Analyse des raum-zeitlichen Zusammentreffens von Amphibien und Landbewirtschaftung als Grundlage für die Ableitung von Strategien zum Amphibienschutz in kleingewässerreichen Ackerbaugebieten

Zusammenfassung Ein großer Teil der Schutzgebiete für gefährdete Amphibienarten (z.B. Kammmolch, Rotbauchunke) befindet sich innerhalb intensiv genutzter Ackerbaugebiete. Das bedeutet, dass die Amphibien auch Ackerflächen für ihre Wanderungen im Frühjahr zu den Laichgewässern und im Spätsommer/Herbst zu den Winterquartieren sowie zwischenzeitlich bei Landaufenthalten nutzen und somit Gefahr laufen, durch landwirtschaftliche Bewirtschaftungsmaßnahmen geschädigt zu werden. In einem am Leibnitz-Zentrum für Agrarlandschaftsforschung durchgeführten Forschungsprojekt (2006-2008) wurden in einem ca. 1.300 ha großen Untersuchungsgebiet mit Hilfe von umfangreichen Amphibienfangeinrichtungen auf Ackerflächen das Raum-Zeit-Verhalten von Amphibienpopulationen, sowie die Bewirtschaftung der betreffenden Ackerflächen erforscht. Anhand der täglich ermittelten Individuen pro Fanggefäß konnten Rückschlüsse auf die Aktivitätsphasen von Amphibien auf Ackerflächen gezogen werden, welche die Grundlage für die Untersuchung der Wahrscheinlichkeit des Zusammentreffens von Amphibien mit landwirtschaftlichen Bewirtschaftungsmaßnahmen bildeten. Es wurde festgestellt, dass Maßnahmen der Bodenbearbeitung die höchste zeitliche Übereinstimmung mit der Aktivität juveniler Tiere haben, die Aktivität adulter Tiere fiel hingegen zeitlich oft mit Maßnahmen des Pflanzenschutzes zusammen. Anhand der Ergebnisse lassen sich Strategien für die Integration des Amphibienschutzes in die ackerbauliche Nutzung ableiten, welche die kurzfristige Unterlassung bestimmter Bewirtschaftungsmaßnahmen in Problemarealen beinhalten, ohne dabei das Betriebsergebnis zu beeinträchtigen. Die dargestellten Untersuchungen bilden die Grundlage für witterungsbasierte Prognosemodelle über das temporäre Auftreten von Amphibienarten auf Ackerflächen. Strategien für die Integration des Amphibienschutzes in die ackerbauliche Nutzung ableiten, welche die kurzfristige Unterlassung bestimmter Bewirtschaftungsmaßnahmen in Problemarealen beinhalten, ohne dabei das Betriebsergebnis zu beeinträchtigen. Die dargestellten Untersuchungen bilden die Grundlage für witterungsbasierte Prognosemodelle über das temporäre Auftreten von Amphibienarten auf Ackerflächen

2-Amino-4-aryl-5-oxo-4,5-dihydropyrano[3,2-c]chromene-3-carbonitriles with Microtubule-Disruptive, Centrosome-Declustering, and Antiangiogenic Effects in vitro and in vivo

A series of fifteen 2‐amino‐4‐aryl‐5‐oxo‐4,5‐dihydropyrano[3,2‐c]chromene‐3‐carbonitriles (1 a–o) were synthesized via a three‐component reaction of 4‐hydroxycoumarin, malononitrile, and diversely substituted benzaldehydes or pyridine carbaldehydes. The compounds were tested for anticancer activities against a panel of eight human tumor cell lines. A few derivatives with high antiproliferative activities and different cancer cell specificity were identified and investigated for their modes of action. They led to microtubule disruption, centrosome de‐clustering and G2/M cell cycle arrest in 518 A2 melanoma cells. They also showed anti‐angiogenic effects in vitro and in vivo

