9,359 research outputs found
Control of the apple sawfly Hoplocampa testudinea Klug in organic fruit growing and possible side effects of control strategies on Aphelinus mali Haldeman and other beneficial insects
The effect of Quassia extract on eggs and larvae of the apple sawfly Hoplocampa testudinea
was studied. The efficacy of this extract is mainly due to an oral toxicity to the
neonate sawfly larvae. The main active ingredients, Quassin and Neoquassin, were
tested separately. Wheras Quassin has a considerable efficacy also on older larvae,
Neoquassin is less efficient in this case. While Quassin and Neoquassin are found in
different Quassia sources in varying relations to each other and have different efficacy,
they have to be considered separately in the definition of extract quality by the content of
active ingredients. These findings mean, that the “egg maturity” is not important for application
date. Nevertheless, the application must take place before the larvae hatch. It
was shown that low rates of Quassin (4-6 g/ha) can show very good results in the field,
in other cases the rates necessary for good efficacy are much higher. This corresponds
to farmers experience. Several factors as application technique and the condition of the
blossom must be taken in consideration and will be object of further studies.
The side effects of Quassin, Neoquassin and Quassia extract on Aphelinus mali and
other beneficial arthropods were tested. Quassia is harmless to all organisms tested
Hamiltonian approach to QCD in Coulomb gauge - a survey of recent results
I report on recent results obtained within the Hamiltonian approach to QCD in
Coulomb gauge. Furthermore this approach is compared to recent lattice data,
which were obtained by an alternative gauge fixing method and which show an
improved agreement with the continuum results. By relating the Gribov
confinement scenario to the center vortex picture of confinement it is shown
that the Coulomb string tension is tied to the spatial string tension. For the
quark sector a vacuum wave functional is used which explicitly contains the
coupling of the quarks to the transverse gluons and which results in
variational equations which are free of ultraviolet divergences. The
variational approach is extended to finite temperatures by compactifying a
spatial dimension. The effective potential of the Polyakov loop is evaluated
from the zero-temperature variational solution. For pure Yang--Mills theory,
the deconfinement phase transition is found to be second order for SU(2) and
first order for SU(3), in agreement with the lattice results. The corresponding
critical temperatures are found to be and , respectively. When quarks are included, the deconfinement
transition turns into a cross-over. From the dual and chiral quark condensate
one finds pseudo-critical temperatures of and , respectively, for the deconfinement and chiral transition.Comment: Talk given by H. Reinhardt at "5th Winter Workshop on
Non-Perturbative Quantum Field Theory", 22-24 March 2017, Sophia-Antipolis,
France. arXiv admin note: text overlap with arXiv:1609.09370,
arXiv:1510.03286, arXiv:1607.0814
The physics and kinematics of the evolved, interacting planetary nebula PN G342.0-01.7
Here we aim to study the physical and kinematical characteristics of the
unstudied old planetary nebula (PN) PN G342.0-01.7, which shows evidence of
interaction with its surrounding interstellar medium. We used Integral Field
Spectra from the Wide Field Spectrograph on the ANU 2.3 m telescope to provide
spectroscopy across the whole object covering the spectral range 3400-7000
{\AA}. We formed narrow-band images to investigate the excitation structure.
The spectral analysis shows that the object is a distant Peimbert Type I PN of
low excitation, formally of excitation class of 0.5. The low electron density,
high dynamical age, and low surface brightness of the object confirm that it is
observed fairly late in its evolution. It shows clear evidence for dredge-up of
CN-processed material characteristic of its class. In addition, the low
peculiar velocity of 7 km s shows it to be a member of the young disk
component of our Galaxy. We built a self-consistent photoionisation model for
the PNe matching the observed spectrum, the H luminosity, and the
diameter. On the basis of this we derive an effective temperature and luminosity . The temperature is much
higher than might have been expected using the excitation class, proving that
this can be misleading in classifying evolved PNe. PN G342.0-01.7 is in
interaction with its surrounding interstellar medium through which the object
is moving in the south-west direction. This interaction drives a slow shock
into the outer PN ejecta. A shock model suggests that it only accounts for
about 10\% of the total luminosity, but has an important effect on the global
spectrum of the PN.Comment: 15 pages, 6 figures, A&A accepted 201
An interval logic for higher-level temporal reasoning
Prior work explored temporal logics, based on classical modal logics, as a framework for specifying and reasoning about concurrent programs, distributed systems, and communications protocols, and reported on efforts using temporal reasoning primitives to express very high level abstract requirements that a program or system is to satisfy. Based on experience with those primitives, this report describes an Interval Logic that is more suitable for expressing such higher level temporal properties. The report provides a formal semantics for the Interval Logic, and several examples of its use. A description of decision procedures for the logic is also included
New Models of General Relativistic Static Thick Disks
New families of exact general relativistic thick disks are constructed using
the ``displace, cut, fill and reflect'' method. A class of functions used to
``fill'' the disks is derived imposing conditions on the first and second
derivatives to generate physically acceptable disks. The analysis of the
function's curvature further restrict the ranges of the free parameters that
allow phisically acceptable disks. Then this class of functions together with
the Schwarzschild metric is employed to construct thick disks in isotropic,
Weyl and Schwarzschild canonical coordinates. In these last coordinates an
additional function must be added to one of the metric coefficients to generate
exact disks. Disks in isotropic and Weyl coordinates satisfy all energy
conditions, but those in Schwarzschild canonical coordinates do not satisfy the
dominant energy condition.Comment: 27 pages, 14 figure
Results of oral TRH test in the differentiation of compensated and decompensated autonomous thyroid nodules
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