bluuebunny/crossref_metadata_2025 huggingface dataset:
Maintaining positive returns in the value and supply chain: applying tomorrow's marketing skills
Authors: Pitta Dennis A. , Franzak Frank J. , Little Michael W.
Published: November 2004

The value and supply chain is an emerging pathway to marketing's emphasis on customers. It integrates a renewed focus on customer value and the economic and behavioral systems of the supply chain. Successful value chains can be developed with emphasis on the four practices that drive a customer orientation. These are: relationships, interactivity, valuing customers over time, and customization. When properly integrated, these practices help to form networks operating as a competitive unit. This paper clarifies the role of value in the value chain, discusses the use of the four major elements in the value chain, and draws implications for marketers.
Gender and feminine identities – women as managers in a UK academic institution
Authors: Priola Vincenza
Published: November 2004

The paper considers gender identities in higher education. It examines how people involved in university life engage in (re)creating gender identities and in (re)producing gender‐related expectations (and stereotypes) of managerial behaviour. The process of construction of feminine identities is explored through the discourses of academics from a UK university (mainly women who hold managerial positions). The paper reports findings from a series of in‐depth interviews with women managers (dean, associate deans and heads of departments) and with university academics (men and women) from a Business School, part of a large British new university. The school was of special interest because women held the majority of senior managerial posts. It appears that the process of construction of femininities is mainly developed around four (stereo‐)typical aspects generally associated with feminine management practices (multi‐tasking, supporting and nurturing, people and communication skills, and team‐work).
An evaluative methodology for virtual communities using web analytics
Authors: Phippen A.D.
Published: November 2004

The evaluation of virtual community usage and user behaviour has its roots in social science approaches such as interview, document analysis and survey. Little evaluation is carried out using traffic or protocol analysis. Business approaches to evaluating customer/business web site usage are more advanced, in particular using advanced web analytics to develop greater understanding of their customers' use of their sites. The application of such techniques to virtual communities is discussed and experimentation of such techniques on a specific virtual community project demonstrates the potential for such techniques in the evaluation of social and culture web usage.
Knowledge broker network based on communication between humans
Authors: Loew Robert , Bleimann Udo , Walsh Paul
Published: November 2004

This paper proposes a new paradigm to overcome many problems in the area of information technology involving communication between humans. The paradigm will be exemplified using the example of knowledge transfer within a company. The solution is not interaction between a user and a highly intelligent system, but communication between people, supported by intelligent systems. The paper's concept of the “knowledge broker” will clarify what the authors mean by man‐man communication. The basic idea of the knowledge broker is that of a hybrid man‐machine system that enables knowledge transfer within companies not only theoretically, but also in practice.
Atlantis University:a new pedagogical approach beyond e‐learning
Authors: Bleimann Udo
Published: November 2004

Atlantis University is an ambitious international project in the area of learning and is currently being developed by a group of universities and companies. It combines three different types of learning and teaching to form a single package offered to Students and people in the workplace alike: face‐to‐face learning, e‐learning and project‐based learning. The paper gives an overview of the advantages and disadvantages of the different learning methodologies, and describes the new Atlantis approach. The first practical solutions Atlantis University has developed, namely the Virtual Classroom, ELAT learning environment and Project Service Center, are likewise briefly introduced.
Translating scalable video streams from wide‐area to access networks
Authors: Griwodz Carsten , Fiksdal Steffen , Halvorsen Pål
Published: November 2004

Transmitting video over user datagram protocol (UDP) has been considered advantageous because it allows for discarding of packets in favor of retransmissions, and sender‐controlled timing. Using UDP has been criticized because it allows video streams to consume more than their fair share of bandwidth, which is typically associated with the back‐off behavior of transmission control protocol (TCP). TCP‐friendly algorithms are meant as a middle path. However, UDP delivery to end systems may still be prevented by firewalls or for other reasons, and TCP must be used. This in turn suffers from bandwidth fluctuations. Investigates an architecture that separates the transfer of a video stream over long distances. Considers a proxy server to translate the traffic and two straightforward approaches for the translation of a layered video stream transmission from the TCP‐friendly transport protocol to TCP. Does not expect that one of these two approaches is by itself suited for the task, but investigating them will provide insights into their basic functions and help in discovering appropriate modifications. For the investigation, an experimental approach was used where network behavior and content are emulated.
User as catalyst
Authors: Fox Robert
Published: November 2004

User interface (UI) development is a complex process that involves the cooperation and input from both the developer and the user population. It is also an iterative process that requires continuous feedback and possibly peer review. Usability is a primary concern for user interface development, and there are several methods that can be used to test the efficacy of UIs in the digital library context. UI design is critical for the effective presentation and manipulation of digital data in virtually every context of the digital library.
Beyond commodification: re‐reading the future of work
Authors: Williams Colin C.
Published: November 2004

