bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microencapsulation
Authors: Prakash Satya , Bhathena Jasmine 
Published: April 2006

AbstractOver the past two decades, microencapsulation research has made great strides in developing approaches for the controlled release of therapeutic agents, targeted delivery of drugs, bacterial cells, mammalian cells, DNA and other nucleic acids, proteins, and so on to the host. Microencapsulation is a process whereby biologically active materials, such as tissue, cells, or cellular constituents, are enclosed within microscopic, semipermeable polymeric membranes which allows for bidirectional diffusion necessary for the entry of nutrients and oxygen and the exit of therapeutic protein products and cellular metabolic waste materials. In addition, the membrane is protective against larger molecules such as antibodies, white blood cells, or tryptic enzymes. The concept of microencapsulation was officially introduced in the 1960s by T. M. S. Chang, who coined the term “artificial cell” to describe the technology. The field has since broadened with the development of novel microencapsulation devices, improved membrane parameters and more suitable cell lines. Consequently, microencapsulation is currently being tested for the treatment of a wide variety of disorders such as kidney and liver failure, diabetes mellitus, anemia, dwarfism, hemophilia, and central nervous system insufficiencies. Although transplantation remains the primary mechanism in which cellular microcapsules are introduced, oral administration through the gastrointestinal tract has been successfully applied. In discussing microencapsulation technology, a major distinction is in the use of artificial cells that now range from macro‐dimensions, to micron‐dimensions, to nano‐dimensions, and to molecular dimensions. Details of the various microcapsule membranes and microencapsulation methods for encapsulation of live mammalian cells, bacterial cells, drugs and other bioactive molecules are described. Further, the uses of microencapsulation technology in pharmaceutical, biotechnological, biomedical and clinical applications including current challenges and future prospects are illustrated.
Flow in Healthy and Stenosed Arteries
Authors: Tang Dalin 
Published: April 2006

AbstractMathematical and computational models for blood flow in normal and diseased arteries include vessel geometry, material properties, governing equations, and proper initial and boundary conditions. Models for stenosis, carotid, coronary, aorta, abdominal aortic aneurysm, pulmonary capillaries, graft, and stent are presented, with controlling factors and research focuses for each model discussed and proper references cited. Recent trends and potential applications for artery modeling are also discussed.
Aortic Stenosis and Systemic Hypertension, Modeling of
Authors: Garcia Damien , Durand Louis-Gilles 
Published: April 2006

AbstractAortic stenosis is the most common cardiovascular disease after systemic hypertension and coronary artery disease in developed countries. It induces an obstruction to blood flow from the left ventricle to the aorta resulting in an increase in left ventricular afterload. More than 30% of patients with aortic stenosis have concomitant systemic hypertension. In such patients, the left ventricle faces a double pressure overload (valvular and vascular). A detailed understanding of the respective impacts of aortic stenosis and hypertension on left ventricular function would help to better predict whether aortic valve replacement and/or antihypertensive medical treatment would be beneficial. To better understand how coexisting aortic stenosis and hypertension affect the left ventricular function, we developed a relatively simple mathematical cardiovascular model to simulate the ventricular‐valvular‐vascular hemodynamic interaction(V3model). The present chapter provides a detailed description of the V3model along with numerical findings as well as their clinical implications. Several simulations with the V3model were performed to describe the effect of aortic stenosis on left ventricular stroke work and show the effect of coexistent systemic hypertension. Our simulations demonstrated that mild or moderate aortic stenosis has a small impact on left ventricular stroke work, whereas the latter increases noticeably when aortic stenosis becomes severe. They also showed that even mild hypertension may greatly influence left ventricular stroke work in patients with aortic stenosis. The mathematical V3model thus provides a potentially useful tool to investigate complex cardiovascular interactions that could be of great clinical interest.
Multivariate Biomedical Signal Processing
Authors: Rezek Iead 
Published: April 2006

Abstract
Modeling physiological functions, such as heart rate and respiration, cannot be done singly, as they are interdependent due to the nervous system. Thus, they must be modeled as a set. This paper discusses modeling entire sets of variables. Probability is taken into consideration. The paper introduces the topic, then discussed multivariate linear models. The next section covers multivariate maximum likelihood inference, followed by a section on multivariate Bayesian inference. Examples and extensions are presented next. The paper concludes with an appendix on expanding a linear model with an uninformative prior.
Functional Optical Imaging of Intrinsic Signals in Cerebral Cortex
Authors: Hallum L. E. , Chen S. C. , Cloherty S. L. , Morley J. W. , Suaning G. J. , Lovell N. H. 
Published: April 2006

