The Cinchona Primary Amine-Catalyzed Asymmetric Epoxidation and Hydroperoxidation of α,β-Unsaturated Carbonyl Compounds with Hydrogen Peroxide

Using cinchona alkaloid-derived primary amines as catalysts and aqueous hydrogen peroxide as the oxidant, we have developed highly enantioselective Weitz–Scheffer-type epoxidation and hydroperoxidation reactions of α,β-unsaturated carbonyl compounds (up to 99.5:0.5 er). In this article, we present our full studies on this family of reactions, employing acyclic enones, 5–15-membered cyclic enones, and α-branched enals as substrates. In addition to an expanded scope, synthetic applications of the products are presented. We also report detailed mechanistic investigations of the catalytic intermediates, structure–activity relationships of the cinchona amine catalyst, and rationalization of the absolute stereoselectivity by NMR spectroscopic studies and DFT calculations

Exploring local knowledge and perceptions on zoonoses among pastoralists in northern and eastern Tanzania

Background: Zoonoses account for the most commonly reported emerging and re-emerging infectious diseases in Sub-Saharan Africa. However, there is limited knowledge on how pastoral communities perceive zoonoses in relation to their livelihoods, culture and their wider ecology. This study was carried out to explore local knowledge and perceptions on zoonoses among pastoralists in Tanzania. Methodology and principal findings: This study involved pastoralists in Ngorongoro district in northern Tanzania and Kibaha and Bagamoyo districts in eastern Tanzania. Qualitative methods of focus group discussions, participatory epidemiology and interviews were used. A total of 223 people were involved in the study. Among the pastoralists, there was no specific term in their local language that describes zoonosis. Pastoralists from northern Tanzania possessed a higher understanding on the existence of a number of zoonoses than their eastern districts' counterparts. Understanding of zoonoses could be categorized into two broad groups: a local syndromic framework, whereby specific symptoms of a particular illness in humans concurred with symptoms in animals, and the biomedical framework, where a case definition is supported by diagnostic tests. Some pastoralists understand the possibility of some infections that could cross over to humans from animals but harm from these are generally tolerated and are not considered as threats. A number of social and cultural practices aimed at maintaining specific cultural functions including social cohesion and rites of passage involve animal products, which present zoonotic risk. Conclusions: These findings show how zoonoses are locally understood, and how epidemiology and biomedicine are shaping pastoralists perceptions to zoonoses. Evidence is needed to understand better the true burden and impact of zoonoses in these communities. More studies are needed that seek to clarify the common understanding of zoonoses that could be used to guide effective and locally relevant interventions. Such studies should consider in their approaches the pastoralists' wider social, cultural and economic set up

Struktur und Entwicklung des spanischen Rindersektors einschliesslich der nachgelagerten Bereiche

.Detaillierte Untersuchung ueber die regionalen Betriebsgroessen und Betriebssysteme der Rinderproduktion in Spanien sowie eine genaue Beschreibung der vorhandenen technischen, wirtschaftlichen und organisatorischen Zusammenhaenge, die Ansatzpunkte fuer eine Beurteilung der zukuenftigen Entwicklung liefern koennenAvailable from: Kiel Univ. (Germany, F.R.). Universitaetsbibliothek / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Asymmetric Counteranion-Directed Catalysis (ACDC): A Remarkably General Approach to Enantioselective Synthesis

Asymmetric counteranion-directed catalysis (ACDC) is a powerful new concept, which can potentially be used to achieve enantioselectivity in any type of reaction proceeding through positively charged intermediates. It has already been applied in different areas of catalysis, such as organocatalysis, transition-metal catalysis, and Lewis acid catalysis. Due to its complementarity with traditional approaches to achieve enantioselection, ACDC holds special promise for long-standing challenges from all areas of catalysis, where matched cases can be designed. ACDC also represents a new way of thinking during method development, which could be of help to chemists from a variety of research areas

Asymmetric Counteranion-Directed Catalysis: Concept, Definition, and Applications

Recently, the use of enantiomerically pure counteranions for the induction of asymmetry in reactions proceeding through cationic intermediates has emerged as an exciting new concept, which has been termed asymmetric counteranion-directed catalysis (ACDC). Despite its success, the concept has not been fully defined and systematically discussed to date. This Review closes this gap by providing a clear definition of ACDC and by examining both clear cases as well as more ambiguous examples to illustrate the differences and overlaps with other catalysis concepts

Agrarkreditsysteme in der Europaeischen Union

.Der vorliegende Band enthaelt eine gemeinsam von der Landwirtschaftlichen Rentenbank und dem Bundesministerium fuer Ernaehrung, Landwirtschaft und Forsten (BMELF) in Auftrag gegebene Studie des Muenchener Ifo-Instituts. Obwohl gerade der Agrarsektor durch die europaeische Agrarpolitik staerker als jeder andere Wirtschaftsbereich gemeinsamen Regeln und Bestimmungen unterworfen ist, weist das Agrarkreditgeschaeft ein erstaunliches Ma an nationalen Besonderheiten und einzelstaatlichen Regelunge n auf. Im Gegensatz zum uebrigen Bankensektor ist daher die Markttransparenz in Bezug auf die jeweiligen Agrarkreditsysteme gering. Die vorliegende Studie erhellt einen Bereich, der bislang in der Literatur kaum beschrieben wurde. Sie versteht sich daher in erster Linie als Ueberblickstudie, die gleichsam auch als Nachschlagewerk geeignet ist. Sie ermoeglicht auch einen Vergleich zwischen den Laendern und zeigt ferner, welche Ansaetze die im Agrarsektor taetigen Banken der einzelnen Laender im Hinblick auf die Vollendung des Europaeischen Binnenmarktes verfolgenSIGLEAvailable from: Zentralstelle fuer Agrardokumentation und -information (ZADI), Villichgasse 17, D-53177 Bonn / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Comercialización de productos ecológico: consideraciones de un estudio a nivel detallista en España

El marketing ecológico es una faceta comercial que está adquiriendo un papel significativo en los países desarrollados. A los problemas que plantea la producción de productos biológicos como alternativa a los cultivos convencionales agrarios, dentro de las nuevas líneas de la Política Agraria Común, hemos de agregar las dificultades del proceso comercial, analizadas en la primera parte del trabajo. La parte principal del trabajo expone una aportación empírica en base a un centenar de encuestas personales realizadas en puntos de venta de 11 Comunidades Autónomas españolas, a lo largo del primer trimestre de 1992. En una primera aproximación, se clasifican los puntos de venta estudiados, investigando entre los comerciantes entrevistados cuales son los objetivos que deseaban alcanzar con la venta de productos biológicos y qué productos tienen mayor demanda. El tema de la autenticidad de los productos ha sido otro de los aspectos considerados. En resumen, se trata de aportar una información básica sobre este sector, que aunque en España no tiene aún la dimensión de otros países, es relativamente dinámico y abastece un segmento de mercado, cualitativamente muy significativo

Development path for industrial enterprises towards urban manufacturing

Industrial enterprises are forced to cope with ever higher challenges resulting from trends like the ongoing individualization tendency which results in ever smaller lot sizes, like the limited availability of talents, and like the pressure towards ever lower emissions. A promising approach to cope with the increasing challenges is the application of new production strategies like urban manufacturing. In this contribution, a development path for companies to guide the transition towards urban manufacturing is presented. The development path is structured in seven essential perspectives which are split into five stages. Based on an as-is analysis, the starting point for the advancement of a company can be determined in the resulting raster, and consequently steps for the advancement of the company can be identified