Showing papers by "University of Iowa published in 1970"
TL;DR: In this paper, the character of the covariance matrix is investigated and it is shown that the matrix may exhibit a more general character than is typically implied to be essential, and the necessary and sufficient condition is the equality of variances of differences for all pairs of treatment measures assumed to be correlated.
Abstract: Investigation is made of the character of the covariance matrix which will result in exact F-distributions for the treatments and interaction variance ratios in repeated measurements designs. It is shown, assuming multivariate normality, that the matrix may exhibit a more general character than is typically implied to be essential. Equality of variances and equality of covariances, with identical matrices for all levels of a second treatment factor, are sufficient but not necessary conditions. The necessary and sufficient condition is the equality of variances of differences for all pairs of treatment measures assumed to be correlated. An alternative statement is that the Box-Geisser-Greenhouse parameter e = 1.0. A test is described which bears on the tenability of this condition.
955 citations
897 citations
TL;DR: The data support the hypothesis that uncomplicated coronary atheromas may regress in primates in appropriate dietary settings.
Abstract: Rhesus monkeys subjected to the atherogenic stimulus of a high-fat, high-cholesterol diet showed significant coronary atheromatosis at the end of 17 months. Smaller fibrotic lesions with scant stainable lipid were found in animals that were subsequently fed either of two cholesterol-free diets for 40 months. The average cross-sectional area of the lumen was more than 80% greater in regression animals than in monkeys with baseline atherosclerosis. The data support the hypothesis that uncomplicated coronary atheromas may regress in primates in appropriate dietary settings.
364 citations
286 citations
TL;DR: Five components of l -β-aspartamido-carbohydrate, prepared from crystalline chicken ovalbumin by digestion with pronase, have been isolated and purified by a combination of ion-exchange chromatography and zone electrophoresis.
270 citations
TL;DR: The results were comparable to those obtained by photometric methods using skeletal pins or skin markers and the electrogoniometric method has the great advantage that it can be used in clinical studies.
Abstract: We have presented the results of an electrogoniometric method of measuring the three planes of knee motion while walking. The results were comparable to those obtained by photometric methods using skeletal pins or skin markers. The electrogoniometric method has the great advantage that it can be used in clinical studies.
Knee motion in men and women differed only in the amount of flexion during stance phase. Less flexion occurred in women.
Motion in the right and left knees was the same in men as a group but may differ in individuals.
The timing of events in the gait cycle differed between individuals but a similar sequence or pattern of motion occurred in all normal knees.
260 citations
Book•
01 Jan 1970247 citations
TL;DR: The first derivative thoracic impedance cardiogram may be used not only as a reference tracing to help identify heart sounds on the phonocardiogram, but also for directly timing the intervals within the cardiac cycle.
Abstract: When an alternating current of high frequency is applied to the thorax, the first derivative of the impedance to this current is affected by the cardiac cycle resulting in a characteristic wave form. Phonocardiograms, electrocardiograms, and first derivative thoracic impedance cardiograms were recorded simultaneously in 91 subjects. The first derivative thoracic impedance cardiograms were found to have sharply demarcated points which occur synchronously with the first heart sound, aortic second sound, pulmonic second sound, mitral opening snap, third heart sound, and fourth heart sound. The first derivative thoracic impedance cardiogram may thus be used not only as a reference tracing to help identify heart sounds on the phonocardiogram, but also for directly timing the intervals within the cardiac cycle.
217 citations
212 citations
197 citations
TL;DR: In this article, four different procedures were applied to computer-simulated samples to provide comparative data pertaining to two questions: (a) which procedure can be expected to produce an equation that yields the most accurate predictions for the population? (b) Which procedure is most likely to identify the optimal set of independent variables?
Abstract: 4 different procedures are commonly employed with sample data to reduce a set of predictor variables. In the present study these procedures were repeatedly applied to computer-simulated samples to provide comparative data pertaining to two questions: (a) Which procedure can be expected to produce an equation that yields the most accurate predictions for the population? (b) Which procedure is most likely to identify the optimal set of independent variables? The samples were drawn from 12, mathematically defined, multivariate normal populations. Each population consisted of 1 criterion and 10 predictor variables. Five or fewer independent variables constituted the optimal set in each case. With respect to both questions small differences among the procedures were observed. However, the forward selection and stepwise procedures consistently produced more favorable results than the 2 backward elimination procedures. The question of the number of sampling units to use is discussed.
TL;DR: Those tissues having a high cell turnover, e.g. thymus and intestinal mucosa, exhibit a greater rate of proteolysis of nucleohistone than is observed for other tissue.
TL;DR: In this paper, the vertical turbulent mass transfer coefficients for suspended sediment particles and dye, and fall velocities of the sediment particles were determined experimentally in a large laboratory flume.
Abstract: Vertical turbulent mass transfer coefficients for suspended sediment particles and dye, and fall velocities of the sediment particles were determined experimentally in a large laboratory flume. Local values of the turbulent mass transfer coefficient, and turbulent fall velocities for the sand, were determined from an integrated form of the transfer equation. The results of the experiments indicate that: (1) Magnitude and distribution of the vertical turbulent mass transfer coefficient for dye and fine sediment are close to those of the momentum transfer coefficient, which lends added support to Reynolds' analogy for the equivalence of mass and momentum transfer in turbulent shear flow; (2) in comparison with dye, the mass transfer coefficient for medium sand is somewhat less in magnitude and its distribution indicates that the transfer coefficient is larger near the bed; and (3) the fall velocity of sediment particles is larger in turbulent channel flow than in quiescent water.
