Language control in the context of L3 acquisition

This book fills an existing gap in the field of third language acquisition (L3A) by bringing together theoretical, empirical, and practical accounts that contribute to informed teaching practices in multilingual classrooms

Specifiable biomimetic microsponges for timed release of crystal entrapped biomolecules useful in bone repair.

Most marine materials, by nature, contain crystals of inorganic matter with specific structures that allow the loading, release, and delivery of biomolecules that can be utilized in clinical applications. These structures can be biomimetically synthesized. Aggregates of inorganic particles generated by biomimetic microsponges may provide surfaces and structures for cell attachment, organization, and promotion of matrix synthesis. Biomimetic microsponges have been developed with tunable release profiles differing by the rate (speed over distance), velocity (rate of change in direction), and the quantity discharged over time, according to biomolecular species. Specifically, the types of proteins involved guide and regulate cells in physical contact with the microsponges, for instance, reprogramming somatic cells, the switching phenotypes, or specifying stem cell differentiation. Applications for these microsponges include gene transfection of localized cells and promotion of bone matrix synthesis by the externalized display of RGD cell adhesive peptides and the release of crystal entrapped, occluded, adsorbed and infused rhBMP-2 and plasmid. A requirement for de novo bone formation is a solid structure to enable osteocytes to lay new bone tissue. In this study, biomimetic microsponges highlight tremendous potential as osteoconductive packing material in bone repair with parallel influence on regeneration. Majorly, microsponges offer pronounced osteoinductivity, unlike many other bone particulates, by solid-state integration of active regenerative biological molecules through the prism of the biomineral crystalline structure

Designer Supersurafaces via Bioinspiration and Biomimetics for Dental materials and Structures

The design of surfaces and interfaces gives rise to superior qualities and properties to materials and structures. The interface between biology and materials in nature is being closely examined at the smallest scales for a number of significant reasons. It is recognised that the properties of surfaces have definite biological effects that can be harnessed in clinical regeneration biology. Also the deeper understanding of surface interactions between cells and matrices in human biology is spurring the fabrication of biomimetic and bioinspired versions of these natural designs. The new emerging science of bioinspired surface engineering is helping to improve clinical performances for biomaterials and biostructures because it resolves the problems necessary to optimise integration of implant biomaterials and structures. One of the major developments is the use of surface topography, which is now being exploited for microbial control, steering stem cell behaviours in proliferation and differentiation and adhesive surfaces for better bonding with tissues. In this Chapter we will explore the status of these super surfaces and examine the possibilities for the next generation of dental biomaterials and implants.published_or_final_versio

Language control and code-switching

Analyses of corpus-based indices of conversational code-switching in bilingual speakers predict the occurrence of intra-sentential code-switches consistent with the joint activation of both languages. Yet most utterances contain no code-switches despite good evidence for the joint activation of both languages even in single language utterances. Varying language activation levels is an insufficient mechanism to explain the variety of language use. We need a model of code-switching, consistent with the joint activation of both languages, which permits the range of language use in bilingual speakers. I treat overt speech as the outcome of a number of competitive processes governed by a set of control processes external to the language networks. In a conversation, the speech of the other person may “trigger” code-switches consistent with bottom-up control. By contrast, the intentions of the speaker may act top-down to set the constraints on language use. Given this dual control perspective, the paper extends the control process model (Green and Wei 2014) to cover a plausible neurocomputational basis for the construction and execution of utterance plans in code-switching. Distinct control states mediate different types of language use with switching frequency as a key parameter in determining the control state for code-switches. The paper considers the nature of these states and their transitions

Language control and code-switching

Analyses of corpus-based indices of conversational code-switching in bilingual speakers predict the occurrence of intra-sentential code-switches consistent with the joint activation of both languages. Yet most utterances contain no code-switches despite good evidence for the joint activation of both languages even in single language utterances. Varying language activation levels is an insufficient mechanism to explain the variety of language use. We need a model of code-switching, consistent with the joint activation of both languages, which permits the range of language use in bilingual speakers. I treat overt speech as the outcome of a number of competitive processes governed by a set of control processes external to the language networks. In a conversation, the speech of the other person may “trigger” code-switches consistent with bottom-up control. By contrast, the intentions of the speaker may act top-down to set the constraints on language use. Given this dual control perspective, the paper extends the control process model (Green and Wei 2014) to cover a plausible neurocomputational basis for the construction and execution of utterance plans in code-switching. Distinct control states mediate different types of language use with switching frequency as a key parameter in determining the control state for code-switches. The paper considers the nature of these states and their transitions

A Data-Based Approach for Selecting Pre- and Intra-Operative Language Mapping Tasks

Background: Pre- and intra-operative language mapping in neurosurgery patients frequently involves an object naming task. The choice of the optimal object naming paradigm remains challenging due to lack of normative data and standardization in mapping practices. The aim of this study was to identify object naming paradigms that robustly and consistently activate classical language regions and could therefore be used to improve the sensitivity of language mapping in brain tumor and epilepsy patients. Methods: Functional magnetic resonance imaging (fMRI) data from two independent groups of healthy controls (total = 79) were used to generate threshold-weighted voxel-based consistency maps. This novel approach allowed us to compare inter-subject consistency of activation for naming single objects in the visual and auditory modality and naming two objects in a phrase or a sentence. Results: We found that the consistency of activation in language regions was greater for naming two objects per picture than one object per picture, even when controlling for the number of names produced in 5 s. Conclusion: More consistent activation in language areas for naming two objects compared to one object suggests that two-object naming tasks may be more suitable for delimiting language eloquent regions with pre- and intra-operative language testing. More broadly, we propose that the functional specificity of brain mapping paradigms for a whole range of different linguistic and non-linguistic functions could be enhanced by referring to databased models of inter-subject consistency and variability in typical and atypical brain responses

The Effect of Focal Damage to the Right Medial Posterior Cerebellum on Word and Sentence Comprehension and Production

Functional imaging studies of neurologically intact adults have demonstrated that the right posterior cerebellum is activated during verb generation, semantic processing, sentence processing, and verbal fluency. Studies of patients with cerebellar damage converge to show that the cerebellum supports sentence processing and verbal fluency. However, to date there are no patient studies that investigated the specific importance of the right posterior cerebellum in language processing, because: (i) case studies presented patients with lesions affecting the anterior cerebellum (with or without damage to the posterior cerebellum), and (ii) group studies combined patients with lesions to different cerebellar regions, without specifically reporting the effects of right posterior cerebellar damage. Here we investigated whether damage to the right posterior cerebellum is critical for sentence processing and verbal fluency in four patients with focal stroke damage to different parts of the right posterior cerebellum (all involving Crus II, and lobules VII and VIII). We examined detailed lesion location by going beyond common anatomical definitions of cerebellar anatomy (i.e., according to lobules or vascular territory), and employed a recently proposed functional parcellation of the cerebellum. All four patients experienced language difficulties that persisted for at least a month after stroke but three performed in the normal range within a year. In contrast, one patient with more damage to lobule IX than the other patients had profound long-lasting impairments in the comprehension and repetition of sentences, and the production of spoken sentences during picture description. Spoken and written word comprehension and visual recognition memory were also impaired, however, verbal fluency was within the normal range, together with object naming, visual perception and verbal shortterm memory. This is the first study to show that focal damage to the right posterior cerebellum leads to language difficulties after stroke; and that processing impairments persisted in the case with most damage to lobule IX. We discuss these results in relation to current theories of cerebellar contribution to language processing. Overall, our study highlights the need for longitudinal studies of language function in patients with focal damage to different cerebellar regions, with functional imaging to understand the mechanisms that support recovery