Multidimensional scaling solution for low-proficiency learners.

Multidimensional scaling solution for low-proficiency learners.</p

Model for predicting whether learners’ uses of L2 words cover the native-like ranges of referents (dependent variable: Degree to which L2 learners understand the adequate categories of L2 words).

Model for predicting whether learners’ uses of L2 words cover the native-like ranges of referents (dependent variable: Degree to which L2 learners understand the adequate categories of L2 words).</p

Model for predicting whether learners’ uses of l2 words include the most typical referents (dependent variable: Whether L2 learners map verbs to their typical referents).

Model for predicting whether learners’ uses of l2 words include the most typical referents (dependent variable: Whether L2 learners map verbs to their typical referents).</p

Multidimensional scaling solution for high-proficiency learners.

Multidimensional scaling solution for high-proficiency learners.</p

Multidimensional scaling solution for native speakers of Mandarin.

Multidimensional scaling solution for native speakers of Mandarin.</p

Dominant verbs produced by native speakers and L2 learners.

Dominant verbs produced by native speakers and L2 learners.</p

Independent variables for eight representative verbs in Japanese.

Independent variables for eight representative verbs in Japanese.</p

Basic information about the L2 learner participants (N = 60).

Basic information about the L2 learner participants (N = 60).</p

Drought Alleviates the Negative Effects of Microplastics on Soil Micro-Food Web Complexity and Stability

Soil ecosystems are under considerable pressure due to anthropogenic factors, including microplastics (MPs) pollution and drought. However, little is known about the interactive effects of MPs and drought on soil organisms, especially soil micro-food web. We conducted a microcosm experiment with MPs pollution (including two types and two sizes of MPs) and drought to investigate their interaction effects on soil microbial, protist, and nematode communities in soil micro-food web. We found that MPs significantly decreased the complexity and stability of soil micro-food web, with greater negative effects of biodegradable and smaller-sized MPs than conventional and larger-sized MPs. Drought had negative effects on soil micro-food web in the non-MPs pollution soils while increasing the complexity and stability of soil micro-food web in the MPs pollution soils. Drought increased the proportion of negative correlations between bacteria and fungi in the biodegradable MPs soils while decreasing the proportion of negative correlations between protists and nematodes in the smaller-sized MPs soils. Our study reveals that drought may alleviate the negative effects of MPs on soil micro-food web by reducing competition among lower trophic levels in the biodegradable MPs pollution soils while reducing competition among higher trophic levels in the smaller-sized MPs pollution soils

Center mapping and boundary delineation.

To attain native-like proficiency in second-language word usage, learners have to discover intricate semantic categories in the target language. We investigated the factors influencing the development of two aspects of second-language learners’ semantic categories: the category center and category boundary of word meanings. In the experiment, second-language learners of Japanese, whose first language is Mandarin, were asked to produce the best verb for 28 videos depicting various cutting and breaking events. Descriptive analyses were conducted to compare the verb patterns used by second-language learners with those of native speakers. The second-language learners’ verb use pattern suggested their struggle in delineating the semantic ranges of breaking verbs in a native-like manner. Model analyses further revealed that different factors contribute to learning two different aspects of word meanings. The learning category center of word meaning depended on the similarity between the lexical domains in the first and second languages. On the contrary, the success of learning the semantic boundaries of verbs required a large input frequency and smaller semantic coverage, and smaller category ambiguity. The results suggest that constructing a semantic domain in the second language should be evaluated from at least two different aspects of semantic representation.</div