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Showing papers by "Indiana University published in 1974"


Journal ArticleDOI
TL;DR: Considerations are given to the usefulness and shortcomings of leaf form, venation and cuticular analysis as diagnostic tools of plant identification and many techniques for the study of the morphology of modern and fossil leaves are included in this paper.
Abstract: During the past 125 years the history of early angiosperms, interpreted through the fossil leaf record has been largely an exercise in paleofloristic studies, ignoring evolution. Imprecise identifications of ancient leaves “matched” to extant genera and families have been used as the basis for reconstructions of paleocommunities and paleoclimates. However, as the result of careful morphological studies of leaf form, venation and cuticular features new insights into the evolution of angiosperms are now available. In this paper considerations are given to the usefulness and shortcomings of leaf form, venation and cuticular analysis as diagnostic tools of plant identification. Many techniques for the study of the morphology of modern and fossil leaves are included in this paper as well as tables outlining features of leaf venation and the epidermis. Careful morphological studies of leaf form (such as the venation and epidermal characters emphasized in this paper) will provide better understanding of the relationships of living angiosperms and transform the fossil leaf record into useful data that can be used to study the evolution of the angiosperms.

709 citations


Journal ArticleDOI
15 Feb 1974-Science
TL;DR: A simple three-stage analysis of flows to, from, and within the firm was used to facilitate comparisons, and a central problem for further research on innovation will be to devise an operational model to account for interfirm and interindustry differences.
Abstract: The varied definitions used in the sources that have been discussed make any aggregate analysis difficult. A simple three-stage analysis of flows to, from, and within the firm was used to facilitate comparisons. Even so, each of the generalizations is drawn from relatively small and unrepresentative samples. Case studies may continue to be a source of ideas and hypotheses for further research, but do not appear to offer a means for deeper understanding of the innovation process. The retrospective nature of nearly all of the sources discussed probably means that the process has been viewed as much more rational and well-ordered than it is in fact. This failing is partially overcome in firsthand accounts such as those of Suites and Bueche (63) and Frey and Goldman (64). Each of these accounts involves a successful innovation according to technical or commercial criteria, or both. However, many of the characteristics of innovations that have failed commercially (10) appear to be similar to those of successful cases. The few longitudinal studies, and studies comparing more and less successful cases, do support the main conclusions drawn above (10, 32, 38). More serious problems are raised by the distinctly nonrepresentative nature of the samples used. There are few cases (17, 33, 65) in which the contributions of more than one organization, or details of interactions over a significant period of time, are discussed. There is a wide variation in the importance of the innovations included, ranging from those affecting the economy as a whole to cases involving production in a single firm, albeit with significant commercial results (66). In addition to questions of comparability and sampling, a central problem for further research on innovation will be to devise an operational model to account for interfirm and interindustry differences. Polar definitions used in past studies, "high technology" and "mature industry," for example, are insufficient. One possibility is to use the strategy for growth or competition evident in a firm or an industry, such as sales maximization (automotive), cost minimization (transportation, communications), performance maximization (aircraft, chemicals), or control of materials resources (mining, petroleum), as a basis for drawing distinctions (67). For example, in an industry that seeks to maximize sales, one would expect innovations that would be highly visible to consumers to be developed rapidly (68). In a cost-minimizing situation, production, as opposed to product technology, would be a major source of uncertainty, while the reverse might be the case in a performance-maximizing situation. Greater uncertainty arising from technical sources would imply greater sophistication in effective firms' product planning approaches, while a more stable technology would imply greater sophistication in market research and market-oriented strategies for innovation, and so forth. Much more work is needed along these lines if outcomes of interventions in the innovative process are to be predicted with any accuracy. Some implications for providing incentives and reducing barriers do seem clear from the work to date. Effective directions for federal action lie in strategies such as creating new markets through purchases or procurement policies; aggregating or focusing markets through regulation and other means; providing for market entry by contracts to smaller firms, venture capital, stronger patent protection, and so on; and providing for mobility and informal contacts within the technical community. Technology "push" strategies (such as tax incentives) to increase most research spending, prizes for new technology, and documentation and information retrieval systems would probably be less important in stimulating innovation. Definitive answers will require the most difficult kind of research-experiments in the field. Since the interventions required are difficult and expensive in most cases, they will not be under the researcher's control. Nor will the effect of policy changes be visible over a short period. Thus it seems imperative to take advantage of interventions that occur fortuitously to construct "quasi-experiments" (69) with as great a degree of control over other factors as possible. For example, have recent changes in policy regarding federally held patents increased the commercial use of these patents? Have changes in the capital gains laws retarded the development and growth of "spin-off" enterprises? Has the identification of technology gaps (3) and competitive opportunities stimulated innovation? The effects of such actions on technical innovation could be carefully observed with a modest but sustained research effort, which promises to yield valuable information beyond that available from largely historical sources.

