bluuebunny/crossref_metadata_2025 huggingface dataset:
Decision Theory and Artificial Intelligence II: The Hungry Monkey*
Authors: Feldman Jerome A. , Sproull Robert F.
Published: October 2005

This paper describes a problem‐solving framework In which aspects of mathematical decision theory are incorporated into symbolic problem‐solving techniques currently predominant in artificial intelligence. The utility function of decision theory IS used to reveal tradeoffs among competing strategies for achieving various goals, taking into account such factors as reliability, the complexity of steps in the strategy, and the value of the goal. The utility function on strategies can therefore be used as a guide when searching for good strategies. It is also used to formulate solutions to the problems of how to acquire a world model, how much planning effort is worthwhile, and whether verification tests should be performed. These techniques are illustrated by application to the classic monkey and bananas problem.
Problem Solving in Semantically Rich Domains: An Example from Engineering Thermodynamics*
Authors: Bhaskar R. , Simon Herbert A.
Published: October 2005

Recent research on human problem solving has largely focused on laboratory tasks that do not demand from the subject much prior, task‐related information. This study seeks to extend the theory of human problem solving to semantically richer domains that are characteristic of professional problem solving. We discuss the behavior of a single subject solving problems in chemical engineering thermodynamics. We use as a protocol‐encoding device a computer program called SAPA which also doubles as a theory of the subject's problem‐solving behavior. The subject made extensive use of means‐ends analysis, similar to that observed in semantically less rich domains, supplemented by recognition mechanisms for accessing information in semantic memory.
What Sort of Taxonomy of Causation Do We Need for Language Understanding?*
Authors: Wilks Yorick
Published: October 2005

A proposal is made concerning the introduction of the notions of cause and reason into a natural language understanding system. Its hypothesis is that one should prefer rational explanations of actions when dealing with human, or human‐like, agents, if one can find them in what one is analyzing, but that in other, nonhuman, cases one should prefer causal explanations. The reader is reminded of the existing state of the preference semantics system, and then are described the changes that would have to be made to incorporate the above proposal and to find examples to test it. Finally, it is argued that there is no reason to think that a more complex taxonomy of causes (beyond the opposition of causes and reasons) is required, at least not if, as here. one seeks a procedural distinction corresponding to any taxonomic distinction among inference rules.
A Simulation of Visual Imagery*
Authors: Kosslyn Stephen M. , Shwartz Steven P.
Published: October 2005

This paper describes an operational computer simulation of visual mental imagery in humans. The structure of the simulation was motivated by results of experiments on how people represent information in, and access information from, visual images. The simulation includes a “surface representation,” which is spatial and quasi‐pictorial, and an underlying “deep representation,” which contains “perceptual” information encoding appearance plus “propositional” information describing facts about an object. The simulation embodies a theory of how surface images are generated from deep representations, and how surface images are processed when one accesses information embedded in them. The simulation also offers an account of various sorts of imagery transformations.
Identifying the Relevant Aspects of a Problem Text*
Authors: Hayes J. R. , Waterman D. A. , Robinson C. S.
Published: October 2005

Forty‐nine subjects judged the relevancy of sentence parts of a word problem (the Allsports problem). Patterns of subjects' judgments suggest three problem‐solving heuristics: a SETS heuristic, a TIME heuristic, and a QUESTION heuristic. Presentation of the question before the problem tends to suppress SETS and TIME heuristics. A computer program (ATTEND) is presented to simulate subjects' behavior on the Allsports problem. The program is context‐sensitive in that it can change a relevance judgment upon the acquisition of further information. Averaged subject judgments and ATTEND judgments agree for 87% of the items.
Framed PAINTING: The Representation of a Common Sense Knowledge Fragment
Authors: Charniak Eugene
Published: October 2005

This paper presents a “frame” representation for common sense knowledge and uses it to formalize our knowledge of “mundane” painting (walls; not portraits). These frames. while designed to aid a computer program to understand stories about the painting process, should be of use to programs which attempt to actually carry out the activity. The paper stresses a “deep” understanding of the activity so that the representation indicates not only what steps to carry out, but also how to do them, and why they should be done. To accomplish this, while at the same time preserving modularity and nonredundancy, a system of interframe pointers is introduced (the COMES‐FROM and LEADS‐TO pointers) which explain how or why something is done in tens of knowledge given in other frames. The paper proceeds by steadily deepening an initial English‐like description of the activity, and a context free grammar for the representation is included.
Rules and Topics in Conversation
Authors: Schank Roger C.
Published: October 2005

Rules of conversation are given that specify what can follow what. A system for deciding what makes a reasonable subject for a conversation is shown. Topics are discussed and rules for topic shift are presented.
Children's Visual Descriptions
Authors: Hayes Jean
Published: October 2005

