Investigations on alternative substances for control of apple scab - results from sanitation trials

The intention of this research project, which was supported within the "Bundesprogramm Ökologischer Landbau", was to look for alternatives in organic fruit growing to control apple scab, Venturia inaequalis. One important part of the investigations was the application of different substances like microbiological nutrient media, enzymes usually used for production of fruit juices and organic fertilizers on their effect on the ascospore potential on depots of fallen leaves. Some substances like TRYPTIC SOY BROTH increased the decomposition of the leaves significantly, other like BACTOFIL B and HUMOFIX showed nearly no effect on the decomposition, but reduced the ascospore potential in early spring by 80 % compared to the untreated control

Investigations on alternative substances for control of apple scab - Results from Conidia germinating tests and experiments with plant extracts

The intention of this research project, which was supported within the "Bundesprogramm Ökologischer Landbau", was to find alternatives for the control of Venturia inaequalis for the organic fruitgrower. Beside the investigations on reducing the ascospore potential on fallen leaves, experiments were conducted in laboratory, greenhouses and in orchard to test direct control of scab with different plant extracts, concentrations and methods of extraction. Extracts from Inula viscosa, Quillaja saponaria-bark, citrus-species (AGROMIL) and Saponaria officinalis revealed a distinct efficacy against apple scab in greenhouse studies on apple seedlings. ELOT-VIS, CHITOPLANT, COMCAT, MOOSEXTRAKT, SILIOPLANT und FZB 24 did not show sufficient efficacy with the application schedule used for control of scab. Mixtures of Quillaja-saponine and sulphur reduced effectively apple scab incidence. In an experiment concerning rain stability Citrus-extract and Quillaja-saponine showed a lower efficacy against scab after a simulated rain of 5 mm. The screening of different supplements to Citrus-extract as surfactants and adhesives revealed GREEMAX and BIOPLUSS as promising additives. Both combinations showed an efficacy comparable to copperoxychloride corresponding to 400 g elementary copper per ha

Coulomb Oscillations in Antidots in the Integer and Fractional Quantum Hall Regimes

We report measurements of resistance oscillations in micron-scale antidots in both the integer and fractional quantum Hall regimes. In the integer regime, we conclude that oscillations are of the Coulomb type from the scaling of magnetic field period with the number of edges bound to the antidot. Based on both gate-voltage and field periods, we find at filling factor {\nu} = 2 a tunneling charge of e and two charged edges. Generalizing this picture to the fractional regime, we find (again, based on field and gate-voltage periods) at {\nu} = 2/3 a tunneling charge of (2/3)e and a single charged edge.Comment: related papers at http://marcuslab.harvard.ed

High-Resolution Imaging and Optical Control of Bose-Einstein Condensates in an Atom Chip Magnetic Trap

A high-resolution projection and imaging system for ultracold atoms is implemented using a compound silicon and glass atom chip. The atom chip is metalized to enable magnetic trapping while glass regions enable high numerical aperture optical access to atoms residing in the magnetic trap about 100 microns below the chip surface. The atom chip serves as a wall of the vacuum system, which enables the use of commercial microscope components for projection and imaging. Holographically generated light patterns are used to optically slice a cigar-shaped magnetic trap into separate regions; this has been used to simultaneously generate up to four Bose-condensates. Using fluorescence techniques we have demonstrated in-trap imaging resolution down to 2.5 micronsComment: 4 pages, 5 figures, 12 reference

Full-field structured-illumination super-resolution X-ray transmission microscopy

Modern transmission X-ray microscopy techniques provide very high resolution at low and medium X-ray energies, but suffer from a limited field-of-view. If sub-micrometre resolution is desired, their field-of-view is typically limited to less than one millimetre. Although the field-of-view increases through combining multiple images from adjacent regions of the specimen, so does the required data acquisition time. Here, we present a method for fast full-field super-resolution transmission microscopy by structured illumination of the specimen. This technique is well-suited even for hard X-ray energies above 30 keV, where efficient optics are hard to obtain. Accordingly, investigation of optically thick specimen becomes possible with our method combining a wide field-of-view spanning multiple millimetres, or even centimetres, with sub-micron resolution and hard X-ray energies

Dynamics of African swine fever virus shedding and excretion in domestic pigs infected by intramuscular inoculation and contact transmission

African swine fever virus (ASFV) is a highly virulent swine pathogen that has spread across Eastern Europe since 2007 and for which there is no effective vaccine or treatment available. The dynamics of shedding and excretion is not well known for this currently circulating ASFV strain. Therefore, susceptible pigs were exposed to pigs intramuscularly infected with the Georgia 2007/1 ASFV strain to measure those dynamics through within- and between-pen transmission scenarios. Blood, oral, nasal and rectal fluid samples were tested for the presence of ASFV by virus titration (VT) and quantitative real-time polymerase chain reaction (qPCR). Serum was tested for the presence of ASFV-specific antibodies. Both intramuscular inoculation and contact transmission resulted in development of acute disease in all pigs although the experiments indicated that the pathogenesis of the disease might be different, depending on the route of infection. Infectious ASFV was first isolated in blood among the inoculated pigs by day 3, and then chronologically among the direct and indirect contact pigs, by day 10 and 13, respectively. Close to the onset of clinical signs, higher ASFV titres were found in blood compared with nasal and rectal fluid samples among all pigs. No infectious ASFV was isolated in oral fluid samples although ASFV genome copies were detected. Only one animal developed antibodies starting after 12 days post-inoculation. The results provide quantitative data on shedding and excretion of the Georgia 2007/1 ASFV strain among domestic pigs and suggest a limited potential of this isolate to cause persistent infection

Current-induced nuclear-spin activation in a two-dimensional electron gas

Electrically detected nuclear magnetic resonance was studied in detail in a two-dimensional electron gas as a function of current bias and temperature. We show that applying a relatively modest dc-current bias, I_dc ~ 0.5 microAmps, can induce a re-entrant and even enhanced nuclear spin signal compared with the signal obtained under similar thermal equilibrium conditions at zero current bias. Our observations suggest that dynamic nuclear spin polarization by small current flow is possible in a two-dimensional electron gas, allowing for easy manipulation of the nuclear spin by simple switching of a dc current.Comment: 5 pages, 3 fig