility of a new generation of directional detectors. The first bi-chamber prototype has been installed at Modane, underground laboratory in June 2012. The first undergournd background events, the gain stability and calibration are shown. The first spectrum of nuclear recoils showing 3D tracks coming from the radon progeny is presented.Comment: Proceedings of the 4th International Conference on Directional Dark Matter Detection CYGNUS2013, held in Toyoma (Japan), June 201

    Do riverine barriers, history or introgression shape the genetic structuring of a common shrew (Sorex araneus) population?

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    The common shrew (Sorex araneus) is subdivided into numerous chromosome races. The Valais and Cordon chromosome races meet and hybridize at a mountain river in Les Houches (French Alps). Significant genetic structuring was recently reported among populations found on the Valais side of this hybrid zone. In this paper, a phylogenetic analysis and partial Mantel tests are used to investigate the patterns and causes of this structuring. A total of 185 shrews were trapped at 12 localities. All individuals were typed for nine microsatellite loci. Although several mountain rivers are found in the study area, riverine barriers do not have a significant influence on gene flow. Partial Mantel tests show that our result is caused by the influence of the hybrid zone with the Cordon race. The geographical patterns of this structuring are discussed in the context of the contact zone, which appears to extend up to a group of two rivers. The glacier they originate from is known to have cut the Arve valley as recently as 1818. The recent history of this glacier, its moraine and possibly rivers, may therefore be linked to the history of this hybrid zone
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