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PubMed1998

Black churches as therapeutic systems: a group process perspective.

This article examines Black churches as therapeutic systems that provide psychological and physical support to African American communities. Systems theory and group relations theory are used as conceptual frameworks to discuss Black churches as indigenous community resources. Instrumental to a systems approach is an understanding of Black churches and the religious experiences they support as part of a dynamic process that may vary across churches while maintaining certain basic similarities. It is also important to explore how Black churches may function differently from one another in addressing the needs of their membership and surrounding community. Consequently, a group process perspective is used to examine how roles and functions of the church may vary as they relate to their particular congregation. Examining the role of Black churches as supportive networks provides invaluable information to professional health providers who are interested in working with Black churches as community-based organizations.

Adaptation, Psychological↗
PubMed2000

Short-term autonomic nervous control of the cardiovascular system: a system theoretic approach.

A non-linear model of the human cardiovascular regulation system (CVS) has been developed, with the aim of studying the short-term regulation process by the autonomic nervous system (ANS). This restricts the time interval under study to range from fractions of seconds to about 30 seconds. As a consequence, the only feedback mechanism taken into account is the baroreceptors loop. Our main guideline has been first to try to capture the main features of the system that have been observed and reported in the relevant publications in physiology--main non-linearities in the elementary components of the system, intrinsic periodicities--while keeping to a minimum the number of model parameters, with the question of identifiability from real data in mind. Also, we have tried to retain as much physiological significance to these parameters as possible, for forthcoming diagnosis purposes, while using non invasive measurements only. At the present time, no venous return has been taken into account but should be included later on. The long term objective of this research is to develop tools for helping in medical diagnosis. This may go through the detection of defaults in this closed loop system, within the framework of control systems theory, hereby using all the known concepts from that field, that have been much used for engineering systems (mechanical, electrical etc...): these include signal processing techniques as well as control algorithms or identification and detection methods.

Autonomic Nervous System↗
PubMed2002

Finance organizations, decisions and emotions.

Analyses of global financial markets are dominated by atomized models of decision-making and behavioural psychology ('exuberance' or 'panic'). In contrast, this paper argues that overwhelmingly, finance organizations rather than 'individuals' make decisions, and routinely use emotions in formulating expectations. Keynes introduced emotion (business confidence and animal spirits) but in economics, emotion remains individualistic and irrational. Luhmann's system theory lies at the other extreme, where emotions like trust and confidence are central variables, functional in the reduction of complexity in sub-systems like the economy. The gap between irrational emotions aggregated to 'herd' behaviour in economics, and 'system trust' applied to finance and money as a 'medium of communication' in sociology, remains largely unfilled. This paper argues that while organizations cannot be said to 'think' or 'feel', they are rational and emotional, because impersonal trust, confidence and their contrary emotions are unavoidable in decision-making due to fundamental uncertainty. These future-oriented emotions are prevalent within and between organizations in the financial sector, primarily in generating expectations. The dynamic of corporate activities of tense and ruthless struggle is a more plausible level of analysis than either financial 'manias' in aggregate or 'system trust'.

Decision Making↗
PubMed2004

Real-time identification and archiving of micro-embolic Doppler signals using a knowledge-based DSP system.

Identification of micro-emboli in the cerebral circulation using transcranial Doppler ultrasound provides valuable clinical information, but, currently, embolic signal detection and analysis are significantly limited because they mainly rely on costly off-line analysis by human experts. In this study, a reliable, high-resolution, real-time automated system for the detection and archiving of embolic signals was designed and implemented using expert system theory and modern DSP technology. Preliminary tests were conducted to evaluate the functions and the performance of the system using data from ten carotid endarterectomy patients and two normal volunteers. Using the widely accepted 7 dB threshold for human reliability and a human expert, majority-decision gold standard, the real-time system reached sensitivity and specificity of 93.6% and 99.3%, respectively, which were close to the results obtained by three human experts under ideal laboratory conditions (90.1% and 99.8%, 98.4% and 99.9%, 98.9 and 99.9%). The new system has the potential to be used either as a bedside monitoring and signal acquisition device, or as a laboratory investigation tool.

Endarterectomy, Carotid↗
PubMed1994

A comparison among different inversion methods for multi-exponential NMR relaxation data.

The inversion of data to be represented by sums or continuous distributions of exponentials is done by different algorithms and compared. The published CONTIN program presents a chosen solution with an appropriate amount of detail. An in-house program EXDISTR allows operative choice of various constraints in order to show the consequences in quality of fit of allowing various features such as extra maxima or minima. Another in-house program based on the system theory approach, IDENT, treats the data as the output samples of a linear, time-invariant, autonomous dynamic system.

