50,564 research outputs found

    The evolution of trilingual code-switching from infancy to school age: the shaping of trilingual competence through dynamic language dominance

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    This article reports on a study of the code-switches produced by two children who acquired their three languages in early childhood. We compared formal and functional aspects of their switches recorded at two different stages of their development. Of particular interest was the consideration of sociolinguistic variables that have intervened in the children’s environment. We undertook a quantitative and qualitative analysis of the children’s code-switches to ascertain the frequency of switching, the use of each of the three languages employed for switching and the linguistic complexity of the switches. We assumed that the sociolinguistic conditions that changed the linguistic landscape in which these children operated would be reflected not only in the development of each of their languages, but also in the kind of switches that they produced. We tried to establish whether it is the case that certain forms and functions of code-switches constitute a "core" of trilingual language behaviour while others are prone to change. Ultimately, our aim was to gain an insight into the specific trilingual language production processes over a given period of time that can shed light on the development and nature of trilingual competence

    Many Particle Hardy-Inequalities

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    In this paper we prove three differenttypes of the so-called many-particle Hardy inequalities. One of them is a "classical type" which is valid in any dimesnion d≠2d\neq 2. The second type deals with two-dimensional magnetic Dirichlet forms where every particle is supplied with a soplenoid. Finally we show that Hardy inequalities for Fermions hold true in all dimensions.Comment: 20 page

    Facilitating Wolbachia introductions into mosquito populations through insecticide-resistance selection.

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    Wolbachia infections are being introduced into mosquito vectors of human diseases following the discovery that they can block transmission of disease agents. This requires mosquitoes infected with the disease-blocking Wolbachia to successfully invade populations lacking the infection. While this process is facilitated by features of Wolbachia, particularly their ability to cause cytoplasmic incompatibility, blocking Wolbachia may produce deleterious effects, such as reduced host viability or fecundity, that inhibit successful local introductions and subsequent spatial spread. Here, we outline an approach to facilitate the introduction and spread of Wolbachia infections by coupling Wolbachia introduction to resistance to specific classes of insecticides. The approach takes advantage of very high maternal transmission fidelity of Wolbachia infections in mosquitoes, complete incompatibility between infected males and uninfected females, the widespread occurrence of insecticide resistance, and the widespread use of chemical control in disease-endemic countries. This approach is easily integrated into many existing control strategies, provides population suppression during release and might be used to introduce Wolbachia infections even with high and seasonally dependent deleterious effects, such as the wMelPop infection introduced into Aedes aegypti for dengue control. However, possible benefits will need to be weighed against concerns associated with the introduction of resistance alleles

    Knowing Which Foods Are Making Us Sick

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    Food Consumption/Nutrition/Food Safety, D18, I18,

    Cloudphysical Parameters in Dependence on Height above Cloud Base in Different Clouds.

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    On flights with the DLR icing research aircraft the dependence of aircraft icing on cloudphysical parameters was determined; both for aircraft-referred icing and for normalized icing, as well as for various clouds and locations in clouds. This is done with an improvement of icing predicitons in mind. The species of the cloud and the distance from cloud base are called here cloud parameters; while under cloudphysical parameters are understood liquid water content, temperature, particle size distribution and particle phase. Results from four icing flights are discussed, selected from a total of forty vertical soundings. —The results are arranged in four classes: Stratus/cumulus mixed, stratus; with and without precipitation at the ground

    Quantitative analysis of ferroelectric domain imaging with piezoresponse force microscopy

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    The contrast mechanism for ferroelectric domain imaging via piezoresponse force microscopy (PFM) is investigated. A novel analysis of PFM measurements is presented which takes into account the background caused by the experimental setup. This allows, for the first time, a quantitative, frequency independent analysis of the domain contrast which is in good agreement with the expected values for the piezoelectric deformation of the sample and satisfies the generally required features of PFM imaging
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