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PubMed1996

On cardinal directions in spatial pattern space and falsifying multi-channel detection models.

It has been generally recognised that in its early stages the human visual system comprises a set of independent subsystems, or channels, acting in parallel. There is general agreement that the receptive fields of neurones constituting the channels overlap considerably, making the task of selectively stimulating individual channels nontrivial. Since such a task is important for estimating the spatio-temporal characteristics of these channels, a method for determining a set of spatial patterns which stimulate multiple channels independently, irrespective of how their receptive fields overlap, is presented here. As an example such patterns were calculated for Wilson and Bergen's model (Wilson and Bergen, 1979, Vision Res. 19, 19-32). Using the modification of the subthreshold summation technique (Logvinenko, 1995, Biol. Cybernet. 73, 547-552) it is shown that in reality these stimuli are not processed independently. It follows that Wilson and Bergen's model involves a set of channels which is inappropriate or incomplete or both.

Humans↗
PubMed1975

The theoretical bases of Soviet psychotherapy.

Beginning in the 1930's all Western psychologic theories, especially psychoanalysis, were labeled reactionary. Pavlov's theory remained as the sole "truly materialistic" basis for Soviet psychotherapy. Only in recent years has theoretical research shown signs of life. Certain concepts from cybernetics, information theory, and even social psychology are now used widely.

History, 20th Century↗
PubMed1986

Three dimensional CT reconstruction for the evaluation and surgical planning of facial fractures.

Despite advances in radiology--including CT scanning--the three-dimensional (3D) nature of facial fractures must still be inferred by the spatial imagination of the physician. A computer system (Insight Phoenix Data Systems, Inc., Albany, N.Y.) uses CT studies as substrate for 3D reconstructions. We have used the Insight computer for the evaluation and surgical planning of facial fractures of 16 patients with complex injuries. We present five illustrative cases, directly photographed from the computer monitor. Images can also be manipulated in real time by rotating or planar sectioning (functions best appreciated on video). The ability to cybernetically extract the facial skeleton from living subjects provides precise anatomic data previously unobtainable. The images are valuable for an accurate assessment of the relationship between the injured and uninjured sections of the face. We conclude that 3D reconstruction is an important advance in the treatment of facial fractures.

Adolescent↗
PubMed1999

The emergence of cognitive science in France.

A comparison between the development of cognitive science in France and the USA enables us to analyze some national differences linked to specific connections between the scientific, military, economic and political worlds. The influence of new practices and tools developed during World War II and the Cold War appears to be of crucial importance in understanding the development of this new field, as well as that of cybernetics, computer science, artificial intelligence and molecular biology. This paper can be considered as a study in how the differing contexts in France and the USA shaped the history of the construction of cognitive science in each of these two countries. In spite of various differences, some common aspects may be pointed out: in both cases, computer experts and psychologists using a computational modelling approach were those first engaged in the construction of cognitive science. If in France neuroscience-oriented cognitive science research was stronger than in the USA, it seems that the artificial intelligence orientation is also of growing importance in France.

Artificial Intelligence↗
PubMed1991

Guilt loops.

Overlooking the role of parental guilt in recurrent parent-child conflict may limit effective interventions in family therapy. This paper presents a conceptual model of the role of parental guilt in the maintenance of recurrent dysfunctional sequences of parent-child conflict. The cybernetic model of guilt loops provides a framework for understanding and intervening in recurrent escalating parent-child conflict which is characterized by ambiguous, inconsistent limit-setting and consequences. Interventions based on guilt loops address the interaction between parental guilt and dysfunctional behavior sequences and broaden the scope of possible interventions for the therapist. A clinical example illustrates the use of this model.

Adolescent↗
PubMed2001

Insect photoperiodism and circadian clocks: models and mechanisms.