A widely held supposition is that goods and services are increasingly produced and delivered for monetised exchange by capitalist firms in pursuit of profit. The result of this view of an ongoing encroachment of the market is that there is only one perceived future for work and it is one characterised by an ever more commodified world. The aim of this paper is to evaluate critically this discourse. Analysing the balance between commodified and non‐commodified work in the advanced economies, a large non‐commodified sphere is identified that, if anything, is found to be expanding relative to the commodified realm. Rather than reading the future of work as a natural and unstoppable progression towards a victorious, all‐powerful and hegemonic commodity economy, this paper thus opens up the feasibility of alternative futures beyond a commodified world.
A challenge to traditional management theory
Authors: Weymes Ed
Published: November 2004

This paper challenges the philosophy underlying traditional management thinking. The historic and possibly arcane purpose of business, to maximise shareholder wealth, is no longer a relevant proposition. Academics and managers need to rethink the philosophical framework of management theory. For the past 50 years the management literature has adopted a more “human” approach to the management of organisations yet the importance of systems and process and performance measurers associated with the scientific theory of management prevails. With the growing importance of knowledge creation and the corporate social responsibility movement it is timely to reflect on the purpose of business as adding value to society and rejecting the focus on accumulation of personal wealth. Knowledge‐creating enterprises are founded on the development of sustainable relationships within the organisation and with stakeholders and thus require a different philosophical perspective.
Performance measurement and evaluation of suppliers in supply chain: an evolutionary fuzzy‐based approach
Authors: Ohdar Rajkumar , Ray Pradip Kumar
Published: November 2004

In order to ensure the uninterrupted supply of items, the purchasing manager needs to evaluate suppliers' performance periodically. The evaluation process typically consists of identifying the attributes and factors relevant to the decision, and measuring the performance of a supplier by considering the relevant factors. Linguistic assessment of suppliers may be carried out based on several criteria. In this paper, an attempt has been made to evaluate the suppliers' performance by adopting an evolutionary fuzzy system. One of the key considerations in designing the proposed system is the generation of fuzzy rules. A genetic algorithm‐based methodology is developed to evolve the optimal set of fuzzy rule base, and a fuzzy inference system of the MATLAB fuzzy logic toolbox is used to assess the suppliers' performance. The proposed methodology, illustrated with the data collected in a process plant, provides acceptable results in determining the suppliers' performance score.
Evaluation of the supplier performance using an evolutionary fuzzy‐based approach
Authors: Jain Vipul , Tiwari M.K. , Chan F.T.S.
Published: November 2004

Different entities in a supply chain network operate in a highly interdependent environment when it comes to improving performance of the network in terms of objectives such as delivery performance, quality assurance and cost minimization, etc. In this research, an attempt has been made to evaluate the supplier performance by adopting evolutionary fuzzy system owing to the linguistic nature of the attributes associated with the suppliers and manufacturing units. The proposed methodology offers consistently good performance when applied to a variety of standard problems related to evaluation of supplier's performance available in the literatures.
Multi‐agent architecture for supply chain management
Authors: Roy Daniel , Anciaux Didier , Monteiro Thibaud , Ouzizi Latifa
Published: November 2004

The purpose of this paper is to propose a new approach for the supply chain management. This approach is based on the virtual enterprise paradigm and the usage of multi‐agent concept. The base component of our approach is a virtual enterprise node (VEN). The supply chain is viewed as a set of tiers (corresponding to the levels of production), in which each partner of the supply chain (VEN) is in relation with several customers and suppliers. Each VEN belongs to one tier. The main customer gives global objectives (quantity, cost and delay) to the supply chain. The mediator agent (MA) is in charge to manage the supply chain in order to respect those objectives as global level. Those objectives are taking over to negotiator agent at the tier level (NAT). This architecture allows supply chains management which is completely transparent seen from simple enterprise of the supply chain. The use of multi‐agent system allows physical distribution of the decisional system. Moreover, the hierarchical organizational structure with a decentralized control guarantees, at the same time, the autonomy of each entity and the whole flexibility.
An object‐based relational data base system using re‐configurable finance and material objects
Authors: Ip W.H. , Chen Bocheng , Lau Henry , Sunjing Wangqi
Published: November 2004

Any manufacturing information system today must be able to both “reconfigure” and “reengineer” operations in a cost‐effective way. The objective of this paper is to propose an enterprise resource planning (ERP) system based on the re‐configurable characteristics of material objects (MO) and finance objects (FO). The implementation of this information system is based on the object technologsy concept, which composes enterprise applications in reusable software components made up of relevant manufacturing data. By analyzing the factors and the methods of integration of MO and FO, it can be shown that the proposed approach is more appropriate for the design and implementation of an ERP system, and that it is particularly suitable for small and medium‐sized enterprises (SMEs). The results demonstrate a flattened organizational structure, better communication, and enhanced workflow reconfiguration.
Collaborative supply chain planning using the artificial neural network approach
Authors: Chiu Matthew , Lin Grier
Published: November 2004

