bluuebunny/crossref_metadata_2025 huggingface dataset:
Beyond the Purely Cognitive: Belief Systems, Social Cognitions, and Metacognitions As Driving Forces in Intellectual Performance*
Authors: Schoenfeld Alan H.
Published: July 2005

This study explores the way that belief systems, interactions with social or experimental environments, and skills at the “control” level in decision‐making shape people's behavior as they solve problems. It is argued that problem‐solvers' beliefs (not necessarily consciously held) about what is useful in mathematics may determine the set of “cognitive resources” at their disposal as they do mathematics. Such beliefs may, for example, render inaccessible to them large bodies of information that are stored in long‐term memory and that are easily retrieved in other circumstances. In other cases, individuals' reactions to an experimental setting (fear of failure, or the desire to “look mathematical” while being videotaped) may induce behavior that is almost pathological—and at the same time, so consistent that it can be modeled. In general, such “environmental” factors establish the context within which individuals access and utilize the information potentially at their disposal.

Protocols illustrating these points are presented and discussed. A model based on an axiomatization of students' beliefs about plane geometry is outlined, and is shown to correspond closely to their problem‐solving performance. A framework is offered for analyzing problem‐solving performance at three qualitatively different levels: access to cognitive resources stored in LTM, executive or control decision‐making, and belief systems.
Learning to Program in LISP1
Authors: Anderson John R. , Farrell Robert , Sauers Ron
Published: July 2005

We have gathered protocols of subjects in their first 30 hours of learning LISP. The processes by which subjects write LISP functions to meet problem specifications has been modeled in a simulation program called GRAPES (Goal Restricted Production System). The GRAPES system embodies the goal‐restricted architecture for production systems as specified in the ACT* theory (Anderson, 1983). We compare our simulation to human protocols on a number of problems. GRAPES simulates the top‐down, depth‐first flow of control exhibited by subjects and produces code very similar to subject code. Special attention is given to modeling student solutions by analogy, how students learn from doing, and how failures of working memory affect the course of problem‐solving. Of major concern is the process by which GRAPES compiles operators in solving one problem to facilitate the solution of later problems.
On the Nature of Verbal Rules and Their Role in Problem Solving*
Authors: Chaiklin Seth
Published: July 2005

This paper develops the idea of a verbal rule as a concise, linguistic description of a plan for problem solving. The first section discusses the properties of verbal rules, including what they are, why they are useful, what kind of plan is described, the additional knowledge needed to convert them into performable procedures, and how they might be used in problem solving. The second section reports the results of an empirical study of the role of signed‐arithmetic verbal rules when they were instructed as a problem‐solving method. Analysis of problem‐solving protocols yields three kinds of results. Mental procedures constructed from verbal rules can be structurally different from the instructed verbal rules. Difficulties arise in selecting and executing procedures because of inadequate parsing procedures. Verbal rules tend to be used optionally and drop out of performance when a person becomes skilled, but they can be recalled and used explicitly when appropriate mental procedures are unavailable. Drawing on the results of the empirical study, the third section discusses the role of verbal rules in learning and problem solving, the process of converting verbal rules into mental procedures, and two hypotheses about the origins of systematic performance errors.
Eye‐Fixation Patterns During Reading Confirm Theories of Language Comprehension*
Authors: Carrithers Caroline , Bever Thomas G.
Published: July 2005

Eye‐movement patterns during reading are consistent with proposition‐by‐proposition models of speech comprehension. (1) Fixation times are least affected by word length at ends of clauses: this confirms the theory based on the study of speech comprehension that, at such points, attention is directed inward to text integration. (2) Fixation time for words at the end of clauses is longer for canonical sequences which conform to the pattern, “N‐V‐N = actor‐action‐object”; this confirms the view that complete semantic integration of such sequences is routinely delayed until their completion. A two‐variable model based on principles of exhaustive visual search and speech comprehension accounts for 80% of the fixation durations in a sample paragraph from Just and Carpenter (1980) and Thibodeou, Just ond Carpenter (1982). This comprehension‐based model compares favorably with their models constructed within a production‐system framework. This result clarifies the relationship between reading and listening.
Teachability of Reflective Processes in Written Composition
Authors: Scardamalia Marlene , Bereiter Carl , Steinbach Rosanne
Published: July 2005

Reflective thought, as sustained in writing, is attributed to two‐way communication between a content problem space and a rhetorical problem space. An instructional experiment involving sixth‐graders aimed at helping them sustain such a two‐way process independently, in place of the more typical one‐way process of generating content and writing it out. Instruction included modeling of thinking aloud, both by instructors and students, use of cues to stimulate self‐questioning during planning monologues, and direct strategy instruction emphasizing dialectical synthesis of conflicting ideas. Increased numbers of reflective statements in thinking‐aloud protocols and rated reflectiveness of compositions indicate gains were made at the level of reflection on individual ideas.
A Critique of Top‐down Independent Levels Models of Speech Production: Evidence from Non‐plan‐Internal Speech Errors*
Authors: Harley Trevor A.
Published: July 2005