624 citations


Journal ArticleDOI
31 May 1974-Science

550 citations


Journal ArticleDOI
TL;DR: The results suggest that acoustic information for stop consonants is available to listeners, although the retrieval of this information in discrimination will depend on the level of processing accessed by the particular information processing task.
Abstract: Same-different reaction times (RTs) were obtained to pairs of synthetic speech sounds ranging perceptually from /ba/ through /pa/. Listeners responded "same" if both stimuli in a pair were the same phonetic segments (i.e., /ba/-/ba/ or /pa/-/pa/) or "different" if both stimuli were different phonetic segments (i.e., /ba/-/pa/ or /pa/-/ba/). RT for "same" responses was faster to pairs of acoustically identical stimuli (A-A) than to pairs of acoustically different stimuli (A-a) belonging to the same phonetic category. RT for "different" responses was faster for large acoustic differences across a phonetic boundary than for smaller acoustic differences across a phonetic boundary. The results suggest that acoustic information for stop consonants is available to listeners, although the retrieval of this information in discrimination will depend on the level of processing accessed by the particular information processing task.

398 citations


Journal ArticleDOI
TL;DR: In this paper, synaptosome fraction was subjected to osmotic shock, subfractionated on a discontinuous sucrose gradient and the distribution of enzymic and chemical markers for synaptic plasma membranes, microsomal membranes and mitochondria was determined.
Abstract: — Synaptic plasma membranes from the cortices of adult rat brain were isolated from synaptosomes prepared by flotation of a washed mitochondrial pellet (P2) in a discontinuous Ficoll-sucrose gradient. Contamination of the synaptosome fraction by microsomes was estimated by enzymic and chemical analysis to be less than 15 per cent. (2) The purified synaptosome fraction was subjected to osmotic shock, subfractionated on a discontinuous sucrose gradient and the distribution of enzymic and chemical markers for synaptic plasma membranes, microsomal membranes and mitochondria was determined. (3) Comparison of synaptosome subfractions prepared in the presence and absence of 1 mM NaH2 PO4/0.1 mM EDTA buffer pH 7.5, indicated that the ionic composition of the isolation medium markedly affected the distribution and enzymic composition of the subfractions. (4) Synaptic plasma membranes prepared in the presence of PO4/EDTA exhibited a 10-fold enrichment in [Na++ K+] ATPase and were characterized by less than 15 and 10 per cent contamination by microsomes and mitochondria respectively. (5) The polypeptide composition of the purified synaptic plasma membranes was compared with the microsomes and mitochondria by polyacrylamide gel electrophoresis in sodium dodecyl sulphate. No differences between the protein and glycoprotein composition of the synaptic plasma membranes and microsomes were detected. The mitochondria, in contrast, possessed a unique protein composition.

335 citations


Journal ArticleDOI
TL;DR: In this article, an alternative approach to the prediction of performance is developed which follows Premack in relating instrumental performance to empirical measures of operant behavior, and it is concluded that instrumental performance is not determined by a probability differential in operant baseline between the instrumental and contingent responses, but by the condition of response deprivation.
Abstract: The empirical law of effect is criticized as an incomplete step in the development of empirical laws of instrumental performance. An alternate approach to the prediction of performance is developed which follows Premack in relating instrumental performance to empirical measures of operant behavior. However, it is concluded that instrumental performance is not determined by a probability differential in operant baseline between the instrumental and contingent responses, but by the condition of response deprivation. This condition depends on the terms of the schedule as well as operant baseline measures. The response deprivation condition occurs in a contingency if, in performing the instrumental response at operant baseline, the subject would perform less than his operant baseline of the contingent response. Instrumental performance appears directly related to the amount of response deprivation. Response selection and the application of the response deprivation approach are discussed.