The purpose of this paper is to show how the concepts of collaborative agents and artificial neural networks (ANNs) can work together to enable collaborative supply chain planning (SCP). An agent‐based supply chain network is decomposed into multiple ANNs in a way that the actual customer requirements and the agents' goals and constraints are matched in different stages. An error‐minimising algorithm which models the agents' collaboration mechanism is used to train three ANNs, namely the supply net, the production net and the delivery net, for pursuing complete order fulfilment across the supply chain. In the example problem, the collaborative SCP paradigm is applied to determine the supply plan of an alliance of small firms, which provides assemble‐to‐order goods with short delivery lead‐time to a regional market. The calculation results showed that the ANN approach achieved complete order fulfilment and significantly increased the resource utilisation of all supply chain agents.
Money, Sex and Happiness: An Empirical Study
Authors: Blanchflower David G. , Oswald Andrew J.
Published: November 2004

The links between income, sexual behavior and reported happiness are studied using recent data on a sample of 16,000 adult Americans. The paper finds that sexual activity enters strongly positively in happiness equations. Higher income does not buy more sex or more sexual partners. Married people have more sex than those who are single, divorced, widowed or separated. The happiness‐maximizing number of sexual partners in the previous year is calculated to be 1. Highly educated females tend to have fewer sexual partners. Homosexuality has no statistically significant effect on happiness.
Choosing the Joneses: Endogenous Goals and Reference Standards
Authors: Falk Armin , Knell Markus
Published: November 2004

A growing economic literature stresses the importance of relative comparisons, e.g., for savings and consumption or happiness. In this literature it is usually assumed that reference standards against which people compare themselves are exogenously given. In contrast, findings from social psychology suggest that people play an active role in determining their reference standards. We introduce a social comparison model where people choose their reference standards to serve motives of self‐improvement and self‐enhancement. The model predicts that reference standards increase in individuals’ abilities and that people thus tend to compare themselves to similar others. The results of a questionnaire study confirm the prediction of the model.
Fairness and Incentives in a Multi‐task Principal–Agent Model
Authors: Fehr Ernst , Schmidt Klaus M.
Published: November 2004

This paper reports on a two‐task principal–agent experiment in which only one task is contractible. The principal can either offer a piece‐rate contract or a (voluntary) bonus to the agent. Bonus contracts strongly outperform piece‐rate contracts. Many principals reward high effort on both tasks with substantial bonuses. Agents anticipate this and provide high effort on both tasks. In contrast, almost all agents with a piece‐rate contract focus on the first task and disregard the second. Principals understand this and predominantly offer bonus contracts. This behavior contradicts the self‐interest theory but is consistent with theories of fairness.
Decreasing Impatience: A Criterion for Non‐stationary Time Preference and “Hyperbolic” Discounting
Authors: Prelec Drazen
Published: November 2004

Despite recent interest in hyperbolic discounting, there has been little discussion of exactly what property of time preferences is instantiated by hyperbolic or quasi‐hyperbolic functional forms. The paper revives an earlier proposal in Prelec (1989) that the key property is Pratt–Arrow convexity of the log of the discount function, which corresponds to decreasing impatience(DI) at the level of preferences. DI provides a natural criterion for assessing the severity of departure from stationarity in that greater DI is equivalent to more choices of dominated options in two‐stage decision problems, as well as greater convexity of the log of the discount function. Inefficient choices may arise as intentional precommitments, or as unintended reversals of preference by “naïve” agents.
Social Comparisons in Ultimatum Bargaining
Authors: Bohnet Iris , Zeckhauser Richard
Published: November 2004

Experiments are used to examine the effects of social comparisons in ultimatum bargaining. We inform responders about the average offer before they decide whether to accept or reject their specific offer. This significantly increases offers and offer‐specific rejection probabilities. For comparison, we consider another change in informational conditions: telling responders the total pie is $30—ex anteit was either $15 or $30—affects offers and rejection probabilities roughly as much. Our results are consistent with people’s dislike for deviations from the norm of equity but inconsistent with fairness theories, where people dislike income disparity between themselves and their referents.
Neuroeconomics: Why Economics Needs Brains
Authors: Camerer Colin F. , Loewenstein George , Prelec Drazen
Published: November 2004