A number of speech errors are examined which are difficult to account for by top‐down serial processing models of speech production which hove independent levels of processing. In particular, most of these errors are characterized by the presence of an interfering element which is external to the utterance under current construction. This paper has two main aims: to classify these errors, and to examine the constraints upon them. It is found that phonological similarity between the target and intrusion is a major determinant of error occurrence. The consequences for models of speech production are discussed in a framework consisting of the architecture and control structure of those models. A particular model to account for these data is proposed, consisting of a spreading activation lexical network.
Cognitive Control of Real‐Time Event‐Driven Systems*
Authors: Anzai Yuichiro
Published: July 2005

The paper discusses the development of cognitive skills in control of real‐time, event‐driven systems with long time lag. Using simulators of ship steering, and based on thinking‐aloud protocol experiments, it is shown that unskilled persons may devote most of the initial period of learning control skills to understanding the causal behavior of the human‐machine interface. Experts employ goal‐oriented strategies, planning from a relatively global view‐point. A possible explanation for the development of cognitive strategies is presented to account for the gathering of information about the control interface, the acquisition of various kinds of strategies, and the learning of control skills for real‐time, event‐driven systems with long time lag. A computer simulation model is presented that merges cognitive and control theory models, and that simulates the process of strategy development.
The Role of a Mental Model in Learning to Operate a Device*
Authors: Kieras David E. , Bovair Susan
Published: July 2005

This report presents three studies concerned with learning how to operate a simple control panel device, and how this learning is affected by understanding a device model that describes the internal mechanism of the device. The first experiment compared two groups, one of which learned a set of operating procedures for the device by rote, and the other learned the device model before receiving the identical procedure training. The model group learned the procedures faster, retained them more accurately, executed them faster, and simplified inefficient procedures far more often, than the rote group. The second study demonstrated that the model group is able to infer the procedures much more easily than the rote group, which would lead to more rapid learning and better recall performance. The third study showed that the important content of the device model was the specific configuration of components and controls, and not the motivational aspects, component descriptions, or general principles. This specific information is what is logically required to infer the procedures. Thus, the benefits of having a device model depend on whether it supports direct and simple inference of the exact steps required to operate the device.
Literal Meaning and Psychological Theory*
Authors: Gibbs Raymond W.
Published: July 2005

This paper evaluates the psychological status of literal meaning. Most linguistic and philosophical theories assume that sentences have well‐specified literal meanings which represent the meaning of a sentence independent of context. Recent debate on this issue has centered on whether literal meaning can be equated with context‐free meaning, or whether a sentence's literal meaning is determined only given a set of background assumptions. Neither of these positions meet the demands of a psychological theory of language understanding. Sentences do not have well‐defined literal meanings, regardless of whether these are determined in light of a set of background assumptions. Moreover, the putative literal meanings of sentences do not contribute in systematic ways toward the understanding of speakers' utterance meanings. These observations suggest that the distinctions between literal and metaphoric meanings, and between semantics and pragmatics, have little psychological validity.
EPAM‐like Models of Recognition and Learning*
Authors: Feigenbaum Edward A. , Simon Herbert A.
Published: July 2005

A description is provided of EPAM‐III, a theory in the form of a computer program for simulating human verbal learning, along with a summary of the empirical evidence for its validity. Criticisms leveled against the theory in a recent paper by Barsalou and Bower are shown to derive largely from their misconception that EPAM‐III employed a binary, rather than n‐ary branching discrimination net. It is shown that Barsalou and Bower also failed to understand how the recursive structure of EPAM‐III eliminates the need to duplicate test nodes that are used to recognize subobjects, and how the possibility of redundant recognition paths controls the sensitivity of EPAM to noticing order. EPAM is also compared briefly with other theories of human discrimination and discrimination learning, including PANDEMONIUM‐like systems and dataflow nets.
Conceptual Combination with Prototype Concepts*
Authors: Smith Edward E. , Osherson Daniel N.
Published: July 2005

This paper deals with how people combine simple, prototype concepts into complex ones; e.g., how people combine the prototypes for brown and apple so they can determine the typicality of objects in the conjunction brown apple. We first consider a proposal from fuzzy‐set theory (Zadeh, 1965), namely, that the typicality of an object in a conjunction is equal to the minimum of that object's typicality in the constituents (e.g., an object's typicality as a brown apple cannot exceed its typicality as a brown or as an apple). We evaluated this “min rule” against the typicality ratings of naive subjects in two experiments. For each of numerous pictured objects, one group of subjects rated its typicality with respect to an adjective concept, a second group rated its typicality vis‐à‐vis a noun concept, and a third group rated its typicality with respect to the adjective‐noun conjunction. In both studies, most objects were rated as more typical of the conjunction than of the noun. These findings violate not only the min rule but also other simple rules for relating typicality in a conjunction to typicalities in the constituents. As an alternative to seeking such rules, we argue for an approach to conceptual combination that starts with the prototype representations themselves. We illustrate one version of this approach in some detail, and show how it accounts for the major findings of the present experiments.
Causal Reasoning in Medicine: Analysis of a Protocol
Authors: Kuipers Benjamin , Kassirer Jerome P.
Published: July 2005

