On the Optimality of Joint Taxation for Non-Cooperative Couples

We present a non-cooperative model of a family’s time allocation between work and a home-produced public good, and examine whether the income tax should apply to couples or individuals. While tax-induced labor supply distortions lead to overprovision of the public good, spouses’ failure to internalize the collective effect of their choices points towards underprovision. A large parameter range exists for which a move from individual to joint taxation improves the welfare of both spouses. The source of Pareto-improvement consists in moving the level of the public good closer to its first-best, while an adjustment of intra-family transfers compensates the secondary earner for the increased tax load.individual taxation, joint taxation, household production, public goods

Experimental salt marsh islands: a model system for novel metacommunity experiments

Shallow tidal coasts are characterised by shifting tidal flats and emerging or eroding islands above the high tide line. Salt marsh vegetation colonising new habitats distant from existing marshes are an ideal model to investigate metacommunity theory. We installed a set of 12 experimental salt marsh islands made from metal cages on a tidal flat in the German Wadden Sea to study the assembly of salt marsh communities in a metacommunity context. Experimental plots at the same elevation were established within the adjacent salt marsh on the island of Spiekeroog. For both, experimental islands and salt marsh enclosed plots, the same three elevational levels were realised while creating bare patches open for colonisation and vegetated patches with a defined transplanted community. One year into the experiment, the bare islands were colonised by plant species with high fecundity although with a lower frequency compared to the salt marsh enclosed bare plots. Initial plant community variations due to species sorting along the inundation gradient were evident in the transplanted vegetation. Competitive exclusion was not observed and is only expected to unfold in the coming years. Our study highlights that spatially and temporally explicit metacommunity dynamics should be considered in salt marsh plant community assembly and disassembly

Entwicklung eines Anforderungsprofils für Kontrolleure im Rahmen des Kontrollsystems nach der EU-Verordnung 2092/91

Ziel der Studie ist es, das Anforderungsprofil für Kontrolleure auf der Grundlage der EU-Öko-Verordnung 2092/91 für die unterschiedlichen Kontrollbereiche zu ermitteln. Grundlage dafür bilden die Analyse der Tätigkeiten von Kontrolleuren aufgegliedert nach Branchen in die verschiedenen Kontrollbereiche Landwirtschaft, Verarbeitung und Import aus Drittländern. Ergänzend wurde erfasst, welche Anforderungen in anderen Kontroll- und Qualitätssicherungsnormen und -verordnungen an das Kontroll- bzw. Auditpersonal gestellt werden. Ableitend von diesen Analysen wurde das Anforderungsprofil für die drei Kontrollbereiche erstellt. Das Anforderungsprofil gliedert sich in vier Teile: die persönliche Qualifikation (in Anlehnung an ISO 10011), die Basisqualifikation (mündliche und schriftliche Kommunikation, Kalkulation, Berufserfahrung), die fachliche Qualifikation, die sich je nach Kontrollbereich unterscheidet sowie die Kenntnisse der gesetzlichen Regelungen. Für jeden Baustein im Anforderungsprofil wurde abgeleitet, mit welcher Berufsausbildung, Trainingsmaßnahme o.ä. diese Qualifikation erreicht und wie sie nachgewiesen werden kann. In diesem Zusammenhang wurde auch das in Deutschland übliche Zulassungsverfahren für Kontrollpersonal diskutiert. Die Verordnung (EWG) 2092/91 sowie der ergänzend geltenden EN 45011 enthält keine Vorgaben, welche die Zulassung von Kontrolleuren durch Aufsichtsbehörden vor dem Einsatz erforderlich machen. Es muss allerdings im Rahmen der Überwachung der Kontrollstellen überprüft werden, ob die Kontrollstellen über sachgerechte Personalkriterien, ein angemessenes dokumentiertes Verfahren für die Auswahl des Personals sowie individuelle Leistungsbeurteilungen verfügen und das Personal angemessen aus- und fortbilden. Eine Umfrage bei den Kontrollstellen im deutschsprachigen Raum erfasste die derzeitigen Aus- und Fortbildungsmaßnahmen für Kontrollpersonal. Auf Grundlage der Auswertung der Tätigkeitsanalysen und der Rückmeldungen der Kontrollstellen wurde festgestellt, dass Bedarf an einem kontrollstellenüber-greifenden Fortbildungsangebot besteht, das sich vor allem auf die Spezialbereiche im Kontrollsystem konzentriert (z.B. Umgang mit schwierigen Kontrollsituationen, Aktuelle Änderungen der VO 2092/91, Hofverarbeitung, Rückstandsanalytik und Probenahmeverfahren, Importkontrolle)