Neuroeconomics uses knowledge about brain mechanisms to inform economic theory. It opens up the “black box” of the brain, much as organizational economics opened up the theory of the firm. Neuroscientists use many tools—including brain imaging, behavior of patients with brain damage, animal behavior and recording single neuron activity. The key insight for economics is that the brain is composed of multiple systems which interact. Controlled systems (“executive function”) interrupt automatic ones. Brain evidence complicates standard assumptions about basic preference, to include homeostasis and other kinds of state‐dependence, and shows emotional activation in ambiguous choice and strategic interaction.
Noisy Directional Learning and the Logit Equilibrium
Authors: Anderson Simon P. , Goeree Jacob K. , Holt Charles A.
Published: November 2004

We specify a dynamic model in which agents adjust their decisions toward higher payoffs, subject to normal error. This process generates a probability distribution of players’ decisions that evolves over time according to the Fokker–Planck equation. The dynamic process is stable for all potential games, a class of payoff structures that includes several widely studied games. In equilibrium, the distributions that determine expected payoffs correspond to the distributions that arise from the logit function applied to those expected payoffs. This “logit equilibrium” forms a stochastic generalization of the Nash equilibrium and provides a possible explanation of anomalous laboratory data.
What’s Causing Overreaction? An Experimental Investigation of Recency and the Hot‐hand Effect
Authors: Offerman Theo , Sonnemans Joep
Published: November 2004

A substantial body of empirical literature provides evidence of overreaction in markets. Past losers outperform past winners in stock markets as well as in sports markets. Two hypotheses are consistent with this observation. The recency hypothesis states that traders overweight recent information; they are too optimistic about winners and too pessimistic about losers. According to the hot‐hand hypothesis, traders try to discover trends in the past record of a firm or a team, and thereby overestimate the autocorrelation in the series. An experimental design allows us to distinguish between these hypotheses. The evidence is consistent with the hot‐hand hypothesis.
Cultural Pragmatics: Social Performance between Ritual and Strategy
Authors: Alexander Jeffrey C.
Published: November 2004

From its very beginnings, the social study of culture has been polarized between structuralist theories that treat meaning as a text and investigate the patterning that provides relative autonomy and pragmatist theories that treat meaning as emerging from the contingencies of individual and collective action—so-called practices—and that analyze cultural patterns as reflections of power and material interest. In this article, I present a theory of cultural pragmatics that transcends this division, bringing meaning structures, contingency, power, and materiality together in a new way. My argument is that the materiality of practices should be replaced by the more multidimensional concept of performances. Drawing on the new field of performance studies, cultural pragmatics demonstrates how social performances whether individual or collective can be analogized systematically to theatrical ones. After defining the elements of social performance, I suggest that these elements have become “de-fused” as societies have become more complex. Performances are successful only insofar as they can ‘“re-fuse” these increasingly disentangled elements. In a fused performance, audiences identify with actors, and cultural scripts achieve verisimilitude through effective mise-en-scène. Performances fail when this relinking process is incomplete: the elements of performance remain apart, and social action seems inauthentic and artificial, failing to persuade. Refusion, by contrast, allows actors to communicate the meanings of their actions successfully and thus to pursue their interests effectively.
Extending Identity Control Theory: Insights from Classifier Systems
Authors: Burke Peter J.
Published: November 2004

Within identity control theory (ICT), identities control meaning and resources by bringing perceptions of these in the situation into alignment with references levels given in the identity standard. This article seeks to resolve three issues in ICT having to do with the source of the identity standard, the correspondence between identity standards and the identity relevant meanings perceived in the situation or environment, and the activation of identities. Classifier systems, as developed by John Holland, are inductive, flexible, rule-based, message-passing, adaptive systems that are able to learn, to fit in, and to adapt to various and changing environments. Classifier systems are introduced and are extended to incorporate the central components of the model of identity as held in ICT. In this manner, a new identity model is proposed that has inductive and adaptive capacities able to resolve the three issues identified. Unexpectedly, the new model also lays the groundwork for the possible resolution of a long-standing issue within the symbolic interaction framework concerning the origins of shared meanings.
Observations of Social Processes and Their Formal Representations
Authors: Tilly Charles
Published: November 2004

Distinctions between quantitative and qualitative social science misrepresent the actual choices confronting analysts of observations concerning social processes. Analysts regularly (if not always self-consciously) choose between adopting and avoiding formal representations of social processes. Despite widespread prejudices to the contrary, formalisms are available and helpful for all sorts of social scientific evidence, including those commonly labeled as qualitative. Available formalisms vary in two important regards: (1) from direct to analogical representation of the evidence at hand; and (2) from numerical to topological correspondence between formalism and evidence. Adoption of formalisms facilitates the identification of erroneous arguments, hence the correction of analytic errors and the production of more adequate explanations.
Creativity, Habit, and the Social Products of Creative Action: Revising Joas, Incorporating Bourdieu
Authors: Dalton Benjamin
Published: November 2004