The aim of the experiments described below was to elucidate aspects of children's mental representations of what they see, through studying their drawings of simple geometric forms when copying from standard models. Two specific questions were studied: (a) Do children produce symbolic representations based, as in machine perception, on decomposition of the visual object into features or properties, subsequently reaggregated to a greater or lesser degree, rather than attempts to copy the visual appearance of the model? The answer was affirmative, though the phenomenon is relatively rare, (b) Does a child's drawings of simple geometric drawings improve if he can watch an adult do the same drawings first? This has been asserted in the literature and bears on the question of static versus procedural representation. In a sample of 499 drawings made by children aged from 2½ to 5 years we showed that such an effect is absent or very small.
The Meaning of Modality
Authors: Johnson‐Laird P. N.
Published: October 2005

This paper describes a semantics for modal terms such as can and may that is intended to model the mental representation of their meaning. The basic assumption of the theory is that the evaluation of a modal assertion involves an attempted mental construction of a specified alternative to a given situation rather than the separate evaluation of each member of a set of possible alternatives as would be required by a “possible worlds” semantics. The theory leads to the conclusion that, contrary to what is often assumed, modal auxiliary verbs are unambiguous.
Planning and Acting*
Authors: McDermott Drew
Published: October 2005

A new theory of problem solving is presented, which embeds problem solving in the theory of action; in this theory, a problem is just a difficult action. Making this work requires a sophisticated language for‐talking about plans and their execution. This language allows a broad range of types of action, and can also be used to express rules for choosing and scheduling plans. To ensure flexibility, the problem solver consists of an interpreter driven by a theorem prover which actually manipulates formulas of the language. Many examples of the use of the system six given. including an extended treatment of the world of blocks. Limitations and extensions of the system are discussed at length. It is concluded that a rule‐based problem solver is necessary and feasible, but that much more work remains to be done on the underlying theory of planning and acting.
Has Artificial Intelligence Contributed to an Understanding of the Human Mind?: A Critique of Arguments For and Against
Authors: Miller Laurence
Published: October 2005

This essay examines arguments for and against the proposition that Artificial Intelligence (AI) research makes an important contribution to the understanding of the human mind. A number of recent articles have seemed to question the value of Al ideas in specific domains (e.g., language. mental imagery, problem solving). In the present paper, it is argued that the real disagreement concerns the form of a scientific psychology. The critics of Artificial Intelligence believe that many acceptable psychological theories exist and the important task of the scientist is to show that certain of these theories are true. They criticize AI research because it has not produced theories whose adequacy can be tested by empirical research. The supporters of AI research believe that no adequate psychological theories exist. They claim that the important task is to develop adequate theories and until such theories have been constructed, it is pointless to worry about empirical tests.

A number of major arguments attacking and defending AI research are examined in order to illustrate that the real issue is methodological. It is concluded that the present debate is counterproductive since both sides assume that the methodological premise of the other side is wrong without attempting to refute it. A more constructive debate would address directly the more fundamental question of what methods offer the greatest promise of solving the major problems of psychology.
Modeling Spatial Knowledge*
Authors: Kuipers Benjamin
Published: October 2005

A person's cognitive map, or knowledge of large‐scale space, is built up from observations gathered as he travels through the environment. It acts as a problem solver to find routes and relative positions, as well as describing the current location. The TOUR model captures the multiple representations that make up the cognitive map, the problem‐solving strategies it uses, and the mechanisms for assimilating new information. The representations have rich collections of states of partial knowledge, which support many of the performance characteristics of common‐sense knowledge.
Interacting Plans
Authors: Bruce Bertram , Newman Denis
Published: October 2005

The paper explores certain phenomena which arise in stories, conversations, and human activity in general when the plans of two individuals are formed and carried out in an interactive situation. A notation system for representing interacting plans is introduced and applied in the analysis of a small portion of “Hansel and Gretel.” The analysis illustrates how a single actor plan can be modified by the needs of cooperative interaction with others and how cooperative interactive episodes can be transformed and used deceptively by one party in achieving his or her own covert goals.
Why John Married Mary: Understanding Stories Involving Recurring Goals
Authors: Wilensky Robert
Published: October 2005

A story understander needs a great deal of knowledge about people's goals. This knowledge is needed to infer explanations for the behavior of the characters in a story. Sometimes a character's behavior cannot be explained in terms of a particular goal, but only in relation to a set of recurring goals that a character anticipates having.

The concept of goal subsumption is introduced to deal with these situations. Goal subsumption is a way of planning for many goals at the same time. It occurs in three different types of story situations, each of which has its own rules for recognition and understanding.
Conversational Coherency*
Authors: Reichman Rachel
Published: October 2005

A major goal of this work is to specify some steps of the process by which participants maintain coherency in their conversations.