TL;DR: No positive correlation between the degree of growth hormone elevation and the abnormality of glucose tolerance was observed, and the carbohydrate intolerance and hyperinsulinism associated with uremia must however be attributed to factors other than growth hormone alone.
Abstract: Fasting plasma growth hormone was 6 mμg./ml. or more in 13 of 21 patients with severe renal failure. Growth hormone levels of control subjects regularly decreased following an intravenous infusion of glucose. In contrast, the growth hormone levels of only three of 21 uremic patients were suppressed by glucose, eleven of the patients exhibiting a paradoxical rise. We observed no positive correlation between the degree of growth hormone elevation and the abnormality of glucose tolerance. Growth hormone levels were also measured at four hourly intervals during hemodialysis. Increasing the glucose concentration of dialysate did not noticeably modify the growth hormone response to hemodialysis in these patients. The pathologic significance of increased growth hormone in uremia is unknown. The carbohydrate intolerance and hyperinsulinism associated with uremia must however be attributed to factors other than growth hormone alone.
TL;DR: Different bracket-archwire-angulation combinations are quantified to show relative comparisons for wires and brackets used clinically to show force needed to overcome friction and coefficient of friction.
TL;DR: The authors compared ionic fluxes across the human gastric mucosa after serial instillation of 200ml of 5.0 to 5.5mm bile salts in HCl (160 milliequivalents per liter) solution to those after serialinstillation of HC1 alone (controls) in 9 normal subjects.
TL;DR: In this article, the density between inner edge plasma sheet and plasmasphere as a function of geocentric radial distance from OGO-3 electrostatic measurements was investigated.
Abstract: Electron densities between inner edge plasma sheet and plasmasphere as function of geocentric radial distance from OGO-3 electrostatic measurements
TL;DR: The results of treatment by drilling and bone grafting in fifty-five hips indicate that the procedure can restore viability to the non-traumatic necrotic femoral head in a majority of instances.
Abstract: The results of treatment by drilling and bone grafting in fifty-five hips indicate that the procedure can restore viability to the non-traumatic necrotic femoral head in a majority of instances (79 per cent). Mold arthroplasty, when warranted, may also result in a satisfactory hip.
TL;DR: In this article, the authors look at how mainstream media are currently reacting to the trend of citizen media and identify similarities and differences that hint at the professional, organizational, socio-cultural and economic factors influencing the evolution of participatory journalism.
Abstract: This paper looks at how mainstream media are currently reacting to the trend of citizen media. In order to look beyond the hype and high expectations about user generated content, we first try to put the debate on citizen and participatory journalism in context. We argue that the revived interest in participatory journalism is the result of both external developments in society and internal evolutions in journalism. Next, we analyze these developments in four European countries – Belgium, Finland, Germany and Spain – in order to identify similarities and differences that hint at the (professional, organizational, socio-cultural and economic) factors influencing the evolution of participatory journalism. Data collected suggests that despite of the differences in context, media in any of the four countries tend to develop very limited opportunities for audience participation. The professional culture of journalists is suggested as the main factor preventing the development of participatory projects, while marketing and business strategies somehow push for the exploration of such proposals.
TL;DR: This paper found that speech clinicians assigned a relatively large number of descriptive items to stuttering boys, and the median number of items mentioned tended to increase with clinical experience, and male and female clinicians were more similar than they were different in the traits they assigned.
TL;DR: In this paper, the virbrational quantum number is proportional to the one-sixth power of the binding energy, as expected theoretically from the long-range r−3 behavior of the internuclear potential.
TL;DR: If recovery data are a valid measure of indicator absorption, indicators underestimate net water absorption by 2 to 3 % and should prove to be increasingly useful.
TL;DR: Studies on human amniotic fluid have shown the presence of several factors which are known to be antibacterial, including lysozyme, transferrin, 7S immunoglobulin, specific antibody activity, and β 1a /β 1c globulin.
TL;DR: The peculiar skeletal development in the child with achondroplasia can be explained on the basis of histological observations.
Abstract: We biopsied the iliac-crest cartilage and the upper fibular epiphyseal plates of seven achondroplastic children and the iliac crest of two more. Histologically the iliac-crest cartilage and its growth plate were nearly normal. The fibular growth plate had cartilage-cell clusters separated by wide septa of fibrous matrix which appeared to be very slowly and irregularly resorbed at the vascular front. Bone formation was normal in the iliac wing and was very stunted in the fibular metaphysis. Bone formed normally in the fibular head, at the insertions of the biceps tendon and collateral knee ligament, and in the periosteum. The peculiar skeletal development in the child with achondroplasia can be explained on the basis of these histological observations.
TL;DR: The chromatic number χ(G) is the minimum number of colors required for (a complete coloring of) the points of a graph G, while the achromatic number is the maximum such number as discussed by the authors.
TL;DR: The intraduodenal technique appears to be an improved method for quantification of small intestinal propulsive motility in rats under conditions expected to alter propulsion, autonomic drugs, morphine, chlorpromazine-induced enteromegaly, indomethacin-induced small intestinal ulcers, ileal obstruction, postirradiation, and fasting.