Hans Joas's The Creativity of Action (1996) posits that conceiving of all action as fundamentally creative would overcome problems inherent in rational and normative theories of action and would provide an alternative basis for action-based theories of macrosociological phenomena. Joas conceives of creativity as a response to the frustration of “prereflective aspirations,” which necessitates innovative adjustment to reestablish habitual intentions. This conceptualization creates an unsupportable duality between habitual action and creativity that neglects other possible sources of creative action, including habit itself. Combining strengths from Bourdieu's concept of habitus, creativity can be redefined as the necessary adaption of habitual practices to specific contexts of action. Creative action continually introduces novel possibilities in practical action and provokes a variety of social responses to its products. This revised concept of creativity overcomes the dichotomy presented by Joas identifies a microsocial source of innovation in creative action and calls attention to patterns of creative authority in society at large.
“What Group?” Studying Whites and Whiteness in the Era of “Color-Blindness”
Authors: Lewis Amanda E.
Published: November 2004

In this article I argue that despite the claims of some, all whites in racialized societies “have race.” But because of the current context of race in our society, I argue that scholars of “whiteness” face several difficult theoretical and methodological challenges. First is the problem of how to avoid essentializing race when talking about whites as a social collective. That is, scholars must contend with the challenge of how to write about what is shared by those racialized as white without implying that their experiences of racialization all will be the same. Second, within the current context of color-blind racial discourse, researchers must confront the reality that some whites claim not to experience their whiteness at all. Third, studies of whiteness must not be conducted in a vacuum: racial discourse or “culture” cannot be separated from material realities. Only by attending to and by recognizing these challenges will empirical research on whiteness be able to push the boundaries of our understandings about the role of whites as racial actors and thereby also contribute to our understanding of how race works more generally.
Ethnomethodology in Italy
Authors: Segre Sandro
Published: November 2004

This article provides an overview on works that have come out in Italy in the field of ethnomethodology. General introductory works are considered first, with reference to their similarities and differences. Subsequently, the interpretations and discussions concerning the ethnomethodological perspective are briefly presented, and the limited amount of empirical investigations on ethnomethodological questions is mentioned. Garfinkel's ethnomethodology has been the object of a few specific introductory and interpretative contributions. The relationship between ethnomethodology and sociolinguistics has been a further and distinct research theme. Discourse and conversational analysis as a research field of its own has elicited a remarkable flow of research, which is—in contrast to ethnomethodology—-not only methodological and epistemological but empirical as well. In particular, a number of authors have studied asymmetrical conversational exchanges in the institutional context provided by an Italian Court of Justice. Conversational analysis also has been instrumental in studying the production of social identity. In the final discussion, some theoretical points Italian students of ethnomethodology and the related disciplines have raised and discussed are presented in a condensed form.
Thermal acclimation of neonates to prolonged cool exposure as regards sleep stages
Authors: Telliez Frédéric , Chardon Karen , Leke André , Cardot Virginie , Tourneux Pierre , Bach Véronique
Published: November 2004

The thermal responses of neonates during a cool acclimation period were studied with regard to sleep stages. Sleep stages, body temperatures and metabolic rate (o2) were studied for seven neonates nursed in incubators and exposed to a cool temperature (thermoneutrality minus 2 °C) for 75 h. Each recording session lasted 3 h in the morning: firstly under thermoneutral baseline conditions, then during the first and last 3‐h periods of the cool acclimation and finally during the last 3 h of a 24‐h recovery period. Sleep structure was modified during the initial hours of cool exposure: the percentage of active sleep increased (AS: +13%, P = 0.028) at the expense of quiet sleep (QS: −11%, P = 0.043). This alteration in sleep structure persisted at the end of the acclimation period. Metabolic heat production only increased in the later period of cool acclimation. Throughout the cool exposure, o2 increased more (P = 0.040) in QS (+33%) than in AS (+20%) so that by the end of the cool period, o2 levels were similar in both sleep stages. During cool acclimation, the maintenance of homeothermy is related not only to a change in sleep organization but also to modifications in the thermoregulatory processes in both sleep stages. Considering the importance of AS/QS patterns in the neurobehavioral development of neonates, the present results could have clinical implications for the thermal management of neonates.
Comparison of the maintenance of wakefulness test (MWT) to a modified behavioral test (OSLER) in the evaluation of daytime sleepiness
Authors: Krieger Ana C. , Ayappa Indu , Norman Robert G. , Rapoport David M. , Walsleben Joyce
Published: November 2004

