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The pharmacokinetics of carfecillin and carindacillin was compared in 10 volunteers. The pharmacokinetic parameters of both antibiotics were also determined using an analog computer. From the pharmacokinetic point of view, no significant differences between the two carbenicillin esters were found.
A novel substance-attributed biophysical theory of brain-mind unity is presented. We separate spiritualism and matters of the soul from the medical sphere. Biophysical principles are responsible for the body's operational regimen (BOR) in the homeostatic state which allows for materialization and emergence of the mind; Excitation and/or inhibition modulate 8 BOR stages. There is automatic (somatic) and non-automatic (biophysical and psychological) Circadian cycle control. Computer-analog input and output occurs in wired neuronal electric pathways. Biotechnological devices located in emotional neurons positively signal homeostatic and negatively signal deranged BOR and biophysical mind operations. Macro and/or micro cerebral lesions which affect homeostasis may cause psychopathology, which can be treated with 'instrumental psychotherapy' (IPT) which enables recovery from homeostatic disorder in Phase 1, refining EGO in Phase 2, and social competence in Phase 3. The theory of brain-mind unity and practice of IPT is geared to medical workers and biophysical psychologists.
Neuropädiatrie 6: 383--397 (1975). CSF samples of 63 normal children 2 days to 14 years of age were concentrated (ultrafiltration in "Kollodiumhülsen") and examined by electrophoresis on cellulose acetate and agarose gel. In the CSF of all children 7 protein fractions were found by cellulose acetate electrophoresis. Analysing the pherograms by the means of an analog computer 15 fractions could be separated by agarose gel electrophoresis. Compared with the children of school age the newborn showed low prealbumin, beta1-globulin and tau-globulin fractions besides high albumin and gamma-globulin concentrations owing to an increased permeability of the blood-CSF barrier. During the following weeks a low prealbumin and a high albumin fraction still was found. Children from 3 month to 2 years of age showed a moderate increase of the relative prealbumin and beta1-globulin concentration in comparison with older children. The gamma-globulin fraction was lowest beyond the third month of life and increased again in the group of the 2--14 years old children. The variation of the protein profile with age could not only be demonstrated by the more difficult agarose gel electrophoresis but also by a simple technique of cellulose acetate electrophoresis.
The dependence of solution behavior to perturbations of the initial function (IF) in a class of nonlinear differential delay equations (DDEs) is investigated. The structure of basins of attraction of multistable limit cycles is investigated. These basins can possess complex structure at all scales measurable numerically although this is not necessarily the case. Sensitive dependence of the asymptotic solution to perturbations in the initial function is also observed experimentally using a task specific electronic analog computer designed to investigate the dynamics of an integrable first-order DDE.
In a previous paper, a model was presented showing how the group of Ca2+/calmodulin-dependent protein kinase II molecules contained within a postsynaptic density could stably store a graded synaptic weight. This paper completes the model by showing how bidirectional control of synaptic weight could be achieved. It is proposed that the quantitative level of the activity-dependent rise in postsynaptic Ca2+ determines whether the synaptic weight will increase or decrease. It is further proposed that reduction of synaptic weight is governed by protein phosphatase 1, an enzyme indirectly controlled by Ca2+ through reactions involving phosphatase inhibitor 1, cAMP-dependent protein kinase, calcineurin, and adenylate cyclase. Modeling of this biochemical system shows that it can function as an analog computer that can store a synaptic weight and modify it in accord with the Hebb and anti-Hebb learning rules.
A theoretical explanation of the development of the memory trace constrained to fit into a computer analog requires a coded reference "image" of the intended motor act, a tentative control program (memory trace) based on mobilizing and coordinating various pre-established motor-control subroutines, and an afferent neural description of the act as actually performed. The afferent information is non-consciously compared with the reference image, and the resulting discrepancy used to modify the control program so as to reproduce the reference image more exactly on the next attempt. The discrepancy consists of the sum of two types of differences, between image and program (present during learning) and the error difference between program and performance. The trial-by-trial discrepancies cumulate in the memory trace, so that during both learning and postlearning practice the error component results in a within-individual odd-even trial correlation. This constitutes a mechanism for a remoteness effect in the inter-trial correlation matrix generated in a group of individuals during post-learning as well as learning conditions. Fifty-one individuals performed 50 trials on a simple arm movement task; 35 of these (the learners) showed individual systematic improvement during the first 20 trials but no improvement during the last 24; 16 (the non-learners) failed to improve with practice. Separate correlational analyses (both within- and inter-individual) of the two groups resulted in a variety of patterns that were predicted a priori in the learners by the theory, as did the 49 learners of another sample of 51 who performed a more complicated arm movement task. Also, as predicted, the non-learners failed to produce organized correlation patterns.
Phase space methods and an analog computer are used to analyze the Hodgkin-Huxley non-linear differential equations for the squid giant axon membrane. V is the membrane potential, m the Na(+) activation, h the Na(+) inactivation, and n the K(+) activation. V and m change rapidly, relative to h and n. The (V, m) phase plane of a reduced system of equations, with h and n held constant at their resting values, has three singular points: a stable resting point, a threshold saddle point, and a stable excited point. When h and n are allowed to vary, recovery and refractoriness result from the movement with subsequent disappearance of the threshold and excited points. Multiplying the time constant of n by 100 or more, and that of h by one-third, reproduces the experimental plateau action potentials obtained with tetraethylammonium by Tasaki and Hagiwara, including the phenomena of abolition and of refractoriness of the plateau duration. The equations have, transiently, two stable states, as found in the real axon by these authors. Since the theoretical membrane conductance curves differ significantly from the experimental ones, further experimental analysis of ionic currents with tetraethylammonium is needed to decide whether the Hodgkin-Huxley model can be generalized to explain these experiments completely.
