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

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

The moduli space of hypersurfaces whose singular locus has high dimension

Let $k$ be an algebraically closed field and let $b$ and $n$ be integers with $n\geq 3$ and $1\leq b \leq n-1.$ Consider the moduli space $X$ of hypersurfaces in $\mathbb{P}^n_k$ of fixed degree $l$ whose singular locus is at least $b$-dimensional. We prove that for large $l$, $X$ has a unique irreducible component of maximal dimension, consisting of the hypersurfaces singular along a linear $b$-dimensional subspace of $\mathbb{P}^n$. The proof will involve a probabilistic counting argument over finite fields.Comment: Final version, including the incorporation of all comments by the refere

Tone-activated, remote, alert communication system

Pocket sized transmitter, frequency modulated by crystal derived tones, with integral loop antenna provides police with easy operating alert signal communicator which uses patrol car radio to relay signal. Communication channels are time shared by several patrol units

Two-particle Hadamard walk on dynamically percolated line and circle

Asymptotic dynamics of a Hadamard walk of two non-interacting quantum particles on a dynamically percolated finite line or a circle is investigated. We construct a basis of the attractor space of the corresponding random-unitary dynamics and prove the completeness of our solution. In comparison to the one-particle case, the structure of the attractor space is much more complex, resulting in intriguing asymptotic dynamics. General results are illustrated on two examples. First, for circles of length not divisible by 4 the boundary conditions reduces the number of attractors considerably, allowing for fully analytic solution. Second, we investigate line of length 4 and determine the asymptotic cycle of reduced coin states and position distributions, focusing on the correlations between the two particles. Our results show that a random unitary evolution, which is a combination of quantum dynamics and a classical stochasticity, leads to correlations between initially uncorrelated particles. This is not possible for purely unitary evolution of non-interacting quantum particles. The shared dynamically percolated graph can thus be considered as a weak form of interaction

Software and Hardware Solutions for Channel Estimation based on Cyclic Golay Sequences

This paper presents channel estimation methods based on cyclic complementary Golay sequences. First, the conventional Golay correlator is investigated, then a frequency domain approach using Discrete Fourier Transform (DFT) is provided. A complex valued fast Golay correlator is introduced which can be used for the estimation of complex valued channel impulse response. Furthermore, this paper presents the Recursive DFT (R-DFT), a signal processing architecture which may be beneficial compared to the well-known Fast Fourier Transform (FFT). The R-DFT is able to efficiently calculate a point-by-point block spectra of the input signal, which makes it suitable for hardware implementation. Throughout the paper, the R-DFT is applied and it is compared to the conventional estimation methods. Finally, the efficiency of the proposed schemes is compared through simulations based on the 60 GHz WiGig and the COST 207 standard, applying various channel models

S-COL: A Copernican turn for the development of flexibly reusable collaboration scripts

Collaboration scripts are usually implemented as parts of a particular collaborative-learning platform. Therefore, scripts of demonstrated effectiveness are hardly used with learning platforms at other sites, and replication studies are rare. The approach of a platform-independent description language for scripts that allows for easy implementation of the same script on different platforms has not succeeded yet in making the transfer of scripts feasible. We present an alternative solution that treats the problem as a special case of providing support on top of diverse Web pages: In this case, the challenge is to trigger support based on the recognition of a Web page as belonging to a specific type of functionally equivalent pages such as the search query form or the results page of a search engine. The solution suggested has been implemented by means of a tool called S-COL (Scripting for Collaborative Online Learning) and allows for the sustainable development of scripts and scaffolds that can be used with a broad variety of content and platforms. The tool’s functions are described. In order to demonstrate the feasibility and ease of script reuse with S-COL, we describe the flexible re-implementation of a collaboration script for argumentation in S-COL and its adaptation to different learning platforms. To demonstrate that a collaboration script implemented in S-COL can actually foster learning, an empirical study about the effects of a specific script for collaborative online search on learning activities is presented. The further potentials and the limitations of the S-COL approach are discussed

Optimization of the Crest Factor for Complex-Valued Multisine Signals

Multisine signals are commonly used in the measurement of dynamic systems and wireless channels. For optimal measurements with a high dynamic range, a low Crest Factor (CF) excitation signal is required. In this paper, a modified approach to optimize the crest factor for complex-valued multisine signals is presented. The approach uses a nonlinear optimization method where the real and imaginary parts can also be optimized for low CF. Furthermore, extensions of the real-valued multisine CF optimization methods are presented for complex-valued cases. The proposed methods are validated and compared using simulations. Based on the results it is shown that the novel approach can lead to more optimal signal design and lower CF compared to other techniques for complex-valued multisine signals