Inhibition of retrogressive reactions in coal/petroleum co-processing

The overall objective of this project is to develop a fundamental understanding of the reactions occurring at the onset of coke formation during the co-processing of coals with petroleum residua. Specific objectives include examination of chemical components, or groups of components, in coals and petroleum feedstocks to quantify and rank the effects of these components in retarding or enhancement of coke formation. The work involves bench scale reactions in microautoclaves, supplemented by studies of the carbonaceous residues by such techniques as diffuse reflectance Fourier transform infrared spectroscopy and {sup 13}C nuclear magnetic resonance spectrometry. This quarter microautoclave testing of mixtures of model compounds and coal was concluded. In addition mixtures of coals and petroleum feedstocks were reacted under the same reaction conditions as used for the model compounds experiments. The petroleum resids were also independently tested in absence of coal. For a set of coal/resid feedstock pairs tests were performed in both horizontal and vertical microautoclaves in order to compare the mixing properties of these two different designs. 7 refs., 25 figs

Experimental and Modeling Investigation of the Effectof H2S Addition to Methane on the Ignition and Oxidation at High Pressures

The autoignition and oxidation behavior of CH₄/H₂S mixtures has been studied experimentally in a rapid compression machine (RCM) and a high-pressure flow reactor. The RCM measurements show that the addition of 1% H₂S to methane reduces the autoignition delay time by a factor of 2 at pressures ranging from 30 to 80 bar and temperatures from 930 to 1050 K. The flow reactor experiments performed at 50 bar show that, for stoichiometric conditions, a large fraction of H₂S is already consumed at 600 K, while temperatures above 750 K are needed to oxidize 10% methane. A detailed chemical kinetic model has been established, describing the oxidation of CH₄ and H₂S as well as the formation and consumption of organosulfuric species. Computations with the model show good agreement with the ignition measurements, provided that reactions of H₂S and SH with peroxides (HO₂ and CH₃OO) are constrained. A comparison of the flow reactor data to modeling predictions shows satisfactory agreement under stoichiometric conditions, while at very reducing conditions, the model underestimates the consumption of both H₂S and CH₄. Similar to the RCM experiments, the presence of H₂S is predicted to promote oxidation of methane. Analysis of the calculations indicates a significant interaction between the oxidation chemistry of H₂S and CH₄, but this chemistry is not well understood at present. More work is desirable on the reactions of H₂S and SH with peroxides (HO₂ and CH₃OO) and the formation and consumption of organosulfuric compounds

Effects of low-temperature catalytic pretreatments on coal structure and reactivity in liquefaction. Technical progress report, July--September 1993

In this quarter, progress has been made in the following two aspects: (1) spectroscopic and chemical reaction studies on the effects of drying and mild oxidation of a Wyodak subbituminous coal on its structure and pretreatment/liquefaction at 350{degrees}C; and (2) effects of dispersed catalyst and solvent on conversion and structural changes of a North Dakota lignite. Drying and oxidation of Wyodak subbituminous coal at 100-150{degrees}C have been shown to have significant effects on its structure and on its catalytic and non-catalytic low-severity liquefaction at 350{degrees}C for 30 min under 6.9 MPa H{sub 2}. Spectroscopic analyses using solid-state {sup 13}C NMR, Pyrolysis-GC-MS, and FT-IR revealed that oxidative drying at 100-150{degrees}C causes the transformation of phenolics and catechol into other related structures (presumably via condensation) and high-severity air drying at 150{degrees}C for 20 h leads to disappearance of catechol-like structure. Increasing air drying time or temperature increases oxidation to form more oxygen functional groups at the expense of aliphatic carbons. Such a clearly negative impact of severe oxidation is considered to arise from significantly increased oxygen functionality which enhances the cross-link formation in the early stage of coal liquefaction. Physical, chemical, and surface physicochemical aspects of drying and oxidation and the role of water are also discussed. A North Dakota lignite (DECS-1) coal was studied for its behaviors in non-catalytic and catalytic liquefaction. Reactions were carried out at temperatures between 250 and 450{degrees}C. Regardless the reaction solvents and the catalyst being used, the optimum temperature was found to be 400{degrees}C. The donor solvent has a significant effect over the conversion especially at temperatures higher than 350{degrees}C

Advanced Thermally Stable Jet Fuels

The Penn State program in advanced thermally stable jet fuels has five components: 1) development of mechanisms of degradation and solids formation; 2) quantitative measurement of growth of sub-micrometer and micrometer-sized particles during thermal stressing; 3) characterization of carbonaceous deposits by various instrumental and microscopic methods; 4) elucidation of the role of additives in retarding the formation of carbonaceous solids; and 5) assessment of the potential of producing high yields of cycloalkanes and hydroaromatics from coal

