4,828 research outputs found

    Above- and belowground herbivory jointly impact defense and seed dispersal traits in Taraxacum officinale

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    Plants are able to cope with herbivores by inducing defensive traits or growth responses that allow them to reduce or avoid the impact of herbivores. Since above- and belowground herbivores differ substantially in life-history traits, for example feeding types, and their spatial distribution, it is likely that they induce different responses in plants. Moreover, strong interactive effects on defense and plant growth are expected when above- and belowground herbivores are jointly present. The strengths and directions of these responses have been scarcely addressed in the literature. Using Taraxacum officinale, the root-feeding nematode Meloidogyne hapla and the locust Schistocerca gregaria as a model species, we examined to what degree above- and belowground herbivory affect (1) plant growth responses, (2) the induction of plant defensive traits, that is, leaf trichomes, and (3) changes in dispersal-related seed traits and seed germination. We compared the performance of plants originating from different populations to address whether plant responses are conserved across putative different genotypes. Overall, aboveground herbivory resulted in increased plant biomass. Root herbivory had no effect on plant growth. Plants exposed to the two herbivores showed fewer leaf trichomes than plants challenged only by one herbivore and consequently experienced greater aboveground herbivory. In addition, herbivory had effects that reached beyond the individual plant by modifying seed morphology, producing seeds with longer pappus, and germination success

    Rappers and Linguistic Variation: A study of Non-Standard Language in Selected Francophone Rap Tracks

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    This thesis examines the use of non-standard language, more specifically non-standard vocabulary (i.e. slang, verlan, colloquialisms, vulgarities, foreign borrowings, and abbreviations), in a corpus of selected francophone rap tracks in order both to quantify its use and to investigate what determines its variation, focusing on the impact of diachronic, diatopic, gender and diaphasic determinants. The methodology relies on a lexicographic analysis to produce quantitative results which are then analysed qualitatively by means of extract analyses and semi-structured interviews with francophone rappers. To answer the research questions, the thesis is divided into five chapters. The first chapter presents the aforementioned methodology and the overall quantitative results from the thesis, while also introducing the notion of variation, which is then tackled in the last four chapters. The second chapter investigates diachronic determinants from two perspectives: different generations of rappers (1990/1991, 2001 and 2011) and one artist throughout his career (Akhenaton in 1991, 2011 and 2011). The third chapter looks at diatopic determinants, analysing the impact of ethnic and spatial origins. Three ethnic origins are compared (rappers of French, Algerian and Senegalese origin), together with three cities (Marseille, Paris and Brussels) and three departments (Hauts-de-Seine, Seine-Saint-Denis and Val-de-Marne). The fourth chapter focuses on gender determinants, with a comparison of male versus female rappers that also takes broader gender performativity into account. Finally, the fifth chapter examines the impact of diaphasic determinants. It analyses three rap genres (jazz/poetic, ego trip and knowledge rap), which then form the foundation for qualitative discussions of the effect of aesthetics, figures of speech, themes and performance. In conclusion, the contribution to knowledge of this work is the observation that the main determinant of high use of non-standard vocabulary is the performance of modern ego trip. The other determinants do not impact non-standard vocabulary to the same extent quantitatively or systematically, due to the complexity of the contextual and fluid identity performances involved with these determinants

    On the origin of bursts in blue compact dwarf galaxies: clues from kinematics and stellar populations

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    Blue compact dwarf galaxies (BCDs) form stars at, for their sizes, extraordinarily high rates. In this paper, we study what triggers this starburst and what is the fate of the galaxy once its gas fuel is exhausted. We select four BCDs with smooth outer regions, indicating them as possible progenitors of dwarf elliptical galaxies. We have obtained photometric and spectroscopic data with the FORS and ISAAC instruments on the VLT. We analyse their infrared spectra using a full spectrum fitting technique, which yields the kinematics of their stars and ionized gas together with their stellar population characteristics. We find that the stellar velocity to velocity dispersion ratio ((nu/sigma)(star)) of our BCDs is of the order of 1.5, similar to that of dwarf elliptical galaxies. Thus, those objects do not require significant (if any) loss of angular momentum to fade into early-type dwarfs. This finding is in discordance with previous studies, which however compared the stellar kinematics of dwarf elliptical galaxies with the gaseous kinematics of star-forming dwarfs. The stellar velocity fields of our objects are very disturbed and the star formation regions are often kinematically decoupled from the rest of the galaxy. These regions can be more or less metal rich with respect to the galactic body and sometimes they are long lived. These characteristics prevent us from pinpointing a unique trigger of the star formation, even within the same galaxy. Gas impacts, mergers, and in-spiraling gas clumps are all possible star formation igniters for our targets