The ability to identify and represent the knowledge that a human expert has about a particular domain is a key method in the creation of an expert computer system. The first part of this paper demonstrates a methodology for collecting and analyzing observations of experts at work, in order to find the conceptual framework used for the particular domain. The second part develops a representation for qualitative knowledge of the structure and behavior of a mechanism. The qualitative simulation, or envisionment, process is given a qualitative structural description of a mechanism and some initialization information, and produces a detailed description of the mechanism's behavior. The simulation process has been fully implemented, and its results are shown for a particular disease mechanisms in nephrology. This vertical slice of the construction of a cognitive model demonstrates an effective knowledge acquisition method for the purpose of determining the structure of the representation itself, not simply the content of the knowledge to be encoded in that representation. Most importantly, it demonstrates the interaction among constraints derived from the textbook knowledge of the domain, from observations of the human expert, and from the computational requirements of successful performance.
An Attempt to Understand Students' Understanding of Basic Algebra*
Authors: Sleeman D.
Published: July 2005

This paper reports the results obtained with a group of 24 14‐year‐old students when presented with a set of algebra tasks by the Leeds Modelling System, LMS. These same students were given a comparable paper‐and‐pencil test and detailed interviews some four months later. The latter studies uncovered several kinds of student misunderstandings that LMS had not detected. Some students had profound misunderstandings of algebraic notation: Others used strategies such as substituting numbers for variables until the equation balanced. Additionally, it appears that the student errors fall into several distinct classes: namely, manipulative, parsing, clerical, and “random.”

LMS and its rule database have been enhanced as the result of this experiment, and LMS is now able to diagnose the majority of the errors encountered in this experiment. Finally, the paper gives a process‐oriented explanation for student errors, and re‐examines related work in cognitive modelling in the light of the types of student errors reported in this experiment. Misgeneralization is a mechanism suggested to explain some of the mal‐rules noted in this study.
Error Detection Processes in Statistical Problem Solving
Authors: Allwood Carl Martin
Published: July 2005

Problem solvers' error detection processes were studied by instructing 16 subjects to think aloud when solving two statistical problems. The evaluative episodes occurring in subjects' protocols were analyzed into Affirmative evaluation, Direct error‐hypotheses, Error suspicion, and Standard check episodes, the last three of which are assumed to cover all main types of error detection processes. Most errors (78%) were found to have contributed to a solution part that triggered some evaluative episode. However, only one‐third of the undetected errors had contributed to such a solution part. The Standard check episodes, seen as centrally‐invoked, only led to the detection of few errors in proportion to the number of times they were performed. Evidence was found for two types of spontaneous error detections, one occurring abruptly and the other as a result of a more elaborated error detection process, initiated by the solver perceiving the solution as dissatisfying or strange. The perception of a symptom was a fairly reliable source of information about errors. However, subjects often did not manage to detect the error after having noticed a symptom. The closer a relevant Error suspicion episode followed an error, the greater was the probability of detecting the error. Good problem solvers detected a higher proportion of their errors compared to poor problem solvers, probably due to differences in the processes leading up to the triggering of an evaluative episode rather than to differences after the episode had been triggered.
A Developmental Neural Model of Visual Word Perception
Authors: Golden Richard M.
Published: July 2005

A neurally plausible model of how the process of visually perceiving a letter in the context of a word is learned, and how such processing occurs in adults is proposed. The model consists of a collection of abstract letter feature detector neurons and their interconnections. The model also includes a learning rule that specifies how these interconnections evolve with experience. The interconnections between neurons can be interpreted as representing the spatially redundant, sequentially redundant, and transgraphemic information in letter string displays. Anderson, Silverstein, Ritz, and Jones's (1977) “Brain‐State‐in‐a‐Box” (BSB) neural mechanism is then used to implement the proposed model. The resulting system makes explicit qualitative predictions using both letter recognition accuracy and reaction time as dependent measures. In particular, the model offers an integrated explanation of some experiments involving manipulations of orthographic regularity, masking, case alternations, and experience with words. The similarities and differences between the model and models proposed by Adams (1979) and McClelland and Rumelhart (1981) are also discussed.
Systematicity and Surface Similarity in the Development of Analogy
Authors: Gentner Dedre , Toupin Cecile
Published: July 2005

This research investigates the development of analogy: In particular, we wish to study the development of systematicity in analogy. Systematicity refers to the mapping of systems of mutually constraining relations, such as causal chains or chains of implication. A preference for systematic mappings is a central aspect of analogical processing in adults (Gentner, 1980, 1983). This research asks two questions: Does systematicity make analogical mapping easier? And, if so, when, developmentally, do children become able to utilize systematicity?