323 citations


Journal ArticleDOI
TL;DR: Results of selective right and left vagosympathetic trunk (VST) and stellate ganglion stimulation (supra-maximal intensity) on atrial refractory period (ARP) in dogs showed the right VST exerted a greater effect on the right atrium than on the left atrium and the region of the sinus node exhibited greater ARP shortening.
Abstract: This study reports results of selective right and left vagosympathetic trunk (VST) and stellate ganglion stimulation (supra-maximal intensity) on atrial refractory period (ARP) in dogs. The effect of selective stellate stimulation on A-V conduction was also evaluated. During right and left VST stimulation, the region of the sinus node exhibited greater ARP shortening than most of the tested sites on the right atrium and all of the tested sites on the left atrium. The right VST exerted a greater effect on the right atrium than on the left atrium. Right VST stimulation shortened ARP at most tested right atrial sites more than did left VST stimulation. Selective vagal stimulation could result in three-fold difference in ARPs at the same electrode site. During right or left stellate ganglion stimulation, the refractory period change at any atrial site was usually minimal and often did not change at all. Supra-maximal right or left stellate stimulation shortened A-H (nodal) conduction by 50% or more in some experiments but shortened conduction time distal to the bundle of His by only 1 to 3 msec.

317 citations


Journal ArticleDOI
TL;DR: It is concluded that agents which inhibit the slow channel directly depress sinus node discharge rate and AV nodal conduction, effects of slow-channel inhibiting agents are not mediated through the activation of cholinergic discharge or inhibition of adrenergic discharge, and beta-receptor stimulation reverses these effects.
Abstract: A slow ionic current carried by calcium, sodium, or both constitutes transmembrane ionic flow through the slow channel; such a current may be involved in normal action potentials of sinus and atrioventricular (AV) nodal cells. In this study, we investigated the effects of the slow-channel inhibiting agents verapamil, D600, manganous chloride, and lanthanum chloride on sinus node automaticity and AV nodal conduction in open-chest dogs treated with atropine (0.5 mg/kg) and propranolol (1.0 mg/kg). The arteries to the sinus node and the AV node were cannulated and perfused with agents that inhibit the slow current. These agents slowed sinus node discharge rate, depressed AV nodal conduction, and lengthened the effective and the functional AV nodal refractory period. Effects were dose related and reversed with time. His-Purkinje conduction remained normal. Isoproterenol and epinephrine reversed the effects of slow-channel inhibiting agents, but calcium, sodium, glucagon, and phenylephrine did not. Concentrations of propranolol which produced beta-receptor blockade prevented Isoproterenol-induced reversal of the effects of slow-channel inhibitors. We concluded that (1) agents which inhibit the slow channel directly depress sinus node discharge rate and AV nodal conduction, (2) effects of slow-channel inhibiting agents are not mediated through the activation of cholinergic discharge or inhibition of adrenergic discharge, and (3) beta-receptor stimulation reverses these effects.

289 citations


Journal ArticleDOI
TL;DR: The results show that macaque monkeys and normal human observers show a rod-cone break at the same flicker frequency, and are very similar in both relative and absolute scotopic and photopic sensitivity.

