25 research outputs found
Online-Bestimmungshilfe für Schadorganismen für das Internetportal www.oekolandbau.de
Organic plant protection can be supported by diagnostic aids for pest organisms. A concept for a user-friendly, scientifically founded diagnostic aid for agriculturally
relevant pest organisms is presented, which is based on a flexible filter structure and conclusive images. To provide practical information on biology and regulation options
along with the diagnosis, recent scientific results and market availability of regulation options in organic farming are being reviewed. The on-going research and transfer
project has launched the first section on storage pests in 2016 at: www.oekolandbau.de/erzeuger/pflanzenbau/allgemeiner-pflanzenbau/pflanzenschut
MITO measurements of the Sunyaev-Zeldovich Effect in the Coma cluster of galaxies
We have measured the Sunyaev-Zeldovich effect towards the Coma cluster
(A1656) with the MITO experiment, a 2.6-m telescope equipped with a 4-channel
17 arcminute (FWHM) photometer. Measurements at frequency bands 143+/-15,
214+/-15, 272+/-16 and 353+/-13 GHz, were made during 120 drift scans of Coma.
We describe the observations and data analysis that involved extraction of the
S-Z signal by employing a spatial and spectral de-correlation scheme to remove
a dominant atmospheric component. The deduced values of the thermal S-Z effect
in the first three bands are DT_{0} = -179+/-38,-33+/-81,170+/-35 microKelvin
in the cluster center. The corresponding optical depth, tau=(4.1+/-0.9)
10^{-3}, is consistent (within errors) with both the value from a previous low
frequency S-Z measurement, and the value predicted from the X-ray deduced gas
parameters.Comment: Ap.J.Letters accepted, 4 pages, 2 figure
The ISOPHOT-MAMBO survey of 3CR radio sources: Further evidence for the unified schemes
We present the complete set of ISOPHOT observations of 3CR radio galaxies and
quasars, which are contained in the ISO Data Archive, providing 75 mid- and
far-infrared spectral energy distributions (SEDs) between 5 and 200 micron. For
28 sources they are supplemented with MAMBO 1.2 mm observations and for 15
sources with new submillimetre data from the SCUBA archive.
We check the orientation-dependent unified scheme, in which the powerful FR2
narrow line galaxies are quasars viewed at high inclination, so that their
nuclei are hidden behind a dust torus intercepting the optical-ultraviolet AGN
radiation and reemitting it in the infrared. We find that (1) both the quasars
and the galaxies show a high mid- to far-infrared luminosity ratio typical for
powerful AGNs and (2) -- when matched in 178 MHz luminosity -- both show the
same ratio of isotropic far-infrared to isotropic 178 MHz lobe power.
Therefore, from our large sample investigated here we find strong evidence for
the orientation-dependent unification of the powerful FR2 galaxies with the
quasars.Comment: 16 pages, 7 figures, 3 tables, accepted by Astronomy & Astrophysic
Dust emission from 3C radio galaxies and quasars: New ISO observations favour the unified scheme
In order to test the unified scheme for luminous radio galaxies and quasars
we observed 10 galaxy/quasar pairs from the 3CR catalogue with ISOPHOT at
infrared wavelengths between 5 and 180 micron. Each pair was selected such that
both the 178 MHz luminosity and the redshift match as close as possible between
the radio galaxy and the quasar in order to minimize effects of cosmic
evolution. 13 of the 20 sources were detected in at least one waveband. 12
sources show clear evidence of a thermal bump at FIR wavelength, while in the
remaining 7 sources the upper limits are still compatible with the presence of
luminous dust emission. In agreement with the predictions of the unified
scheme, the quasars and galaxies in our sample cannot be distinguished by their
observed mid- and far-infrared properties. This is in contrast to the IRAS
results which indicated that radio galaxies radiate significantly less mid- to
far-infrared emission than quasars. However, the IRAS samples are dominated by
low-redshift sources (z < 0.5), while our sample contains several of the most
luminous radio galaxies at redshift z ~ 1. The latter have already been
suspected to contain a hidden quasar for other reasons, e.g. an extended
emission line region aligned with the radio axis. From the ratio between FIR
luminosity emitted by dust and the radio power at 178 MHz, we conclude that the
radio galaxy/quasar unification might be perfectly valid for the most luminous
3C sources at high redshift (z > 0.8). At lower redshifts (z < 0.5), however,
some of the FRII radio galaxies contain active nuclei which emit less
