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PubMed1998

Theory and practice for the implementation of 'in-house', continuous improvement participatory ergonomic programs.

This paper presents a case study of an implementation of a participatory ergonomics program in a public service agency. The objective of the study was to develop a theoretical model and related design principles for the implementation of 'in-house', continuous improvement participatory programs. The proposed model is based on the behavioral cybernetic theory of learning (Smith and Smith, 1966, Cybernetic Principles of Learning and Educational Design held, Rhinehart and Winsten, New York) and emphasizes the concepts of action, feedback, feedback control, and individual learning as essential for a progression from external regulation (by outside experts) to internal regulation (by organizational members) of participatory programs. Results support the proposed model, but do suggest an expansion of the model to include macro-level organizational variables as additional factors necessary for developing internally regulated participatory programs. Results have led to the specification of several design principles for implementing 'in-house', continuous improvement participatory programs.

Ergonomics↗
PubMed2001

Processes underlying adaptation to tempo changes in sensorimotor synchronization.

In synchronizing finger taps with an auditory sequence, a small sudden tempo ("step") change in the sequence tends to be followed by rapid adaptation of the tapping period but slow adaptation of the relative phase of the taps, whereas a larger step change leads to initial period overshoot followed by rapid adaptation of both period and phase [M.H. Thaut, R.A. Miller, L.M. Schauer, Biological Cybernetics 79 (1998a) 241-250]. Experiment 1 replicated these findings and showed that the transition between the two patterns of adaptation occurs near the perceptual detection threshold for a tempo change. A reasonable explanation of these data was provided by a dual-process model of internal error correction [J. Mates, Biological Cybernetics 70 (1994a) 463-473, 70 (1994b) 475-484], with the added assumption that one process (period correction) depends on conscious awareness of a tempo change whereas the other (phase correction) does not. This assumption received support in Experiment 2, where a synchronization-continuation tapping task was used in combination with perceptual judgments to probe into the process of period correction following step changes. The results led to the conclusion that rapid adaptation of the tapping period to a small, undetected tempo change is in fact due to rapid internal phase correction, whereas slow adaptation of the relative phase of the taps is due to slow internal period correction.

Adaptation, Physiological↗
PubMed2003

Human stem cells as targets for the aging and diseases of aging processes.

While many theories have been proposed for the aging process, and many debates on the matter of aging and the diseases of aging being either the result of the same or independent processes, most have not considered humans as a hierarchical system made up of cybernetically interacting levels of organization. To understand the aging process and the diseases of aging, one must view the human as the result of the total genomic DNA in the single fertilized egg that proliferates, differentiates and develops into an individual of about 100 trillion cells, organized by different cell types (pluri-potent stem cells, progenitor stem cells, terminally differentiated cells) into multiple tissue, organ and organ systems which interact with each other via endogenous factors and with exogenous factors. Our hypothesis is that both aging and diseases of aging are dependent of the normal functioning of the pluri-potent stem cell pool. Specifically, the concept involves the cybernetic feedback between the 'quantity' of the stem cell pool in each tissue niche with the 'quality' of the stem cells in the pool. The process of gap junctional inter-cellular communication (GJIC), which has been implicated in the evolution from the single cell organism to the multi-cellular organisms, requiring growth control, differentiation, apoptosis, adaptive response capability of differentiated cells and senescence, is speculated to be a shared mechanism in stem cell biology and in many chronic disease processes (teratogenesis; carcinogenesis, atherogenesis, diabetigenesis, etc.). Specifically, stem cells are assumed to be 'immortal' until induced to express their connexin genes and have functional GJIC, at which time they can differentiate and become 'mortal'. As long as the stem cells are communicating with their differentiated daughters via some extra-cellular soluble negative growth factor, the homeostatic control of their growth and differentiation is maintained for the organism. However, if the stem cell pool is depleted by any process, replacement of tissue due to wear and tear is diminished. The dependence of this tissue/organ to maintain homeostatic control of other organ systems then diminishes, leading to 'systems failure'. In addition, if the stem cells in the pool have been exposed to agents that prevent the normal terminal differentiation of that cell, but whereby these 'initiated' stem cells can be expanded in any tissue, clones of partially differentiated and non-functional appear in the tissue. This diminishes the efficacy of that tissue to function properly and, thereby, also contributes to 'system failure' by contributing to the breakdown of homeostatic organ system control. One clear example, that of carcinogenesis, illustrates this point.

Aging↗
PubMed1999

[Everything was done--patient still not satisfied: introduction to evidence-based surgery].