The objectives were to evaluate the correlation between sleep onset as defined by the Oxford sleep resistance (OSLER) test and by simultaneous electroencephalography (EEG) and to determine the correlation between sleep latencies measured by the OSLER test and maintenance of wakefulness test (MWT) performed on the same day. This was a prospective, cross‐sectional study carried out in a tertiary‐care university‐based sleep laboratory. Participants were 11 consecutive subjects presenting to the sleep center with clinical indications for nocturnal polysomnography and MWT. The interventions included MWT and OSLER test. Mean sleep latencies for the OSLER and MWT in each subject were closely correlated (ICC = 0.94, [Intra‐class correlation]P < 0.05). Sleep latency by OSLER and simultaneous measurement of EEG also had excellent agreement (ICC = 0.91) with a bias of −0.97 min. The OSLER test is a practical and reliable tool for evaluating daytime sleepiness when compared with the MWT. No obvious systematic adaptation was seen during sequential OSLER test performance. Given its portability and minimal technical requirements, the OSLER test may be useful for large‐scale applications in the evaluation of daytime wakefulness and vigilance.
Testing thermogenesis as the basis for the evolution of cetacean sleep phenomenology
Authors: Pillay Praneshri , Manger Paul R.
Published: November 2004

Cetacean sleep phenomenology consists of a combination of unihemispheric slow wave sleep and a massive reduction in the amount of rapid eye movement sleep. Despite various proposals, the selection pressure driving the evolution of this combined sleep phenomenology is unknown. It was recently suggested that the need to produce heat in the thermally challenging aquatic environment might have been the selection pressure. Mechanisms of heat loss and heat production can be measured directly or indirectly. The present study was designed to test the thermogenetic proposal by recording indirect measurements of heat loss (surface area to volume ratio) and heat production (tail‐beats per minute). A strong correlation was found between these two parameters, such that increases in potential heat loss were matched by increases in potential heat production. This result suggests that the need to compensate for heat loss can provide an evolutionary rationale for the appearance of extant cetacean sleep physiology.
Incorporation of presleep stimuli into dream contents: evidence for a consolidation effect on declarative knowledge during REM sleep?
Authors: Cipolli Carlo , Fagioli Igino , Mazzetti Michela , Tuozzi Giovanni
Published: November 2004

Presleep stimuli to be retained for further recall is often incorporated into dream contents. To establish whether processing for insertion into dream contents may improve consolidation, we compared the retention rate at delayed recall of contents resulting from incorporation of presleep sentence‐stimuli with those of other contents of the same dream experiences. We hypothesized that association with a cognitive task of recall facilitates access to recently acquired items of declarative knowledge such as presleep stimuli, and triggers the deep elaboration of their semantic features, which involves rehearsal. Twelve subjects were given a task of delayed recall for three nonsense sentences delivered once a time before each of the sleep (re‐)onsets over an experimental night. After each awakening in rapid eye movement sleep, subjects were asked to report dream experience and recall the sentence to be retained. In the morning, after spontaneous awakening, subjects were unexpectedly requested to again report their dream experiences and to recall the stimuli. Two pairs of judges independently identified possible incorporations of the stimuli, and parsed dream reports into propositional content units. The proportion of night reports with at least one incorporation of the stimulus delivered (i.e. valid incorporations) was higher than that of reports with contents similar to a stimulus(‐i) not yet delivered (forward pseudo‐incorporations) or delivered prior to an earlier sleep period (backward pseudo‐incorporations). The proportion of content units common to night and morning reports (considered to be better consolidated) was significantly higher for incorporated contents than for other contents, including pseudo‐incorporated contents. Instead, the retention at morning recall of words of sentence‐stimuli corresponding to incorporated contents was not significantly higher than that of other words. The better retention of incorporated contents provides a partial confirmation (that is, limited to the output of the processing) that a generation effect, which benefits retention of actively processed information, is operative during sleep as well as in waking.
Immediate and delayed incorporations of events into dreams: further replication and implications for dream function
Authors: Nielsen Tore A. , Kuiken Don , Alain Geneviève , Stenstrom Philippe , Powell Russell A.
Published: November 2004

The incorporation of memories into dreams is characterized by two types of temporal effects: the day‐residue effect, involving immediate incorporations of events from the preceding day, and the dream‐lag effect, involving incorporations delayed by about a week. This study was designed to replicate these two effects while controlling several prior methodological problems and to provide preliminary information about potential functions of delayed event incorporations. Introductory Psychology students were asked to recall dreams at home for 1 week. Subsequently, they were instructed to select a single dream and to retrieve past events related to it that arose from one of seven randomly determined days prior to the dream (days 1–7). They then rated both their confidence in recall of events and the extent of correspondence between events and dreams. Judges evaluated qualities of the reported events using scales derived from theories about the function of delayed incorporations. Average ratings of correspondences between dreams and events were high for predream days 1 and 2, low for days 3 and 4 and high again for days 5–7, but only for participants who rated their confidence in recall of events as high and only for females. Delayed incorporations were more likely than immediate incorporations to refer to events characterized by interpersonal interactions, spatial locations, resolved problems and positive emotions. The findings are consistent with the possibility that processes with circaseptan (about 7 days) morphology underlie dream incorporation and that these processes subserve the functions of socio‐emotional adaptation and memory consolidation.
The effects of sleep debt and monotonous work on sleepiness and performance during a 12‐h dayshift
Authors: Sallinen Mikael , Härmä Mikko , Akila Ritva , Holm Anu , Luukkonen Ritva , Mikola Hannu , Müller Kiti , Virkkala Jussi
Published: November 2004

