Экологическая безопасность способов борьбы с вредителями и болезнями растений

Данная статья посвящена рассмотрению основных способов борьбы с вредителями и болезнями сельскохозяйственных культур, приводится их краткая сравнительная характеристика. На основе анализ литературных источников делается вывод о том, что оптимальным является использование интегрированной системы защиты растений в агропромышленном земледелии как наиболее экологически безопасной и эффективной. This article discusses the main ways of combating pests and diseases of agricultural crops, provides a brief comparative characteristics. Based on the literature analysis it is concluded that the optimum integrated system of plant protection in the agricultural agriculture as the most environmentally safe and effective

Entscheidungsstrukturen in Schulen. Eine differenzielle Analyse der Schulorganisation

Vor dem Hintergrund der Diskussion um die Einzelschule als Gestaltungseinheit werden Ergebnisse aus einem empirischen Forschungsprojekt vorgestellt, in dem die Entscheidungsstrukturen von Schulen Gegenstand einer explorativen Analyse sind. Ziel der Analyse ist eine differenzierende Darstellung von Strukturmustern der Schulorganisation, in denen die Perspektiven von Lehrern und Schulleitern berücksichtigt werden. Die Ergebnisse bieten einen Ausgangspunkt für multidimensionale Modellierungen der Schulorganisation. (DIPF/Orig.)Against the background of the debate on the individual school as organizational unit, the author presents results of an empirical research project focussing on an explorative analysis of decision-structures in schools. This analysis aims at a discriminative outline of structural patterns of school organization which take into account the perspectives of both teachers and principals. The results provide a starting point for a multi-dimensional modeling of school organization. (DIPF/Orig.

Vergleichende Bewertung von Elutionsverfahren für die Beurteilung des Auslaugverhaltens organischer Stoffe aus Böden

Es wurde eine vergleichende Bewertung der Ergebnisse von Schüttel- und Säulenverfahren als Übereinstimmungstest für die Untersuchung des Auslaugverhaltens von organischen Schadstoffen aus Böden vorgenommen. Dafür wurden die Ergebnisse von Ringversuchen zur Validierung der entsprechenden Elutionsverfahren genutzt. Der Methodenvergleich zeigte, dass keine signifikanten Unterschiede zwischen den Ergebnissen beider Elutionsverfahren beobachtet wurden. Es wurden beim Schüttelverfahren tendenziell etwas geringere Gesamtmittelwerte der Ringversuchsteilnehmer als beim Säulenverfahren erzielt

Biological and Pharmacokinetic Studies with β-Peptides

Interactions and cleavage reactions of β-amino acids and β-oligopeptides (up to nine residues, carrying the side chains of Ala, Val, Leu, Ile, Phe, Ser, Lys, and Hop) with biological systems, such as the most potent peptidases (pronase, proteinase K, 20S proteasome), microorganisms (Pseudomonas aeruginosa and Pseudomonas putida), and mammalian blood (intravenous application to rats) have been investigated and compared with ?-peptides. The results are: i) the three peptidases do not cleave β-peptides at all (within 24 h), and they are not inhibited by a β-peptide; ii) except for certain 3-aminobutanoic-acid (β-HAla) derivatives, neither free, nor N-acetyl-β-amino acids, nor β-peptides (offered as sole N and C source) lead to growth of the two bacteria tested; iii) two water-soluble β-heptapeptides (with Lys side chains) were shown to have elimination half-lives t1/2(β) of 3 and 10 h at 100- and 30-ng/ml levels, respectively, in the rodent blood – much larger than those of α-peptides. Thus, the preliminary results described here confirm the much greater stability of β-peptides, as compared to α-peptides, towards metabolization processes, but they also suggest that there may be interactions (by hitherto unknown mechanisms) between the worlds of α- and β-peptides

Element-specific magnetization dynamics of complex magnetic systems probed by ultrafast magneto-optical spectroscopy

The vision to manipulate and control magnetism with light is driven on the one hand by fundamental questions of direct and indirect photon-spin interactions, and on the other hand by the necessity to cope with ever growing data volumes, requiring radically new approaches on how to write, read and process information. Here, we present two complementary experimental geometries to access the element-specific magnetization dynamics of complex magnetic systems via ultrafast magneto-optical spectroscopy in the extreme ultraviolet spectral range. First, we employ linearly polarized radiation of a free electron laser facility to demonstrate decoupled dynamics of the two sublattices of an FeGd alloy, a prerequisite for all-optical magnetization switching. Second, we use circularly polarized radiation generated in a laboratory-based high harmonic generation setup to show optical inter-site spin transfer in a CoPt alloy, a mechanism which only very recently has been predicted to mediate ultrafast metamagnetic phase transitions. © 2020 by the authors. Licensee MDPI, Basel, Switzerland