Although the best knowledge in academic medicine has been used, some patients are still unsatisfied. By reason of these experiences there is a certain need to reflect our patterns of thinking. The surgical act is based on the laws of causality from Newton and Galilei and it is determined by the principle of cause and effect. Therefore the healing process must be interpreted as a turning back of pathogenesis or the linear chain of causalities. Scientific knowledge of this century demonstrate, that biologic healing processes are connected with the laws of cybernetics and the principles of semiotics. There are functional relations between the level of the organ (impairments) of the individual (disabilities) and of the society (handicaps). This International Classification of Impairments, Disabilities and Handicaps (ICIDH) serves as the key for the management of chronic diseases. An independent and a separate classification of the severity in each level is necessary to identify the consequences of the disease to the patient. Surgical interventions occur on the organ level, benefit and evidence are reflected especially on the individual level (gain of abilities). The assessment and the integration of the so called "sensory impairment", influenced by the biographical events of the patient, an the evaluation of the psychosocial resistance are important factors to recognize a unfavourable conformity between the degree of impairment and the degree of disability. With this classification a more patient-oriented discussion of the indications regarding operative procedures can be realised. The MARA model (mean age related ability) serves as a pragmatic basis for the description of the benefits of carried out and omitted interventions as changes of abilities by using the MARA curve as ethical guideline. This model, which is derived on ICIDH, the hierarchy of needs and the salutogenesis (semiotics, cybernetics), facilitate the introduction of evidence based surgery. It helps to estimate the several predictive values and correlation factors influencing the manifestation of the disease. On this way astonishing results in evidence can be expected. Finally many misunderstandings in health care discussions are explained by the fact that the differences between pathology and illness are not clearly interpreted.

Adult↗
PubMed1995

Speech technology in the year 2001.

This paper introduces the session "Technology in the Year 2001" and is the first of four papers dealing with the future of human-machine communication by voice. In looking to the future it is important to recognize both the difficulties of technological forecasting and the frailties of the technology as it exists today--frailties that are manifestations of our limited scientific understanding of human cognition. The technology to realize truly advanced applications does not yet exist and cannot be supported by our presently incomplete science of speech. To achieve this long-term goal, the authors advocate a fundamental research program using a cybernetic approach substantially different from more conventional synthetic approaches. In a cybernetic approach, feedback control systems will allow a machine to adapt to a linguistically rich environment using reinforcement learning.

Computers↗
PubMed2000

Intersubjectivity and narcissism in group psychotherapy: how feedback works.

In group psychotherapy, inter-subjectivity is complicated by the number and quality of therapist-member, member-member, and member-group relations. Inter-member feedback structures the relational process. However, fears of narcissistic injury engender resistance to this form of engagement. The nature of the narcissistic belief system that motivates such resistance is discussed. Then, two models of feedback are presented: the cybernetic and the inter-subjective. In the cybernetic model, feedback is intended to inform recipients about themselves and to change their behavior accordingly. As such, this model is consistent with narcissistic beliefs in the power of others' perceptions to control one's being, identity, or value. The inter-subjective model focuses, instead, on what feedback tells recipients about their donors' worlds. This model and some of its parameters are exemplified clinically.

Feedback↗
PubMedDate not supplied

Perspectives in the modeling and optimization of PHB production by pure and mixed cultures.

Poly(beta-hydroxybutyrate) or PHB is an important member of the family of polyhydroxyalkanoates with properties that make it potentially competitive with synthetic polymers. In addition, PHB is biodegradable. While the biochemistry of PHB synthesis by microorganisms is well known, improvement of large-scale productivity requires good fermentation modeling and optimization. The latter aspect is reviewed here. Current models are of two types: (i) mechanistic and (ii) cybernetic. The models may be unstructured or structured, and they have been applied to single cultures and co-cultures. However, neither class of models expresses adequately all the important features of large-scale non-ideal fermentations. Model-independent neural networks provide faithful representations of observations, but they can be difficult to design. So hybrid models, combining mechanistic, cybernetic and neural models, offer a useful compromise. All three kinds of basic models are discussed with applications and directions toward hybrid model development.

Algorithms↗
PubMedDate not supplied

[What is the subject of science "bioinformatics"?].

The paper is concerned with some problems of terminology, in particular the term "bioinformatics". In the last few years, the term "bioinformatics" has been intensively used among molecular biologists to indicate a subject that is only a constituent of genomics and is considered to involve a computer-assisted analysis of all data on nucleotide sequences of DNA. However, a wide circle of scientists, including biologists, physicists, mathematicians, and specialists in the field of cybernetics, informatics, and other disciplines have accepted and accept, as a rule, the "bioinformatics" as a synonym of science cybernetics and as a successor of this science. In this case, the subject of science "bioinformatics" should embrace not only genomics but practically all sections of the biological science. It should involve a study of information processes (storage, transfer, and processing of information, etc.) participating in the regulation and control at all levels of living systems, from macromolecules to the brain of higher animals and human.