    AVOCAAD - A First Step Towards Distance Learning

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    In the industrial world knowledge is developed very fast. As most countries are depending on employees with a high level of knowledge and skills the term "Life Long Learning" has been formulated and the concept is more and more accepted. Institutions of higher education are more and more involved in creating supplementary education more independent of time and place. Distance learning was originally carried out by ordinary mail, which was slow but might then have been the only solution for people in remote places. With the Internet and e-mail the distance-learning concept has got a far better tool, for instance better interaction facilities. Architects and engineers in practise are deeply involved in solving the problems of the present projects. Education which is independent of time and place must be of great interest to both parties. The AVOCAAD project has created an education model for students to meet the possibilities of CAAD. The education model can be used in a curriculum at a school as well as for distance learning. Among the possible experiences from it, the one concerning distance learning might be the most important future application of the system in architectural education. This paper sketches the pedagogical background and gives examples from other areas of knowledge, where distance learning is already in use. We will put the question how the AVOCAAD concept meets the experiences from distance learning

    The evolution of coronal mass ejections in the inner heliosphere : Implementing the spheromak model with EUHFORIA

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    Aims. We introduce a new model for coronal mass ejections (CMEs) that has been implemented in the magnetohydrodynamics (MHD) inner heliosphere model EUHFORIA. Utilising a linear force-free spheromak (LFFS) solution, the model provides an intrinsic magnetic field structure for the CME. As a result, the new model has the potential to predict the magnetic components of CMEs at Earth. In this paper, we present the implementation of the new model and show the capability of the new model. Methods. We present initial validation runs for the new magnetised CME model by considering the same set of events as used in the initial validation run of EUHFORIA that employed the Cone model. In particular, we have focused on modelling the CME that was responsible for creating the largest geomagnetic disturbance (Dst index). Two scenarios are discussed: one where a single magnetised CME is launched and another in which we launch all five Earth-directed CMEs that were observed during the considered time period. Four out of the five CMEs were modelled using the Cone model. Results. In the first run, where the propagation of a single magnetized CME is considered, we find that the magnetic field components at Earth are well reproduced as compared to in-situ spacecraft data. Considering a virtual spacecraft that is separated approximately seven heliographic degrees from the position of Earth, we note that the centre of the magnetic cloud is missing Earth and a considerably larger magnetic field strength can be found when shifting to that location. For the second run, launching four Cone CMEs and one LFFS CME, we notice that the simulated magnetised CME is arriving at the same time as in the corresponding full Cone model run. We find that to achieve this, the speed of the CME needs to be reduced in order to compensate for the expansion of the CME due to the addition of the magnetic field inside the CME. The reduced initial speed of the CME and the added magnetic field structure give rise to a very similar propagation of the CME with approximately the same arrival time at 1 au. In contrast to the Cone model, however, the magnetised CME is able to predict the magnetic field components at Earth. However, due to the interaction between the Cone model CMEs and the magnetised CME, the magnetic field amplitude is significantly lower than for the run using a single magnetised CME. Conclusions. We have presented the LFFS model that is able to simulate and predict the magnetic field components and the propagation of magnetised CMEs in the inner heliosphere and at Earth. We note that shifting towards a virtual spacecraft in the neighbourhood of Earth can give rise to much stronger magnetic field components. This gives the option of adding a grid of virtual spacecrafts to give a range of values for the magnetic field components.Peer reviewe

    Fingerprinting of the Deceased by the Dusting-Tape Method

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    Europeans and Traditional Foods: Definition and Image from the Consumers' Perspective

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    This paper provides a consumer-driven definition of traditional food products (TFP) and investigates the image European consumers have about this food product category. Data were collected from representative consumer samples in six European countries, including Belgium, France, Italy, Norway, Poland and Spain, with a total sample size of 4,828 participants. European consumers define traditional foods as well-know products, products that one can eat very frequently, and products that were already eaten by grandparents. Although positive, association of TFP with naturalness and low processing is less pronounced. Sensory, health- and environment-related attribute perceptions contribute positively to the image of TFP, whereas perceived convenience, price, and availability contribute negatively to the TFP image. Finally, TFP are mainly pictured as foods that agree well with people who love national or regional cuisine, with people living in the countryside, equally so with men and women, though more so with families with children rather than singles or household without children. The empirical findings provide insights with particular relevance for TFP positioning, marketing communications around TFP and further development of the TFP market in Europe.Traditional food, Consumer, Europe, Demand and Price Analysis, Food Consumption/Nutrition/Food Safety,

    Personal selling constructs and measures: Emic versus etic approaches to cross-national research

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    Evaluates transportability of personal selling measures across cultural boundaries. Concept of measurement development; Emic and etic approaches to developing measures for cross-cultural applications; Cross-national dimensionality, reliability and construct validity of adaptive selling (ADAPTS) and customer-oriented selling (SOCO)
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