Children aged 5–7 and 8–10 acted out stories with toy characters. Then they were asked to act out the same stories with new characters. Two variables were manipulated: systematicity, or the degree of explicit causal structure in the original stories, and the transparency of the object‐mappings. Transparency was manipulated by varying the similarity between the original characters and the corresponding new characters: it was included in order to vary the difficulty of the transfer task. If children can utilize systematicity, then their transfer accuracy should be greater for systematic stories.

The results show: (1) As expected, transparency strongly influenced transfer accuracy (for both age groups, transfer accuracy dropped sharply as the object correspondences became less transparent); and (2) for the older group, there was also a strong effect of systematicity and an interaction between the two variables. Given a systematic story, 9‐year‐olds could transfer it accurately regardless of the transparency of the object correspondence.
Parallel Computation and the Mind‐Body Problem
Authors: Thagard Paul
Published: July 2005

The position in the philosophy of mind called functionalism claims that mental states are to be understood in terms of their functional relationships to other mental states, not in terms of their material instantiation in any particular kind of hardware. But the argument that material instantiation is irrelevant to functional relationships is computationally naive. This paper uses recent work on parallel computation to argue that software and hardware are much more intertwined than the functionalists allow. Parallelism offers qualitative as well as quantitative advantages, leading to different styles of programming as well as increased speed. Hence hardware may well matter to the mental: only by further empirical investigations of the relation between the mind and brain and between artificial intelligence software and underlying hardware will we be able to achieve a defensible solution to the mind‐body problem. The major disadvantage of parallel systems is the need to coordinate their subprocesses, but recent proposals that consciousness provides a serial control for parallel computation are implausible.
Imputations and Explications: Representational Problems in Treatments of Prepositional Attitudes
Authors: Barnden John A.
Published: July 2005

The representation of propositional attitudes (beliefs, desires, etc.) and the analysis of natural‐language, propositional‐attitude reports presents difficult problems for cognitive science and artificial intelligence. In particular, various representational approaches to attitudes involve the incorrect “imputation,” to cognitive agents, of the use of artificial theoryladen notions. Interesting cases of this problem are shown to occur in several approaches to attitudes. The imputation problem is shown to arise from the way that representational approaches explicate properties and relationships, and in particular from the way they explicate propositional attitudes themselves. Another factor contributing to imputation is the compositional nature of typical semantic approaches to propositional‐attitude reports. Some strategies for avoiding undesirable imputation are examined. One of the main conclusions is that the importance of imputations that arise in a representation scheme depends strongly on the use to which the scheme is put—on whether, for instance, the scheme is used as part of a formal, objective account of natural language, or is used rather as a representational tool within an agent.
Logical Foundations for Belief Representation
Authors: Rapaport William J.
Published: July 2005

This essay presents a philosophical and computational theory of the representation of de re, de dicto, nested, and quasi‐indexical belief reports expressed in natural language. The propositional Semantic Network Processing System (SNePS) is used for representing and reasoning about these reports. In particular, quasi‐indicators (indexical expressions occurring in intentional contexts and representing uses of indicators by another speaker) pose problems far natural‐language representation and reasoning systems, because—unlike pure indicators—they cannot be replaced by coreferential NPs without changing the meaning of the embedding sentence. Therefore, the referent of the quasi‐indicator must be represented in such a way that no invalid coreferential claims are entailed. The importance of quasi‐indicators is discussed, and it is shown that all four of the above categories of belief reports can be handled by a single representational technique using belief spaces containing intensional entities. Inference rules and belief‐revision techniques for the system ore also examined.
Grammatical Morphemes and Conceptual Structure in Discourse Processing
Authors: Morrow Daniel G.
Published: July 2005

The present paper analyzes how the semantic and pragmatic functions of closed class categories, or grammatical morphemes (i.e., inflections and function words), organize discourse processing. Grammatical morphemes tend to express a small set of conceptual distinctions that organize a wide range of objects and relations, usually expressed by content or open class words (i.e., nouns and verbs), into situations anchored to a discourse context. Therefore, grammatical morphemes and content words cooperate in guiding the construction of a situation model during discourse comprehension by specifying complementary aspects of described situations. The paper reviews and extends analytical and empirical evidence for this grammatical‐conceptual correspondence, and suggests that the correspondence developed in response to the cognitive demands of discourse processing. Thus the distinction between open and closed linguistic categories is interpreted in terms of a fundamental correspondence between conceptual and linguistic structure that helps organize discourse processing.
Linguistic Intuitions are the Result of Interactions Between Perceptual Processes and Linguistic Universals
Authors: Gerken Louann , Bever Thomas G.
Published: July 2005