261 citations


Journal ArticleDOI
TL;DR: Electrophysiologic evaluation in five patients who exhibited manifestations of the pre-excitation syndrome and/or supraventricular tachycardia provided functional evidence that the properties of the accessory fibers may be quite variable, and anomalies in conduction over accessory pathways were demonstrated.
Abstract: Electrophysiologic evaluation in five patients who exhibited manifestations of the pre-excitation syndrome and/or supraventricular tachycardia provided functional evidence that the properties of the accessory fibers may be quite variable. The unusual responses to electrical stimulation in these patients included: 1) failure to depolarize the His bundle from the site of ventricular pre-excitation; 2) supraventricular tachycardia with two types of re-entry; 3) anterograde block in the accessory pathway with intact retrograde conduction; and 4) retrograde delay or block in the accessory pathway and atrioventricular (A-V) node with intact anterograde conduction. Understanding these variations may provide important therapeutic implications regarding drug and surgical management. In addition to these anomalies in conduction over accessory pathways we demonstrated in these patients the occurrence of retrograde functional right bundle branch block and retrograde "gap" phenomenon, and ventricular reciprocation wit...

235 citations


Journal ArticleDOI
TL;DR: Close observation for development of previously unrecognized inguinal hernia and other intra-abdominal complications is advised following VP-shunt operations in infants with hydrocephalus.
Abstract: Forty-five of 185 (24%) infants and children with hydrocephalus treated by ventriculoperitoneal (VP) shunt procedures developed intra-abdominal complications. The occurrence of a previously unrecognized inguinal hernia was noted in 31 patients (16.8%). The mean interval from VP shunt to hernia occurrence was 6.8 months. Seventy-five percent had bilateral findings and 20% were incarcerated. Perforation of the colon occurred in five patients and of the bladder in two. Intra-abdominal cerebrospinal fluid (CSF) cyst was noted in three cases, catheter disconnection in two, knotted catheter in one, and intestinal obstruction due to volvulus around a shunt in one. There was only one death. Abdominal x-ray was often diagnostic; demonstrating the VP-shunt catheter in the scrotum in six patients with otherwise unrecognized inguinal hernia, and in instances of knotted shunt, shunt disconnection, bladder perforation, CSF cysts, and intestinal obstruction. In addition, contrast studies in instances of shunt dysfunction documented bowel perforation and CSF cyst formation. These data indicate that intra-abdominal complications are not uncommon following VP-shunt operations. Close observation for development of previously unrecognized inguinal hernia and other intra-abdominal complications is advised following VP-shunt operations in infants with hydrocephalus.

Journal ArticleDOI
TL;DR: In the first study, 52 subjects were required to judge the appropriateness of IS behaviors in each of IS situations in a behavior-situation matrix as mentioned in this paper, and different methods of measurement provided initial construct validity evidence for the concepts.
Abstract: In the first of two studies, 52 subjects were required to judge the appropriateness of IS behaviors in each of IS situations in a behavior-situation matrix. Differences among behaviors, situations, and their interaction contributed substantial proportions of the total variance in judgments. The concepts of behavioral appropriateness and situational constraint were offered to account for the differences obtained among behaviors and situations, respectively. A second study using a new sample of 42 subjects and different methods of measurement provided initial construct validity evidence for the concepts. Implications of these results for the construction of situational response hierarchies, the development of behavior and situation taxonomies, and causal attribution were discussed.

Journal ArticleDOI
TL;DR: The half-life of gentamicin, tobramycin, kanamycin, and streptomycin, after a single subcutaneous injection, was measured in homogenates of lung, liver, and kidney in rats, and the results were compared with the half- life of these drugs in serum.
Abstract: The half-life of gentamicin, tobramycin, kanamycin, and streptomycin, after a single subcutaneous injection, was measured in homogenates of lung, liver, and kidney in rats, and the results were compared with the half-life of these drugs in serum. Urinary excretion of antibiotics was also monitored. The half-life of the four drugs in serum and lung was approximately 30-35 min. Concentrations in the liver were regularly lower than concentrations in serum or lung. In renal tissue, gentamicin, tobramycin, and kanamycin had long half-lives of 109, 74, and 60 hr, respectively. Streptomycin, on the other hand, had a half-life of 4.6 hr. Separation of the kidneys into cortex and medulla showed that streptomycin was uniformly distributed, whereas 85% of the gentamicin, tobramycin, and kanamycin resided in the cortex. These antibiotics accumulate in the renal cortex, probably intracellularly, and have long half-lives.

