236 research outputs found
Leaf color and vine size are related to yield in a phylloxera-infested vineyard
The uneven spread of phylloxera infestation and associated vine symptoms in vineyards usually complicates yield estimates and vineyard replacement decisions. In a Cabernet Sauvignon vineyard with AXR#1 rootstock the current season's and following season's yields of 40 vine plots correlated (r ≥ 0.77, p ≤ 0.05) with early to midseason leaf and canopy spectra measured in the field, laboratory and remotely with aircraft-borne sensors
A low energy optimization of the CERN-NGS neutrino beam for a theta_{13} driven neutrino oscillation search
The possibility to improve the CERN to Gran Sasso neutrino beam performances
for theta_{13} searches is investigated. We show that by an appropriate
optimization of the target and focusing optics of the present CNGS design, we
can increase the flux of low energy neutrinos by about a factor 5 compared to
the current tau optimized focalisation. With the ICARUS 2.35 kton detector at
LNGS and in case of negative result, this would allow to improve the limit to
sin^22 theta_{13} by an order of magnitude better than the current limit of
CHOOZ at Delta m^2 approximately 3 times 10^{-3} eV^2 within 5 years of nominal
CNGS running. This is by far the most sensitive setup of the currently approved
long-baseline experiments and is competitive with the proposed JHF superbeam.Comment: 19 pages, 8 figure
ATLAS Infrastructure
This document describes the civil engineering and infrastructure work done on the surface and underground for the ATLAS experiment at point 1 of the LHC ring
Neutrino oscillation physics at an upgraded CNGS with large next generation liquid Argon TPC detectors
The determination of the missing element (magnitude and phase) of
the PMNS neutrino mixing matrix is possible via the detection of \numu\to\nue
oscillations at a baseline and energy given by the atmospheric
observations, corresponding to a mass squared difference . While the current optimization of the CNGS
beam provides limited sensitivity to this reaction, we discuss in this document
the physics potential of an intensity upgraded and energy re-optimized CNGS
neutrino beam coupled to an off-axis detector. We show that improvements in
sensitivity to compared to that of T2K and NoVA are possible with
a next generation large liquid Argon TPC detector located at an off-axis
position (position rather distant from LNGS, possibly at shallow depth). We
also address the possibility to discover CP-violation and disentangle the mass
hierarchy via matter effects. The considered intensity enhancement of the CERN
SPS has strong synergies with the upgrade/replacement of the elements of its
injector chain (Linac, PSB, PS) and the refurbishing of its own elements,
envisioned for an optimal and/or upgraded LHC luminosity programme.Comment: 37 pages, 20 figure
Site Layout of the proposed new Hadrons' Injector Chain at CERN
The replacement of almost all the LHC injector complex on the Meyrin-site of CERN (Linac2, PSB and PS) is planned within the next 10 years. The layout foreseen for the new accelerators is described in this paper, together with its compatibility with the existing experimental physics facilities. These machines can, after upgrade, supply with high beam power future physics facilities for radioactive ions and/or neutrinos. Their possible layout is also sketched in this document
Infecção por Trypanosoma cruzi em candidatos a doador de sangue
INTRODUCTION: Transmission of American trypanossomiasis by transfusion has been reduced by expansion of control measures of blood quality in Brazil. A research project was, therefore, undertaken to evaluate soropositivity for Trypanosoma cruzi infection on blood donors and to compare this rate with those found in 1958 and 1975 in blood banks. METHOD: A transversal study was carried out on blood donors in Londrina, Paraná, Brazil. ELISA and Immunofluorescence were the serological test techniques used in the diagnosis of Trypanosoma cruzi infection. RESULTS AND CONCLUSION: A serumprevalence rate of 1.3% was found with a tendency for positive serum findings for Trypanosoma cruzi infection on blood donors to decrease over Aime (1958, 1975, and 1995).INTRODUÇÃO: A transmissão transfusional da tripanossomíase americana tem-se reduzido no Brasil, com a progressiva ampliação do controle de qualidade do sangue. Nesse sentido, realizou-se pesquisa para avaliar a atual soro-prevalência da infecção por Trypanosoma cruzi em candidatos a doador de sangue em Londrina, Paraná (Brasil), e comparar essa taxa com a encontrada em candidatos a doador estudados em 1958 e 1975, na mesma cidade. MÉTODO: Estudo transversal para determinação da soroprevalência. O imuno-diagnóstico de infecção por Trypanosoma cruzi foi realizado através das técnicas imunoenzimática (ELISA) e imunofluorescência indireta. RESULTADOS E CONCLUSÃO: A taxa de soroprevalência encontrada foi de 1,3%. Foi detectada tendência de queda temporal da taxa de positividade dos testes sorológicos para o diagnóstico de infecção por Trypanosoma cruzi nos bancos de sangue do município estudado nos anos de 1958, 1975 e 1995