We found a direct relationship between variation in informants' grammaticality intuitions about pronoun coreference and variation in the same informants' use of a clause segmentation strategy during sentence perception. It has been proproposed that ‘c‐command’, a structural principle defined in terms of constituent dominance relations, constrains within‐sentence coreference between pronouns and noun antecedents. The relative height of the pronoun and the noun in the phrase structure hierarchy determines whether the c‐command constraint blocks coreference: Coreference is allowed only when the complement structure containing the noun is attached higher than the pronoun. We collected informants' judgments on pronoun‐noun coreference in which the noun antecedent was contained in a complement structure dominated by either the Sentence‐node (S‐node) (higher than the pronoun) or the Verb‐phrase‐node (VP‐node) (not higher than the pronoun). We also assessed each informant's perceptual clause‐closure tendency using an auditory word‐monitor paradigm. Informants who strongly segmented clauses in the perceptual task did not differentiate between an S‐ and VP‐attachment of sentence complements, as revealed in their coreference judgments, but rather appeared to attach all sentence complements to the S‐node. Informants with relatively weak perceptual segmentation differentiated their coreference judgments according to the node attachment of the complement structure. These results indicate that the linguistic universal controlling within‐sentence coreference applies to the perceptually available structure for a sequence, not to its pure linguistic structure. Hence, linguistic intuitions result from the interaction of three independent faculties: language‐specific knowledge, perceptual processes, and linguistic universals.
How much Do People Remember? Some Estimates of the Quantity of Learned Information in Long‐term Memory
Authors: Landauer Thomas K.
Published: July 2005

How much information from experience does a normal adult remember? The “functional information content” of human memory was estimated in several ways. The methods depend on measured rates of input and loss from very long‐ term memory and on analyses of the informational demands of human memory‐based performance. Estimates ranged around 109 bits. It is speculated that the flexible and creative retrieval of facts by humans is a function of a large ratio of “hardware” capacity to functional storage requirements.
Resveratrol Regulates Insulin-Like Growth Factor-II in Breast Cancer Cells
Authors: Vyas Sharda , Asmerom Yayesh , De León Daisy D.
Published: July 2005

IGF-II is a potent mitogen and inhibitor of apoptosis in breast cancer. Regulation of IGF-II is complex and includes inhibition by tumor suppressors, stimulation by oncogenes, and imprinting and hormonal regulation by estrogens. Resveratrol (RSV) is a phytoestrogen that displays estrogen-like agonistic and antagonistic activity. Recent studies have shown that RSV inhibits the growth of breast cancer cells and may represent a potent agent in chemopreventive therapy. Because 17β-estradiol regulates IGF-II, we hypothesized that RSV may have a similar effect on IGF-II. The present study was designed to examine whether: 1) RSV modulates IGF-II in breast cancer cells; 2) regulation of IGF-II by RSV is dependent on the ER status; and 3) IGF-II (not IGF-I) mediates RSV effects on breast cancer cells. Treatment of MCF-7 and T47D cells with RSV (10−6m) caused stimulation of precursor IGF-II mRNA and protein; this effect was blocked by coincubation with 17β-estradiol (10−9m). Cell growth stimulated by RSV (10−6m) was blocked by addition of a blocking IGF-I receptor antibody, or the antiestrogen tamoxifen (10−7m). In contrast, RSV treatment (10−4m) inhibited IGF-II secretion and cell growth in MCF-7 and T47D cells. No increase in IGF-II levels is seen in estrogen receptor (−) MCF-10 cells, even though cell growth was inhibited by RSV 10−4m and precursor IGF-II blocked the inhibitory effect of resveratrol. No change in IGF-I was observed with RSV treatment (10−6 to 10−4m). Our study demonstrates that RSV regulates IGF-II and that IGF-II mediates RSV effect on cell survival and growth in breast cancer cells.
Role of Sulfated Tyrosines of Thyroglobulin in Thyroid Hormonosynthesis
Authors: Nlend Marie-Christine , Cauvi David M. , Venot Nicole , Chabaud Odile
Published: July 2005

Our previous studies showed that sulfated tyrosines (Tyr-S) are involved in thyroid hormone synthesis and that Tyr5, the main hormonogenic site of thyroglobulin (Tg), is sulfated. In the present paper, we studied the role of Tyr-S in the formation and activity of the peroxidase-Tg complex. Results show that noniodinated 35SO3-Tg specifically binds (Kd = 1.758 μm) to immobilized lactoperoxidase (LPO) via Tyr-S linkage by using saturation binding and competition experiments. We found that NIFEY-S, a 15-amino acid peptide corresponding to the NH2-end sequence of Tg and containing the hormonogenic acceptor Tyr5-S, was a better competitor than cholecystokinin and Tyr-S. 35SO3-Tg, iodinated without peroxidase, bound to LPO with a Kd (1.668 μm) similar to that of noniodinated Tg, suggesting that 1) its binding occurs via Tyr-S linkage and 2) Tyr-S requires peroxidase to be iodinated, whereas nonsulfated Tyr does not. Iodination of NIFEY-S with [125I]iodide showed that Tyr5-S iodination increased with LPO concentration, whereas iodination of a nonsulfated peptide containing the donor Tyr130 was barely dependent on LPO concentration. Enzymatic hydrolysis of iodinated Tg or NIFEY-S showed that the amounts of sulfated iodotyrosines also depended on LPO amount. Sulfated iodotyrosines were detectable in the enzyme-substrate complex, suggesting they have a short life before the coupling reaction occurs. Our data suggest that after Tyr-S binding to peroxidase where it is iodinated, the sulfate group is removed, releasing an iodophenoxy anion available for coupling with an iodotyrosine donor.
Negative Regulation of Growth Hormone Receptor Signaling
Authors: Flores-Morales Amilcar , Greenhalgh Christopher J. , Norstedt Gunnar , Rico-Bautista Elizabeth
Published: July 2005

