Six Principles of Language Development: Implications for Second Language Learners

The number of children growing up in dual language environments is increasing in the United States. Despite the apparent benefits of speaking two languages, children learning English as a second language (ESL) often face struggles, as they may experience poverty and impoverished language input at home. Early exposure to a rich language environment is crucial for ESL children’s academic success. This article explores how six evidenced-based principles of language learning can be used to provide support for ESL children.     

Diving decompression models and bubble metrics: Modern computer syntheses

A quantitative summary of computer models in diving applications is presented, underscoring dual phase dynamics and quantifying metrics in tissue and blood. Algorithms covered include the multitissue, diffusion, split phase gradient, linear-exponential, asymmetric tissue, thermodynamic, varying permeability, reduced gradient bubble, tissue bubble diffusion, and linear-exponential phase models. Defining relationships are listed, and diver staging regimens are underscored. Implementations, diving sectors, and correlations are indicated for models with a history of widespread acceptance, utilization, and safe application across recreational, scientific, military, research, and technical communities. Presently, all models are incomplete, but many (included above) are useful, having resulted in diving tables, underwater meters, and dive planning software. Those herein employ varying degrees of calibration and data tuning. We discuss bubble metrics in tissue and blood as a backdrop against computer models. The past 15 years, or so, have witnessed changes and additions to diving protocols and table procedures, such as shorter nonstop time limits, slower ascent rates, shallow safety stops, ascending repetitive profiles, deep decompression stops, helium based breathing mixtures, permissible reverse profiles, multilevel techniques, both faster and slower controlling repetitive tissue halftimes, smaller critical tensions, longer flying-after-diving surface intervals, and others. Stimulated by Doppler and imaging technology, table and decompression meter development, theory, statistics, chamber and animal testing, or safer diving consensus, these modifications affect a gamut of activity, spanning bounce to decompression, single to multiday, and air to mixed gas diving. As it turns out, there is growing support for many protocols on operational, experimental, and theoretical grounds, with bubble models addressing many concerns on plausible bases, but with further testing or profile data analyses requisite.     

Language and the aging brain: patterns of neural compensation revealed by functional brain imaging

Human aging brings with it declines in sensory function, both in vision and in hearing, as well as a general slowing in a variety of perceptual and cognitive operations. Yet in spite of these declines, language comprehension typically remains well preserved in normal aging. We review data from functional magnetic resonance imaging (fMRI) to describe a two-component model of sentence comprehension: a core sentence-processing area located in the perisylvian region of the left cerebral hemisphere and an associated network of brain regions that support the working memory and other resources needed for comprehension of long or syntactically complex sentences. We use this two-component model to describe the nature of compensatory recruitment of novel brain regions observed when healthy older adults show the same success at comprehending sentences as their younger adult counterparts. We suggest that this plasticity in neural recruitment contributes to the stability of language comprehension in the aging brain.     

Language, gesture, and the developing brain

Do language abilities develop in isolation? Are they mediated by a unique neural substrate, a “mental organ” devoted exclusively to language? Or is language built upon more general abilities, shared with other cognitive domains, and mediated by common neural systems? Here, we review results suggesting that language and gesture are “close family”, then turn to evidence that raises questions about how real those “family resemblances” are, summarizing dissociations from our developmental studies of several different child populations. We then examine both these veins of evidence in light of some new findings from the adult neuroimaging literature and suggest a possible reinterpretation of these dissociations as well as new directions for research with both children and adults. © 2002 Wiley Periodicals, Inc. Dev Psychobiol 40: 293–310, 2002. DOI 10.1002/dev.10034     

Language,music, syntax and the brain

The comparative study of music and language is drawing an increasing amount of research interest. Like language, music is a human universal involving perceptually discrete elements organized into hierarchically structured sequences. Music and language can thus serve as foils for each other in the study of brain mechanisms underlying complex sound processing, and comparative research can provide novel insights into the functional and neural architecture of both domains. This review focuses on syntax, using recent neuroimaging data and cognitive theory to propose a specific point of convergence between syntactic processing in language and music. This leads to testable predictions, including the prediction that that syntactic comprehension problems in Broca's aphasia are not selective to language but influence music perception as well.     