Photoperiodic clocks allow organisms to predict the coming season. In insects, the seasonal adaptive response mainly takes the form of diapause. The extensively studied photoperiodic clock in insects was primarily characterized by a "black-box" approach, resulting in numerous cybernetic models. This is in contrast with the circadian clock, which has been dissected pragmatically at the molecular level, particularly in Drosophila. Unfortunately, Drosophila melanogaster, the favorite model organism for circadian studies, does not demonstrate a pronounced seasonal response, and consequently molecular analysis has not progressed in this area. In the current article, the authors explore different ways in which identified molecular components of the circadian pacemaker may play a role in photoperiodism. Future progress in understanding the Drosophila circadian pacemaker, particularly as further output components are identified, may provide a direct link between the clock and photoperiodism. In addition, with improved molecular tools, it is now possible to turn to other insects that have a more dramatic photoperiodic response.

Animals↗
PubMed1996

The life and death of Alexander Bogdanov, physician.

It was early in April in 1928 when the word went out in Moscow that Alexander Bogdanov had died. He was a controversial figure, an old Bolshevik who had left that party long before the 1917 revolution and never returned. All the same, he had had Lenin's respect as a scientist (as long as he stayed out of politics). More recently, he also had the support of the new party strong man, Stalin. Bogdanov opposed the growing despotism of the "dictatorship of the proletariat", under which slogan Communist autocracy was being developed. But he was respected as a tireless propagandist for the socialist cause, an enthusiastic teacher of the proletariat, and a writer of arcane science and philosophy. Bogdanov was held in such respect that Communist bigwigs spoke glowingly at the funeral, praising his intellect, courage, and dedication to science and humanity. They did not fail to point out that he had split with his one-time friend, Lenin, and had succumbed to ideological "errors". Indeed, he had powerful enemies in the early Soviet state. Bogdanov was a physician, economist, philosopher, natural scientist, writer of utopian science fiction, poet, teacher, politician (unsuccesful), lifelong revolutionary, forerunner of what we now call cybernetics and organizational science, and founder of the world's first institution devoted entirely to the field of blood transfusion. You could call him a Renaissance man. Although he clearly fitted the category of the late-nineteenth-century Russian intellectual revolutionary, Bogdanov differed from most of them in being no dilettante. More than just a theorist, he was an active scientist and physician. As a teacher, he firmly believed that education and indoctrination could alter people's ways of thinking and behaving, and that humanity could be perfected under socialism. Like many revolutionaries, Bogdanov tried to keep ahead of the Tsar's police by using a variety of pseudonyms, among them Riadavoy, Werner, Maximov, and Bogdanov. After the revolution, he kept the name Bogdanov.

Blood Transfusion↗
PubMed2006

Pathways to recovery: promoting change within a developmental-systemic framework.

This article describes a format for the process of achieving therapeutic change through structured individual sessions with adolescents or adults with eating disorders. It is a model for change based on three separate existing theoretical or conceptual strands: Developmental theory; the application of systems theory and cybernetics to clinical practice; and feminist ideology. It was developed as a pragmatic, clinician-friendly model that could be successfully used by therapists from different disciplines, and is referred to here as developmental-systemic-feminist therapy or individual developmental-systemic therapy. Change in this context is defined as the overt and measurable alteration in feelings, thoughts and behaviours of the participant(s) over the course of treatment. The article provides an overview of the treatment model and outlines the five steps used to achieve change (explore; understand; accept; challenge; change). Essential components of the therapist's stance, skills and knowledge are described, followed by a discussion of the structure and content of sessions in different stages of the therapy. Finally, clinical examples are given to illustrate the clinical use of this model in young patients with eating disorders.

Adolescent↗
PubMed2005

Effect of interocclusal appliance on masticatory performance of patients with bruxism.