The underlying element of the analysis is a construct called a “context space.” Roughly, a group of utterances that refers to a single issue or episode forms the basis for a context space. Superficially, a conversation is a sequence of utterances; at a deeper level it is a structured entity whose utterances can be parsed into hierarchically related context spaces.

As a conversation proceeds, each conversant builds a discourse model that includes the conversation's context space structure, a notion of the present discourse topic, and a list of items being focused upon. Conversational coherency depends upon a lack of conflict between the respective models of the participants. Conflicts are prevented by speakers following high level syntactic and semantic relational rules that enable listeners to identify their discourse models. These rules, given in the study, are highly integrated with the view of conversation presented here—a hierarchy of related context spaces.
Understanding Understanding Mathematics
Authors: Michener Edwina Rissland
Published: October 2005

In this paper we look at some of the ingredients and processes involved in the understanding of mathematics. We analyze elements of mathematical knowledge, organize them in a coherent way and take note of certain classes of items that share noteworthy roles in understanding. We thus build a conceptual framework in which to talk about mathematical knowledge. We then use this representation to describe the acquisition of understanding. We also report on classroom experience with these ideas.
Narrative Models of Action and Interaction*
Authors: de Beaugrande Robert , Colby Benjamin N.
Published: October 2005

This paper explores some issues which a humanlike story system ought to encompass, but which are usually not in the main focus of narrative models since Propp. We argue that knowledge about actions and interactions can account not only for how stories are constructed, but also for why some stories are more interesting and enduring than others. We analyze a traditional English folktale in these terms, and show how classes of surface expressions make recoverable the underlying structures and dependencies that schema‐based understanders comprise.
Micro‐ and Macrodevelopmental Changes in Language Acquisition and Other Representational Systems*
Authors: Karmiloff‐Smith Annette
Published: October 2005

In this paper, it will be argued that each time a procedure in a representational system is functioning adequately and automatically, the child steps up to a metaprocedural level and considers the procedure as a unit in its own right. Data will be drawn from microdevelopment in children's creation of external memory devices (i.e., changes in representation of a spatial task during a one hour's session) as well as from macrodevelopment in language acquisition (i.e., changes occurring over age in a study of nominal determiners, pronouns and gender markers). These two aspects of development of representational systems are examined with respect to the spontaneous passage from concrete reference to abstract systems, from idiosyncratic to conventional notations, from redundant to economic marking, from unifunctional to plurifunctional meaningful units. These micro‐ and manodevelopmental changes take place in a spontaneous fashion despite the fact that the child's earlier system is adequate for successfully conveying the information required. A discussion will be made of the way in which children tend to indicate externally, by unifunctional markers, information which was implicit in their earlier use of an adult‐like system. They appear to be striving for the delicate balance between encoding and decoding efforts, ultimately leading to a felicitous representational system. Metaprocedural behavior is hypothesized to act as a control mechanism in the striving for this delicate balance of information content and information processing effort. It also appears to act as a control mechanism for the interprocedural organizotion of what was previously a plethora of juxtaposed, unconnected procedures yielding superficially analogous behavior. The stepping‐up to a metaprocedural level seems to occur each time the child has a handle on his currently functioning, goal‐oriented system. This enables the child to treat the system, or procedures which are part thereof, as units functioning in their own right. Thus there appears to be a deep‐rooted psychological tendency for a representational tool which functions well procedurally to become subsequently a problem‐space per se.
Configural Effects in Human Memory: The Superiority of Memory over External Information Sources as a Basis for Inference Verification*
Authors: Hayes‐Roth Barbara , Walker Carol
Published: October 2005

The ability to integrate information from diverse texts and to detect logical implications of the integrated information is fundamental to the understanding process. This paper shows that identifying and configuring relevant facts in order to support hypothesized inferences is extremely difficult unless the facts have been committed to memory. Simply reading relevant texts for familiarization and then referring to them as needed provides an inadequate basis for deductive logic. Further, apprehension of the logical configuration of fads underlying a particular inference can be an essentially automatic process for the reasoner who has structured the facts appropriately in memory. A model of search and memory mechanisms is proposed. It accounts for accuracy and reaction time data, as well as individual differences in inference evaluation. The implications of the superiority of memorization over familiarization‐plus‐referencing as a basis for learning and reasoning are discussed.
Inferring Conceptual Graphs*
Authors: Salveter Sharon C.
Published: October 2005

This paper investigates the mechanisms a program may use to learn conceptual structures that represent natural language meaning. A computer program named Moran is described that infers conceptual structures from pictorial input data. Moran is presented with “snapshots” of an environment and an English sentence describing the action that takes place between the snapshots. The learning task is to associate each root verb with a conceptual structure that represents the types of objects that participate in the action and the changes the objects undergo during the action. Four learning mechanisms are shown to be adequate to accomplish this learning task. The learning mechanisms are described along with the conditions under which each is invoked and the effect each has on existing memory structures. The conceptual structure Moran inferred for one root verb is shown.
An Evaluation of Story Grammars*
Authors: Black John B. , Wilensky Robert
Published: October 2005

