Volatile compounds of original African black and white shea butter from Tchad and Cameroon

Shea butter is used as an edible vegetable fat in many African countries. It can be utilized as a substitute or complete replacement for cocoa butter in various applications and plays an important role in traditional African medicinal practice. Although detection of volatile compounds by solid‐phase micro‐extraction gas‐chromatography mass‐spectroscopy (SPME‐GC‐MS) is a very reliable and reproducible technique, which can be used as an important part of authenticity checking, production monitoring and contamination detection, no published data about volatile compounds of shea butter are available so far. In this investigation, the characteristic volatiles in the headspace of original African shea butter samples were identified by using SPME‐capillary‐GC coupled to a mass selective detector. Almost 100 different volatile components were identified, e.g. fatty acids, saturated and unsaturated aldehydes and ketones, terpenes, and typical Maillard reaction products such as methylfuranes and pyrazines. Furthermore, the samples have been olfactorily evaluated by a panel of professional flavorists and trained analytical chemists. It can be stated that variations in processing conditions of shea butter result in considerable differences in the composition of headspace volatiles, detected by SPME‐GC‐MS and human olfaction.     

Forming an intention to act on recommendations given via online social networks

Online social networks (OSN) are technology-enabled relationship tools in which a user creates a profile, connects to other individuals, and shares user-generated content with them. One of the many features OSN offer is the ability to post messages in the form of product and service recommendations. Although word-of-mouth research has examined this type of personal communication to intentionally influence consumer decisions, limited understanding exists regarding when a user acts upon a recommendation received from one of their contacts. In this study, we draw on relationship theories and research on trust to analyze the impact relationship characteristics and behaviors of the OSN contacts have on trust in the recommendation that subsequently leads a user to act on this OSN contact’s recommendation. The results of a survey of 116 OSN users showed that closeness, excessive posting behavior, and past recommendation experience have a positive impact on trust and intention to act on the recommendation. One characteristic of the relationships, that is, similarity, however, does not affect recommendation trust in the context of OSN. The findings enhance our understanding of relationships and their defining characteristics in OSN. The results also provide insights into how companies might leverage OSN in their marketing efforts.     

,,Location-based Services“ – Personalisierung mobiler Dienste durch Verortung

Zusammenfassung Im Zeitalter der Informationsgesellschaft, so wurde postuliert, spielten r?umliche Distanzen keine Rolle mehr und unsere r?umliche Mobilit?t n?hme ab. Die Mobilit?t in den letzten Jahren, speziell die Freizeitmobilit?t, hat hingegen zugenommen. Die Bereitstellung ortsbezogener Dienste – ,,Location-based Services“ – unterstützt und f?rdert dieses Verhalten.     

The relationship between learning styles and cognitive traits – Getting additional information for improving student modelling

Student modelling is an important process for adaptive virtual learning environments. Student models include a range of information about the learners such as their domain competence, learning style or cognitive traits. To be able to adapt to the learners’ needs in an appropriate way, a reliable student model is necessary, but getting enough information about a learner is quite challenging. Therefore, mechanisms are needed to support the detection process of the required information. In this paper, we investigate the relationship between learning styles, in particular, those pertaining to the Felder–Silverman learning style model and working memory capacity, one of the cognitive traits included in the cognitive trait model. The identified relationship is derived from links between learning styles, cognitive styles, and working memory capacity which are based on studies from the literature. As a result, we demonstrate that learners with high working memory capacity tend to prefer a reflective, intuitive, and sequential learning style whereas learners with low working memory capacity tend to prefer an active, sensing, visual, and global learning style. This interaction can be used to improve the student model. Systems which are able to detect either only cognitive traits or only learning styles retrieve additional information through the identified relationship. Otherwise, for systems that already incorporate learning styles and cognitive traits, the interaction can be used to improve the detection process of both by including the additional information of a learning style into the detection process of cognitive traits and vice versa. This leads to a more reliable student model.     