A study of the directional response of ultraviolet radiometers: II. Implications for ultraviolet phototherapy derived from computer simulations

A theoretical model has been used to simulate irradiances for ultraviolet (UV) phototherapy cabinets and other sources. The accuracy of the simulation results has been checked by comparison with experimental measurements. The simulations have been used to study the influence of different factors on UV phototherapy exposure and to develop recommendations for the operation and calibration of phototherapy cabinets. Many radiometers used in the evaluation of skin doses have input optics with directional responses that are not proportional to the cosine of the angle of incidence for the UV radiation. Data on radiometer directional responses have been incorporated into the simulations, which show that the poor directional responses for some radiometers currently in use will give errors of 20-50% in the assessment of irradiance. The influence of lamp source geometries employed for radiometer calibration has been investigated. UV phototherapy dosimetry commonly uses a spectroradiometer and a radiometer in the transfer of irradiance calibrations from a small standard UV lamp to a large-area source with a different UV spectrum. Recommendations are given on the range of acceptability for radiometer directional responses and a method is described for determining whether these are fulfilled. Recommendations are made on the techniques that should be used for calibration.     

"脑-机接口"的研究进展

脑-机接口(brain computerinterface,BCI)是一种全新的通讯和控制技术.本文分析和讨论了一些现有的脑-机接口系统及其控制信号,并指出了其中一些有待于进一步解决的问题和今后的研究发展方向.     

Allostasis and the developing human brain: explicit consideration of implicit models

We previously used the theory of allostasis as the foundation for a model of the current stress process. This work highlighted the core emotional systems of the brain as the central mediator of the relationship between stress and health. In this paper, we extend this theoretical approach to consider the role of developmental timing. In doing so, we note that there are strong implicit models that underlie current developmental stress research in the social and life sciences. We endeavor to illustrate these models explicitly as we review the evidence behind each one and discuss their implications. We then extend these models to reflect recent findings from research in life span human neuroscience. The result is a new set of developmental allostatic models that provide fodder for future empirical research, as well as novel perspectives on intervention.     

A new algorithm for computer tomographic reconstruction from partial view projections

Conventional algorithms for tomographic reconstruction require the acquisition of a complete set of projections at uniform angular displacements. In many cases, however, the geometry of the sample or a loss of data can significantly reduce the range of the available projections. Several algorithms have been proposed in literature to handle such situations, but their performances are low or they require strong constraints and hypothesis about the nature of the sample or the data. Here a new method is proposed. It is based on a novel morphing technique, which affords in general terms the problem of curve matching and is here specialized to the case of tomographic reconstruction. The proposed algorithm is very fast in comparison to other approaches having similar effectiveness; furthermore, it allows one to obtain good quality images even when a significant fraction of the views is absent, without any hypothesis about the nature of the sample or the kind of measurement. The results obtained by applying this technique to the Shepp-Logan phantom and to a clinical scan are reported here and discussed.     

Brain drains: new insights into brain clearance pathways from lymphatic biology

The lymphatic vasculature act as the drainage system for most of our tissues and organs, clearing interstitial fluid and waste and returning them to the blood circulation. This is not the case for the central nervous system (CNS), which is devoid of parenchymal lymphatic vessels. Nevertheless, the brain is responsible for 25% of the body’s metabolism and only compromises 2% of the body’s mass. This high metabolic load requires an efficient system to remove waste products and maintain homeostasis. Well-described mechanisms of waste clearance include phagocytic immune cell functions as well as perivascular fluid flow; however, the need for active drainage of waste from the brain is becoming increasingly appreciated. Recent developments in lymphatic vascular biology challenge the proposition that the brain lacks lymphatic drainage or an equivalent. In this review, we describe the roles of the glymphatic system (a key drainage mechanism in the absence of lymphatics), the recently characterized meningeal lymphatic vessels, and explore an enigmatic cell population found in zebrafish called mural lymphatic endothelial cells. These systems may play important individual and collective roles in draining and clearing wastes from the brain.     