We evaluate the “story grammar” approach to story understanding from three perspectives. We first examine the formal properties of the grammars and find only one to be formally adequate. We next evaluate the grammars empirically by asking whether they generate all simple stories and whether they generate only stories. We find many stories that they do not generate and one major class of nonstory that they do generate. We also evaluate the grammars' potential as comprehension models and find that they would add nothing to semantic models that focus on the story content. Hence we advocate a story content oriented approach to studying story understanding instead of the structural story grammar approach.
Knowledge of Language and Knowledge about the World: A Reaction Time Study of Invited and Necessary Inferences*
Authors: Chaffin Roger
Published: October 2005

Necessary inferences (e.g., The jury was not able to deliver its verdict by 3 o'clock. The jury did not deliver its verdict by 3 o'clock.) depend on linguistic knowledge. Invited inferences, (e.g., The jury was able to deliver its verdict by 3 o'clock. The jury delivered its verdict by 3 o'clock) depend on knowledge about the world. Responses were faster to necessary than to invited inferences when subjects verified only one of the two inference types (Experiments 1 and 3). When subjects verified both inference types there was no difference between invited and necessary inferences (Experiments 2 and 4). These data suggest that linguistic and world knowledge are psychologically distinct and that when factual knowledge is not needed in a task it is not processed. In Experiments 3 and 4 incongruent world knowledge slowed response times for both inference types. This suggests that linguistic and factual knowledge are both port of the initial representation of a sentence.
User Modeling via Stereotypes*
Authors: Rich Elaine
Published: October 2005

This paper addresses the problems that must be considered if computers are going to treat their users as individuals with distinct personalities, goals, and so forth. It first outlines the issues, and then proposes stereotypes as a useful mechanism for building models of individual users on the basis of a small amount of information about them. In order to build user models quickly, a large amount of uncertain knowledge must be incorporated into the models. The issue of how to resolve the conflicts; hot will arise along such inferences is discussed. A system, Grundy, is described that builds models of its users, with the aid of stereotypes, and then exploits those models to guide it in its task, suggesting novels that people may find interesting. If stereotypes are to be useful to Grundy, they must accurately characterize the users of the system. Some techniques to modify stereotypes on the basis of experience are discussed. An analysis of Grundy's performance shows that its user models are effective in guiding its performance.
The Process of Retrieval from Very Long‐Term Memory
Authors: Williams Michael David , Hollan James D.
Published: October 2005

In this paper we argue that the protocols of subjects recalling the names of their high school classmates, as well as an army of traditional memory phenomena, can be understood from an information processing analysis which interprets retrieval as a problem‐solving process. This characterization of retrieval focuses on the reconstructive and recursive nature of the process of remembering. Retrieval is viewed as a process in which some information about a target item is used to construct a description of the item and this description is used in attempts to recover new fragments of information. A new description i s formed and the process continues recursively. Three subprocesses are identified: FIND A CONTEXT, in which a proper environment for conducting a search i s established: SEARCH, in which bits and pieces of information appropriate to the context are recovered until an adequate description can be formed within the search context; and VERIFY, in which recovery information is checked for consistency.

From the perspective this characterization, we examine the protocols of subjects asked to think aloud while recalling the names of their classmates. Subjects' retrievals continued for a surprisingly long period and were characterized by the phenomena of overshoot, systematic hypothesizing, fabrications, establishment of search contexts, self‐corrections, and the use of a number of basic search strategies. The view of memory as a problem‐solving process not only leads us to the identification of these phenomena but also to a framework for a coherent interpretation for them.
Categorization and Representation of Physics Problems by Experts and Novices*
Authors: Chi Michelene T. H. , Feltovich Paul J. , Glaser Robert
Published: October 2005

The representation of physics problems in relation to the organization of physics knowledge is investigated in experts and novices. Four experiments examine (a) the existence of problem categories as a basis for representation; (b) differences in the categories used by experts and novices; (c) differences in the knowledge associated with the categories; and (d) features in the problems that contribute to problem categorization and representation. Results from sorting tasks and protocols reveal that experts and novices begin their problem representations with specifiably different problem categories, and completion of the representations depends on the knowledge associated with the categories. For, the experts initially abstract physics principles to approach and solve a problem representation, whereas novices base their representation and approaches on the problem's literal features.
Errors in Children's Subtraction
Authors: Young Richard M. , O'Shea Tim
Published: October 2005

