88 research outputs found
Manifestation of Chaos in Real Complex Systems: Case of Parkinson's Disease
In this chapter we present a new approach to the study of manifestations of
chaos in real complex system. Recently we have achieved the following result.
In real complex systems the informational measure of chaotic chatacter (IMC)
can serve as a reliable quantitative estimation of the state of a complex
system and help to estimate the deviation of this state from its normal
condition. As the IMC we suggest the statistical spectrum of the non-Markovity
parameter (NMP) and its frequency behavior. Our preliminary studies of real
complex systems in cardiology, neurophysiology and seismology have shown that
the NMP has diverse frequency dependence. It testifies to the competition
between Markovian and non-Markovian, random and regular processes and makes a
crossover from one relaxation scenario to the other possible. On this basis we
can formulate the new concept in the study of the manifestation of chaoticity.
We suggest the statistical theory of discrete non-Markov stochastic processes
to calculate the NMP and the quantitative evaluation of the IMC in real complex
systems. With the help of the IMC we have found out the evident manifestation
of chaosity in a normal (healthy) state of the studied system, its sharp
reduction in the period of crises, catastrophes and various human diseases. It
means that one can appreciably improve the state of a patient (of any system)
by increasing the IMC of the studied live system. The given observation creates
a reliable basis for predicting crises and catastrophes, as well as for
diagnosing and treating various human diseases, Parkinson's disease in
particular.Comment: 20 pages, 8 figures, 3 tables. To be published in "The Logistic Map
and the Route to Chaos: From the Beginnings to the Modern Applications", eds.
by M. Ausloos, M. Dirickx, pp. 175-196, Springer-Verlag, Berlin (2006
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Timber for Oregon's tomorrow : an analysis of reasonably possible occurrences
This study was conducted by the School of Forestry at Oregon State University to provide some of the information needed by the Oregon Board of Forestry to develop a forestry program for Oregon. The study makes three contributions: One, a data base that provides an up-to-date timber inventory and information on timber management practices and growth needed for projecting future timber availability; two, a computer simulation model that provides a unique capability for policy-makers to examine the projected effects of various courses of action as a step in developing a preferred action program; and three, specific projections of possible changes in future timber harvests in Oregon and their contributions to the economies of local areas (timbersheds) within the state. This report focuses on the projections.Gerald W. Williams Collectio
The septate junction protein Snakeskin is critical for epithelial barrier function and tissue homeostasis in the Malpighian tubules of adult Drosophila
Transporting epithelia provide a protective physical barrier while directing appropriate transport of ions, solutes and water. In invertebrates, epithelial integrity is dependent on formation, and maintenance, of âtightâ septate junctions (SJs). We demonstrated that Drosophila Malpighian (renal) tubules undergo an age-dependent decline in secretory transport capacity, which correlates with mislocalisation of SJ proteins and coincident progressive degeneration in cellular morphology and tissue homeostasis. By restrictively impairing, in adult tubules, the cell adhesion protein Snakeskin, which is essential for smooth SJ formation, we observed progressive changes in cellular and tissue morphology that phenocopied these effects, including mislocalisation of junctional proteins with concomitant loss of cell polarity and barrier function. Resulting in significant accelerated decline in tubule secretory capacity and organismal viability. Our investigations highlight the tubuleâs essential role in maintenance of organismal health, while providing measurable markers of compromised epithelial barrier and tissue function that manifest in advanced morbidity and death
Complex Dynamics and Multistability in a Damped Harmonic Oscillator with Delayed Negative Feedback
A center manifold reduction and numerical calculations are used to demonstrate the presence of limit cycles, two-tori, and multistability in the damped harmonic oscillator with delayed negative feedback. This model is the prototype of a mechanical system operating with delayed feedback. Complex dynamics are thus seen to arise in very plausible and commonly occurring mechanical and neuromechanical feedback systems
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Oregon's forestry outlook: an uncertain future
The theme for the 1989 Starker Lectures concerned uncertainty surrounding forests and forestry in Oregon and the Pacific Northwest. It was a timely theme.
Indeed, the uncertainties concerning trade-offs among commodity production
and environment and the allocation of forest land, especially public lands, loom large as we enter the decade of the 90's.
We invited for the 1989 lectures speakers who would address current issues not in the value-laden terms of the day, but in a more detached and analytical way, an approach that better permits the listener or reader to make judgements based on factual and scientific information. This, we believe, is a proper role for the College of Forestry
Low level methylmercury exposure affects neuropsychological function in adults
BACKGROUND: The neurotoxic effects of methylmercury (MeHg) have been demonstrated in both human and animal studies. Both adult and fetal brains are susceptible to the effects of MeHg toxicity. However, the specific effects of adult exposures have been less well-documented than those of children with prenatal exposures. This is largely because few studies of MeHg exposures in adults have used sensitive neurological endpoints. The present study reports on the results of neuropsychological testing and hair mercury concentrations in adults (>17 yrs) living in fishing communities of Baixada Cuiabana (Mato Grosso) in the Pantanal region of Brazil. METHODS: A cross-sectional study was conducted in six villages on the Cuiaba River. Participants included 129 men and women older than 17 years of age. They were randomly selected in proportion to the age range and number of inhabitants in each village. Questionnaire information was collected on demographic variables, including education, occupation, and residence history. Mercury exposure was determined by analysis of hair using flameless atomic absorption spectrophotometry. The neurocognitive screening battery included tests from the Wechsler Memory Scale and the Wechsler Adult Intelligence Scale, Concentrated Attention Test of the Toulouse-Pierron Factorial Battery, the Manual Ability Subtests of the Tests of Mechanical Ability, and the Profile of Mood States. RESULTS: Mercury exposures in this population were associated with fish consumption. The hair mercury concentration in the 129 subjects ranged from 0.56 to 13.6 Όg/g; the mean concentration was 4.2 ± 2.4 micrograms/g and the median was 3.7 Όg/g. Hair mercury levels were associated with detectable alterations in performance on tests of fine motor speed and dexterity, and concentration. Some aspects of verbal learning and memory were also disrupted by mercury exposure. The magnitude of the effects increased with hair mercury concentration, consistent with a dose-dependent effect. CONCLUSIONS: This study suggests that adults exposed to MeHg may be at risk for deficits in neurocognitive function. The functions disrupted in adults, namely attention, fine-motor function and verbal memory, are similar to some of those previously reported in children with prenatal exposures
Complex dynamics and multistability in a damped harmonic oscillator with delayed negative feedback
A mĂșsica terapĂȘutica como uma tecnologia aplicada ao cuidado e ao ensino de enfermagem
Effectiveness of a nursing intervention in decreasing the anxiety levels of family members of patients undergoing cardiac surgery: a randomized clinical trial
Adequacy and Consistency of Animal Studies to Evaluate the Neurotoxicity of Chronic Low-Level Manganese Exposure in Humans
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