The CAMP-binding Ectoprotein from Saccharomyces cereuisiae Is Membrane-anchored by Glycosyl-Phosphatidylinositol

Saccharomyces cerevisiae contains an amphiphilic CAMP-binding glycoprotein at the outer face of the plasma membrane (M, = 54,000). It is converted to a hydrophilic form byt reatment withg lycosyl-phosphatidylinositol- specific phospholipases C and D (GPIPLC/ D), suggesting membrane anchorage by a covalently bound glycolipid. Determination of the constituents of the purified anchor by gas-liquid chromatography and amino acid analysis reveals the presence of glycerol, myo-inositol, glucosamine, galactose, mannose, ethanolamine, and asparagine (as the carboxylterminal amino acido f the Pronase-digested proteitno which the anchor is attached). Complementary results are obtained by metabolic labeling, indicating that fatty acids and phosphorus are additional anchor constituents. The phosphoruiss resistant to alkalinep hosphatase, whereas approximately half is lost from the protein after treatment with GPI-PLD or nitroaucisd , and all is removed by aqueous HF indicating the presence of two phosphodiester bonds. Inhibition of Nglycosylation by tunicamycin or removal of proteinbound glycan chains by N-glycanase or Pronase does not abolish radiolabeling of the anchor structure by any of the above compounds. Analysis of the products obtained after sequential enzymic and chemical degradation of the anchor agrees with the arrangemoefn t constitutents in GPIs from higher eucaryotes. Evidence for anchorage of the yeast CAMP-binding protein by a GPI anchoris strengthened additionallyb y the reactivity of the GPI-PLC-cleaved anchor with antibodies directed against the cross-reacting determinoaf nttr ypanosomal variant surface glycoproteins

Vertices of Lie Modules

Let Lie(n) be the Lie module of the symmetric group S_n over a field F of characteristic p>0, that is, Lie(n) is the left ideal of FS_n generated by the Dynkin-Specht-Wever element. We study the problem of parametrizing non-projective indecomposable summands of Lie(n), via describing their vertices and sources. Our main result shows that this can be reduced to the case when n is a power of p. When n=9 and p=3, and when n=8 and p=2, we present a precise answer. This suggests a possible parametrization for arbitrary prime powers.Comment: 26 page

Trading schemes for greenhouse gas emissions from European agriculture: A comparative analysis based on different implementation options

A rational negotiation strategy for coming multilateral negotiations regarding climate change requires knowledge about possible social, economic and environmental effects of policy instruments for the abatement of greenhouse gas emissions. With this purpose, an agricultural sector model is expanded to cover greenhouse gas emissions from agricultural sources in Europe and policy instruments for their reduction. This modelling approach concentrates on the application of a permit trade scheme for emission abatement within the Kyoto Protocol ‘first commitment’ baseline. The effects derived of three alternative schemes are described in detail: the EU ‘burden sharing’ agreement option defined as regional emission standards, emission trading between regions inside each Member State, and finally, emission trading between all European regions. The analysis shows the importance of selecting an adequate combination of instruments of emission abatement for the design of efficient emission reduction policies.Kyoto Protocol, agricultural policy, economic modelling, tradable emission permits

Pitfalls and potential of institutional change: Rain-index insurance and the sustainability of rangeland management

Rain-index insurance is strongly advocated in many parts of the developing world to help farmers to cope with climatic risk that prevail in (semi-)arid rangelands due to low and highly uncertain rainfall. We present a modeling analysis of how the availability of rain-index insurance affects the sustainability of rangeland management. We show that a rain-index insurance with frequent payos, i.e. a high strike level, leads to the choice of less sustainable grazing management than without insurance available. However, a rain-index insurance with a low to medium strike level enhances the farmer's well-being while not impairing the sustainability of rangeland management.ecological-economic modeling, weather-index insurance, Namibia, grazing management, risk, sustainability, weather-based derivatives

Relating the philosophy and practice of ecological economics: The role of concepts, models, and case studies in inter- and transdisciplinary sustainability research

We develop a comprehensive multi-level approach to ecological economics (CML-approach) which integrates philosophical considerations on the foundations of ecological economics with an adequate operationalization. We argue that the subject matter and aims of ecological economics require a specific combination of inter- and transdisciplinary research, and discuss the epistemological position on which this approach is based. In accordance with this understanding of inter- and transdisciplinarity and the underlying epistemological position, we develop an operationalization which comprises simultaneous analysis on three levels of abstraction: concepts, models and case studies. We explain these levels in detail, and, in particular, deduce our way of generic modeling in this context. Finally, we illustrate the CML-approach and demonstrate its fruitfulness by the example of the sustainable management of semi-arid rangelands. --ecological economics,interdisciplinarity,philosophy of science,transdisciplinarity

Modulation of pancreatic islet allo immunogenicity and immunobiological in vitro and in vivo consequences

No abstract available

Pharmakologische Beeinflussung natürlicher Antikörper als Vorbedingung für die erfolgreiche Xenotransplantation

No abstract available

Sols, végétation et occupation du sol dans la région de la Chaîne de Gobnangou

Située dans l'extrême sud-est de Burkina Faso, la Chaîne grèseuse de Gobnangou se détache du reste du paysage par d'abruptes falaises. Autant les terres au nord que celles au sud sont exceptionnellement densément peuplées. Les Gulmances qui y vivent font de l'agriculture itinérante. Les périodes de cultures varient selon la qualité du sol de 5 à 20 ans. Les périodes de jachères pour la régénération des sols varient énormément selon les types de sols et l'intensité de l'utilisation précédente et peuvent aller jusqu'à 30 ans. Mais ici aussi, l'explosion démographique entraîne une diminution du temps de jachères. L'aspect de la végétation et sa composition diffèrent beaucoup et dépendent de nombreux facteurs. Ils sont surtout influencés par l'homme: outre l'agriculture itinérante, le pâturage, la coupe du bois de chauffage et les feux peuvent être citer. On decrirá ici les communautés de végétations de deux types de sites qui ont pour point commun d'être portées par des sols pauvres. La principale différence entre ces types de sites est la profondeur des sols et donc leur ressources en eau