Many of the errors that occur in children' subtraction are due to the use of incorrect strategies rather than to the incorrect recall of number facts. A production system is presented for performing written subtraction which is consistent with an earlier analysis of the nature of such a cognitive skill. Most of the incorrect strategies used by schoolchildren can be accounted for in a principled way by simple changes in the production system, such as the omission of individual rules or the inclusion of rules appropriate to other arithmetical tasks. The production system model is evaluated against a corpus of over 1500 subtraction problems done by 10‐year olds and is shown to account for about two‐thirds of the (nonnumber fact) errors. It also provides an alternative, simpler interpretation of the subtraction errors analysed by Brown and Burton (1978). Some implications for teaching are discussed.
The Cultural Part of Cognition
Authors: D'Andrade Roy Goodwin
Published: October 2005

This paper discusses the role of cultural anthropology in Cognitive Science. Culture is described as a very large pool of information passed along from generation to generation, composed of learned “programs” for action and understanding. These cultural programs differ in important ways from computer programs. Cultural programs tend to be unspecified and inexplicit rather than clearly stated algorithms learned through a slow process of guided discovery, and involve the manipulation of content based rather than formal symbol systems. Cultural symbol systems often have affective as well as objective referents, giving them a strong directive effect. The argument is made that in the process of repeated social transmission and use, cultural programs come to take forms which have a good “fit” to the natural capacities and constraints of the human information processing system.
The Case‐Slot Identity Theory*
Authors: Charniak Eugene
Published: October 2005

Many people have noted the similarities between case theories in linguistics and frame representations in artificial intelligence. In particular, the cases of a verb seem to correspond to the slots of a frame. This has led many people, including Fillmore [1977] and Winston [1977] to assert that cases and slots are one and the same. This hypothesis has not attracted much attention, probably because the notion of “slot” in frame representations is so underconstrained that the theory would seem to be content free. In this note, we wish to show that this is not true. For one thing, the case‐slot identity theory can explain the difficulty linguists have had in deciding how many cases there are. Furthermore, its adoption will place certain interesting, and plausible constraints on the frame and case theories compatible with it.
Toward a Theory of Intrinsically Motivating Instruction*
Authors: Malone Thomas W.
Published: October 2005

First, a number of previous theories of intrinsic motivation are reviewed. Then, several studies of highly motivating computer games are described. These studies focus on what makes the games fun, not on what makes them educational. Finally, with this background, a rudimentary theory of intrinsically motivating instruction is developed, based on three categories: challenge, fantasy, and curiosity.

Challenge is hypothesized to depend on goals with uncertain outcomes. Several ways of making outcomes uncertain are discussed, including variable difficulty level, multiple level goals, hidden information, and randomness. Fantasy is claimed to have both cognitive and emotional advantages in designing instructional environments. A distinction is made between extrinsic fantasies that depend only weakly on the skill used in a game, and intrinsic fantasies that are intimately related to the use of the skill. Curiosity is separated into sensory and cognitive components, and it is suggested that cognitive curiosity can be aroused by making learners believe their knowledge structures are incomplete, inconsistent, or unparsimonious.
Models of Concepts*
Authors: Cohen Benjamin , Murphy Gregory L.
Published: October 2005

Over the last 10 years research on concepts has produced on important new theory known as prototype theory. Despite its empirical successes, prototype theory has been challenged by various arguments purporting to show its descriptive inadequacy for a variety of phenomena, including complex concepts and quantification. These arguments are primarily based on a set theoretic model of concepts. We consider the advantages and disadvantages of the set‐theoretic approach and argue that if we instead model concepts as knowledge representations of a certain kind, it is possible not only to answer prototype theory's critics, but to address more fundamental issues in the theory of concepts. We also consider the implications of these different approaches for psychology, linguistics, and artificial intelligence (AI). To substantiate our claims, a knowledge representation model of prototype theory is outlined, based on work in schema theory and AI knowledge representation.
Specification of muscle neurotransmitter sensitivity by a Paired-like homeodomain protein inCaenorhabditis elegans
Authors: Branicky Robyn , Hekimi Siegfried
Published: October 2005

The effects of neurotransmitters depend on the receptors expressed on the target cells. In Caenorhabditis elegans, there are two types of GABA receptors that elicit opposite effects: excitatory receptors that open cation-selective channels, and inhibitory receptors that open anion-selective channels. The four non-striated enteric muscle cells required for the expulsion step of the defecation behavior are all sensitive to GABA: the sphincter muscle expresses a classical GABA-sensitive chloride channel(UNC-49) and probably relaxes in response to GABA, while the other three cells express a cation-selective channel (EXP-1) and contract. Here we show that the expression of the exp-1 gene is under the control of dsc-1,which encodes a Paired-like homeodomain protein, a class of transcription factors previously associated with the terminal differentiation of neurons in C. elegans. dsc-1 mutants have anatomically normal enteric muscles but are expulsion defective. We show that this defect is due to the lack of expression of exp-1 in the three cells that contract in response to GABA. In addition, dsc-1, but not exp-1,affects the periodicity of the behavior, revealing an unanticipated role for the enteric muscles in regulating this ultradian rhythm.
Fgf signals from a novel signaling center determine axial patterning of the prospective neural retina
Authors: Picker Alexander , Brand Michael
Published: October 2005

