689 research outputs found
Effect of different diets on the development, mortality, survival, food uptake and fecundity of Tupiocoris cucurbitaceus (Hemiptera: Miridae)
Several Miridae (Hemiptera) species have been identified as useful predators for biological control of the greenhouse whitefly, Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae). There is interest in determining the effects of different diets on Tupiocoris cucurbitaceus (Spinola) (Hemiptera: Miridae) in order to facilitate their breeding and use in biological control. Given that mirids can be both phytophagous and zoophytophagous, the developmental time, mortality, survival, feeding and fecundity of this species on tomato and tobacco leaves with and without the addition of T. vaporariorum or Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) eggs were studied. To determine embryonic duration, T. cucurbitaceus was allowed to oviposit on tobacco plants for 24 h at 26 °C, 83% RH and a photoperiod of 16:8 h L:D. The time of onset of the first instar nymphs was recorded. Subsequently, these nymphs fed on different diets on 9 cm × 1.5 cm plates under the same environmental conditions. Results showed that diet influences the duration of development in T. cucurbitaceus, with nymphal stadia being shorter and the adult stadium being longer when fed prey than when not fed prey. With the addition of prey, nymphal mortality was generally lower and adult survival was higher. The high consumption of T. vaporariorum eggs by T. cucurbitaceus suggests the need for subsequent studies on the latter for inclusion of this species in biological control programs in greenhouses
Method, System And Device For Transmitting Lighting Device Data
It is presented a method for transmitting lighting device data. The method comprises the steps of obtaining, in a lighting device, a subset of lighting device data, the lighting device data containg information of the lighting device, transmitting, from the lighting device, using light, the subset of lighting device data, and repeating the above steps until all subsets jointly corresponding to the complete lighting device data have been transmitted. A corresponding lighting device and lighting system are also presented.<br/
Satellite-based trends of solar radiation and cloud parameters in Europe
Solar radiation is the main driver of the Earth\u2019s climate. Measuring solar radiation and analysing its
interaction with clouds are essential for the understanding of the climate system. The EUMETSAT Satellite Application
Facility on Climate Monitoring (CM SAF) generates satellite-based, high-quality climate data records,
with a focus on the energy balance and water cycle. Here, multiple of these data records are analyzed in a common
framework to assess the consistency in trends and spatio-temporal variability of surface solar radiation,
top-of-atmosphere reflected solar radiation and cloud fraction. This multi-parameter analysis focuses on Europe
and covers the time period from 1992 to 2015. A high correlation between these three variables has been found
over Europe. An overall consistency of the climate data records reveals an increase of surface solar radiation and
a decrease in top-of-atmosphere reflected radiation. In addition, those trends are confirmed by negative trends
in cloud cover. This consistency documents the high quality and stability of the CM SAF climate data records,
which are mostly derived independently from each other. The results of this study indicate that one of the main
reasons for the positive trend in surface solar radiation since the 1990\u2019s is a decrease in cloud coverage even if
an aerosol contribution cannot be completely ruled out
Superdiffusion in a Model for Diffusion in a Molecularly Crowded Environment
We present a model for diffusion in a molecularly crowded environment. The
model consists of random barriers in percolation network. Random walks in the
presence of slowly moving barriers show normal diffusion for long times, but
anomalous diffusion at intermediate times. The effective exponents for square
distance versus time usually are below one at these intermediate times, but can
be also larger than one for high barrier concentrations. Thus we observe sub-
as well as super-diffusion in a crowded environment.Comment: 8 pages including 4 figure
Phenomenological model of elastic distortions near the spin-Peierls transition in
A phenomenological model of the Landau type forms the basis for a study of
elastic distortions near the spin-Peierls transition in . The
atomic displacements proposed by Hirota {\it et al.} [Phys. Rev. Lett. {\bf
73}, 736 (1994)] are accounted for by the model which includes linear coupling
between and distortions. displacements are seen to be responsible
for anomalies in the elastic properties {\it at} , whereas incipient
distortions give rise to temperature dependence below . A discussion of
possible critical behavior is also made.Comment: 1 figure available upon reques
Accurate Atmospheric Parameters at Moderate Resolution Using Spectral Indices: Preliminary Application to the MARVELS Survey
Studies of Galactic chemical and dynamical evolution in the solar
neighborhood depend on the availability of precise atmospheric parameters
(Teff, [Fe/H] and log g) for solar-type stars. Many large-scale spectroscopic
surveys operate at low to moderate spectral resolution for efficiency in
observing large samples, which makes the stellar characterization difficult due
to the high degree of blending of spectral features. While most surveys use
spectral synthesis, in this work we employ an alternative method based on
spectral indices to determine the atmospheric parameters of a sample of nearby
FGK dwarfs and subgiants observed by the MARVELS survey at moderate resolving
power (R~12,000). We have developed three codes to automatically normalize the
observed spectra, measure the equivalent widths of the indices and, through the
comparison of those with values calculated with pre-determined calibrations,
derive the atmospheric parameters of the stars. The calibrations were built
using a sample of 309 stars with precise stellar parameters obtained from the
analysis of high-resolution FEROS spectra. A validation test of the method was
conducted with a sample of 30 MARVELS targets that also have reliable
atmospheric parameters from high-resolution spectroscopic analysis. Our
approach was able to recover the parameters within 80 K for Teff, 0.05 dex for
[Fe/H] and 0.15 dex for log g, values that are lower or equal to the typical
external uncertainties found between different high-resolution analyzes. An
additional test was performed with a subsample of 138 stars from the ELODIE
stellar library and the literature atmospheric parameters were recovered within
125 K for Teff, 0.10 dex for [Fe/H] and 0.29 dex for log g. These results show
that the spectral indices are a competitive tool to characterize stars with the
intermediate resolution spectra.Comment: Accepted for publication in AJ. Abstract edited to comply with arXiv
standards regarding the number of character
Mesoscopic modelling of financial markets
We derive a mesoscopic description of the behavior of a simple financial
market where the agents can create their own portfolio between two investment
alternatives: a stock and a bond. The model is derived starting from the
Levy-Levy-Solomon microscopic model (Econ. Lett., 45, (1994), 103--111) using
the methods of kinetic theory and consists of a linear Boltzmann equation for
the wealth distribution of the agents coupled with an equation for the price of
the stock. From this model, under a suitable scaling, we derive a Fokker-Planck
equation and show that the equation admits a self-similar lognormal behavior.
Several numerical examples are also reported to validate our analysis
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