This study was designed to evaluate masticatory performance in bruxist patients. The experimental group was composed of 16 dentate volunteers presenting with bruxism and treated by interocclusal appliances and a control group, consisting of 16 dentate volunteers with no symptoms of bruxism. To evaluate masticatory performance, the volunteers chewed .03 grams of peanuts contained in polyvinyl wrapper for four and twelve masticatory cycles. The number of chewed particles was counted using an optical scanning method by Image-Pro Plus 1.4 software (Media Cybernetics, Inc., Silverspring, MD). The score was expressed as the mean of the number of chewed particles for each wrapper. Masticatory performance evaluations were carried out in a single period for the control group and for the experimental group, before interocclusal appliance insertion, and after seven, 15, 30, and 60 days. Comparison between groups, as well as between before and after interocclusal appliance insertion, showed no significant differences (P>.05), irrespective of the number of masticatory cycles.

Adult↗
PubMed1988

Feedback regulators in normal and tumour tissues.

Regulation of cell behaviour and population size is presumed to be not unlike classical regulation in non-biological systems, i.e. it is controlled by the cybernetic principle of negative feedback whereby the performance of progenitor cells depends inversely on a signal from their product, the size of which is proportional to the mass of the product. This signal may be inhibitory, acting directly on the progenitor cells. Alternatively, it may operate via an indirect and integrated inhibitor/stimulator feedback loop in which the one influences the production of the other. Illustrations taken from the various phases of haemopoietic development show the operation of these loops. Haemopoietic stem cells are under the direct influence of both inhibitor and stimulator but it is a feedback signal from the stem cell population that dictates the production of the one rather than the other. A second inhibitor acting at the stem cell level is a low molecular weight tetrapeptide which blocks the entry of cells into DNA synthesis, thus protecting them during a regimen of treatment with an S-phase cytotoxic drug. Proliferation of the maturing cells is also inhibited by feedback products of their fully mature descendants. Here, the effect is one of cell cycle modulation, whereas in the stem cell population the inhibitor and stimulator effect an on/off switch. Attempts to characterize the molecules involved have been limited. A series of tri- to pentapeptides has been described for haemopoietic or epithelial cell inhibitors. A common feature of several is a pGlu-Glu end though whether this has any significance is not known. In tumours it has been shown that some ascites are self-limiting and treatment of small tumours with cell-free fluid from a mature growth blocks their further growth. It appears that many tumour cells produce the feedback signals characteristic of their normal counterparts but are themselves less sensitive to it. The same is true of transforming growth factor-beta which is produced and detected by virtually all cell types. In this case, the factor, inhibiting in most cases, is produced in inactive form and achieves its target specificity by a localized capacity to activate it. Some tumours, while responding to exogenous active TGF-beta are incapable of activating the latent molecule. It is concluded that the differential sensitivity of normal and neoplastic tissues to physiological feedback regulators is a potentially exploitable property in cancer therapy.

Cell Division↗
PubMed1990

The Mikamo lecture. Role of higher nervous activity in sudden cardiac death.

The brain receives and catalogues myriads of information from within and without the organism. These inputs promote neural integration of bodily function through a multiplicity of cybernetic feedback loops. Higher nervous activity shapes the contours of perceived well-being and determines the course and progress of disease. Behavioral and neural factors play an important role in cardiovascular function and are especially relevant to the problem of sudden cardiac death (SCD). Clinical data attesting to the role of biobehavioral factors in SCD derive from a diversity of sources. It has long been known that bereavement increases the prevalence of cardiac fatality. Business failure rates are strongly related to increased mortality among persons aged 55 and over. Recession in economic activity, with increasing unemployment, is associated with augmented death rates from ischemic heart disease. In extensive surveys conducted among London civil servants, Rose and Marmot found not only the level but the type of employment to be a factor determining coronary heart disease mortality. Blue collar workers had a 3.6 times greater chance of dying from heart disease than an age-matched population in the higher ranks of civil service. A man's employment status was a stronger predictor of risk for dying from coronary heart disease than any of the usual risk factors, such as smoking, blood pressure, height-weight ratio, leisure time activities, glucose tolerance, or plasma cholesterol. Operation of behavioral factors is also suggested by the time of occurrence of sudden death. Among 3,983 men followed for more than 30 years, Rabkin and co-workers observed an excess proportion of fatalities on Mondays. No such pattern was noted for cancer mortality. Not only the day of the week but the time of day appears to be a factor. Muller and co-workers found a significant preponderance in the occurrence of myocardial infarction and sudden death from 6:00 AM to noon. They could not implicate operation of circadian rhythm, but suggested a role for augmented autonomic neural discharge associated with early morning activities following waking from sleep. The longitudinal epidemiologic studies of the Health Insurance Plan of New York (HIP) have indicated an important association between behavioral and psychologic factors and the prevalence of sudden cardiac death.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed2002

High-tech brains: a history of technology-based analogies and models of nerve and brain function.