Book ChapterDOI
TL;DR: This chapter discusses the role of phospholipids in transport and enzymic reactions, as the nonpolar environment can assist in binding and orientation of ligands, and influence the activity of water at the active site.
Abstract: Publisher Summary This chapter discusses the role of phospholipids in transport and enzymic reactions. A large number of cellular components are localized in/on membranes. Extraction of lipids from active particulate preparations results in a marked decrease in activity of several enzymes of mitochondrial electron transport system. The activity can be restored by addition of crude mitochondrial lipids or other highly unsaturated phospholipids. In addition to the well-known propensity of phospholipids to form bilayers, many of them have a direct influence on specific membrane components that are involved in catalytic and/or transport functions. Lipid–protein interactions modulate the catalytic activity of proteins by influencing or determining their tertiary and quaternary structures. Phospholipids provide a relatively nonpolar environment in which some reactions can proceed more efficiently, as the nonpolar environment can assist in binding and orientation of ligands, and influence the activity of water at the active site.

Journal ArticleDOI
TL;DR: Noncategorical perception of the voicing distinction, reflected by an improvement in discrimination within phonetic categories, was obtained for the group of listeners who experienced both the sequential identification procedure and the 4IAX discrimination test.
Abstract: Native speakers of English identified and then discriminated between stimuli which varied in voice onset time (VOT). One group of listeners identified a randomized sequence of stimuli; another group identified an ordered sequence of stimuli, in which stimuli from the VOT continuum were presented in a consecutive order. Half of the Ss in each group then received one of two discrimination formats: the ABX discrimination test in which X was identified with A or with B, or 4IAX test of paired similarity in which two pairs of stimuli—one pair always the same and one pair always different—were presented on each trial. Noncategorical perception of the voicing distinction, reflected by an improvement in discrimination within phonetic categories, was obtained for the group of listeners who experienced both the sequential identification procedure and the 4IAX discrimination test. The results are interpreted as providing evidence for separate auditory and phonetic levels of discrimination in speech perception.

Journal ArticleDOI
TL;DR: A highly significant positive correlation was found between the magnitude of Ca2-dependent tension developed by restored hearts and the level of cyclic AMP in those hearts, which appears to modulate slow Ca2+ influx channels in myocardial cells.
Abstract: The relationship between cellular levels of cyclic adenosine monophosphate (AMP) and slow inward calcium ion (Ca 2+ ) current was studied in isolated perfused guinea pig hearts in which fast sodium ion (Na + ) channels had been inactivated by depolarization with potassium ions (K + ) or blockade with tetrodotoxin. Perfusion with 22 mM K + depolarized cardiac tissue to approximately -40 mv and rendered hearts inexcitable. Tetrodotoxin (3 x 10 -5 M) blocked excitability without altering resting membrane potential. Excitability and contractions could be restored to these hearts with a variety of inotropic agents that also raised the measured tissue levels of cyclic AMP or with high concentrations of Ca 2+ . The magnitude of steady-state tension developed by restored hearts was directly related to the external Ca 2+ concentration as well as to the concentration of the restoring agent used. The tension of restored hearts was markedly reduced by Ca 2+ -channel antagonists. Elevation of cyclic AMP levels preceded restoration of excitability to inactivated hearts. A highly significant positive correlation was found between the magnitude of Ca 2+ -dependent tension developed by restored hearts and the level of cyclic AMP in those hearts. Glucagon and ouabain, inotropic drugs that do not elevate myocardial levels of cyclic AMP, failed to restore depolarized or tetrodotoxin-blocked hearts. Therefore, cyclic AMP appears to modulate slow Ca 2+ influx channels in myocardial cells.