GH has been of significant scientific interest for decades because of its capacity to dramatically change physiological growth parameters. Furthermore, GH interacts with a range of other hormonal pathways and is an established pharmacological agent for which novel therapeutical applications can be foreseen. It is easy to see the requirement for a number of postreceptor mechanisms to regulate and control target tissue sensitivity to this versatile hormone. In recent years, some of the components that take part in the down-regulatory mechanism targeting the activated GH receptor (GHR) have been defined, and the physiological significance of some of these key components has begun to be characterized. Down-regulation of the GHR is achieved through a complex mechanism that involves rapid ubiquitin-dependent endocytosis of the receptor, the action of tyrosine phosphatases, and the degradation by the proteasome. The suppressors of cytokine signaling (SOCS) protein family, particularly SOCS2, plays an important role in regulating GH actions. The aim of this review is to summarize collected knowledge, including very recent findings, regarding the intracellular mechanisms responsible for the GHR signaling down-regulation. Insights into these mechanisms can be of relevance to several aspects of GH research. It can help to understand growth-related disease conditions, to explain GH resistance, and may be used to develop pharmaceuticals that enhance some the beneficial actions of endogenously secreted GH in a tissue-specific manner.
Embryonal rhabdomyosarcoma of adult nasopharynx
Authors: EL-Ghazali A M S , McLaren K M
Published: July 2005

Adult rhabdomyosarcomas in the head and neck are extremely rare and carry a poor prognosis. They should be considered as a distinct clinical entity. The authors report a case of embryonal rhabdomyosarcoma in an adult nasopharynx treated with a combined modality treatment of chemotherapy and radiotherapy as per the European International Society of Paediatric Oncology (SIOP) MMT 89 study, group D. The patient responded to treatment and 10 years later, he is still alive with no signs of metastatic disease.
Pott’s puffy tumour caused by mucormycosis
Authors: Effat K G , Karam M , El-Kabani A
Published: July 2005

A case of Pott’s puffy tumour in a diabetic patient with renal failure is reported. The patient did not respond to intravenous antibiotics and further investigation revealed that the patient had mucormycosis. As far as we are aware, this is the first case of Pott’s puffy tumour due
to mucormycosis to be reported in the literature.
Trans-telephonic monitoring of continuous haemodynamic measurements in heart failure patients
Authors: Kjellström Barbro , Igel David , Abraham JoAnn , Bennett Tom , Bourge Robert
Published: July 2005

The development of an implantable haemodynamic monitor (IHM) has made possible the home monitoring of a patient's central haemodynamic trends during daily living. We have evaluated the usability and transmission success of such a system over a 3.2-year period. Patients with an IHM were able to transmit the stored data every week to a Web server, where trend plots and tables of haemodynamic variables could be viewed by the health-care staff concerned. Data transfer was examined from August 2000 to November 2003. During this period, 148 patients had an IHM implanted. Over the study period, 7791 data transmissions were performed and an average of 286 downloads per month were sent to the Web server. In all, 86% of data transmissions were successful, although 10% required more than one attempt. The study demonstrated that telemonitoring of haemodynamic data from an IHM was feasible. A patient survey showed that the technology was user-friendly and that the training material provided sufficient information for patients and their families to install and use the transmission equipment at home. It also suggested that transmission success was independent of patient age or gender.
E-health and the Universitas 21 organization: 2. Telemedicine and underserved populations
Authors: Wootton Richard , Jebamani Laurel S , Dow Shannon A
Published: July 2005

Telemedicine activities in underserved communities were reviewed as part of the Universitas 21 (U21) e-health project. A SWOT analysis (strengths, weaknesses, opportunities, threats) was conducted on 12 articles identified in a literature review, supplemented by expertise from U21 members. The analysis showed that threats include the reluctance of populations to use telemedicine services, and a general absence of infrastructure and resources to sustain them. Opportunities centre around potential research, including cost-effectiveness analyses and quantitative assessments of existing telemedicine services. The great strength of telemedicine is that it can improve access to health services among those most in need. However, its greatest weakness is the lack of evidence supporting its clinical and cost advantages relative to traditional services. This represents an important opportunity for research on telemedicine initiatives among underserved populations.
A review of the first five years of the University of Arizona telepsychiatry programme
Authors: Cruz Mario , Krupinski Elizabeth A , Lopez Ana Maria , Weinstein Ronald S
Published: July 2005

