991 research outputs found
Mangelnde Kenntnis über den Anbau von Körnerleguminosen bei Luxemburger Landwirten
Grain legume production in Europe has decreased in recent years, while legume demand has rapidly increased. Various investigations have identified problems and benefits of grain legume cultivation. Studies investigating why farmers do not cultivate these crops are missing. Here we surveyed farmers about grain legume cultivation. We sent a questionnaire to 1373 farmers in Luxembourg, with a response rate of 29%. Results show that 12% of the conventional and 85% of the organic farmers cultivated grain legumes. We observed that farmers feel badly informed about grain legume
cultivation. The main barriers to not cultivate these crops are not economic issues but a lack of knowledge about grain legumes. Even though grain legume producers mentioned several negative experiences with grain legume cultivation, they are not discouraged by the poor economic conditions and appreciate the benefits of grain legume cultivation. Overall our findings show that research results on grain legumes
should be better disseminated to extension services and farmers
The small reservoirs project: Research to improve water availability and economic development in rural semi-arid areas
Millimeter Wave Scattering from Neutral and Charged Water Droplets
We investigated 94GHz millimeter wave (MMW) scattering from neutral and
charged water mist produced in the laboratory with an ultrasonic atomizer.
Diffusion charging of the mist was accomplished with a negative ion generator
(NIG). We observed increased forward and backscattering of MMW from charged
mist, as compared to MMW scattering from an uncharged mist. In order to
interpret the experimental results, we developed a model based on classical
electrodynamics theory of scattering from a dielectric sphere with
diffusion-deposited mobile surface charge. In this approach, scattering and
extinction cross-sections are calculated for a charged Rayleigh particle with
effective dielectric constant consisting of the volume dielectric function of
the neutral sphere and surface dielectric function due to the oscillation of
the surface charge in the presence of applied electric field. For small
droplets with (radius smaller than 100nm), this model predicts increased MMW
scattering from charged mist, which is qualitatively consistent with the
experimental observations. The objective of this work is to develop indirect
remote sensing of radioactive gases via their charging action on atmospheric
humid air.Comment: 18 pages, 8 figure
A template of atmospheric O2 circularly polarized emission for CMB experiments
We compute the circularly polarized signal from atmospheric molecular oxygen.
Polarization of O2 rotational lines is caused by Zeeman effect in the Earth
magnetic field. We evaluate the circularly polarized emission for various sites
suitable for CMB measurements: South Pole and Dome C (Antarctica), Atacama
(Chile) and Testa Grigia (Italy). An analysis of the polarized signal is
presented and discussed in the framework of future CMB polarization
experiments. We find a typical circularly polarized signal (V Stokes parameter)
of ~ 50 - 300 {\mu}K at 90 GHz looking at the zenith. Among the other sites
Atacama shows the lower polarized signal at the zenith. We present maps of this
signal for the various sites and show typical elevation and azimuth scans. We
find that Dome C presents the lowest gradient in polarized temperature: ~ 0.3
{\mu}K/\circ at 90 GHz. We also study the frequency bands of observation:
around {\nu} \simeq 100 GHz and {\nu} \simeq 160 GHz we find the best
conditions because the polarized signal vanishes. Finally we evaluate the
accuracy of the templates and the signal variability in relation with the
knowledge and the variability of the Earth magnetic field and the atmospheric
parameters.Comment: 10 pages, 12 figures, accepted for publication on Mon. Not. R.
Astron. So
Geographical interdependence, international trade and economic dynamics: the Chinese and German solar energy industries
The trajectories of the German and Chinese photovoltaic industries differ significantly yet are strongly interdependent. Germany has seen a rapid growth in market demand and a strong increase in production, especially in the less developed eastern half of the country. Chinese growth has been export driven. These contrasting trajectories reflect the roles of market creation, investment and credit and the drivers of innovation and competitiveness. Consequent differences in competiveness have generated major trade disputes
Hydrogen-like nitrogen radio line from hot interstellar and warm-hot intergalactic gas
Hyperfine structure lines of highly-charged ions may open a new window in
observations of hot rarefied astrophysical plasmas. In this paper we discuss
spectral lines of isotopes and ions abundant at temperatures 10^5-10^7 K,
characteristic for warm-hot intergalactic medium, hot interstellar medium,
starburst galaxies, their superwinds and young supernova remnants. Observations
of these lines will allow to study bulk and turbulent motions of the observed
target and will broaden the information about the gas ionization state,
chemical and isotopic composition.
The most prospective is the line of the major nitrogen isotope having
wavelength 5.65 mm (Sunyaev and Churazov 1084). Wavelength of this line is
well-suited for observation of objects at z=0.15-0.6 when it is redshifted to
6.5-9 mm spectral band widely-used in ground-based radio observations, and, for
example, for z>=1.3, when the line can be observed in 1.3 cm band and at lower
frequencies. Modern and future radio telescopes and interferometers are able to
observe the absorption by 14-N VII in the warm-hot intergalactic medium at
redshifts above z=0.15 in spectra of brightest mm-band sources. Sub-millimeter
emission lines of several most abundant isotopes having hyperfine splitting
might also be detected in spectra of young supernova remnants.Comment: 12 pages, 5 figures, accepted by Astronomy Letters; v3: details
added; error fixe
Ground-based astrometry calibrated by Gaia DR1: new perspectives in asteroid orbit determination
Context. The Gaia Data Release 1 (GDR1) is a first, important step on the path of evolution of astrometric accuracy towards a much improved situation. Although asteroids are not present in GDR1, this intermediate release already impacts asteroid astrometry.
