The role of memory and integration in early time concepts.

The nature of 5- to 8-year-old childrens ' time concepts was examined by analyzing two possible explanations for the greater difficulty children demonstrate in comparing durations that differ in beginning times as compared to those that differ in ending times. The explanations were (a) poor recall of beginnings as compared to endings due to their lower salience, (b) difficulty in integrating information from both points and reliance on endings only due to their greater salience. The subjects were 630 boys and girls from kindergarten to second grade.

A developmental analysis of early time concepts: the equivalence and additivity of the effect of interfering cues on duration comparisons of young children.

Young children compare durations correctly and explain their conclusions logically only when no interfering cues such as distance and speed are introduced. We investigated whether type of cue and additivity of interfering cues affect children's duration comparisons. 4- and 5-year-old children were asked to compare the burning times of pairs of partially synchronous lights differing in intensity, bulb size, or both.

Infrared spectroscopic study of the secondary structure of melittin in water, 2-chloroethanol, and phospholipid bilayer dispersions.

The conformations of melittin, an amphipathic polypeptide consisting of 26 amino acid residues, and its hydrophobic (residues 1--19) and hydrophilic (residues 20--26) fragments were examined in various solvent systems, including H2O, 2H2O, 2-chloroethanol, and 1,2-dimyristoylphosphatidylcholine (DMPC) multilayers, by infrared spectroscopy. Water and 2-chloroethanol were used as reference solvents for characterizing the amide I and II vibrational frequencies of the polypeptide in systems reflecting unordered, beta-structure, or alpha-helical forms. In DMPC bilayer assemblies both melittin and its hydrophobic fragment F1 exhibit alpha-helical conformations.

Effect of water on the molecular structure of a phosphatidylcholine hydrate. Raman spectroscopic analysis of the phosphate, carbonyl and carbon-hydrogen stretching mode regions of 1,2-dipalmitoylphosphatidylcholine dihydrate.

The Raman spectra of 1,2-dipalmitoylphosphatidylcholine (DPPC) dihydrate crystals were examined in (a) the 1250 and 1080 cm-1 PO-2 antisymmetric and symmetric stretching mode regions, (b) the 1730 cm-1 carbonyl stretching mode region and (c) the 2800-3100 cm-1 C-H stretching mode interval. No evidence was observed for hydrogen bonding effects involving the nonester phosphate oxygen atoms. Spectra of the DPPC dihydrate crystal in the 1250 cm-1 region are compared to spectra of both anhydrous and successively hydrated systems and to spectra of crystalline glycerylphosphorylcholine.

[State of the cerebral ventricular system in cerebral autonomic vascular paroxysms (clinico-echoencephalographic study)].

For diagnosing hydrocephalus of the third ventricle in cases of affections of the hypothalamic region use was made of echoencephalography. Under examination there were 71 patients with hypothalamic vegetovascular paroxysms, as well as 40 healthy subjects that constituted the control group. It was found that in the healthy subjects the width of the third ventricle varied from 3.

[Features of the polygraphic picture of natural sleep in patients with subacute sclerosing panencephalitis].

The results of electropolygraphic examinations of 6 patients suffering from subacute sclerosing panencephalitis are presented. The polygraphic examination of sleep revealed a pronounced disorganization of the latter, the degree of which depended on the disease duration (the EEG of awakeness was abnormal, too). An importance of electromyographic changes (within the polygram) for differentiating the states of the sleep and awakeness is demonstrated.

Comparative effects of melittin and its hydrophobic and hydrophilic fragments on bilayer organization by Raman spectroscopy.

For bilayer systems consisting of 1,2-dimyristoyl phosphatidylcholine (DMPC) incubated with melittin, a polypeptide capable of integrating itself within the membrane, temperature profiles derived from Raman spectroscopic data indicate the existence of an immobilized lipid annulus surrounding the polypeptide. In particular, temperature profiles derived from C--H, C--D and C--C stretching mode parameters for 25:1, 14:1 and 10:1 lipid:protein mole ratios exhibit two order-disorder transitions. The primary (lower) gel to liquid crystalline phase transition is depressed when polypeptide concentration is increased.

Evidence for acyl chain trans/gauche isomerization during the thermal pretransition of dipalmitoyl phosphatidylcholine bilayer dispersions.