Algorithms↗
PubMed2001

Neurovascular coupling in terms of a control system: validation of a second-order linear system model.

Neurovascular coupling (NC) adapts cerebral blood flow to cortical activity. Functional transcranial Doppler (f-TCD) investigations revealed a typical time course of evoked blood flow responses with an initial overshoot and a stabilization at a lower, but stable, level. This blood flow reaction can be described in terms of a control-system model. We tested reliability and validity of this new approach using different stimulation paradigms. The P2 segment of the posterior cerebral artery was insonated in 14 healthy volunteers and, subsequently, NC was stimulated using two tests, a checkerboard stimulus of 1 s with different repetition rates and a reading test. Data were analyzed according to algorithms of control-system theory. The reading test was used to measure test reliability and side differences. A second-order linear system can describe blood flow regulation of NC. Different stimulation protocols of the checkerboard test and the related evoked blood flow curves could be described by the same control-system model. Further, there were no differences between the checkerboard and reading test nor between right and left side or test and retest of the reading test. NC can be described in a much more detailed manner using control-system analysis. We were able to show that blood flow response due to different visual stimuli follow one common control-system model. Unlike quantification of NC using overshoot, parameters of the control system have smaller SDs, increasing the statistical power and, thereby, usefulness of f-TCD as a diagnostic instrument.

Adult↗
PubMed2004

Search for organising principles: understanding in systems biology.

Due in large measure to the explosive progress in molecular biology, biology has become arguably the most exciting scientific field. The first half of the 21st century is sometimes referred to as the 'era of biology', analogous to the first half of the 20th century, which was considered to be the 'era of physics'. Yet, biology is facing a crisis--or is it an opportunity--reminiscent of the state of biology in pre-double-helix time. The principal challenge facing systems biology is complexity. According to Hood, 'Systems biology defines and analyses the interrelationships of all of the elements in a functioning system in order to understand how the system works.' With 30000+ genes in the human genome the study of all relationships simultaneously becomes a formidably complex problem. Hanahan and Weinberg raised the question as to whether progress will consist of 'adding further layers of complexity to a scientific literature that is already complex almost beyond measure' or whether the progress will lead to a 'science with a conceptual structure and logical coherence that rivals that of chemistry or physics.' At the core of the challenge is the need for a new approach, a shift from reductionism to a holistic perspective. However, more than just a pronouncement of a new approach is needed. We suggest that what is needed is to provide a conceptual framework for systems biology research. We propose that the concept of a complex system, i.e. a system of systems as defined in mathematical general systems theory (MGST), is central to provide such a framework. We further argue that for a deeper understanding in systems biology investigations should go beyond building numerical mathematical or computer models--important as they are. Biological phenomena cannot be predicted with the level of numerical precision as in classical physics. Explanations in terms of how the categories of systems are organised to function in ever changing conditions are more revealing. Non-numerical mathematical tools are appropriate for the task. Such a categorical perspective led us to propose that the core of understanding in systems biology depends on the search for organising principles rather than solely on construction of predictive descriptions (i.e. models) that exactly outline the evolution of systems in space and time. The search for organising principles requires an identification/discovery of new concepts and hypotheses. Some of them, such as coordination motifs for transcriptional regulatory networks and bounded autonomy of levccels in a hierarchy, are outlined in this article. Experimental designs are outlined to help verify the applicability of the interaction balance principle of coordination to transcriptional and posttranscriptional networks.

Cell Physiological Phenomena↗
PubMedDate not supplied

Beyond the milestone model--a systems framework for alternative infant assessment procedures.

Recent theoretical and methodological advances in developmental psychology offer new possibilities in the assessment of developmentally disordered infants which carry significant advantages over current procedures. It is argued that infant competence is not solely a quality inherent within the individual, but is a function of a particular individual within a particular environment. The understanding of early developmental processes as being based upon infant-environment transactions, requires an assessment methodology which can take account of complex and changing relationships, and can recognize the role of the infant in determining characteristics of the caregiving environment. It is proposed that systems theory offers a useful framework on which to construct new assessment procedures. Different levels of the infant environment system are identified, and examples of the ways in which recently developed procedures may be incorporated into the model are described.

Adaptation, Psychological↗
PubMed1978

Systemic structural analysis of the electroencephalogram of depressed patients. General principles and preliminary results of an international collaborative study.