We performed a retrospective review of the first five years of activity in the University of Arizona Telepsychiatry Programme. The programme began in 1998 as part of a telemedicine service for underserved rural areas. Over the first five years, 1086 teleconsultations were carried out for a total of 206 patients. There were 159 adult (77%) and 47 paediatric patients (23%). During the study period, the racial/ethnic diversity of the paediatric patients increased, as did the number of follow-up visits for adult patients (average 5.3/patient). These trends suggested that telepsychiatry became an integral part of the mental health service system at the six referring sites. Adult patients completed 81 satisfaction surveys (51%) and psychiatrists completed 47 (23%). The responses showed that providers and patients found telepsychiatry services satisfactory, although in a minority of teleconsultations (18% for providers and 17% for patients) equipment problems were distracting. The continued use of the services suggests that the telepsychiatry programme fills a service gap in rural areas of the state.
Telemedicine in radiotherapy: a study exploring remote treatment planning, supervision and economics
Authors: Norum Jan , Bruland Øyvind S , Spanne Oddvar , Bergmo Trine , Green Tor , Olsen Dag R , Olsen Jan H , Sjåeng Elisabeth E , Burkow Tatiana
Published: July 2005

In January 2002, the departments of radiotherapy at the University Hospital of North Norway and the Norwegian Radium Hospital were connected through a 2 Mbit/s digital telecommunication line. The treatment planning systems at the two institutions were connected and videoconferencing units were installed. We explored the feasibility of remote treatment planning, supervision, second opinions and education. Tests involved two dummy cases and six patients. Remote simulation procedures were carried out for five patients. A cost-minimization analysis was performed. Treatment planning was not completely successful as the software could not handle plans including bolus or weighting between the fields. Remote supervision was possible. A common patient record and radiotherapy system, including digital imaging, digital prescription and approval forms and digital signature, were felt to be desirable. The threshold (break-even point) comparing the costs of telemedicine with those of transportation by air was 12 patients/year. Telemedicine in radiotherapy appears to be feasible, but some limitations must be overcome.
E-health and the Universitas 21 organization: 3. Global policy
Authors: Scott Richard E , Lee Anna
Published: July 2005

There is an urgent need to develop global e-health policy in order both to facilitate and to manage the potential of e-health. As part of the Universitas 21 (U21) project in e-health, an evaluation of the status of global e-health policy was performed using a SWOT analysis (strengths, weaknesses, opportunities and threats). The analysis showed that the greatest threat to global e-health policy is the autonomous nature of domestic health-care systems. The greatest opportunity may be the prospect for nations and individuals to work together in establishing mechanisms necessary to offer health-care access through global e-health – a new 'global public good'. Full integration of e-health into existing health-care systems could be achieved in both a practical and a policy sense through global e-health policy initiatives that facilitate integration across jurisdictions. There is a pressing need to resolve a range of e-health policy issues, and a concomitant need for research that will inform and support the process. A process that adopts a global approach is recommended.
Telemedicine in haemodialysis: a university department and two remote satellites linked together as one common workplace
Authors: Rumpsfeld Markus , Arild Eli , Norum Jan , Breivik Elin
Published: July 2005

A common workplace was established between the renal unit at the University Hospital of North Norway and two satellite dialysis centres, in Alta and Hammerfest. A 2 Mbit/s ATM network was employed for IP-based videoconferencing. A common electronic medical record system and dialysis monitoring software were used. During an eight-month study period, nine patients were enrolled and 225 videoconferences were performed for daily visits and regular rounds. A bandwidth of 768 kbit/s was required for satisfactory teledialysis. Although technical (28%) and logistical problems (10%) were frequent, five hospitalizations and one-third of the planned visiting rounds were avoided. An economic analysis showed that annual savings amounted to US$46,613, while annual costs were US$79,489. Despite the technical difficulties in about 30% of conferences, the nurses were satisfied with the videoconferencing system. Digital X-rays were communicated without problems. The pilot study indicates that satellite units may be incorporated into the daily management at the central institution by telemedicine.
E-health and the Universitas 21 organization: 4. Professional portability
Authors: Goldberg Michael A , Sharman Zena , Bell Brandi , Ho Kendall , Patil Niv
Published: July 2005

Professional portability is the ease with which health-care professionals can move in person or virtually across barriers, and among and between jurisdictions, to transfer their knowledge, skills and care. As part of the Universitas 21 (U21) project on e-health, professional portability was examined using a SWOT analysis (strengths, weaknesses, opportunities and threats). The analysis showed that many factors hamper the development of global professional portability; on the other hand, the potential exists to substantially improve access to health care and its quality around the world. The study suggests that professional portability can be advanced in a number of ways. These include exploring policy, technology and medical training. The field of professional portability, while of considerable relevance to health and other professions, is undeveloped and is clearly an area that would benefit from discussion, research and global collaboration.
E-health and the Universitas 21 organization: 1. Global e-health through synergy
Authors: Ho Kendall , Sharman Zena
Published: July 2005