Tissue renin-angiotensin systems: new insights from experimental animal models in hypertension research

Renin was first isolated in the kidney by Tigerstedt and Bergman over 100 years ago. Almost 50 additional years were necessary to isolate the renin substrate angiotensinogen and to show its cleavage to angiotensin (Ang). Further studies were then needed to demonstrate that Ang I is converted via an angiotensin-converting enzyme to Ang II. The circulating renin-angiotensin system, with blood pressure regulatory and aldosterone stimulatory roles, served well for decades. However, more recent information on Ang II and its action in terms of cell proliferation, hypertrophy, and hyperplasia as well as immune-modulatory and even intracellular functions, have focused attention on local Ang II generation and effects. These investigations necessarily began in the kidney, but quickly moved to other organs including the brain, heart, adrenal gland, and vessel wall and formed the basis for the concept of independent tissue renin-angiotensin systems. Both renin and Ang II have even been implicated in intracellular activities. This review presents some selected aspects of the historical development of this concept and summarizes discoveries relying primarily on animal models which demonstrate that Ang II is generated locally and acts in tissues as a local peptidergic system. Comprehensiveness in such an endeavor is not possible. We focus largely on work from our own group, not because the work is necessarily worthy of such scrutiny but rather because of our own familiarity with the contents.     

Stroke induced brain changes: Implications for stem cell transplantation

Ischemic stroke remains a major health problem associated with high mortality and severe morbidity. In spite of the extensive research in the field of stroke biology, there is little effective treatment for a completed disease onset. Numerous neuroprotective strategies have failed in clinical trials because of lack of efficacy or unacceptable side-effects. The challenge of clinical trial design is now to understand the process leading to ischemic brain injury and thus identify the targets for intervention in stroke. Therefore, uncovering cellular and molecular processes involved in ischemic brain injury is of critical importance. The review discusses the current understanding of these processes engaged in pathogenesis of stroke including excitotoxicity and inflammation. In addition recruitment of endogenous progenitors engaged in neurogenesis and vascular regeneration has been implicated. All of the aforementioned changes opted for therapeutic intervention to protect neurons in the region adjacent to the ischemic cerebral tissue and enhance cell recovery. Stem cell transplantation seems to offer a major promise of this therapy in stroke disorders.     

Semantic impairment with and without surface dyslexia: Implications for models of reading

The two best-developed computational models of reading aloud, the DRC model of Coltheart and colleagues and the connectionist attractor model of Plaut and colleagues, offer very different views about the degree to which semantic knowledge is involved in lexical processing, and hence make differing predictions about how semantic impairment (as seen, for example, in semantic dementia) will impact on lexical processing in clinical cases. Two cases meeting the criteria for semantic dementia, PC and EM, were given a battery of tests comprising comprehension tasks, a reading task, and a visual word recognition (lexical decision) task. All tasks used the same target words allowing cross-test and cross-patient comparisons. Both cases showed significant impairment of semantic memory, and word comprehension was found to be related to the word frequency of the target words. PC demonstrated poor reading of irregular words, with a surface dyslexic pattern of reading aloud, and he performed poorly on the visual lexical decision task. His ability to read irregular words was related to their frequency and to his ability to comprehend them. In contrast, his visual lexical decision performance was not reliably influenced by his comprehension of the same words or by their frequency. EM demonstrated essentially perfect reading aloud of irregular words and essentially perfect visual lexical decision, despite her severe semantic impairment. The pattern of performance shown by EM is consistent with the DRC model of reading, but inconsistent with the connectionist attractor model and with the view, associated with that model, that orthographic and phonological processes cannot remain intact when semantic representations are degraded.