The study examined the effects of the amount of preceding sleep and work pace on sleepiness and cognitive performance during a 12‐h dayshift. Twelve process operators (aged 28–56 years) completed a study with four single 12‐h dayshifts and preceding night sleep in the laboratory. A simulated distillation process served as a work task. The 12‐h shifts differed from each other in terms of the amount of preceding night sleep (23:00–06:30 hours or 2:30–6:30 hours) and work pace (slow or fast). All shifts contained four work simulation sessions of 1.5 h, and each of them included a 15‐min alarm session. Cognitive performance was also measured with a 10‐choice reaction time test and a mental subtraction test. Objective sleepiness was measured with a continuous electroencephalography/electro‐oculography (EEG/EOG) recording during the work periods and with a sleep latency test. Subjective sleepiness at work was measured with the Karolinska Sleepiness Scale. Sleep debt increased the proportion of EEG/EOG‐defined and subjective sleepiness at work, but did not impair work or test performance. The fatiguing effect of monotonous work as indicated by EEG/EOG‐defined sleepiness was comparable with the effect of sleep debt. The alarm epochs in the middle of monotonous work temporarily decreased EEG/EOG‐defined sleepiness. Sleep debt or monotonous work did not have a significant effect on the results of the sleep latency test. None of the sleepiness or performance measures indicated the impairment of a subject's functional capacity at the end of the 12‐h shift. Our results suggest that monotonous work is at least as harmful as moderate sleep debt for alertness at work. The results support the view that the last hours of a single 12‐h dayshift with frequent pauses are not associated with an increase in sleepiness or performance errors.
Daytime variation in performance and tiredness/sleepiness ratings in patients with insomnia, narcolepsy, sleep apnea and normal controls
Authors: Schneider C. , Fulda S. , Schulz H.
Published: November 2004

Daytime tiredness or sleepiness and deficits in cognitive performance are common complaints in sleep disordered patients. Till now there are few studies comparing patients from different diagnostic groups of sleep disorders in the same experimental protocol. We studied the time course of cognitive functions and subjective alertness in a parallel group design with four groups of patients [narcolepsy, untreated or treated obstructive sleep apnea (OSA), or psychophysiological insomnia] and a control group of subjects without sleep complaints. Each group consisted of 10 subjects, matched for age and gender. After a night with polysomnography, subjects were studied for 10 h from 08:00 hours to 18:00 hours at 20 min intervals under standardized environmental conditions. Four psychological tests were applied, (1) a critical flicker fusion (CFF) test to measure optical fusion threshold (alertness); (2) a paper‐and‐pencil visual line tracking test (selective attention); (3) a visual analog scale (VAS) for tiredness/sleepiness; and (4) the Tiredness Symptoms Scale (TSS), a 14 items check list. Each test session lasted for 8 min, followed by a 12 min pause. The level and time course of cognitive performance and self‐rating data were analysed with hierarchical linear mixed effects models. Cognitive tests showed decrements in alertness and selective attention in untreated patients with insomnia, narcolepsy, and sleep apnea. Narcoleptic patients and untreated OSA had a lower CFF threshold than controls, and for narcoleptic patients the time course differed from that of all other groups. In the visual tracking test the performance of all groups of patients was worse compared with normal controls. Self‐rated tiredness/sleepiness was significantly more pronounced in the three groups of untreated patients than in control subjects.
Inter‐ and intra‐individual variability in performance near the circadian nadir during sleep deprivation
Authors: Frey Danielle J. , Badia Pietro , Wright Kenneth P.
Published: November 2004

The study purpose was to assess inter‐ and intra‐individual variability in neurobehavioral function near the circadian nadir during sleep deprivation and conduct exploratory factor analyses to assess relationships among alertness and performance measures during sleep deprivation. Twenty‐five healthy individuals (16 females) aged 18–25 years participated. Participants were sleep deprived for two nights under controlled laboratory conditions using a modified constant routine procedure. A comprehensive battery of neurobehavioral performance tests, subjective sleepiness (SSS), and objective alertness (MWT) were assessed. Seventeen of the 22 neurobehavioral measures were impaired by sleep deprivation (all P < 0.01). The use of multiple neurobehavioral performance measures revealed impairments for all individuals during sleep deprivation. However, sleep deprivation effects were task dependent within and between individuals. Gender contributed minimally to inter‐individual variability in performance. Exploratory factor analysis reduced the 22 measures to seven independent factors. Our findings indicate that no individual was especially vulnerable or resistant to the performance impairing effects of sleep deprivation. Instead, inter‐ and intra‐individual variability in performance during sleep deprivation was task dependent. The finding that subjective sleepiness and objective alertness were not related to any performance measure during sleep deprivation suggests that these measures may assess independent brain functions.
Effect of cognitive behavioural therapy for insomnia on sleep architecture and sleep EEG power spectra in psychophysiological insomnia
Authors: Cervena Katerina , Dauvilliers Yves , Espa Fabrice , Touchon Jacques , Matousek Milos , Billiard Michel , Besset Alain
Published: November 2004