Abstract
Functional optical imaging of intrinsic signals (OIIS) measures very small changes in the absorption and reflectance of light from neural tissue during a physiological event. These small changes, usually less than 2% of the dc‐coupled signal, may be captured by a light‐sensitive device such as a CCD (charge‐coupled device) camera. These small signals are, by way of cerebral metabolism and hemodynamics, an indirect means of measuring neural activity. As a result of the small size of the signals, many aspects of the acquisition system are designed so as to minimize noise and nontrivial image processing is often required to extract the signals from the raw image sequence. The OIIS technique has been central to neuroscience research in the past two decades and is of increasing clinical relevance. It is frequently used to identify functional maps of cortical regions of interest, especially, but not limited to, the visual cortex, auditory cortex, somatosensory cortex, and olfactory bulb. Animal models studied include rats, cats, chinchillas, and monkeys. More recently, OIIS has been used intraoperatively in humans to further the understanding of the diseased brain, such as the brain in seizure. Optical imaging may resolve the spatial details of neural activity to within 50 μm, yet the temporal resolution of neural activity observed via intrinsic signals is limited because of the origin of the intrinsic signals in cerebral metabolism and hemodynamics. OIIS requires the tissue in question to be exposed to the light‐sensitive device. However, with respect to the target tissue, it is less invasive than traditional microelectrode recordings of single‐cell activity or fluorescent dye imaging techniques.
A perceptual discrimination investigation of the own‐race effect and intergroup experience
Authors: Walker Pamela M. , Hewstone Miles 
Published: April 2006

AbstractResearch over the past two decades has demonstrated that individuals are better at the recognition and discrimination of own‐ versus other‐race faces. Recent evidence, however, supports an own‐race effect at the level of perceptual encoding in adults. The current study examines the perceptual basis of the own‐race effect in secondary students from two racially segregated communities (White and South Asian). The contact hypothesis is investigated, as other‐race experience may influence other‐race face perception. Face stimuli were generated by morphing together South Asian and White faces along a linear continuum. In a same/different perceptual discrimination task participants judged whether face stimuli were physically identical to, or different from, the original faces. Results revealed a significant own‐race effect for the White participants only, wherein they were better at discriminating White relative to South Asian faces. Other‐race individuating experience was found to predict the own‐race effect, indicating that other‐race experience influences other‐race face perceptual expertise. Copyright © 2006 John Wiley & Sons, Ltd.
Learning a spatial skill for surgery: how the contributions of abilities change with practice
Authors: Keehner Madeleine , Lippa Yvonne , Montello Daniel R. , Tendick Frank , Hegarty Mary 
Published: April 2006

AbstractWe examined changes in performance as people learned to use an angled laparoscope, a challenging spatial skill that must be mastered by surgeons who perform minimally invasive techniques. In Experiment 1, novices took tests of spatial and general reasoning ability, and then learned to operate an angled laparoscope, simulated in a virtual environment, over 12 learning sessions. Initial performance showed considerable variability among learners, with performance related to general and spatial abilities. As learning progressed, interindividual variability diminished and all learners attained proficiency; the correlation with general ability diminished but the correlation with spatial ability remained significant. In Experiment 2, performance by highly experienced surgeons on the simulation was excellent from the first session, confirming its ecological validity. The findings contribute to theories of skill acquisition. They also have practical implications for the selection of surgeons and for the potential use of virtual environments in surgical training. Copyright © 2006 John Wiley & Sons, Ltd.
The impact of background musical tempo and timbre congruity upon ad content recall and affective response
Authors: Oakes Steve , North Adrian C. 
Published: April 2006

AbstractThis study investigated whether the tempo and timbre of background music influenced responses to radio ads. In Experiment 1 (in addition to a no‐music control condition), slow‐ or fast‐tempo background music was superimposed over the same ad. The slow‐tempo music treatment produced significantly higher levels of ad content recall compared to the fast‐tempo music treatment. Musical presence (slow‐ and fast‐tempo treatments combined vs. no‐music) significantly reduced levels of ad content recall. In Experiment 2, when three versions of digitally produced background music timbres were superimposed over a no‐music version of another ad, results revealed positive main effects of timbre congruity upon recall of ad content and affective responses to the ad. Copyright © 2006 John Wiley & Sons, Ltd.
The effects of aging on remembering intentions: performance on a simulated shopping task
Authors: Farrimond Samantha , Knight Robert G. , Titov Nick 
Published: April 2006

