Interaction between learners under group work setting is considered to be significantly influenced by task types. The present empirical study was designed to explore interaction characteristics under convergent tasks ...Interaction between learners under group work setting is considered to be significantly influenced by task types. The present empirical study was designed to explore interaction characteristics under convergent tasks and divergent tasks from three aspects: language production, meaning negotiation and attention to form while performing different types of tasks. The results reveal that there was significant statistical difference in the total language production between two types of tasks. In terms of the occurrence of meaning negotiation and the extent to which students paid attention to language form, there were no significant difference between the two task types.展开更多
The study aims to investigate whether repetition of the same task type affects quality of writing production in terms of complexity, accuracy and fluency(CAF). Data is collected in the form of TOEFL integrated and ind...The study aims to investigate whether repetition of the same task type affects quality of writing production in terms of complexity, accuracy and fluency(CAF). Data is collected in the form of TOEFL integrated and independent essays repetitively written at weekly intervals. Fluency, complexity and accuracy of each essay were gauged using various measures to reflect multidimensionality of these constructs. Data analysis reveals that there is improvement in both integrated and independent writing, especially in terms of linguistic accuracy, which could be attributed to repetition of these two tasks.展开更多
Task-based language teaching(TBLT)has caused considerable interests among curriculum developers,language testers and language teachers during the past several decades.In order to use the approach rightly,throughout li...Task-based language teaching(TBLT)has caused considerable interests among curriculum developers,language testers and language teachers during the past several decades.In order to use the approach rightly,throughout literature review,the essay is going to analyze what the task is critically and the factors teachers should consider when they design tasks.At the end of the study,it is concluded that even though the definition of task is various,the main criteria are that a task is mainly focusing on meaning;has a clear goal;involves the outcome;and is related to the real world.When design tasks,teachers need to balance the fluency,accuracy and complexity,making task difficulties be appropriate to students’levels,considering thematic content and the range of task types and the phases of tasks.展开更多
针对新型时空众包平台出现的3类对象在线任务匹配问题,现有工作往往假设工人拥有最大可匹配任务数量,将多个任务一次性分配给一个工人,忽略了工人的工作时间,可能会导致后匹配到的任务等待时间过长。因此,本文考虑了工作时长的在线3类...针对新型时空众包平台出现的3类对象在线任务匹配问题,现有工作往往假设工人拥有最大可匹配任务数量,将多个任务一次性分配给一个工人,忽略了工人的工作时间,可能会导致后匹配到的任务等待时间过长。因此,本文考虑了工作时长的在线3类对象动态匹配(online dynamic assginment for three types of objects,ODAT)问题,结合遗传算法(genetic algorithm,GA)提出一种延迟匹配算法来解决该问题。通过构造任务森林结构,借鉴蒙特卡罗树搜索思想随机模拟生成初始解,采用双重变异算子、局部最优算子融合贪心算法实现定向最优进化,使用随机部分重启机制跳出局部最优解;同时还提出一种延迟阈值策略来进一步提升效用。最终在真实数据集和合成数据集上进行大量实验,验证了算法的有效性和可行性。展开更多
Many studies have shown that fibronectin type III domain-containing protein 5(FDNC5) and brain-derived neurotrophic factor(BDNF) play vital roles in plasticity after brain injury. An enriched environment refers to an ...Many studies have shown that fibronectin type III domain-containing protein 5(FDNC5) and brain-derived neurotrophic factor(BDNF) play vital roles in plasticity after brain injury. An enriched environment refers to an environment that provides animals with multi-sensory stimulation and movement opportunities. An enriched environment has been shown to promote the regeneration of nerve cells, synapses, and blood vessels in the animal brain after cerebral ischemia;however, the exact mechanisms have not been clarified. This study aimed to determine whether an enriched environment could improve neurobehavioral functions after the experimental inducement of cerebral ischemia and whether neurobehavioral outcomes were associated with the expression of FDNC5 and BDNF. This study established ischemic mouse models using permanent middle cerebral artery occlusion(pMCAO) on the left side. On postoperative day 1, the mice were randomly assigned to either enriched environment or standard housing condition groups. Mice in the standard housing condition group were housed and fed under standard conditions. Mice in the enriched environment group were housed in a large cage, containing various toys, and fed with a standard diet. Sham-operated mice received the same procedure, but without artery occlusion, and were housed and fed under standard conditions. On postoperative days 7 and 14, a beam-walking test was used to assess coordination, balance, and spatial learning. On postoperative days 16–20, a Morris water maze test was used to assess spatial learning and memory. On postoperative day 15, the expression levels of FDNC5 and BDNF proteins in the ipsilateral cerebral cortex were analyzed by western blot assay. The results showed that compared with the standard housing condition group, the motor balance and coordination functions(based on beam-walking test scores 7 and 14 days after operation), spatial learning abilities(based on the spatial learning scores from the Morris water maze test 16–19 days after operation), and memory abilities(based on the memory scores of the Morris water maze test 20 days after operation) of the enriched environment group improved significantly. In addition, the expression levels of FDNC5 and BDNF proteins in the ipsilateral cerebral cortex increased in the enriched environment group compared with those in the standard housing condition group. Furthermore, the Pearson correlation coefficient showed that neurobehavioral functions were positively associated with the expression levels of FDNC5 and BDNF(r = 0.587 and r = 0.840, respectively). These findings suggest that an enriched environment upregulates FDNC5 protein expression in the ipsilateral cerebral cortex after cerebral ischemia, which then activates BDNF protein expression, improving neurological function. BDNF protein expression was positively correlated with improved neurological function. The experimental protocols were approved by the Institutional Animal Care and Use Committee of Fudan University, China(approval Nos. 20160858 A232, 20160860 A234) on February 24, 2016.展开更多
文摘Interaction between learners under group work setting is considered to be significantly influenced by task types. The present empirical study was designed to explore interaction characteristics under convergent tasks and divergent tasks from three aspects: language production, meaning negotiation and attention to form while performing different types of tasks. The results reveal that there was significant statistical difference in the total language production between two types of tasks. In terms of the occurrence of meaning negotiation and the extent to which students paid attention to language form, there were no significant difference between the two task types.