Ultrafast opto-magnetic effects in the extreme ultraviolet spectral range

Coherent light-matter interactions mediated by opto-magnetic phenomena like the inverse Faraday effect (IFE) are expected to provide a non-thermal pathway for ultrafast manipulation of magnetism on timescales as short as the excitation pulse itself. As the IFE scales with the spin-orbit coupling strength of the involved electronic states, photo-exciting the strongly spin-orbit coupled core-level electrons in magnetic materials appears as an appealing method to transiently generate large opto-magnetic moments. Here, we investigate this scenario in a ferrimagnetic GdFeCo alloy by using intense and circularly polarized pulses of extreme ultraviolet radiation. Our results reveal ultrafast and strong helicity-dependent magnetic effects which are in line with the characteristic fingerprints of an IFE, corroborated by ab initio opto-magnetic IFE theory and atomistic spin dynamics simulations

Impact of simulated sunlight on the degradation of pendimethalin in surface water in a scale-up experiment in accordance to OECD TG 309

BACKGROUND: OECD TG 309 “Aerobic Mineralisation in Surface Water” (OECD Test Guideline 309 (2004)) is currently used in regulation for the assessment of the persistence of chemicals in surface water. The test is performed in a batch under defined conditions. Processes which might be relevant for the fate of a chemical in surface water like direct and indirect photolysis are not addressed. In order to study the impact of sunlight on the fate in surface water, pendimethalin, a herbicidal active substance with known sensitivity to aqueous photolysis, was used. This was tested in an experiment based on OECD 309, but scaled up to 900 L size with a 1.40 m water column and irradiated with special lamps in order to monitor the fate of the substance at different water depths, in comparison to dark controls. RESULTS: Pendimethalin degraded significantly under the applied test conditions. The test setups with exposure to simulated sunlight showed a significant faster degradation compared to the dark experiments. Application of 900 g sediment (1% of test system) to the test system further increased the degradation rate. In the simulated sunlight setups a faster degradation was observed in the upper water layer, hence, the concentration of the photolysis products were highest in the upper water layer, where the highest light intensity was measured. With decreasing light intensity in deeper water layers photolysis products were still detected at a water depth of 125 cm. Mineralisation up to 22% of the applied radioactivity was observed. In the dark controls neither significant amounts of photolysis products nor any mineralisation were detected. Among the different sampling depths no significant differences were observed. It was further observed that the dark controls became anaerobic at the end of the incubation time. This has been observed previously in standard laboratory tests according to OECD 309. CONCLUSIONS: The study proves that for a substance sensitive to photolysis like pendimethalin, exposure to simulated sunlight leads to a significantly reduced degradation half-life (DegT₅₀) in surface water compared to the dark control. In the standard test according to OECD guideline 309 the influence of photolytical degradation is not considered and thus the laboratory test can lead to the overestimation of the persistence of a chemical in surface water and consequently to a false-positive evaluation in the overall PBT assessment (ECHA Guidance on Information Requirements and Chemical Safety Assessment 2004), when only the results of the standard OECD 309 study are considered

Cationic polyacrylamide copolymers (PAMs): environmental half life determination in sludge-treated soil

Abstract Background Cationic polyacrylamide copolymers (PAMs) are used for sludge dewatering in municipal waste water treatment and might enter the environment by spreading of the sludge on agricultural land. Concern has been expressed since little is known about the degradation of PAMs in soils. To obtain detailed information on the polymer’s fate in the soil compartment, the degradation of 14C-radiolabelled PAM in an outdoor lysimeter was studied. Results No plant uptake and leaching of radioactivity was observed. There was practically no vertical movement of polymer and no transformation products found at the end of the study. For the top 10 cm soil layer, a mass balance was established throughout the study. About 10% of applied radioactivity was not extractable from soil even with a matrix destructive method, and this was concluded to be bound residue. Characterization of extractable radioactivity by means of GPC-analysis showed a significant decrease of the molecular weight of the PAM with time. The decrease in molecular weight indicates a breakdown of the polymer backbone (the C–C-chain), and is assumed to be primary degradation. The total radioactivity content in the 10 cm top soil layer was quantified every 6 months over a period of 3 years. The results show a significant decrease of the total radioactivity over time and this is defined as ultimate degradation following the definition of OECD and EPA. Based on the data, a half-life time of 2.0 × 103 days and a rate constant of 0.00035/day were calculated. With a χ 2 of 12.0 the results of the calculation are thus valid and reliable. The rate constant indicates a mineralization of 22.5% within a period of 2 years based on the total recovered radioactivity. This half-life time is solely based on mineralization and does not take into account the degradation of the polymer backbone, hydrolysis of the side chains, incorporation into the soil matrix, and thus is a conservative approach. Conclusions 14C-PAM degrades very slowly in soil after land-spreading as a component of sewage sludge. Even in a very conservative evaluation which only considered the loss of radioactivity, a half-life time of 5.4 years was determined