Effects of low-temperature catalytic pretreatments on coal structure and reactivity in liquefaction

This work is a fundamental study of catalytic pretreatments as a potential preconversion step to low-severity liquefaction. The ultimate goal of this work is to provide the basis for the design of an improved liquefaction process and to facilitate our understanding of those processes that occur when coals are initially dissolved. The main objectives of this project are to study the effects of low-temperature pretreatments on coal structure and their impacts on the subsequent liquefaction. The effects of pretreatment temperatures, catalyst type, coal rank and influence of solvent will be examined. We have made significant progress in the following four aspects during this quarterly period: (1) influence of drying and oxidation of coal on the conversion and product distribution in catalytic liquefaction of Wyodak subbituminous coal using a dispersed catalyst; (2) spectroscopic characterization of dried and oxidized Wyodak coal and the insoluble residues from catalytic and thermal liquefaction; (3) the structural alteration of low-rank coal in low-severity liquefaction with the emphasis on the oxygen-containing functional groups; and (4) effects of solvents and catalyst dispersion methods in temperature-programmed and non-programmed liquefaction of three low-rank coals

Create a Consortium and Develop Premium Carbon Products from Coal

The objective of these projects was to investigate alternative technologies for non-fuel uses of coal. Special emphasis was placed on developing premium carbon products from coal-derived feedstocks. A total of 14 projects, which are the 2003 Research Projects, are reported herein. These projects were categorized into three overall objectives. They are: (1) To explore new applications for the use of anthracite in order to improve its marketability; (2) To effectively minimize environmental damage caused by mercury emissions, CO{sub 2} emissions, and coal impounds; and (3) To continue to increase our understanding of coal properties and establish coal usage in non-fuel industries. Research was completed in laboratories throughout the United States. Most research was performed on a bench-scale level with the intent of scaling up if preliminary tests proved successful. These projects resulted in many potential applications for coal-derived feedstocks. These include: (1) Use of anthracite as a sorbent to capture CO{sub 2} emissions; (2) Use of anthracite-based carbon as a catalyst; (3) Use of processed anthracite in carbon electrodes and carbon black; (4) Use of raw coal refuse for producing activated carbon; (5) Reusable PACs to recycle captured mercury; (6) Use of combustion and gasification chars to capture mercury from coal-fired power plants; (7) Development of a synthetic coal tar enamel; (8) Use of alternative binder pitches in aluminum anodes; (9) Use of Solvent Extracted Carbon Ore (SECO) to fuel a carbon fuel cell; (10) Production of a low cost coal-derived turbostratic carbon powder for structural applications; (11) Production of high-value carbon fibers and foams via the co-processing of a low-cost coal extract pitch with well-dispersed carbon nanotubes; (12) Use of carbon from fly ash as metallurgical carbon; (13) Production of bulk carbon fiber for concrete reinforcement; and (14) Characterizing coal solvent extraction processes. Although some of the projects funded did not meet their original goals, the overall objectives of the CPCPC were completed as many new applications for coal-derived feedstocks have been researched. Future research in many of these areas is necessary before implementation into industry

Analogs of the Catechol Derivative Dynasore Inhibit HIV-1 Ribonuclease H, SARS-CoV-2 nsp14 Exoribonuclease, and Virus Replication

Viral replication often depends on RNA maturation and degradation processes catalyzed by viral ribonucleases, which are therefore candidate targets for antiviral drugs. Here, we synthesized and studied the antiviral properties of a novel nitrocatechol compound (1c) and other analogs that are structurally related to the catechol derivative dynasore. Interestingly, compound 1c strongly inhibited two DEDD box viral ribonucleases, HIV-1 RNase H and SARS-CoV-2 nsp14 3′-to-5′ exoribonuclease (ExoN). While 1c inhibited SARS-CoV-2 ExoN activity, it did not interfere with the mRNA methyltransferase activity of nsp14. In silico molecular docking placed compound 1c in the catalytic pocket of the ExoN domain of nsp14. Finally, 1c inhibited SARS-CoV-2 replication but had no toxicity to human lung adenocarcinoma cells. Given its simple chemical synthesis from easily available starting materials, these results suggest that 1c might be a lead compound for the design of new antiviral compounds that target coronavirus nsp14 ExoN and other viral ribonucleases