Computational Biology↗
PubMed1991

A review of the literature on the prevalence of Class III malocclusion and the mandibular prognathic growth hypotheses.

From this review of the literature it appears that we may draw the following conclusions. The incidence of Class III malocclusions is at most 4.2% (Goose et al. 1957, Ast et al. 1965; Knowles 1966, Thylander and Myrberg 1973). The development of various condyle growth hypotheses have lead us to believe that the condyle behaves in a rather unique manner. The condyle does not appear to be an epiphysis, neither does it behave the same as the cranium. It is a unique cartilaginous structure that cannot grow against intermittent or continuous forces (Copray 1985). The cybernetic model as proposed by Petrovic and co workers (1977) that eloquently describes the condyle to be stimulated by a cybernetic switch that connects to the periodontal ligament also does not seem to have much validity. It appears that the lateral pterygoid muscle and the temporo-mandibular condylar frenum have been ascribed capabilities that do not comply to the results of condylotomy studies. Gorette-Nicaise, Awn, and Dhem (1983) as well as the study by Whetten, and Johnston (1985) have shown that neither the absence of the lateral pterygoid muscle nor the physical volumetric expansion of the airway increases condylar growth. It appears that increase in the pressure applied to the condyle could decrease condyle cell proliferation (Armstrong 1961; Thilander 1963; 1965: Janzen and Bluher 1965; Graber 1969; Petrovic 1972; Graber and Muller 1974; Graber 1975;) with resulting growth attenuation. Accordingly, condylar growth is controlled by physical restraint, the absence which leads to incremental growht. The presence of mechanical pressure of adequate duration and magnitude, thus, should limit growth of the young actively growing condyle.

Humans↗
PubMedDate not supplied

[Clinical vestibulometry: current status and future prospects].

Rotation and caloric methods of vestibular stimulation proposed and adopted during the last decades have been reviewed in terms of their efficacy in differential and topic diagnosis, clinical practicability. Systemic and bio-cybernetics approaches to vestibular apparatus and function have been analyzed. The need of using neurophysiological and cybernetics methods for further progress in relevant research and most promising trends in advancing clinical vestibulometry have been determined.

Diagnosis, Differential↗
PubMed1994

A benchmark of cell survival models using survival curves for human cells after completion of repair of potentially lethal damage.

Six models of radiation action (the linear-quadratic model, the multitarget model with initial slope, the repair-misrepair model, the lethal-potentially lethal model, the cybernetic model, the saturable repair model) were tested for their goodness of fit to survival curves for human cells. Fifty-three survival curves for human cells irradiated in plateau phase and after completion of repair of potentially lethal damage (PLD) provided the experimental basis for the tests. Three criteria were considered. The capacity to describe the survival data was estimated, using the error left unexplained by the model. A validation of models was achieved by consideration of the mean residual squared errors. The ability of the parameters to characterize survival curves was investigated, studying their variation within and among curves. The models were not equivalent, whatever the test. The saturable repair model and the multitarget with initial slope model gave the most accurate description of survival data. The linear-quadratic model had the most reliable parameters, so that comparisons of the cell survival curves could be made advantageously. The cybernetic model and the lethal-potentially lethal model were found inappropriate for the analysis of survival curves for human cells after completion of PLD repair.

Analysis of Variance↗
PubMed1984

The dynamics of quantifiable homeostasis. V: Homeostasis of higher order.

The properties are explored of a cybernetic process with lag L and force of restoration equal to the size of displacement one lag unit earlier, raised to any arbitrary positive power (w greater than 1), multiplied by the restoration constant b, the sign being opposite to that of the displacement at that time. No closed-form solution is available, but a converging Taylor series expansion is presented that gives a solution of arbitrary precision. Unlike the linear system previously discussed, the amplitude of the displacement (A) is germane, and it is shown that the criterion that the effect of a perturbation be damped out is whether or not LbAw-1 exceeds a constant, kw, that depends only on w. The counterpart of this pattern of higher-order homeostasis is closer to the biological behavior of many forms of homeostasis than the scaled invariance characteristic of the linear process. kw is shown to be bounded between pi/2 and 2, and increases monotonically with w. Exactly computed values and large-sample approximations are given for the critical values below which no overshoot at all occurs. It is shown that where it does not, the minimum expected cost decreases with increasing w and reaches a minimum at infinite w. However, this evolutionary gain is vitiated where large displacements are involved, and may need to be redressed by a change in the restoration constant. Thus, the dynamic balance becomes much more subtle than with lower-order processes. Several brief clinical illustrations of these ideas are presented.