Aims. Our goal is to investigate how the GDR1 can change the approach to a few typical problems, including the determination of orbits from short-arc astrometry, the exploitation of stellar occultations, and the impact risk assessment.
Methods.We employ optimised asteroid orbit determination tools, and study the resulting orbit accuracy and post-fit residuals. For this goal, we use selected ground-based asteroid astrometry, and occultation events observed in the past. All measurements are calibrated by using GDR1 stars.
Results. We show that, by adopting GDR1, very short measurement arcs can already provide interesting orbital solutions, capable of correctly identifying near-Earth asteroids (NEAs) and providing a much more accurate risk rating. We also demonstrate that occultations, previously used to derive asteroid size and shapes, now reach a new level of accuracy at which they can be fruitfully used to obtain astrometry at the level of accuracy of Gaia star positions
The virulence factor p25 of beet necrotic yellow vein virus interacts with multiple Aux/IAA proteins from Beta vulgaris: Implications for rhizomania development
Rhizomania caused by Beet necrotic yellow vein virus (BNYVV) is characterized by excessive lateral root (LR) formation. Auxin-mediated degradation of Aux/IAA transcriptional repressors stimulates gene regulatory networks leading to LR organogenesis and involves several Aux/IAA proteins acting at distinctive stages of LR development. Previously, we showed that BNYVV p25 virulence factor interacts with BvIAA28, a transcriptional repressor acting at early stages of LR initiation. The evidence suggested that p25 inhibits BvIAA28 nuclear localization, thus, de-repressing transcriptional network leading to LR initiation. However, it was not clear whether p25 interacts with other Aux/IAA proteins. Here, by adopting bioinformatics, in vitro and in vivo protein interaction approaches we show that p25 interacts also with BvIAA2 and BvIAA6. Moreover, we confirmed that the BNYVV infection is, indeed, accompanied by an elevated auxin level in the infected LRs. Nevertheless, expression levels of BvIAA2 and BvIAA6 remained unchanged upon BNYVV infection. Mutational analysis indicated that interaction of p25 with either BvIAA2 or BvIAA6 requires full-length proteins as even single amino acid residue substitutions abolished the interactions. Compared to p25-BvIAA28 interaction that leads to redistribution of BvIAA28 into cytoplasm, both BvIAA2 and BvIAA6 remained confined into the nucleus regardless of the presence of p25 suggesting their stabilization though p25 interaction. Overexpression of p25-interacting partners (BvIAA2, BvIAA6 and BvIAA28) in Nicotiana benthamiana induced an auxin-insensitive phenotype characterized by plant dwarfism and dramatically reduced LR development. Thus, our work reveals a distinct class of transcriptional repressors targeted by p25
Disentangling the Pure Time Effect From Site and Preference Heterogeneity Effects in Benefit Transfer: An Empirical Investigation of Transferability
Gaming the system:Practices against the algorithmic makeover of everyday life
The introduction of technical, algorithmically-controlled interactive medial systems into virtually all contexts of everyday life is a relatively recent phenomenon. Implications, for instance, for social and political contexts are still emerging. One probably unexpected but certainly unintended effect is the emergence of gaming the system behaviours. Gaming is seen here as participants taking advantage of systems by interacting with them in unintended ways to gain unjustified benefits. These behaviours are regularly seen as problematic, and measures to prevent or to detect and to react to them are discussed in the academic discourse. This study aims to establish characteristics, practices and causes of such behaviours, exemplatory in the area of interactive, educational tutoring systems. The study is informed by positions from Game Studies, Cognitive Evaluation Theory (CET; Deci, Ryan) and the (post-) phenomenological discourse on the intentionality of non-human actors. It finds that users feel disenfranchised rather than empowered by the intentionality embodied in algorithmic systems; that those systems afford play; and that gaming behaviour can be read as defensive and evasive, rather than aggressive and criminal.The introduction of technical, algorithmically-controlled interactive medial systems into virtually all contexts of everyday life is a relatively recent phenomenon. Implications, for instance, for social and political contexts are still emerging. One probably unexpected but certainly unintended effect is the emergence of gaming the system behaviours. Gaming is seen here as participants taking advantage of systems by interacting with them in unintended ways to gain unjustified benefits. These behaviours are regularly seen as problematic, and measures to prevent or to detect and to react to them are discussed in the academic discourse. This study aims to establish characteristics, practices and causes of such behaviours, exemplatory in the area of interactive, educational tutoring systems. The study is informed by positions from Game Studies, Cognitive Evaluation Theory (CET; Deci, Ryan) and the (post-) phenomenological discourse on the intentionality of non-human actors. It finds that users feel disenfranchised rather than empowered by the intentionality embodied in algorithmic systems; that those systems afford play; and that gaming behaviour can be read as defensive and evasive, rather than aggressive and criminal
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