598 research outputs found

    A Theory of Social Forces and Immigrant Second Language Acquisition

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    The preponderance of minimal second language acquisition by immigrants worldwide is striking. This paper proposes a theoretical model, which analyzes the underlying forces that contribute to this outcome of minimal secondary language acquisition by immigrants in such diverse immigrant-receiving countries as Canada, Germany, Israel and the United States. It is argued that the weak incentive structures for second language acquisition for an immigrant appear in four analytically separate spheres including the labour market, political, social, and education spheres. Furthermore, two integration regimes are imposed in these spheres – no government interference, or government-mandated minimum language acquisition after arrival. In all cases and in all spheres, it is argued that, for the majority of immigrants, the weakest level of second language acquisition – minimum oral and minimum written – is the optimal outcome given their incentive structure. In addition, the labour market is the primary determinant of this outcome. Finally, several policy measures to increase the incentives for further second language acquisition are explored

    How Much Language is Enough? Some Immigrant Language Lessons from Canada and Germany

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    Germany and Canada stand at polar ends of the scientific debate over language integration and ascension to citizenship. German naturalization, as of January 2000, contains an explicit language criterion for naturalization. The first German immigration act that will presumably come into effect on January 1, 2003, does not only concentrate on control aspects but also aims at language as a criterion for legal immigration. Canada, in effect, does not base entry or citizenship on knowledge of either of its official languages. Acquisition of a second language in Canada is voluntary and largely dependent on labour market incentives. Which system of second language acquisition – the statist German system or the laissez faire Canadian model – provides the best milieu for immigrant second language acquisition? This paper undertakes a comparative review of Canadian and German legal and educational programs in order to answer this question

    Fast jets from bubbles close to solid objects: examples from pillars in water to infinite planes in different liquids

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    The dynamics of a single, laser-induced cavitation bubble on top of a solid cylinder and right at a plane solid boundary is studiedboth experimentally and numerically. The most intriguing phenomenon that occurs for a millimeter sized bubble right at a flatsolid boundary in water is the formation of a fast jet that is directed towards the solid with a speed of the order of 1000 m/s.Paradoxically, in this setting, fast jet formation causally is related to the viscosity of the liquid.Thus, results from numericalsimulations with varying liquid viscosity and bubble size are presented. Bubble dynamics and jet formation mechanisms arediscussed. It is shown, that fast jet formation persists for a wide range of liquid viscosities, including e.g. 50 cSt silicone oil. Forbubbles generated close to the flat top of a long, thin cylinder the parameter space of initial distance to the cylinder, bubble size andcylinder radius is scanned numerically and partly compared to experiments. When the maximum radius of the bubble exceeds theone of the cylinder the bubble collapses in the form of a mushroom or can resemble a trophy, depending on the values of thegeometry parameters. Complex patterns of jet formation with jet speeds ranging from the order of a few hundred m/s to severalthousand m/s are found.The results represent a contribution to understand the behavior of bubbles collapsing close to solid surfaces,in particular, how thin, fast jets are generated

    Perilla Extract improves gastrointestinal discomfort in a randomized placebo controlled double blind human pilot study

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    BACKGROUND: Gastrointestinal (GI) discomfort, e.g. bloating or rumbling, is a common symptom in otherwise healthy adults. Approximately 20% of the population, particularly women suffer from gastrointestinal discomfort and this affects quality of life. Recent studies discovered a link between the body and mind, called the gut-brain axis. Psychosocial factors, such as e.g. daily stress may cause altered gut physiology leading to ileum contractions and consequently gastrointestinal symptoms. In vitro and ex vivo studies clearly showed that a Perilla frutescens extract combines prokinetic, antispasmodic and anti-inflammatory effects. The aim of the intervention was to investigate the effects of the proprietary Perilla extract on GI discomfort in healthy subjects with gastrointestinal discomfort and reduced bowel movements in comparison to a placebo product. METHODS: The pilot study was performed according to a double-blind, randomized, placebo-controlled parallel design. Fifty healthy subjects with gastrointestinal discomfort and reduced bowel movements, 30-70 years, documented their GI symptoms, stool frequency and consistency daily during a 2-week run-in phase and a 4-week intervention phase with Perilla frutescens extract or placebo. GI symptoms were assessed on a 5-point scale daily and average scores over 14 days intervals were calculated. RESULTS: All GI symptoms were significantly improved over time by Perilla frutescens extract during the intervention phase (bloating: -0.44 ± 0.56, p = 0.0003; passage of gas: -0.30 ± 0.66, p = 0.0264; GI rumbling: -0.55 ± 0.87, p = 0.0014; feeling of fullness: -0.36 ± 0.72, p = 0.0152; abdominal discomfort: -0.54 ± 0.75, p = 0.004), whereas in the placebo group only abdominal discomfort was significantly improved (-0.31 ± 0.55, p = 0.0345). In the subgroup of women results were strengthened and a subscore out of bloating and abdominal discomfort was significantly improved against placebo (95%CI 0.003 to 0.77; p = 0.048). CONCLUSION: The demonstrated effects of Perilla frutescens extract to improve GI complaints offer very promising results, taking into consideration the challenging set up of a nutritional human study with healthy subjects and in the area of digestive health, which is known for high placebo effects. TRIAL REGISTRATION NUMBER: NCT01931930 at ClinicalTrials.gov, Registration date 23(rd) August 2013
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