A simple mathematical model of the chest wall was constructed so that during tidal breathing the relative volume contributions of the rib cage and abdomen/diaphragm could be measured in man, using four mercury-in-rubber strain gauges around the trunk. From the dimensions of the trunk and the change in circumference determined by the four gauges, the separate contributions of rib cage and abdomen/diaphragm could be determined using a purpose-built analog computer. The system was evaluated in 13 laboratory personnel, and in 13 other subjects before and after anaesthesia. There was a linear relationship between tidal volumes computed and measured at the mouth, over the residual volume to (FRC + 1 litre) range, with an error of +/- 8%. The relative contribution of rib cage to tidal breathing showed a large scatter from 5 to 42% with a non-significant tendency to decrease with age.
In animal experiments regurgitant flow through competent and incompetent pulmonary valves was evaluated with electromagnetic flow velocity catheters by using the ratio of the separately integrated backward and forward flow velocity signals. This ratio was obtained with a special purpose analog computing circuit set by an in-vitro zero flow reference signal, which was in good agreement with in-vivo zero flow signals.
The absorption and fluorometric changes of the reaction mixture of luciferase-FMNH2 complex with O2 were re-examined. Rapid formation (k2(app) = 2.0 s-1 at [O2] = 120 micrometer) of an intermediate with a single absorption maximum at 380 nm within the range of 350-550 nm, and a weak fluorescence at 520 nm (less than or equal to 10% of that of FMN when excited at 380 nm) was observed. The absorption and fluorescence spectra and decay rate of the intermediate were estimated by simulation using an analog computer. The decay rate (0.27 s-1 at 20 degrees C) was in agreement with that of an obligatory intermediate of the luminescent reaction previously determined by measuring aldehyde-initiated luminescence. The process of decay of X1 to FMN involved another intermediate X1' with spectroscopic characteristics rather similar to those of FMN.
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It is noted that 2x2 "S" matrices in multilayer optics can be represented by the Sp(2) group whose algebraic property is the same as the group of Lorentz transformations applicable to two spacelike and one timelike dimensions. It is also noted that Wigner's little groups have a slide-rule-like property that allows us to perform multiplications by additions. It is shown that these two mathematical properties lead to a cyclic representation of the S matrix for multilayer optics, as in the case of ABCD matrices for laser cavities. It is therefore possible to write the N-layer S matrix as a multiplication of the N single-layer S matrices resulting in the same mathematical expression with one of the parameters multiplied by N. In addition, it is noted, as in the case of lens optics, that multilayer optics can serve as an analog computer for the contraction of Wigner's little groups for internal space-time symmetries of relativistic particles.
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How multiple specialized cortical areas in the brain interact with each other to give rise to an integrated behavior is a largely unanswered question. This paper proposes that such an integration can be understood under the framework of analogy and that part of the thalamus and the thalamic reticular nucleus (TRN) may be playing a key role in this respect. The proposed thalamocortical model of analogy heavily depends on a diverse set of temporal parameters including axonal delay and membrane time constant, each of which is critical for the proper functioning of the model. The model requires a specific set of conditions derived from the need of the model to process analogies. Computational results with a network of integrate and fire (IF) neurons suggest that these conditions are indeed necessary, and furthermore, data found in the experimental literature also support these conditions. The model suggests that there is a very good reason for each temporal parameter in the thalamocortical network having a particular value, and that to understand the integrated behavior of the brain, we need to study these parameters simultaneously, not separately.
CSF-proteins of 1770 children and adolescents with different neurological diseases and of 75 controls were examined by zone electrophoresis in agarose gel electrophoresis and by immunofixation electrophoresis. The quantitative evaluation of the phoretograms by an analog computer revealed oligoclonal changes of the gamma-globulin profile in 53 patients with subacute or chronic CNS-infections and in 5 children with a medulloblastoma. Seventeen of 37 children with congenital infections had 1--5 oligoclonal gamma-fractions consisting of IgG. Five to seven oligoclonal IgG fractions were detected in each of 16 children with SSPE. All 6 adolescents with multiple sclerosis had 2--5 oligoclonal IgG fractions. One to five oligoclonal gamma-bands occurred transiently in the CSF of 4 children with prolonged meningoencephalitis caused by different viruses, in 3 children with a prolonged non-bacterial meningitis of probable viral origin, in 2 infants with prolonged bacterial meningitis after corticosteroid therapy, and in 1 child with prolonged bacterial meningitis during cytostatic therapy. Four to six oligoclonal gamma-subfractions were found at different times during progressive viral encephalitis that developed during maintenance therapy of acute lymphoblastic leukaemia, and in 2 patients with chronic meningoencephalitis of unknown origin. Since oligoclonal gamma-globulin was detected almost invariably in the CSF of patients with prolonged or chronic neurologic infections, this finding implies persistence of antigens in the CNS and pathologic invasion of lymphocytes with selective proliferation of antigen-stimulated clones.
An electronic instrument with digital readout has been designed and constructed for indirect determination of the kVp applied to diagnostic x-ray tubes. The signals from two detectors exposed simultaneously to a differentially filtered x-ray beam are processed by analog computing circuitry to yield an output signal directly proportional to the applied peak kilovoltage. Theory and preliminary results are presented and discussed.