Journal ArticleDOI
TL;DR: Echocardiographic tracings of the pulmonic valve were examined in two groups of patients and there was no difference in amplitude of leaflet opening between the two groups.
Abstract: Pulmonic valve echograms were examined in 24 normal subjects and 32 patients with pulmonary hypertension (PHT), (mean pulmonary arterv pressure, 20 mm Hg). Atrial systole normally imparted a slight posterior or opening motion (“a” wave) to the posterior pulmonic leaflet. This “a” wave varied with respiration and the maximum “a” wave depth (A Max.) in normals averaged 3.7±1.2 mm (range 2–7 mm). In 19 of 24 patients with PHT and sinus rhythm no “a” wave was present. In the other 5, the “a” waves were 2 mm or less. In 4 of these 5, right heart failure was present. The diastolic slope (e–f) averaged 36.9±25.4 mm/sec (range 6–115 mm/sec) in normals. With PHT this slope became flat, averaging 5.2±8.9 mm/ sec.(range 9–30 mm/sec. p.001). In 6 patients with PHT a negative e-f slope occurred, this was never seen in normals. Mid-systolic closure or “notching” of the systolic (c–d) segment occurred in 18 of 20 subjects with PHT in whom the leaflet was clearly recorded in mid-systole. This finding was not observed in normals. This study confirms a previous observation that the echocardiographic recording of pulmonic valve motion may be a useful indicator of PHT.


Journal ArticleDOI
TL;DR: An improved cresolphthalein complexone procedure for calcium in which diethylamine is replaced by a nontoxic amino alcohol is described, which results in increased sensitivity, excellent baseline stability, a more optimum reaction environment, and freedom from interference by magnesium.
Abstract: We describe an improved cresolphthalein complexone procedure for calcium in which diethylamine is replaced by a nontoxic amino alcohol. Advantages of the procedure are increased sensitivity, excellent baseline stability, a more optimum reaction environment (pH 10.0) that eliminates blanking problems, and freedom from interference by magnesium. Values obtained by this method are not significantly different ( P < 0.05) from those obtained by atomic absorption spectrophotometry.


Journal ArticleDOI
TL;DR: Fifteen catecholamine- containing cell groups and eight indoleamine-containing cell groups are present in the brain of the squirrel monkey.
Abstract: Fifteen catecholamine-containing cell groups and eight indoleamine-containing cell groups are present in the brain of the squirrel monkey. Most of the catecholamine-containing cell groups (12) are similar to catecholamine-containing cell groups previously described in the rat. However, three catecholamine-containing cell groups not previously noted are found in the squirrel monkey brain. The indoleamine-containing cell groups are found within, or adjacent to, the raphe nuclei. Differences between the localization of indoleamine-containing cell bodies in the brain of the rat and the squirrel monkey are minor.

Journal ArticleDOI
TL;DR: Computer calculations showed that there is a range of parameters that results in permanent coexistence of all three species, in apparent contradiction to the competitive exclusion principle and to a theorem of Volterra that no odd membered ecosystem can persist.

Journal ArticleDOI
TL;DR: The results are consistent with the view that pyridoxal is an important transport form of the vitamin B 6 compounds, and indicate that a small amount of free PLP normally exists in equilibrium with the albumin-PLP complex.

Book ChapterDOI
B. E. Rhoades1
TL;DR: In this paper, the authors extended the work of Browder and Petryshyn, Dotson, Franks and Marzec, Johnson, Kannan, Mann, and Reinermann.
Abstract: Let E be a closed, bounded, convex subset of a Banach space X, f: E → E. Consider the iteration scheme defined by , where A is a regular weighted mean matrix. For particular spaces X and functions f this iterative scheme converges to a fixed point of f. [5] extends or generalizes related work of Browder and Petryshyn, Dotson, Franks and Marzec, Johnson, Kannan, Mann, and Reinermann. This paper continues investigations begun in [6].

Journal ArticleDOI
TL;DR: In this paper, subjects' proficiency to recover from sympathetic arousal induced by strenuous exercise was assessed in a pretest, and the results were used to determine conditions of high, intermediate, and low recovery proficiency (fitness).