This article reviews some of the technological devices and ideas which have been used over the years to answer the question, how does the brain work? It describes some of the early technology-based analogies and models of nerve fibers, and then discusses other analogies and models of the brain based on mechanical and electrical technologies. There are also short sections on cybernetics, telephone exchanges, and computers. Although all of these ideas are flawed to some extent, this article offers a brief argument on the usefulness of analogy and abstraction in brain science.

Brain↗
PubMed1992

Psychoanalysis and psychosomatics: a new synthesis.

The usefulness of psychoanalysis to psychosomatic medicine has been limited by the longstanding assumption that the psychological disorder in psychosomatic patients resembles the conflict-based psychopathology that Freud identified in psychoneurotic patients. Recent investigations of the alexithymia construct, and the discovery that social relationships can influence health over the entire life span, have challenged this assumption and created an opportunity for a new and active involvement of psychoanalysis with psychosomatic medicine. In this contribution, I offer a synthesis of contemporary psychoanalytic observations and theories with concepts and research findings from developmental psychology, developmental biology, and the biomedical sciences. The proposed synthesis is consistent with the view that living organisms are self-regulating cybernetic systems; it also extends an evolving new psychosomatic model that conceptualizes illnesses and diseases as disorders of psychobiological regulation. A modern psychoanalytic approach to physically ill and disease-prone individuals focuses less on the resolution of neurotic conflicts, and more on correcting deficits in these patients' self and object representations and capacity cognitively to process emotions.

Affective Symptoms↗
PubMedDate not supplied

[Qualitative and quantitative evaluation of gastric emptying using a videofluoroscopic method].

We studied the gastric emptying of 21 healthy volunteers using a standard contrasted diet composed of a lipid, carbohydrate, protein and barium sulfate solution homogenate. We did six one-minute videofluoroscopic recordings in a 12-minute interval for the first hour, and in a 30 minute interval until the complete emptying. We selected eight exams for the emptying quantification. We could observe and estimate subjectively the functional behavior and the gastric emptying. Digital representative images of each emptying time point we were able to quantify those observations and describe them as a mathematical function. We developed a macro procedure using the Media Cybernetics ImagePro-Plus software for this quantification. We conclude that: 1--The videofluoroscopic method provides better resolution than the other methods in the analysis of the gastric motility and emptying. 2--It is possible to computationally quantify the morphological differences observed with the sequential registration radiological methods, specially the videofluoroscopic method that generates 30 frames per second. 3--Our results generate a gastric emptying index, based on the area of a gastric projection in radiological images obtained in a standing position over a one-hour period (T1/2). 4--The quantitative analysis should not exclude the qualitative analysis.

Adult↗
PubMed2003

Enalapril alters the formation of the collagen matrix in spontaneously hypertensive rats.

OBJECTIVE: To assess the effect of the inhibition of the angiotensin-converting enzyme on the collagen matrix (CM) of the heart of newborn spontaneously hypertensive rats (SHR) during embryonic development. METHODS: The study comprised the 2 following groups of SHR (n=5 each): treated group - rats conceived from SHR females treated with enalapril maleate (15 mg. kg-1.day-1) during gestation; and nontreated group - offspring of nontreated females. The newborns were euthanized within the first 24 hours after birth and their hearts were removed and processed for histological study. Three fields per animal were considered for computer-assisted digital analysis and determination of the volume densities (Vv) of the nuclei and CM. The images were segmented with the aid of Image Pro Plus 4.5.029 software (Media Cybernetics). RESULTS: No difference was observed between the treated and nontreated groups in regard to body mass, cardiac mass, and the relation between cardiac and body mass. A significant reduction in the Vv[matrix] and a concomitant increase in the Vv[nuclei] were observed in the treated group as compared with those in the nontreated group. CONCLUSION: The treatment with enalapril of hypertensive rats during pregnancy alters the collagen content and structure of the myocardium of newborns.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1998

Schistosoma mansoni Sambon, 1907: morphometric differences between adult worms from sympatric rodent and human isolates.