Underground Neutrino Detectors for Particle and Astroparticle Science: the Giant Liquid Argon Charge Imaging ExpeRiment (GLACIER)
The current focus of the CERN program is the Large Hadron Collider (LHC),
however, CERN is engaged in long baseline neutrino physics with the CNGS
project and supports T2K as recognized CERN RE13, and for good reasons: a
number of observed phenomena in high-energy physics and cosmology lack their
resolution within the Standard Model of particle physics; these puzzles include
the origin of neutrino masses, CP-violation in the leptonic sector, and baryon
asymmetry of the Universe. They will only partially be addressed at LHC. A
positive measurement of would certainly give a
tremendous boost to neutrino physics by opening the possibility to study CP
violation in the lepton sector and the determination of the neutrino mass
hierarchy with upgraded conventional super-beams. These experiments (so called
``Phase II'') require, in addition to an upgraded beam power, next generation
very massive neutrino detectors with excellent energy resolution and high
detection efficiency in a wide neutrino energy range, to cover 1st and 2nd
oscillation maxima, and excellent particle identification and
background suppression. Two generations of large water Cherenkov
detectors at Kamioka (Kamiokande and Super-Kamiokande) have been extremely
successful. And there are good reasons to consider a third generation water
Cherenkov detector with an order of magnitude larger mass than Super-Kamiokande
for both non-accelerator (proton decay, supernovae, ...) and accelerator-based
physics. On the other hand, a very massive underground liquid Argon detector of
about 100 kton could represent a credible alternative for the precision
measurements of ``Phase II'' and aim at significantly new results in neutrino
astroparticle and non-accelerator-based particle physics (e.g. proton decay).Comment: 31 pages, 14 figure
Visual ecology of aphids – a critical review on the role of colours in host finding
We review the rich literature on behavioural responses of aphids (Hemiptera: Aphididae) to stimuli of different colours. Only in one species there are adequate physiological data on spectral sensitivity to explain behaviour crisply in mechanistic terms.
Because of the great interest in aphid responses to coloured targets from an evolutionary, ecological and applied perspective, there is a substantial need to expand these studies to more species of aphids, and to quantify spectral properties of stimuli rigorously. We show that aphid responses to colours, at least for some species, are likely based on a specific colour opponency mechanism, with positive input from the green domain of the spectrum and negative input from the blue and/or UV region.
We further demonstrate that the usual yellow preference of aphids encountered in field experiments is not a true colour preference but involves additional brightness effects. We discuss the implications for agriculture and sensory ecology, with special respect to the recent debate on autumn leaf colouration. We illustrate that recent evolutionary theories concerning aphid–tree interactions imply far-reaching assumptions on aphid responses to colours
that are not likely to hold. Finally we also discuss the
implications for developing and optimising strategies
of aphid control and monitoring
Leaf-associated fungal diversity in acidified streams: insights from combining traditional and molecular approaches
We combined microscopic and molecular methods to investigate fungal assemblages on alder leaf litter exposed in the benthic and hyporheic zones of five streams across a gradient of increasing acidification for 4 weeks. The results showed that acidification and elevated Al concentrations strongly depressed sporulating aquatic hyphomycetes diversity in both zones of streams, while fungal diversity assessed by denaturing gradient gel electrophoresis (DGGE) appeared unaffected. Clone library analyses revealed that fungal communities on leaves were dominated by members of Ascomycetes and to a lesser extent by Basidiomycetes and Chytridiomycetes. An important contribution of terrestrial fungi was observed in both zones of the most acidified stream and in the hyporheic zone of the reference circumneutral stream. The highest leaf breakdown rate was observed in the circumneutral stream and occurred in the presence of both the highest diversity of sporulating aquatic hyphomycetes and the highest contribution to clone libraries of sequences affiliated with aquatic hypho- mycetes. Both methods underline the major role played by aquatic hyphomycetes in leaf decom- position process. Our findings also bring out new highlights on the identity of leaf-associated fungal communities and their responses to anthropogenic alteration of running water ecosystems
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