文摘The study aims to investigate whether repetition of the same task type affects quality of writing production in terms of complexity, accuracy and fluency(CAF). Data is collected in the form of TOEFL integrated and independent essays repetitively written at weekly intervals. Fluency, complexity and accuracy of each essay were gauged using various measures to reflect multidimensionality of these constructs. Data analysis reveals that there is improvement in both integrated and independent writing, especially in terms of linguistic accuracy, which could be attributed to repetition of these two tasks.
文摘Task-based language teaching(TBLT)has caused considerable interests among curriculum developers,language testers and language teachers during the past several decades.In order to use the approach rightly,throughout literature review,the essay is going to analyze what the task is critically and the factors teachers should consider when they design tasks.At the end of the study,it is concluded that even though the definition of task is various,the main criteria are that a task is mainly focusing on meaning;has a clear goal;involves the outcome;and is related to the real world.When design tasks,teachers need to balance the fluency,accuracy and complexity,making task difficulties be appropriate to students’levels,considering thematic content and the range of task types and the phases of tasks.
文摘针对新型时空众包平台出现的3类对象在线任务匹配问题,现有工作往往假设工人拥有最大可匹配任务数量,将多个任务一次性分配给一个工人,忽略了工人的工作时间,可能会导致后匹配到的任务等待时间过长。因此,本文考虑了工作时长的在线3类对象动态匹配(online dynamic assginment for three types of objects,ODAT)问题,结合遗传算法(genetic algorithm,GA)提出一种延迟匹配算法来解决该问题。通过构造任务森林结构,借鉴蒙特卡罗树搜索思想随机模拟生成初始解,采用双重变异算子、局部最优算子融合贪心算法实现定向最优进化,使用随机部分重启机制跳出局部最优解;同时还提出一种延迟阈值策略来进一步提升效用。最终在真实数据集和合成数据集上进行大量实验,验证了算法的有效性和可行性。
基金supported by the National Natural Science Foundation of China,Nos.81601961(to KWY),81672242(to YW)the Key Construction Projects of Shanghai Health and Family Planning on Weak Discipline,China,No.2015ZB0401(to YW)
文摘Many studies have shown that fibronectin type III domain-containing protein 5(FDNC5) and brain-derived neurotrophic factor(BDNF) play vital roles in plasticity after brain injury. An enriched environment refers to an environment that provides animals with multi-sensory stimulation and movement opportunities. An enriched environment has been shown to promote the regeneration of nerve cells, synapses, and blood vessels in the animal brain after cerebral ischemia;however, the exact mechanisms have not been clarified. This study aimed to determine whether an enriched environment could improve neurobehavioral functions after the experimental inducement of cerebral ischemia and whether neurobehavioral outcomes were associated with the expression of FDNC5 and BDNF. This study established ischemic mouse models using permanent middle cerebral artery occlusion(pMCAO) on the left side. On postoperative day 1, the mice were randomly assigned to either enriched environment or standard housing condition groups. Mice in the standard housing condition group were housed and fed under standard conditions. Mice in the enriched environment group were housed in a large cage, containing various toys, and fed with a standard diet. Sham-operated mice received the same procedure, but without artery occlusion, and were housed and fed under standard conditions. On postoperative days 7 and 14, a beam-walking test was used to assess coordination, balance, and spatial learning. On postoperative days 16–20, a Morris water maze test was used to assess spatial learning and memory. On postoperative day 15, the expression levels of FDNC5 and BDNF proteins in the ipsilateral cerebral cortex were analyzed by western blot assay. The results showed that compared with the standard housing condition group, the motor balance and coordination functions(based on beam-walking test scores 7 and 14 days after operation), spatial learning abilities(based on the spatial learning scores from the Morris water maze test 16–19 days after operation), and memory abilities(based on the memory scores of the Morris water maze test 20 days after operation) of the enriched environment group improved significantly. In addition, the expression levels of FDNC5 and BDNF proteins in the ipsilateral cerebral cortex increased in the enriched environment group compared with those in the standard housing condition group. Furthermore, the Pearson correlation coefficient showed that neurobehavioral functions were positively associated with the expression levels of FDNC5 and BDNF(r = 0.587 and r = 0.840, respectively). These findings suggest that an enriched environment upregulates FDNC5 protein expression in the ipsilateral cerebral cortex after cerebral ischemia, which then activates BDNF protein expression, improving neurological function. BDNF protein expression was positively correlated with improved neurological function. The experimental protocols were approved by the Institutional Animal Care and Use Committee of Fudan University, China(approval Nos. 20160858 A232, 20160860 A234) on February 24, 2016.