The anxiolytic effects of a Valerian extract is based on Valerenic acid

BACKGROUND: Valerian is commonly used for the treatment of insomnia and anxiety. Valerian extracts allosterically modulate GABA-A receptors and induced an anxiolytic activity. This activity is closely related to valerenic acid. In the present experiments it was investigated whether acetoxy valerenic acid may interfere with the anxiolytic action of valerenic acid. METHODS: Situational anxiety was measured using male CD-1 mice in the elevated plus maze test after oral administration of the test substances. In addition the body core temperature was measured. For the (3)H-GABA binding assay dissected tissue from frontal cortex of male RjHan:WI rats were used. Statistical evaluation was performed by means of the non-parametric Kruskal-Wallies H-test, followed by the two-tailed Mann–Whitney U-test. RESULTS: Adding of acetoxy valerenic acid abolished the anxiolytic action of valerenic acid. There was no effect on body core temperature. Moreover, the valerian extract did not show any affinity to benzodiazepine binding sites. CONCLUSION: The determining compound for the observed anxiolytic effect of the valerian extract is its content of valerenic acid

High Diversity of Diazotrophs in the Forefield of a Receding Alpine Glacier

Forefields of receding glaciers are unique and sensitive environments representing natural chronosequences. In such habitats, microbial nitrogen fixation is of particular interest since the low concentration of bioavailable nitrogen is one of the key limitations for growth of plants and soil microorganisms. Asymbiotic nitrogen fixation in the Damma glacier (Swiss Central Alps) forefield soils was assessed using the acetylene reduction assay. Free-living diazotrophic diversity and population structure were resolved by assembling four NifH sequence libraries for bulk and rhizosphere soils at two soil age classes (8- and 70-year ice-free forefield). A total of 318 NifH sequences were analyzed and grouped into 45 unique phylotypes. Phylogenetic analyses revealed a higher diversity as well as a broader distribution of NifH sequences among phylogenetic clusters than formerly observed in other environments. This illustrates the importance of free-living diazotrophs and their potential contribution to the global nitrogen input in this nutrient-poor environment. NifH diversity in bulk soils was higher than in rhizosphere soils. Moreover, the four libraries displayed low similarity values. This indicated that both soil age and the presence of pioneer plants influence diversification and population structure of free-living diazotroph

The BBCH system to coding the phenological growth stages of plants – history and publications –