The Universitas 21 (U21) organization funded a one-year project to examine global e-health. An e-health steering committee surveyed the opinions of e-health researchers at U21 member schools and conducted a literature review. Information about key themes was analysed and the findings were summarized. The steering committee recommended an eight-step strategy to establish a sustainable endeavour in global e-health. This included implementing a dissemination strategy within the U21 organization to engage a progressively larger community of faculty members and others, and translating e-health knowledge into global practice in those areas in which the U21 has special expertise. While the recommendations in the discussion paper are specific to the U21 organization, the e-health steering committee believes they can be generalized and applied to any globally minded educational or research institutions seeking to contribute to e-health.
Evaluation of a realtime, remote monitoring telemedicine system using the Bluetooth protocol and a mobile phone network
Authors: Jasemian Yousef , Arendt-Nielsen Lars
Published: July 2005

A generic, realtime wireless telemedicine system has been developed that uses the Bluetooth protocol and the general packet radio service for mobile phones. The system was tested on 10 healthy volunteers, by continuous monitoring of their electrocardiograms (ECGs). Under realistic conditions, the system had 96.5% uptime, a data throughput of 3.3 kbit/s, a mean packet error rate of 8.5 × 10−3 packet/s and a mean packet loss rate of 8.2 × 10−3 packet/s. During 24 h testing, the total average downtime was 66 min and 90% of the periods of downtime were of only 1–3 min duration. Less than 10% of the ECGs were of unacceptable quality. Thus, the generic telemedicine system showed high reliability and performance, and the design may provide a foundation for realtime monitoring in clinical practice, for example in cardiology.
Preparation and Properties of Reduced-Charge Smectites — A Review
Authors: Komadel Peter , Madejová Jana , Bujdák Juraj
Published: July 2005

Layer charge reduction of selected homoionic swelling clay minerals upon heating is reviewed. This phenomenon is known for Li+-montmorillonites as the Hofmann-Klemen effect. Aspects covered in the review include: mechanism of the charge reduction caused by the irreversible migration of small cations into the mineral layers; final sites of the fixed cations in the octahedral and/or tetrahedral sheets, as deduced on the basis of structural and spectroscopic data obtained in several studies; effects of octahedral and tetrahedral components of the layer charge; properties of the exchangeable cations; and the chemistry and structure of the mineral on charge reduction. Current knowledge has been summarized on the changes of various mineral properties connected with charge reduction, including the loss of swelling and the decrease in the cation exchange capacity, the most important change upon cation fixation. Also discussed are the preparation, properties, and advantages of uses of series of reduced-charge montmorillonites (RCMs) in research; interactions of RCMs with alkylammonium cations and organic cationic dyes, with some examples on the interactions with organic polymers and other organic compounds. Properties of organo-complexes and composite materials prepared from RCMs are also included in this review.
Cation Exchange and Pillaring of Smectites by Aqueous Fe Nitrate Solutions
Authors: Dramé Harouna
Published: July 2005

A comparative study of the behavior of four types of smectite is reported: two with a low Fe content, SHCa-1 (hectorite from San Bernadino, California), SWy-1 (montmorillonite from Wyoming) and two nontronites NG-1 (from Hohen Hagen, Germany) and SWa-1 (Grant County, Washington). Cation exchange was performed with a freshly prepared 1 M Fe nitrate aqueous solution. Intercalation with the same solution partially neutralized with an anhydrous carbonate solution, giving a molar ratio of OH−/Fe = 2 was also studied. The modified clays were characterized by X-ray diffraction, N2 adsorption-desorption, Mossbauer spectroscopy, thermogravimetric analysis, atomic absorption spectroscopy, X-ray fluorescence and inductively coupled plasma analysis.

In the cation exchange process, the goethite impurities grew with the Fe-rich clays but not with the Fe-poor clays. This exchange was also found to have no effect on the thermal stability and structure of the clay minerals with low Fe content, whereas it had a slight effect on the structure of the Fe-rich clays and on their thermal stability. The extent of the intercalation, however, appears to depend on the expandability of the clay layers to accommodate the Fe(III) polycations, and increases from the nontronites to montmorillonite and to hectorite. This intercalation treatment has only a slight effect on both the structure and the thermal stability of hectorite and montmorillonite. In contrast, the nontronites undergo a dramatic change in both their structure and thermal stability. The formation of Fe oxyhydroxide and oxide phases in both procedures becomes very important when the initial structural Fe content of the clay minerals is high, increasing from SHCa-1, SWy-1, SWa-1 to NG-1. The contribution of the structural Fe of the clays to the formation of the Fe oxyhydroxide is not negligible, because of partial leaching of Fe from the octahedral sheet of Fe-rich clays due to the low pH of the solutions.