In previous articles, evidence has been presented which supports the hypothesis that detectable neurophysiological changes occur in the course of affective disorders, mainly of a depressive type. The scope of the present report has been to expand the previous investigation to comprise variables not hitherto taken into account and to present a new approach to the analysis of EEG in psychiatry. This new approach, a systemic structural analysis, follows the concepts borrowed from the general system theory, and is based on the assumption that brain activity can be regarded as a type of hierarchical system. Hints about the theoretical principles beyond a systemic structural analysis of EEG are given, and the point is stressed that possible correlations between, e.g., neurophysiological and clinical variables must be south starting from characteristics which are at a comparable level of integration in both realms. The preliminary findings of an international collaborative study of depressive syndromes are presented. 45 patients suffering from depressive syndromes of different aetiology and of varying severity participated in the study. These were rated by means of a rating scale which permitted a division for further analysis into subgroups according to the main symptomatology. The results show that characteristic neurofunctional structures can be identified which correspond to various symptomatological patterns. The occurrence of pronounced interhemispheric differences in electrical activity, related to the severity of the depressive syndrome, has also found further support in the results of this present investigation.

Adult↗
PubMed1987

A public school-based referral system for psychiatric mental health nursing experiences.

Numerous advantages are anticipated with the implementation of the school-based referral system as a method of providing outpatient clinical experiences for a group of Psychiatric/Mental Health Nursing students. The school setting, when used as a clinical site, can provide valuable learning experiences where the student can apply the nursing process with individuals, families and groups. This multi-dimensional involvement reinforces family systems theory as well as group concepts. The nature of the students' experiences through the school-based referral system gives them the opportunity to increase their knowledge and understanding of the three levels of prevention: primary, secondary, and tertiary. The referrals generally constitute secondary intervention, with early recognition/intervention being the focus. Students are also encouraged to assess for factors that would place a child at risk for the development of other problems. With the identification of such factors, primary intervention strategies can be structured and implemented to reduce the child's risk. In some cases, students are involved in tertiary prevention, with a rehabilitative approach employed to assist individuals/families cope with a long-term problem situation. This expanded clinical experience facilitates the application of leadership concepts and reinforces the collaborative role of the nurse in the multidisciplinary provision of client services. Since the Psychiatric/Mental Health component of the curriculum is in the senior year, involvement in such a clinical experience also provides the students with a positive stimulus for the assumption of their professional roles and an opportunity to synthesize all previous learning.

Adolescent↗
PubMed2001

Overcoming barriers to quality wound care: a systems perspective.

The societal burden of chronic wound care is guaranteed to intensify given the increasing elderly population of the United States. Currently 1.5 to 3 million patients with pressure ulcers are being treated at an estimated cost of $5 billion dollars annually. Many more millions suffer from venous, arterial, and neuropathic leg ulcers. When the huge scope of the issue is considered, the enormous challenge of providing quality wound care in the future is evident. Using general systems theory, this article analyzes contemporary salient barriers to quality chronic wound care from individual, group, and societal level systems perspectives. Factors that can help overcome these barriers are targeted, including newly emerging technological facilitators.

Aged↗
PubMed1990

[Psychological management in critical care units. History of a long way].

Some concepts of the General Systems Theory issued from the Social Sciences are used by Liaison psychiatrist and psychologist in the Intensive Care Unit. Human system, interaction process and circular causality, all concepts from the Systemic approach, are useful in order to describe and analyse both vital and existential crisis situation of the patient. As an expansion of the therapeutic context, the relationship among the patient, the family and the medical team are defined in terms of a partnership instead of a power conflict. Then, attention is focused on the distress resulting from these stressful situations, influenced by the "pangs of death". Emphasizing the importance and the role of anxiety allows to recognize a place for it and to offer to everybody an opportunity to talk about it. Finally, the psychotherapeutic function can be defined as the creation of a place given to the person as a Subject, based on the recognition of the fundamental misunderstanding of human illness.

Anxiety↗
PubMed1993

[Psyche and soma--Descartes in our hearts?].

The essay deals with the mind-body problem. The first part describes the different views held by philosophers from Plato up to modern times, stressing the standpoint of René Descartes for medical philosophy and dualism. The author outlines the new research field of psychoneuroimmunology, and asks whether this could be one of the keys to the mind-body problem. The concept of anomaly is discussed, taking placebo and nocebo as prominent examples. Finally the author outlines modern holistic thinking based on a general systems theory, with biology as a dynamic interplay of culture, ecology, mind, and body in an open non-lineary system.

Europe↗
PubMed1980

A study of the psychoanalytic theory of anxiety, III: A preliminary formulation of the anxiety response.

An attempt is here made to apply the propositions of psychoanalytic ego psychology and certain ideas from systems theory to problems in the theory of anxiety. Conscious affect experience in adults is taken as a clinical starting point. The propositions advanced place concepts of processes by which events or fantasies are located in time at the center of anxiety theory and, perhaps, of affect theory generally.