In order to clarify, in dipalmitoyl phosphatidylcholine multilayers, the effect of the 34 degrees C thermal pretransition on the acyl chain intramolecular disordering process, Raman spectra of dipalmitoyl phosphatidylcholine gels at 20 and 34 degrees C were compared in the 1000--1200 cm-1 skeletal C-C stretching region. In addition to an overall intensity decrease associated with a change in chain packing characteristics, the growth of intensity in the 1080--1090 and 1122 cm-1 regions in the 34--20 degrees C) difference spectrum clearly indicates that the thermal pretransition is accompanied by an increase in the population of hydrocarbon chain gauche rotamers toward the center of the bilayer.

[Mono- and polyradicular syndromes in lumbar osteochondrosis].

The authors studied the clinical picture of lumbar osteochondritis in 1,020 patients, 151 of whom were operated on. The monoradicular syndrome was diagnosed in 68%, the biradicular (involvement of two radicles) in 27%, and the polyradicular (involvement of three and more radicles) in 7% of the patients. In the authors' opinion, the development of the mono- or polyradicular syndromes in lumbar osteochondritis depends on the character of the disc hernia (lateral, paramedian, median) and on the degree of the reactive inflammatory changes in the radicles, the epidural tissue and the spinal meninges.

Molecular conformations of cerebrosides in bilayers determined by Raman spectroscopy.

Vibrational Raman spectra of the solid and gel phases of bovine brain cerebrosides and the component fractions, kerasin and phrenosin, provide conformational information for these glycosphingolipids in bilayer systems. The carbon-carbon stretching mode profiles (1,150-1,000 cm-1) indicate that at 22 degrees C the alkyl chains assume an almost all-trans arrangement. These spectral data, combined with those from the C-H stretching region (3,050-2,800 cm-1), show that phrenosin forms the most highly ordered polycrystalline solid and kerasin the most ordered gel phase.

[Hemo- and lymphosorption in cardiogenic shock (an experimental study)].

The important role of toxemia in the pathogenesis of cadiogenic shock was demonstrated in 38 experiments on dogs. It was found that the blood becomes toxic later than the lymph. Lymphosorption arrests the progress of toxemia but does not relieve it if it has already developed.

Structural reorganizations in lipid bilayer systems: effect of hydration and sterol addition on Raman spectra of dipalmitoylphosphatidylcholine multilayers.

Vibrational Raman spectroscopy was used in investigate the conformational behavior of dipalmitoylphosphatidylcholine (DPPC) bilayers perturbed by cholesterol and water, two membrane components whose lipid interactions involve different regions of the bilayer matrix. Upon the addition of cholesterol, an intrinsic membrane constituent, to an anhydrous bilayer in concentrations varying from 7 to 30 mol %, modifications in lateral chain interactions were observed by monitoring spectral changes in the methylene C-H stretching and the CH2 deformation regions. The perturbation in the 1460-cm-1 region was not spectroscopically observed until after the addition of 7 mol % of the sterol.

Interaction of melittin with dimyristoyl phosphatidylcholine liposomes: evidence for boundary lipid by Raman spectroscopy.

The interaction of melittin, a polypeptide consisting of 26 amino acid residues, with dimyristoyl phosphatidylcholine bilayers was investigated by vibrational Raman spectroscopy. Spectral peak height intensity ratios, involving vibrational transitions in both the 3000 cm-1 acyl chain methylene carbon-hydrogen stretching mode region and the 1100 cm-1 acyl chain carbon-carbon skeletal stretching mode interval, served as temperature profile indices for monitoring the bilayer order-disorder processes. For a lipid : melittin molar ratio of 14 : 1 two order-disorder transitions were observed.

Interference of time-related and unrelated cues with duration comparisons of young children: analysis of Piaget's formulation of the relation of time and speed.

The analysis of the relation of time and speed led Piaget to conclude that the time-speed confusion characterizing the intuitive stage undergoes development. He claimed that in the first stage, a child comparing the duration of two moving bodies attributes longer duration to the faster body, whereas in the second stage, he attributes longer duration to the slower body. It is proposed here that time-speed confusion is mediated simply by "more is more," and hence, as long as the child continues to confuse time with speed, he believes "faster" implies longer duration.