2,573 research outputs found
Evaluation of an active mating disruption concept against codling moth (Cydia pomonella) under the aspects of different application systems and varieties
Beside standard systems of mating disruption the activity of the product Exosex CM and
Exosex 2 CM under the aspect of different application systems and several varieties were
tested at the research station of the Federal College and Institute for Viticulture and
Pomology Klosterneuburg. Male insects were attracted into the Exosex dispenser by using
the appropriate pheromone, which acts on the pheromone receptive sensors on the male
so that they cannot locate calling females. Standard mating disruption techniques usually
rely on the introduction of amounts of pheromone emitted by natural populations of pest
species into the atmosphere. Exosex CM significantly reduces deployment time and labour
costs in the orchards, additionally the flexibility to fit in with IPM programmes was tested.
The assessments were done visually on windfall fruits, fruits on the tree and on all fruits at
harvest followed by statistical evaluation. Among the fruits sprayed with the IPM system
there was an infestation rate of the first (Cydia pomonella) generation at the variety Idared
of 0,8%, the second generation treated with Exosex showed an infestation of 13%. In the
biological trial however the infestation by the first generation was about 4% and the
infestation of the second generation about 31%
Regularized Ordinal Regression and the ordinalNet R Package
Regularization techniques such as the lasso (Tibshirani 1996) and elastic net
(Zou and Hastie 2005) can be used to improve regression model coefficient
estimation and prediction accuracy, as well as to perform variable selection.
Ordinal regression models are widely used in applications where the use of
regularization could be beneficial; however, these models are not included in
many popular software packages for regularized regression. We propose a
coordinate descent algorithm to fit a broad class of ordinal regression models
with an elastic net penalty. Furthermore, we demonstrate that each model in
this class generalizes to a more flexible form, for instance to accommodate
unordered categorical data. We introduce an elastic net penalty class that
applies to both model forms. Additionally, this penalty can be used to shrink a
non-ordinal model toward its ordinal counterpart. Finally, we introduce the R
package ordinalNet, which implements the algorithm for this model class
Interfaces within graphene nanoribbons
We study the conductance through two types of graphene nanostructures: nanoribbon junctions in which the width changes from wide to narrow, and curved nanoribbons. In the wide-narrow structures, substantial reflection occurs from the wide-narrow interface, in contrast to the behavior of the much studied electron gas waveguides. In the curved nanoribbons, the conductance is very sensitive to details such as whether regions of a semiconducting armchair nanoribbon are included in the curved structure -- such regions strongly suppress the conductance. Surprisingly, this suppression is not due to the band gap of the semiconducting nanoribbon, but is linked to the valley degree of freedom. Though we study these effects in the simplest contexts, they can be expected to occur for more complicated structures, and we show results for rings as well. We conclude that experience from electron gas waveguides does not carry over to graphene nanostructures. The interior interfaces causing extra scattering result from the extra effective degrees of freedom of the graphene structure, namely the valley and sublattice pseudospins
A search for neutrino-antineutrino mass inequality by means of sterile neutrino oscillometry
The investigation of the oscillation pattern induced by the sterile neutrinos
might determine the oscillation parameters, and at the same time, allow to
probe CPT symmetry in the leptonic sector through neutrino-antineutrino mass
inequality. We propose to use a large scintillation detector like JUNO or LENA
to detect electron neutrinos and electron antineutrinos from MCi electron
capture or beta decay sources. Our calculations indicate that such an
experiment is realistic and could be performed in parallel to the current
research plans for JUNO and RENO. Requiring at least 5 confidence level
and assuming the values of the oscillation parameters indicated by the current
global fit, we would be able to detect neutrino-antineutrino mass inequality of
the order of 0.5% or larger, which would imply a signal of CPT anomalies.Comment: 14 pages, 10 figure
Wick calculus
In quantum field theory the “normal ordering” of operators is routinely used, which amounts to shuffling all creation operators to the left. Potentially confusing is the occurrence in the literature of normal-ordered functions, sometimes called “Wick transforms.” In this paper, we introduce the reader to some basic results, ideas, and mathematical subtleties about normal ordering of operators and functions. The intended audience are instructors of quantum field theory and researchers who are interested but not specialists in mathematical physics
Triazolinedione-'clicked' poly(phosphoester)s : systematic adjustment of thermal properties
The thermal properties of halogen-free flame retardant poly(phosphoester)s from acyclic diene metathesis polycondensation have been optimized by a systematic post-modification using 1,2,4-triazoline- 3,5-dione derivatives. The straightforward modification not only increased their glass transition temperatures significantly but also improved the thermal stability with respect to their char yields
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