Grundrechtsschutz im Europa des Lissaboner Vertrags

Nachdem als letzter Mitgliedstaat der Europ?ischen Union auch Tschechien im November 2009 den Lissaboner Vertrag ratifiziert hatte, konnte das Vertragswerk¹ zum 01. Dezember 2009 in Kraft treten. Seither sind allerdings die mit der neuen Rechtsgrundlage der Europ?ischen Union verbundenen vielf?ltigen Wirkungen kaum ins Bewusstsein der europ?ischen ?ffentlichkeit gelangt. Sie werden von den globalen Banken- und Wirtschaftsproblemen sowie von der aktuellen Krise der europ?ischen W?hrungsunion überlagert, die die nationalen Politiken der EU-Mitgliedstaaten und die gemeinschaftliche europ:aische Politik vor gro?e Herausforderungen stellen und deren Aufmerksamkeit in hohem Ma?e in Anspruch nehmen. Es mag also noch dauern, bis Europa in absehbarer Zeit und hoffentlich ohne an seinen politischkonstitutiven Fundamenten Schaden zu nehmen die aktuellen Krisen überwunden haben wird. Erst dann dürfte den Bürgerinnen und Bürgern Europas deutlicher werden, dass mit dem Inkrafttreten des Vertrages von Lissabon eine unter mehreren Gesichtspunkten neue Epoche des Europ?ischen Integrationsprozesses begonnen hat. Das gilt nicht nur, aber vor allem für die Innen- und Rechtspolitik — für jene Bereiche europ?ischer Politik also, die die Herstellung des seit 1999 im Amsterdamer Vertrag avisierten „Raumes der Freiheit, der Sicherheit und des Rechts“ zum Ziel haben. Innerhalb dieser im hohen Ma?e grundrechtssensiblen Politikfelder wird die neue Epoche vor allem von erheblichen Ver?nderungen sowohl im materiellen, rechtlichen als auch im institutionellen, gerichtlichen Schutz der Grund- und Freiheitsrechte der europ?ischen Bürgerinnen und Bürger gepr?gt sein.     

Nanoparticles in polymer-matrix composites

Regarding the development of nanoparticles for polymer matrix composites the particle/agglomerate size and particle/agglomerate distribution in the composites, respectively, is often crucial. This is exemplarily shown for, e.g. optical applications with measurements of refractive index and transmittance. Classical blending techniques, where nanoparticles are dispersed in polymers or resins, are compared to a combination of a special gas-phase synthesis method with subsequent in-situ deposition of nanoparticles in high-boiling liquids. The particles/agglomerates were characterized regarding particle size and particle size distribution using transmission electron microscopy and dynamic light scattering. Additionally, important material properties like mechanical properties, relevant for application, or like viscosity, relevant for processing, are determined. It is shown, that with in-situ dispersed nanoparticles synthesized in a microwave plasma process composites with finely dispersed particles/agglomerates are attainable.     

Smart Citizens: Exploring the Tools of the Urban Bottom-Up Movement

As web technology and (big) data continue to transform how we organize ourselves, scholarly research increasingly zooms in on the socio-material conditions of citizen participation and public engagement, the objects and devices that organize publics. Where social issues may often be the driver of such public engagement, increasingly the city and, more specifically, the neighborhood itself have become a central objects connecting their inhabitants through online networks and neighborhood events. Tools and apps for citizen participation then weave together neighborhood stakeholders (e.g. inhabitants, municipal parties and entrepreneurs). This paper zooms in on a sample of 40 such tools that enable and organize bottom-up citizen participation in the city of Amsterdam. Combining a theoretical framework with content analysis, digital methods and data visualization, this paper marks the starting point of a longitudinal analysis of online tools for the urban bottom-up movement.     

Geschlechterforschung ist Wissenschaftsforschung – Wissenschaftsforschung ist Geschlechterforschung

The articles collected in this number all originate from a section of the 2004 annual meeting of the Deutsche Gesellschaft für Geschichte der Medizin, Naturwissenschaft und Technik.The section was organized by the Berlin Feminist Science Studies Workgroup (BFSSW) at the Max Planck Institute for the History of Science, Berlin. The contributions are dedicated to recent accounts and research topics in a field constituted by the intersection between 20th century (life) sciences and gender studies.They view modern life sciences as situated in hybrid fields of theory and practice, public and scientific discourse, of experimental procedures and practices of control. Methodological approaches range from Derrida’s notion of deconstruction, Foucault’s regulatory power and governmentality, Butler’s method of analyzing performativity and Haraway’s situated knowledge. They focus on dispositifs of research and regulation, visualizing procedures in the human sciences, and the emergence of new objects of biopolitics. One contribution focuses on the ‘politics of emotions’ and the paradoxical effects of laughter in ‘sexed’ and ‘gendered’ discourses and explores the productivity of humor for a gender-sensitive way of ‘doing history’. This introduction deals with recent developments in – mainly German – gender studies during the last two decades under the triple perspective of women in science, science of gender and gender in science.

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Geschlechterforschung ist Wissenschaftsforschung – Wissenschaftsforschung ist Geschlechterforschung Einführung in den Themenschwerpunkt “Wissenschaftsgeschichte als Geschlechtergeschichte”

     

Multiresolution Visualization of Higher Order Adaptive Finite Element Simulations

h –p–adaptive projection with respect to any prescribed threshold value for the visual error. This projection can then be processed by various local rendering methods, e.g. color coding of data or isosurface extraction. Especially for color coding purposes modern texture capabilities are used to directly render higher polynomial data by superposition of polynomial basis function textures and final color look-up tables. Numerical experiments from CFD clearly demonstrate the applicability and efficiency of our approach. Received September 25, 2001; revised March 31, 2003 Published online: May 26, 2003 The authors acknowledge the valuable hints of the anonymous referees.