Axial eye patterning determines the positional code of retinal ganglion cells (RGCs), which is crucial for their topographic projection to the midbrain. Several asymmetrically expressed determinants of retinal patterning are known, but it is unclear how axial polarity is first established. We find that Fgf signals, including Fgf8, determine retinal patterning along the nasotemporal (NT) axis during early zebrafish embryogenesis: Fgf8 induces nasal and/or suppresses temporal retinal cell fates; and inhibition of all Fgf-receptor signaling leads to complete retinal temporalization and concomitant loss of all nasal fates. Misprojections of RGCs with Fgf-dependent alterations in retinal patterning to the midbrain demonstrate the importance of this early patterning process for late topographic map formation. The crucial period of Fgf-dependent patterning is at the onset of eye morphogenesis. Fgf8 expression, the restricted temporal requirement for Fgf-receptor signaling and target gene expression at this stage suggests that the telencephalic primordium is the source of Fgf8 and acts as novel signaling center for non-autonomous axial patterning of the prospective neural retina.
Evolution of regulatory interactions controlling floral asymmetry
Authors: Costa Maria Manuela R. , Fox Samantha , Hanna Andy I. , Baxter Catherine , Coen Enrico
Published: October 2005

A key challenge in evolutionary biology is to understand how new morphologies can arise through changes in gene regulatory networks. For example, floral asymmetry is thought to have evolved many times independently from a radially symmetrical ancestral condition, yet the molecular changes underlying this innovation are unknown. Here, we address this problem by investigating the action of a key regulator of floral asymmetry, CYCLOIDEA (CYC), in species with asymmetric and symmetric flowers. We show that CYC encodes a DNA-binding protein that recognises sites in a downstream target gene RADIALIS (RAD)in Antirrhinum. The interaction between CYC and RADcan be reconstituted in Arabidopsis, which has radially symmetrical flowers. Overexpression of CYC in Arabidopsis modifies petal and leaf development, through changes in cell proliferation and expansion at various stages of development. This indicates that developmental target processes are influenced by CYC in Arabidopsis, similar to the situation in Antirrhinum. However, endogenous RAD-like genes are not activated by CYC in Arabidopsis, suggesting that co-option of RAD may have occurred specifically in the Antirrhinum lineage. Taken together, our results indicate that floral asymmetry may have arisen through evolutionary tinkering with the strengths and pattern of connections at several points in a gene regulatory network.
Mice deficient in Ext2 lack heparan sulfate and develop exostoses
Authors: Stickens Dominique , Zak Beverly M. , Rougier Nathalie , Esko Jeffrey D. , Werb Zena
Published: October 2005

Hereditary multiple exostoses (HME) is a genetically heterogeneous human disease characterized by the development of bony outgrowths near the ends of long bones. HME results from mutations in EXT1 and EXT2,genes that encode glycosyltransferases that synthesize heparan sulfate chains. To study the relationship of the disease to mutations in these genes, we generated Ext2-null mice by gene targeting. Homozygous mutant embryos developed normally until embryonic day 6.0, when they became growth arrested and failed to gastrulate, pointing to the early essential role for heparan sulfate in developing embryos. Heterozygotes had a normal lifespan and were fertile; however, analysis of their skeletons showed that about one-third of the animals formed one or more ectopic bone growths (exostoses). Significantly, all of the mice showed multiple abnormalities in cartilage differentiation, including disorganization of chondrocytes in long bones and premature hypertrophy in costochondral cartilage. These changes were not attributable to a defect in hedgehog signaling, suggesting that they arise from deficiencies in other heparan sulfate-dependent pathways. The finding that haploinsufficiency triggers abnormal cartilage differentiation gives insight into the complex molecular mechanisms underlying the development of exostoses.
mab-2encodes RNT-1, aC. elegansRunx homologue essential for controlling cell proliferation in a stem cell-like developmental lineage
Authors: Nimmo Rachael , Antebi Adam , Woollard Alison
Published: October 2005

In this report, we demonstrate that C. elegans mab-2 mutants have defects in the development of a male-specific sense organ because of a failure in the proliferation of the stem cell-like lateral hypodermal (seam) cells. We show, by positional cloning, that mab-2 encodes RNT-1, the only C. elegans member of the Runx family of transcriptional regulators,which are postulated to act both as oncogenes and tumour suppressors in mammalian cells. Importantly, we find that rnt-1 is a rate-limiting regulator of seam cell proliferation in C. elegans, as overexpression of rnt-1 at particular developmental stages is capable of driving extra cell divisions, leading to seam cell hyperplasia. Loss of rnt-1is correlated with upregulation of cki-1, a CDK inhibitor. Deregulated expression of Runx genes in humans is associated with various cancers, particularly leukaemias, suggesting a conserved role for Runx genes in controlling cell proliferation during development, especially in stem cell lineages. C. elegans is therefore an important model system for studying the biology, and oncogenic potential, of Runx genes.
Involuntary automaticity: a work-system induced risk to safe health care
Authors: Toft Brian , Mascie-Taylor Hugo
Published: October 2005