Die Entwicklungsstadien der wichtigsten Kulturpflanzen wurden in den vergangenen 19 Jahren von zahlreichen Wissenschaftlern nach den Prinzipien der erweiterten BBCH-Skala beschrieben. Die BBCH-Skalen sind inzwischen weltweit bekannt und werden von Wissenschaft, Administration und Praxis in Landwirtschaft und Gartenbau ebenso genutzt, wie in der Phänologie als integrative Wissenschaft im Bereich Umwelt, Meteorologie und Klimatologie. Diese Tatsache weist darauf hin, dass Zielsetzung und Hoffnung, die seit dem Beginn der Arbeit damit verbunden waren, sich erfüllt haben. Die BBCH-Skalen haben sich als hilfreich und praktisch erwiesen. Das Ziel, die Harmonisierung in der Anwendung von Dezimalcodes für die Beschreibung der phänologischen Entwicklungsstadien von Kulturpflanzen und Unkräutern herbeizuführen, wurde erreicht. Sie erfüllten auch die Hoffnung der Initiatoren, damit zur Verbesserung der internationalen agrarwissenschaftlichen und interdisziplinären Kommunikation beizutragen. In der vorliegenden Arbeit soll die Geschichte der BBCH-Skalen aufgezeigt werden, weil diese Einblick in die Hintergründe ihrer Entstehung und Entwicklung erlaubt. Alle Original-Publikationen werden mit ihren Literaturquellen zusammenfassend dargelegt. Die Arbeit soll die unterschiedliche Nutzung der BBCH-Skalen in den verschiedenen wissenschaftlichen Disziplinen dokumentieren. Es soll deutlich werden, dass der weltweite Erfolg der BBCH-Skalen vielen Wissenschaftlern rund um den Globus zu verdanken ist.The growth stages of development of many cultivated plants have been described by numerous scientists according to the principles of the extended BBCH scale within the last 19 years. The BBCH scales are now well- known worldwide and are used by research, administration and practise in agriculture and horticulture, as in the phenology as an integrative science in environment, meteorology and climatology. This fact indicates that the basic objectives and hope have been reached, justifying the practical approach taken by the authors of this scale. The BBCH scale is a contribution to improve the communication between different groups of scientists and to allow the interchange of data and scientific results in a transparent way. The BBCH scales have turned out helpful and practical. The aim to cause the harmonisation in the application of decimal codes for the description of the phenological growth stages of plants and weeds was reached. They also fulfilled the hope of the initiators to contribute with it to the improvement of the international agrarian-scientific and interdisciplinary communication. This paper will describe the history and background of the BBCH scales. The original publications are described and explained with reference of the original literature sources. The paper will describe the different area of use of the scales and list the different scientific disciplines using them. The worldwide success of the BBCH scales is the work of many scientists around the globe

Entanglement and correlation in anisotropic quantum spin systems

Analytical expressions for the entanglement measures concurrence, i-concurrence and 3-tangle in terms of spin correlation functions are derived using general symmetries of the quantum spin system. These relations are exploited for the one-dimensional XXZ-model, in particular the concurrence and the critical temperature for disentanglement are calculated for finite systems with up to six qubits. A recent NMR quantum error correction experiment is analyzed within the framework of the proposed theoretical approach.Comment: 8 pages, 3 figure

Genetic inactivation of the Fanconi anemia gene FANCC identified in the hepatocellular carcinoma cell line HuH-7 confers sensitivity towards DNA-interstrand crosslinking agents

Background: Inactivation of the Fanconi anemia (FA) pathway through defects in one of 13 FA genes occurs at low frequency in various solid cancer entities among the general population. As FA pathway inactivation confers a distinct hypersensitivity towards DNA interstrand-crosslinking (ICL)-agents, FA defects represent rational targets for individualized therapeutic strategies. Except for pancreatic cancer, however, the prevalence of FA defects in gastrointestinal (GI) tumors has not yet been systematically explored. Results: A panel of GI cancer cell lines was screened for FA pathway inactivation applying FANCD2 monoubiquitination and FANCD2/RAD51 nuclear focus formation and a newly identified FA pathway-deficient cell line was functionally characterized. The hepatocellular carcinoma (HCC) line HuH-7 was defective in FANCD2 monoubiquitination and FANCD2 nuclear focus formation but proficient in RAD51 focus formation. Gene complementation studies revealed that this proximal FA pathway inactivation was attributable to defective FANCC function in HuH-7 cells. Accordingly, a homozygous inactivating FANCC nonsense mutation (c.553C > T, p.R185X) was identified in HuH-7, resulting in partial transcriptional skipping of exon 6 and leading to the classic cellular FA hypersensitivity phenotype; HuH-7 cells exhibited a strongly reduced proliferation rate and a pronounced G2 cell cycle arrest at distinctly lower concentrations of ICL-agents than a panel of non-isogenic, FA pathway-proficient HCC cell lines. Upon retroviral transduction of HuH-7 cells with FANCC cDNA, FA pathway functions were restored and ICL-hypersensitivity abrogated. Analyses of 18 surgical HCC specimens yielded no further examples for genetic or epigenetic inactivation of FANCC, FANCF, or FANCG in HCC, suggesting a low prevalence of proximal FA pathway inactivation in this tumor type. Conclusions: As the majority of HCC are chemoresistant, assessment of FA pathway function in HCC could identify small subpopulations of patients expected to predictably benefit from individualized treatment protocols using ICL-agents