A computer software for image analysis (IMAGE PRO PLUS, MEDIA CYBERNETICS) was utilized in male and females adult worms, aiming the morphological characterization of Schistosoma mansoni samples isolated from a slyvatic rodent, Nectomys squamipes, and humans in Sumidouro, Rio de Janeiro, Brazil and recovered from Mus musculus C3H/He. The following characters for males's testicular lobes were analyzed: number, area, density, larger and smaller diameter, longer and shorter axis and perimeter and extension; for females: area, longer and shorter axis, larger and smaller diameter and perimeter of the eggs and spine; oral and ventral suckers area and distance between them in both sex were determined. By the analysis of variance (one way ANOVA) significant differences (p < 0.05) were observed in all studied characters, except for the density of testicular lobes. Significant differences (p < 0.05) were detected for all characters in the female worms. Data ratify that sympatric isolates present phenotypic differences and the adult female characters are useful for the proper identification of S. mansoni isolates.

Analysis of Variance↗
PubMedDate not supplied

Differences in Brazilian strains of Schistosoma mansoni evaluated by means of morphometric analysis of cercariae of both sexes.

Morphometrics of Brazilian strains (BH, SJ and CMO) of Schistosoma mansoni cercariae were obtained with a computerized image analyzer (IMAGE PRO PLUS, MEDIA CYBERNETICS), considering the following characters: body area, tail, furcae, oral and ventral suckers and distance between them. For statistical analysis, the variance test (one-way Anova) was applied and significant differences of p< 0.05 were considered. All morphometric values in the BH strain were significantly higher (p< 0.05) than in the others. Lower values were obtained in females of SJ strain for all characters, excepting the body area. Only this character showed to be significantly different in males and females of the three strains. Specimens of both sexes in the BH and SJ strains showed significant differences regarding all characters. It was observed that this morphometric analysis permits the characterization of strains and also the sex identification in S. mansoni cercariae. Due to its feasibility, this method can be applied as a tool in laboratories devoid of more complex equipment.

Analysis of Variance↗
PubMed2004

Evaluation of the Image-Pro Plus 4.5 software for automatic counting of labeled nuclei by PCNA immunohistochemistry.

The objective of this study was to create and evaluate a routine (macro) using Image-Pro Plus 4.5 software (Media Cybernetics, Silver Spring, USA) for automatic counting of labeled nuclei by proliferating cell nuclear antigen (PCNA) immunohistochemistry. A total of 154 digital color images were obtained from eleven sections of reticular oral lichen planus stained by PCNA immunohistochemistry. Mean density (gray-level), red density, green density, blue density, area, minor axis, perimeter rate and roundness were parameters used for PCNA labeled nuclei discrimination, followed by their outlined presentation and counting in each image by the macro. Mean density and area thresholds were automatically defined based, respectively, on mean density and mean area of PCNA labeled nuclei in the assessed image. The reference method consisted in visual counting of manually outlined labeled nuclei. Statistical analysis of macro results versus reference countings showed a very significant correlation (rs = 0.964, p < 0.001) for general results and a high level (89.8 +/- 3.8%) of correctly counted labeled nuclei. We conclude that the main parameters associated with a high correlation between macro and reference results were mean density (gray-level) and area thresholds based on image profiles; and that Image-Pro Plus 4.5 using a routine with automatic definition of mean density and area thresholds can be considered a valid alternative to visual counting of PCNA labeled nuclei.

Cell Count↗