AbstractThree studies are described in which age differences on a task measuring memory for delayed intentions using naturalistic stimuli were examined. A simulated street scene was constructed from a network of photographs and sounds that participants could move through using a touch screen while completing a series of event‐based shopping errand instructions. The objective of the research was to identify the cognitive processes involved in the task that were vulnerable to the effects of ageing. Memory search but not cue detection was specifically affected in older persons when participants were given fewer trials to learn the instructions. There was no age specific effect on cue detection or memory search in either an unfamiliar street or one with increased levels of irrelevant visual and auditory noise. Cue detection but not memory search was disproportionately affected in older persons after filled interruptions, suggesting that the capacity for self‐initiated reinstatement of working memory is reduced in old age. In general, using a computer‐based simulation of a real‐life task was found to be a practical means of examining the effects on behaviour and cognition of task parameters that are significant in assessing everyday memory abilities. Copyright © 2006 John Wiley & Sons, Ltd.
Learner and information characteristics in the design of powerful learning environments
Authors: Paas Fred , Kester Liesbeth 
Published: April 2006

AbstractThis themed issue aims to present some current directions in cognitive load research. The contributions to this issue represent a compilation of symposia contributions to the 11th European Conference for Research on Learning and Instruction (EARLI), 2005, in Nicosia, Cyprus. These cognitive load symposia were focused on empirical and theoretical perspectives on designing powerful learning environments by aligning learner characteristics, information characteristics, or both with the knowledge structures underlying the cognitive architecture. This article provides an introduction to cognitive load theory and the instructional design consequences of these characteristics, and a short overview of the contributions to this issue. Copyright © 2006 John Wiley & Sons, Ltd.
Impact of reducing intrinsic cognitive load on learning in a mathematical domain
Authors: Ayres Paul 
Published: April 2006

AbstractThis paper examines the effectiveness of instructional strategies that lower cognitive load by reducing task complexity (intrinsic cognitive load). Three groups of 13‐year‐old students were required to learn a mathematical task under different conditions. One group (Isolated) followed a strategy that used part‐tasks where the constituent elements were isolated from each other (element isolation). A second group (Integrated) received whole tasks where all elements were fully integrated, and a third group (Mixed) followed a mixed strategy progressing from part‐tasks to whole‐tasks. Results indicated that the part‐task strategy was effective in lowering cognitive load for all students, but only benefitted learning for students with low prior knowledge. In contrast, students with a higher prior knowledge learned significantly more having studied whole tasks during instruction compared with part‐tasks. The mixed‐mode method proved to be ineffective for both levels of prior knowledge. These results are discussed in terms of cognitive load theory. Copyright © 2006 John Wiley & Sons, Ltd.
Problem format and presentation sequence: effects on learning and mental effort among US high school students
Authors: Olina Zane , Reiser Robert , Huang Xiaoxia , Lim Jung , Park Sanghoon 
Published: April 2006

AbstractThe study involving 209 high school students in an instructional program about comma rules was an attempt to test the concepts of cognitive load theory in a real classroom setting. It investigated the effects of (a) cued versus conventional problems and (b) blocked versus random problem presentation sequence during practice on the performance and perceived mental effort of lower‐ and higher‐achieving students. The researchers anticipated that cued problems would reduce learner extraneous cognitive load while random problem presentation sequence would increase germane cognitive load. The researchers also predicted that expected effects may not hold true for higher‐achieving students. The treatments yielded a near‐significant interaction effect for mental effort ratings indicating that conventional problems may have appeared harder to lower‐achieving students while cued problems may have appeared harder to higher‐achieving students. There were no notable performance differences. Issues related to researching cognitive load theory effects in a real classroom setting are discussed. Copyright © 2006 John Wiley & Sons, Ltd.
Modality and variability as factors in training the elderly
Authors: van Gerven Pascal W. M. , Paas Fred , van Merriënboer Jeroen J. G. , Schmidt Henk G. 
Published: April 2006

AbstractCognitive load theory (CLT) predicts that bimodal processing of instructional material decreases the level of extraneous cognitive load, whereas increased training variability increases the level of germane cognitive load. It was hypothesized that a combination of these strategies leads to optimal learning, especially in older adults. Forty young and forty elderly learners were trained to solve complex problems. The results showed that bimodal training leads to lower cognitive load than unimodal training. Furthermore, random presentation of examples (high variability) led to higher performance than blocked presentation (low variability) in both age groups. However, there was no combined effect of modality and variability. Moreover, the elderly did not take disproportionate advantage of the bimodal and random conditions. It was concluded that these training methods bear important potential in the light of lifelong learning. Copyright © 2006 John Wiley & Sons, Ltd.
Cognitive load and the format of instructional aids for coherence formation
Authors: Seufert Tina , Brünken Roland 
Published: April 2006

AbstractLearning with multiple representations is a highly demanding cognitive process because learners have to build referential connections between externally presented representations in order to construct a coherent mental representation. Several approaches for supporting coherence formation have been examined, which can be assigned to two types of helping strategies: first, learners can be assisted in recognising corresponding elements and structures on a surface feature level (e.g. by hyperlinking). Second, they can be supported on a deep structure level (i.e. by explaining the relations of corresponding structures more or less explicitly). In a 2 × 2 experimental study the effects on learning performance and cognitive load of both types of help were compared. Results show that coherence formation can be efficiently supported by deep structure level help (DLH) especially in combination with surface level help (SLH). Hyperlinks seem to guide learners' attention to relevant connections that are additionally explained by the deep structure help. Copyright © 2006 John Wiley & Sons, Ltd.
Assessment of learners' organised knowledge structures in adaptive learning environments
Authors: Kalyuga Slava 
Published: April 2006