Journal ArticleDOI
TL;DR: The specific echocardiographic abnormality demonstrated in left bundle branch block is a very dynamic posterior motion of the interventricular septum occurring within 0.04 seconds of the onset of the QRS and preceding the anterior motion ofthe posterior left ventricular wall during ventricular ejection.
Abstract: Seventeen patients with left bundle branch block were studied using standard echocardiographic techniques employing a strip chart recorder. All 17 patients were found to have specific echocardiographic findings of abnormal septal motion uniquely different from previously described forms found in volume overload states of the right ventricle as well as coronary artery disease. The specific echocardiographic abnormality demonstrated in left bundle branch block is a very dynamic posterior motion of the interventricular septum occurring within 0.04 seconds of the onset of the QRS and preceding the anterior motion of the posterior left ventricular wall during ventricular ejection. This type of septal motion is not seen in the other forms of abnormal septal motion and appears to be specific for left bundle branch block.

Journal ArticleDOI
Sidney Ochs1
TL;DR: In this review the linearly organized internal systems of transport present in the nerve fiber are emphasized, carrying materials down the axon needed to maintain its excitability, materials involved in neurotransmission at the terminal, and trophic materials which, after release, control p t synaptic cells or, in the case of sensory terminals, the secondary cells around the nerve ending.
Abstract: In this review the linearly organized internal systems of transport present in the nerve fiber are emphasized. These systems carry materials down the axon needed to maintain its excitability, materials involved in neurotransmission at the terminal, and trophic materials which, after release from the terminal, control p t synaptic cells or, in the case of sensory terminals, the secondary cells around the nerve ending, as well as feedback “signal” substances moving back to ,the cell body to control the level of synthesis. To facilitate the discussion of the several transport systems now recognized and thek relation to nerve functions, the neuron is diaf l a m e d in FIGURE l. A represents the region of the cell body; B, the axon with its Schwann cell and myelin sheath; and C, the nerve terminal ending (in the figure presented at the neuromuscular junction of a muscle fiber). Protein synthesis takes place in the nerve cell body (region A) at the ribosomes (S). The entry of precursor is indicated by an an-ow (1) and the nucleus (N) containing DNA controls (arrow 2) the kinds of proteins made. Compartment C indicates storage of incorporated proteins and other materials (arrow 3) which later exit into the axon (4) via a gate (G). This is presumed to be the Golgi apparatusz5.98 controlling the export of materials from the cell body into the axon of eirher justsynthesized materials (arrow 5 ) or those that have entered a compartment (arrow 4) to exit later. In region B the arrow directed down the axon (arrow 6) represents both the fast and slow forward transport systems; the mechanisms believed to underlie them will be discussed in a later *section. The transport systems carry e n z F a and other materials needed to maintain the function of the fiber, including components that enter the membrane (arrow 7) to maintain its excitability. The membrane has recently been viewed as a bilayer of phospholipids with globular proteins embedded in it (cf. FIGURE 2 in Singerla). Depending on their nature, these proteins could confer selective permeability through the membrane on the ions Na+ and K+ and, possibly, other ions involved in excitability; they could also maintain ionic asymmetry through the NaK ATPase involved in sodium pumping. Proteins have a turnover; such special proteins in the membrane would therefore require replenishment. This need is represented by arrow 7 in FIGURE 1 where some part of the proteins carried down by axoplasmic transport is shown inserted into the membrane. The Schwann cells in which myelin is layered around the myelinated nerve fibers also appear to be controlled by materials carried into it from the nerve fiber

Journal ArticleDOI
TL;DR: Initial IQ measurements of subnormal and autistic children analyzed for repeatability and also for relationship to other factors such as severity of illness and outcome of treatment found IQ estimates were significantly related to the severity of symptoms and effectively predicted performance at school.
Abstract: A study is presented with a focus on IQ measurements of subnormal and autistic children analyzed for repeatability and also for relationship to other factors such as severity of illness and outcome of treatment. Initial IQ measurements correlated well with those obtained c. 5 years later (M=5.32). Of the 115 autistic children tested, 94% had General IQs in the retarded range ( 50 at initial evaluation, who were subsequently treated, showed a greater increase in IQ than untreated children in the same IQ range. Treatment was without differential effect for children with < 40 IQs. After treatment, Verbal IQ gains tended to be maintained or improved in groups with higher initial IQs, but stagnated or were even lost in the lower IQ groups.