UV-optical continuum than the quasars of similar radio power. (abrigded)Comment: 10 pages, 6 figures, Late
On the constraining observations of the dark GRB 001109 and the properties of a z = 0.398 radio selected starburst galaxy contained in its error box
We present optical and NIR (near infrared) follow up observations of the GRB
001109 from 1 to 300 days after the burst. No transient emission was found at
these wavelengths within this GRB's (Gamma Ray Burst) 50" radius BeppoSAX error
box. Strong limits (3 sigma) are set with: R >~ 21, 10.2 hr after the GRB; I >~
23, 11.4 hr after the GRB; H >~ 20.7, 9.9 hr after the GRB; and Ks >~ 20, 9.6
hours after the GRB. We discuss whether the radio source found in the GRB's
error box (Taylor et al. 2000) might be related to the afterglow. We also
present a multiwavelength study of a reddened starburst galaxy, found
coincident with the potential radio and the X ray afterglow. We show that our
strong I band upper limit makes of the GRB 001109 the darkest one localised by
the BeppoSAX's NFI (Narrow Field Instrument), and it is one of the most
constraining upper limits on GRB afterglows to date. Further to it, the
implications of these observations in the context of dark GRBs are considered.Comment: 7 pages, 5 figures, accepted for publication in A&
A very young star forming region detected by the ISOPHOT Serendipity Survey
We present a multi-wavelength study of the star forming region ISOSS J
20298+3559, which was identified by a cross-correlation of cold compact sources
from the 170 micron ISOPHOT Serendipity Survey (ISOSS) database coinciding with
objects detected by the MSX, 2MASS and IRAS infrared surveys. ISOSS J
20298+3559 is associated with a massive dark cloud complex (M ~ 760
M) and located in the Cygnus X giant molecular cloud. We derive a
distance of 1800 pc on the basis of optical extinction data. The low average
dust temperature (T ~ 16 K) and large mass (M ~ 120 M) of the dense
inner part of the cloud, which has not been dispersed, indicates a recent begin
of star formation. The youth of the region is supported by the early
evolutionary stage of several pre- and protostellar objects discovered across
the regio n: I) Two candidate Class 0 objects with masses of 8 and 3.5
M, II) a gravitationally bound, cold (T ~ 12 K) and dense (n(H)
\~ 2 x 10 cm) cloud core with a mass of 50 M and III) a
Herbig B2 star with a mass of 6.5 M and a bolometric luminosity of
2200 L, showing evidence for ongoing accretion and a stellar age of
less than 40000 years. The dereddened SED of the Herbig star is well reproduced
by an accretion disc + star model. The externally heated cold cloud core is a
good candidate for a massive pre-protostellar object. The star formation
efficiency in the central cloud region is about 14 %.Comment: 14 pages, 14 figures, 7 tables. Accepted for publication in Astronomy
& Astrophysic
Secondary Metabolites of Marine Microbes: From Natural Products Chemistry to Chemical Ecology
Marine natural products (MNPs) exhibit a wide range of pharmaceutically relevant bioactivities, including antibiotic, antiviral, anticancer, or anti-inflammatory properties. Besides marine macroorganisms such as sponges, algae, or corals, specifically marine bacteria and fungi have shown to produce novel secondary metabolites (SMs) with unique and diverse chemical structures that may hold the key for the development of novel drugs or drug leads. Apart from highlighting their potential benefit to humankind, this review is focusing on the manifold functions of SMs in the marine ecosystem. For example, potent MNPs have the ability to exile predators and competing organisms, act as attractants for mating purposes, or serve as dye for the expulsion or attraction of other organisms. A large compilation of literature on the role of MNPs in marine ecology is available, and several reviews evaluated the function of MNPs for the aforementioned topics. Therefore, we focused the second part of this review on the importance of bioactive compounds from crustose coralline algae (CCA) and their role during coral settlement, a topic that has received less attention. It has been shown that certain SMs derived from CCA and their associated bacteria are able to induce attachment and/or metamorphosis of many benthic invertebrate larvae, including globally threatened reef-building scleractinian corals. This review provides an overview on bioactivities of MNPs from marine microbes and their potential use in medicine as well as on the latest findings of the chemical ecology and settlement process of scleractinian corals and other invertebrate larvae