Automaticity is the term given by psychologists to the skilled action that people develop through repeatedly practising the same activity, for example driving a car. Usually, automaticity is discussed in terms of the benefits it brings to people, such as the reduction in the degree of conscious attention a person needs to pay to such skilled activities. However, there is evidence to suggest that substantial costs may also be associated with such learned behaviour.

Managing patient safety is a difficult task and one of the ways in which health-care professionals seek to accomplish it is through the use of verbal challenge-response protocols. However, it is argued in this paper that it is possible for the negative effects of automaticity to involuntarily capture those using such verbal checklist techniques and cause them to erroneously believe that the treatment that they are about to administer to a patient is safe when it is not. This phenomenon does not, however, seem to have been recognized by the health-care community nationally or internationally. We conclude that patient safety could be significantly improved worldwide if the organizational arrangements which appear to induce involuntary automaticity were to be robustly addressed by the management of all health-care organizations.
End-of-life care volunteers: a systematic review of the literature
Authors: Wilson Donna M , Justice Christopher , Thomas Roger , Sheps Sam , MacAdam Margaret , Brown Margaret
Published: October 2005

This report presents a review of 1988 and onwards research and other literature on end-of-life (EOL) care volunteers. Only 18 research or case studies articles were identified for an integrative review through a search of nine library databases. A review of this literature revealed three themes: (1) the roles of EOL volunteers, (2) volunteer training and other organizational needs or requirements, and (3) outcomes, particularly the impact of volunteering on volunteers and the impact of volunteers on EOL care. Despite limited statistical evidence, the available literature on EOL care volunteers clearly indicates that considerable potential benefit can be derived from EOL care volunteers' contributions, with their efforts benefiting dying persons, their families, paid EOL staff, and the volunteers themselves. More specifically, willing volunteers, particularly those with diverse skills and abilities, have the potential to significantly and positively impact EOL care in that they can perform many necessary and extra functions of value. Volunteers often augment and enhance the range of EOL care services provided to terminally ill individuals and their families. Volunteers should also be recognized as increasing the accessibility of EOL care. The role of the volunteer is not without challenge, however, both for the individuals who volunteer and the organizations that must orient them and provide a meaningful role for them.
The nursing shortage and the scope for reducing it by redefining their role
Authors: Thomas Janet , Davies Christopher
Published: October 2005

The objective of this research is to measure the extent to which nurses are undertaking tasks that could be left to support workers. The method employed was firstly to classify the activities being undertaken by nurses. This was achieved by surveying appropriate professional groups. Secondly, the amount of time nurses spent on each activity was measured. The results indicate that nurses spend at least 8% of their time undertaking activities which could be undertaken by less-qualified staff. It was also found that 6% of unregistered nurses' time is spent on activities which are classified as being within the remit of a registered nurse. The scale of these results raises significant efficiency and effectiveness issues with respect to the use of both groups of staff and therefore has major implications for their management.
Face processing and familiarity: Evidence from eye‐movement data
Authors: Stacey Paula C. , Walker Stephanie , Underwood Jean D. M.
Published: October 2005

How is information extracted from familiar and unfamiliar faces? Three experiments, in which eye‐movement measures were used, examined whether there was differential sampling of the internal face region according to familiarity. Experiment 1 used a face familiarity task and found that whilst the majority of fixations fell within the internal region, there were no differences in the sampling of this region according to familiarity. Experiment 2 replicated these findings, using a standard recognition memory paradigm. The third experiment employed a matching task, and once again found that the majority of fixations fell within the internal region. Additionally, this experiment found that there was more sampling of the internal region when faces were familiar compared with when they were unfamiliar. The use of eye fixation measures affirms the importance of internal facial features in the recognition of familiar faces compared with unfamiliar faces, but only when viewers compare pairs of faces.
Dissociational body experiences: Differences between respondents with and without prior out‐of‐body‐experiences
Authors: Murray Craig D. , Fox Jezz
Published: October 2005