AbstractOrganised knowledge structures (schemas) in long‐term memory (LTM) alter the characteristics of working memory (WM). Therefore, tracing the content of WM during problem solving may provide a measure of levels of acquisition of corresponding schematic knowledge structures. In this paper, a proposed rapid approach to diagnostic assessment of levels of acquisition of organised domain‐specific knowledge structures has been used as a means of optimising cognitive load by tailoring instructions to levels of learner expertise in an adaptive computer‐based tutor in kinematics. Two alternative adaptation procedures were compared to the control condition without an adaptation. The first procedure used only results of learners' rapid test performance, and the second one combined rapid measures of performance with measures of mental load. The study indicates that the developed assessment instruments could be embedded into adaptive e‐learning packages as diagnostic tools for tailoring instructional materials to changing levels of student expertise in cognitively optimal ways. Copyright © 2006 John Wiley & Sons, Ltd.
Teaching complex rather than simple tasks: balancing intrinsic and germane load to enhance transfer of learning
Authors: van Merriënboer Jeroen J. G. , Kester Liesbeth , Paas Fred 
Published: April 2006

AbstractResearch indicates that effective instructional methods for practicing simple tasks differ from effective methods for complex tasks. But unfortunately, load‐reducing methods that work relatively well to reach high retention performance for complex tasks, such as low variability and complete guidance and feedback, are precisely those methods that hinder transfer of learning. This article presents a training design approach aimed at high transfer performance for complex tasks. The basic idea is that learning tasks should always be combined with methods that induce germane cognitive load, such as high variability and limited guidance or feedback. However, especially for novices, this can only be realised by decreasing intrinsic load early in training by manipulating the element interactivity of the learning tasks. Copyright © 2006 John Wiley & Sons, Ltd.
Discussion of ‘emerging topics in cognitive load research: using learner and information characteristics in the design of powerful learning environments’
Authors: Sweller John 
Published: April 2006

AbstractCognitive load theory began by using our knowledge of human cognition to devise instructional procedures. Insofar as those procedures have been successful, they have strengthened the cognitive theory that gave rise to them. Indeed, it has been possible to expand our knowledge of cognition by studying the manner in which information can be successfully presented to learners. As a consequence, today, cognitive load theory spans a range from the evolutionary origins of human cognitive structures to the instructional consequences that flow from those structures. In this discussion I will begin by outlining five principles that give rise to the cognitive architecture basic to cognitive load theory. I will then discuss the papers of this issue in light of this theoretical framework. Copyright © 2006 John Wiley & Sons, Ltd.
Comparison of Charge‐Carrier Transport in Thin Films of Spiro‐Linked Compounds and Their Corresponding Parent Compounds
Authors: Saragi T. P. I. , Fuhrmann‐Lieker T. , Salbeck J. 
Published: April 2006

AbstractThe charge‐transport properties of the spiro‐linked compounds 2,2′,7,7′‐tetrakis(diphenylamino)‐9,9′‐spirobifluorene, 2,2′,7,7′‐tetrakis(N,N′‐di‐p‐methylphenylamino)‐9,9′‐spirobifluorene, 2,2′,7,7′‐tetra(m‐tolyl‐phenylamino)‐9,9′‐spirobifluorene, and 2,2′,7,7′‐tetra(N‐phenyl‐1‐naphthylamine)‐9,9′‐spirobifluorene, and their corresponding parent compounds, N,N,N′,N′‐tetraphenylbenzidine, N,N,N′,N′‐tetrakis(4‐methylphenyl)benzidine, and N,N′‐bis(3‐methylphenyl)‐(1,1′‐biphenyl)‐4,4′‐diamine, N,N′‐diphenyl‐N,N′‐bis(1‐naphthyl)‐1,1′‐biphenyl‐4,4′‐diamine, are investigated. The field‐effect mobilities of charge carriers in thin films of the parent compounds are slightly higher than those of the spiro‐linked compounds. However, the transistor action of the parent‐compound thin films vanishes because the films crystallize after being stored in ambient atmosphere for a few days. In contrast, the hole mobilities in thin films of the spiro‐linked compounds do not change significantly after the samples are stored in ambient atmosphere for up to nine months. Also discussed is the temperature dependency of the mobilities of charge carriers, which is presented using two models, namely the Arrhenius and the Gaussian disorder models.