Biological Evolution↗
PubMed1982

Towards an alternative evolution model.

Lamarck and Darwin agreed on the inconstancy of species and on the exclusive gradualism of evolution (nature does not jump). Darwinism, revived as neo-Darwinism, was almost generally accepted from about 1930 till 1960. In the sixties the evolutionary importance of selection has been called in question by the neutralists. The traditional conception of the gene is disarranged by recent molecular-biological findings. Owing to the increasing confusion about the concept of genotype, this concept is reconsidered. The idea of the genotype as a cluster of genes is replaced by a cybernetical interpretation of the genotype. As nature does jump, exclusive gradualism is dismissed. Saltatory evolution is a natural phenomenon, provided by a sudden collapse of the thresholds which resist against evolution. The fossil record and the taxonomic system call for a macromutational interpretation. As Lamarck and Darwin overlooked the resistance of evolutionary thresholds, an alternative evolution model is needed, the first to be constructed on a palaeontological and taxonomic basis.

Animals↗
PubMed1991

Dynamic theory of action-perception patterns: the "moving room" paradigm.

Action-perception patterns are studied theoretically in terms of equations of motion that capture the coordination capacity of the nervous system. We consider intrinsic dynamics in the absence of visual information that contain a single posture state as a fixed point attractor. We couple these intrinsic dynamics to visual information that stabilizes posture in the visual world. This leads to a theory of postural sway induced by an optic flow field ("moving room" paradigm). The optic flow is parametrized in a simplest approximation by the expansion rate of a relevant perceptual target. We show how temporal stability as the key concept of this theory can lead to prediction and serve as a measure of perceptual coupling. Finally, we discuss the relation of the present theory to biological cybernetics.

Animals↗
PubMed1989

[Signal-flow diagrams as aids to describe hypnotic trance states: an impulse for our statement].

A model is developed to show the formation of the hypnotic trance states. As experimental results are rare in this field the development of the model is mainly done by assuming possible and practicable connections. It is the beginning of cybernetic models for this domain and may encourage further work in this direction. The focal point is the separation of energy-flow from information-flow. Only the latter is needed with the arrangement of signal-flow diagrams. These diagrams show that the different trance states may be explained as different information-processing systems. We don't require the physiological background as we have transformed the problem into a pure psychology-problem - On this way we find two switch-over systems: One that opens the loop between the model of outer world and the inner decision system. By this way it gives to the other system the possibility to follow word-for-word the suggestions, given by the hypnotist.

Cybernetics↗
PubMed1993

[The role of ergonomics in the prevention of work-related diseases].

Processes linking individual situations and behaviours, as disclosed by the ergonomic analysis of job, to populations' epidemiological characteristics are discussed here. Epidemiology proposes deterministic models of general significance, reflecting stable phenomenons within wide populations. Ergonomics proposes cybernetic (or systemic) models of time- and space-limited significance, reflecting the variety of adapting and assimilating behaviours in homogeneous groups of workers. Regarding prevention, both approaches complement one another.

Cybernetics↗
PubMed2006

What is a gene? From molecules to metaphysics.

Mendelian genes have become molecular genes, with increasing puzzlement about locating them, due to increasing complexity in genomic webworks. Genome science finds modular and conserved units of inheritance, identified as homologous genes. Such genes are cybernetic, transmitting information over generations; this too requires multi-leveled analysis, from DNA transcription to development and reproduction of the whole organism. Genes are conserved; genes are also dynamic and creative in evolutionary speciation-most remarkably producing humans capable of wondering about what genes are.

Adaptation, Biological↗
PubMed1985

A sociological conceptualization of trauma.

The epistemological difficulties with the model of 'stressful life events' are reviewed and contrasted with the epistemologies of the pioneers of stress research: Cannon, Selye, Durkheim, Freud, Bernard and Dubos. The paper focuses on the question 'What is an event?' as opposed to a fact and on the neo-Humean difficulties of relying upon explanations of events. It is demonstrated that the pioneers of stress research avoided event-explanations and relied instead (sometimes implicitly) on the notion of 'trauma'. A trauma is not just an event. The concept of trauma is linked to the ideas of arrangements and derangements of collective representations in the context of society conceived of as a cybernetic system.

Cybernetics↗