Many people report having had an experience in which they felt as if their phenomenal self was separated in Cartesian space from their physical body. This phenomenon is often referred to as an ‘out‐of‐body’ (OBE) experience. Prior work has found OBE experients to score higher on measures of dissociation and to differ in regards to the perceptual experience of their body. Based upon this work, we theorized that the daily bodily experiences of people with and without a prior OBE would differ along a number of dimensions. In order to test this theory a questionnaire study was conducted. Of 243 respondents, 62 reported at least one prior OBE. Six scales on different aspects of bodily experience were administered. Respondents reporting a previous OBE were found to score significantly higher on measures of somatoform dissociation, self‐consciousness, body dissatisfaction, and lower on a measure of confidence in their physical self‐presentation than respondents without a previous OBE. The findings are discussed as supporting a dissociational theory of the OBE.
Affective valence and the self‐reference effect: Influence of retrieval conditions
Authors: Argembeau Arnaud D' , Comblain Christine , Van der Linden Martial
Published: October 2005

Positive trait information is typically better recalled than negative trait information when encoded in reference to the self, but not when encoded in reference to someone else or when processed for general meaning. This study examined whether this influence of affective meaning is modulated by retrieval conditions. Participants encoded positive and negative trait adjectives in reference to themselves or to a celebrity. They were then presented with either a free‐recall task (Experiment 1) or a recognition memory task (Experiment 2). Positive adjectives were better recalled than negative adjectives, but only when they were encoded in reference to the self. In contrast, encoding condition and valence did not interact in the recognition memory task. Taken together, these findings suggest that the difference in memory between positive and negative self‐referent information is due, at least in part, to a control exerted on memory retrieval.
Compulsive buying – a growing concern? An examination of gender, age, and endorsement of materialistic values as predictors
Authors: Dittmar Helga
Published: October 2005

Compulsive buying is an understudied, but growing, dysfunctional consumer behaviour with harmful psychological and financial consequences. Clinical perspectives treat it as a psychiatric disorder, whereas recent proposals emphasize the increasing endorsement of materialistic values as a cause of uncontrolled buying (e.g. Dittmar, 2004b; Kasser & Kanner, 2004). The present research aims to improve understanding of compulsive buying through examining gender, age, and endorsement of materialistic values as key predictors in three UK questionnaire studies, which sampled individuals who had contacted a self‐help organization and residentially matched ‘controls’ (N=330), consumer panelists from a multinational corporation (N=250), and 16‐ to 18‐year‐old adolescents (N=195). The results confirmed previously documented gender differences, and showed that younger people are more prone to compulsive buying. The central findings were that materialistic value endorsement emerged as the strongest predictor of individuals' compulsive buying, and that it significantly mediated the observed age differences.
Sex differences in means and variability on the progressive matrices in university students: A meta‐analysis
Authors: Irwing Paul , Lynn Richard
Published: October 2005

A meta‐analysis is presented of 22 studies of sex differences in university students of means and variances on the Progressive Matrices. The results disconfirm the frequent assertion that there is no sex difference in the mean but that males have greater variability. To the contrary, the results showed that males obtained a higher mean than females by between .22d and .33d, the equivalent of 3.3 and 5.0 IQ conventional points, respectively. In the 8 studies of the SPM for which standard deviations were available, females showed significantly greater variability (F(882,656)=1.20, p<.02), whilst in the 10 studies of the APM there was no significant difference in variability (F(3344,5660)=1.00, p>.05).
Extracellular Heat Shock Protein 70: A Critical Component for Motoneuron Survival
Authors: Robinson Mac B. , Tidwell J. Lille , Gould Thomas , Taylor Anna R. , Newbern Jason M. , Graves Jason , Tytell Michael , Milligan Carol E.
Published: October 2005

The dependence of developing spinal motoneuron survival on a soluble factor(s) from their target, muscle tissue is well established bothin vivoandin vitro. Considering this apparent dependence, we examined whether a specific component of the stress response mediates motoneuron survival in trophic factor-deprived environments. We demonstrate that, although endogenous expression of heat shock protein 70 (HSP70) did not change during trophic factor deprivation, application of e-rhHsp70 (exogenous recombinant human Hsp70) promoted motoneuron survival. Conversely, depletion of HSP70 from chick muscle extract (MEx) potently reduces the survival-promoting activity of MEx. Additionally, exogenous treatment with or spinal cord overexpression of Hsp70 enhances motoneuron survivalin vivoduring the period of naturally occurring cell death [programmed cell death (PCD)]. Hindlimb muscle cells and lumbar spinal astrocytes readily secrete HSP70in vitro, suggesting potential physiological sources of extracellular Hsp70 for motoneurons. However, in contrast to exogenous treatment with or overexpression of Hsp70in vivo, muscle-targeted injections of this factor in anex vivopreparation fail to attenuate motoneuron PCD. These data (1) suggest that motoneuron survival requirements may extend beyond classical trophic factors to include HSP70, (2) indicate that the source of this factor is instrumental in determining its trophic function, and (3) may therefore influence therapeutic strategies designed to increase motoneuron Hsp70 signaling during disease or injury.