There is now an overwhelming preponderance of evidence that cognitive behavioural therapy for insomnia (CBT‐I) is effective, as effective as sedative hypnotics during acute treatment (4–8 weeks), and is more effective in long term (following treatment). Although the efficacy of CBT‐I in the treatment of chronic insomnia is well known, however there is little objective data on the effects of CBT‐I on sleep architecture and sleep EEG power densities. The present study evaluated, first, subjective change in sleep quality and quantity, and secondly the modifications occurring in polysomnography and EEG power densities during sleep after 8 weeks of CBT‐I. Nine free drug patients with psychophysiological insomnia, aged 33–62 years (mean age 47 ± 9.7 years), seven female and two male participated in the study. Self‐report questionnaires were administered 1 week before and 1 week after CBT‐I, a sleep diary was completed each day 1 week before CBT‐I, during CBT‐I and 1 week after CBT‐I. Subjects underwent two consecutive polysomnographic nights before and after CBT‐I. Spectral analysis was performed the second night following 16 h of controlled wakefulness. After CBT‐I, only scales assessing insomnia were significantly decreased, stages 2, REM sleep and SWS durations were significantly increased. Slow wave activity (SWA) was increased and the SWA decay shortened, beta and sigma activity were reduced. In conclusion CBT‐I improves both subjective and objective sleep quality of sleep. CBT‐I may enhance sleep pressure and improve homeostatic sleep regulation.
Insights into the cellular mechanisms of desiccation tolerance among angiosperm resurrection plant species
Authors: VICRÉ M. , FARRANT J. M. , DRIOUICH A.
Published: November 2004

Water is a major limiting factor in growth and reproduction in plants. The ability of tissues to survive desiccation is commonly found in seeds or pollen but rarely present in vegetative tissues. Resurrection plants are remarkable as they can tolerate almost complete water loss from their vegetative tissues such as leaves and roots. Metabolism is shut down as they dehydrate and the plants become apparently lifeless. Upon rehydration these plants recover full metabolic competence and ‘resurrect’. In order to cope with desiccation, resurrection plants have to overcome a number of stresses as water is lost from the cells, among them oxidative stress, destabilization or loss of membrane integrity and mechanical stress. This review will mainly focus on the effect of dehydration in angiosperm resurrection plants and some of the strategies developed by these plants to tolerate desiccation. Resurrection plants are important experimental models and understanding the physiological and molecular aspects of their desiccation tolerance is of great interest for developing drought‐tolerant crop species adapted to semi‐arid areas.
Physiological and anatomical changes during the early ontogeny of the heteroblastic bromeliad, Vriesea sanguinolenta, do not concur with the morphological change from atmospheric to tank form
Authors: ZOTZ G. , ENSLIN A. , HARTUNG W. , ZIEGLER H.
Published: November 2004

Two distinct morphological forms characterize the ontogeny of many epiphytic bromeliads. Smaller plants exhibit an atmospheric habit, while larger plants form water‐impounding tanks. The study of the functional significance of heteroblasty in epiphytes is severely hampered by considerable size‐related variation in morphological, anatomical and physiological parameters. To overcome this problem, plants of varying size of both atmospheric and tank form were included in the present study with Vriesea sanguinolenta. The results show that virtually all morphological, anatomical and physiological characteristics vary during ontogeny, but changes were rarely directly related to the step change in gross morphology. Changes were either: (1) gradual from smallest atmospheric to small tank (e.g. leaf divergence angles, reduction in photosystem II efficiency during drought, speed of recovery after drought); (2) there was no change between atmospheric and small tank, but a gradual or step change within the tank form (stomatal density, relationship of leaf N and specific leaf area); or (3) developmental patterns were more complicated with decreases and increases during ontogeny (photosynthetic capacity, carbon isotope ratios, abscisic acid levels during drought). Although the comparisons between ontogenetic phases were always confounded by size differences, a hypothetical small tank plant is expected to suffer higher water loss than a real atmospheric, whereas a hypothetical, large atmospheric plant would show reduced access to resources, such as nutrients, in comparison with the real tank. The present results are consistent with the notion of heteroblasty as an adaptation of early ontogenetic stages to drought, but highlight that size‐related variation greatly modifies any difference directly associated with the step change from atmospheric to tank.