Adult↗
PubMed1986

Structure and dynamics of human communication at the beginning of life.

Although the beginning of postpartum social integration and communication has been long viewed as relevant to psychiatric theories, early parent-infant communication has become a matter of scientific investigation only recently. The present survey explains the significance of an approach based upon the general systems theory and explores to what extent the early parent-infant interaction can function as a didactic system to support the development of thought and speech. Evidence of this function has been found in those forms of parental behavior that escape the parent's conscious awareness and control, as exemplified in the vocal communication with presyllabic infants. Parents unknowingly adjust the structure and dynamics of speech to the constraints of infant capacities, detach prosodic musicality from lexical structure, and use it in particularly expressive forms for the delivery of the first prototypical messages. In this and other similar ways, parents offer an abundance of learning situations in which infants can try out various integrative operations. A biological rather than cultural provenience of the support of communicative development indicates a potential relevance for the interpretation of speech evolution. In addition to qualities of the vocal tract and to complex symbolic capacities in humans, the early intuitive support of communicative development and its playful character are suggested as species-specific determinants of speech evolution. Implications for clinical research are suggested.

Communication↗
PubMedDate not supplied

Dynamics of brain electrical activity.

In addition to providing important theoretical insights into chaotic deterministic systems, dynamical systems theory has provided techniques for analyzing experimental data. These methods have been applied to a variety of physical and chemical systems. More recently, biological applications have become important. In this paper, we report applications of one of these techniques, estimation of a signal's correlation dimension, to the characterization of human electroencephalographic (EEG) signals and event-related brain potentials (ERPs). These calculations demonstrate that the magnitude of the technical difficulties encountered when attempting to estimate dimensions from noisy biological signals are substantial. However, these results also suggest that this procedure can provide a partial characterization of changes in cerebral electrical activity associated with changes in cognitive behavior that complements classical analytic procedures.

Brain↗
PubMed1994

C.E.B.A.S.-AQUARACK project: the Mini-Module as tool in artificial ecosystem research.

The evolution of the C.E.B.A.S-AQUARACK project including results of the scientific frame program was frequently presented at the IAA Man in Space Symposia 1989 and 1991 and the IAF/IAA congresses since 1990. C.E.B.A.S. (Closed Equilibrated Biological Aquatic System) is a combined animal/plant system for long-term multi-generation experiments with aquatic organisms in ground laboratories and in a space station. For short-term missions a miniaturized version was developed which fits into a spacelab middeck locker together with all surrounding equipment. The latest development is an optimized prototype with a total volume of about 11 liters which consists of a main animal tank (Zoological Component) with integrated bacteria filter, a semibiological coarse filter, an illuminated higher plant container (Botanical Component) and combined small animal and electrode compartment. A silastic tubing gas exchanger in a closed side-loop serves as an emergency unit in case of the malfunction of the Botanical Component and the water is driven through the system by rotatory pumps. It is operative for several weeks in closed state. This C.E.B.A.S. Mini-Module also represents an aquatic artificial ecosystem in which basic scientific problems of component interactions and system theory can be solved with the side aspects of combined production of animal and plant food in bioregenerative life support systems. The paper presents details of the current status of the hardware development and data about the function of the fully biological life support of the system, e. g. mid-term registrations of water parameters. Moreover, morphological and physiological data of the experimental animals (-the teleost fish Xiphophorus helleri-) and plants (-a tropical Ceratophyllum species-) demonstrate the biological stability of the system. These are used to elaborate first details of population interactions and inter-dependencies as a basis of a disposed comprehensive system analysis which is the essential precondition for the design of possible aquatic modules for bioregenerative life support systems.

Animals↗
PubMed1999

Dynamical systems analysis of arterial blood pressure signals in relation to heart rate fluctuations in chick embryos.

We attempted a new approach based on a modern dynamical system theory to reconstruct the arterial blood pressure signals in relation to heart rate fluctuations of developing chick embryos. The dynamical systems approach in general is to model a phenomenon that is presented by a single time series record and approximate the dynamical property (e.g. heart rate fluctuations) of a system based only on information contained in a single-variable (arterial blood pressure) of the system. The time-series data of the arterial blood pressure was reconstructed in 3-dimensional space to draw characteristic orbits. Since the reconstructed orbits of the blood pressure should retain information contained in the pressure signals, we attempted to derive instantaneous heart rate (IHR) from the reconstructed orbits. The derived IHR presenting HR fluctuations coincided well with the IHR obtained conventionally from the peak-to-peak time intervals of the maximum blood pressure. Movements of the reconstructed orbits of the arterial blood pressure in 3-dimensional space reflected HR fluctuations (i.e. transient decelerations and accelerations).

Animals↗