Individual Discrepancies Research Articles

Purification and variability in thrombin-like activity of Bothrops atrox venom from different geographic regions

Bothrops atrox snake venoms from two different Amazon regions, i.e., Manaus, AM (3°0.6′40″S; 60°0.1′6.0″W) and Tucuruı́, PA (3°0.42′30″S; 49°0.41′45″W), were analyzed with respect to the thrombin-like activity component by elution profile on gel-filtration and reverse phase HPLC chromatography, electrophoretic mobility on SDS-PAGE, and enzymatic activity on fibrinogen. Despite some individual discrepancies among venom specimens, the thrombin-like activity present in the Manaus pool was eluted earlier compared with the Tucuruı́ pool but its enzymatic specific activity on thrombin was lower (s.a.=6.0) than that observed in the Tucuruı́ pool (s.a.=134.0). However, the electrophoretic mobilities of the pools were similar, with most protein bands being concentrated around three main regions, i.e., protein bands with an apparent mr of 100 kDa, of 38–37 kDa and 30 kDa. However, no significant differences were observed in amidolytic activity on the synthetic substrate Tos.Gly-Pro-Arg- pNa, and there was no correlation between thrombin-like and amidolytic activities. A 32 kDa protein endowed with thrombin-like activity and specific activity of 2444 recognized and neutralized by horse anti- B. atrox antivenom, was purified by the successive use of gel filtration, electrofocusing and reverse phase HPLC.

Accurate Noninvasive Estimation of Left Ventricular End-Diastolic Pressure: Comparison with Catheterization

We evaluated the accuracy of a new Doppler-based method using the mitral regurgitant velocity at the time of aortic valve opening for the noninvasive estimation of left ventricular end-diastolic pressure. Sixty unselected patients were studied immediately before routine catheterization. Invasive left ventricular end-diastolic pressure was obtained using a fluid-filled pig-tail catheter. Noninvasive estimation of left ventricular pressure at aortic valve opening was taken as systemic diastolic pressure using an automated cuff. Noninvasive left ventricular end-diastolic pressure was calculated as diastolic blood pressure - 4 × (mitral regurgitant velocity at aortic opening) 2 . Those making noninvasive determinations were blinded to catheterization results. An adequate mitral regurgitant Doppler recording was obtained in 24 patients (40%). In patients with a left ventricular end-diastolic pressure greater than 15 mm Hg the yield was 65%. Left ventricular end-diastolic pressures ranged from 4 mm Hg to 30 mm Hg. Bland and Altman analysis revealed no systematic bias and close agreement was found, with individual discrepancies not exceeding 5 mm Hg. (J Am Soc Echocardiogr 1998;11:126–31.)

Otoliths Reveal a Diverse Age Structure for Humper Lake Trout in Lake Superior

Humpers are one of at least three morphological variants of wild lake trout Salvelinus namaycush that maintain self-sustaining populations in Lake Superior. In an early study, bumpers from Isle Royale were shown to have a sharply truncated age distribution that was attributed to high mortality after age 11, but we suspected that these fish were underaged. In August of 1989 and 1992 we collected spawning humper lake trout from the same area and estimated their ages using both scales and sagittal otoliths. Humpers in our sample ranged from 5 to 13 years, based on scale annuli, but counts of sagitta annuli revealed ages of 8 to 28 years. Individual discrepancies between ages from scales and sagittae varied from –2 to 20 years, but differences between scale and otolith ages did not increase with individual age. We applied the von Bertalanffy growth model to the humper length-at-age data to indirectly assess the accuracy of aging estimates. The model significantly overestimated mean asymptotic length when scale ages were used, but the mean asymptotic length estimate was more similar to observed lengths when sagitta ages were used. Our results corroborate evidence that bumpers in Lake Superior grow more slowly and mature at a smaller size than lean lake trout; however, the age composition of bumpers is more diverse than previously thought. This particular population experiences little or no exploitation; the presence of older fish provides one standard by which the success of lake trout rehabilitation programs can be evaluated and emphasizes the need for accurate aging techniques.

Acoustic correlates of the emotional expression in vocal performance

Listening experiments and physical analyses of vocal performances were made to investigate how the emotional expressions were transmitted to listeners and to find acoustic correlates of each emotional expression. Three female singers were instructed to perform a short piece of music so as to communicate five basic emotions to listeners. The five basic emotions were ‘‘happiness,’’ ‘‘sadness,’’ ‘‘anger,’’ ‘‘fear,’’ and ‘‘without expression.’’ Some listening experiments revealed that, on the whole, the singer’s intention and the listener’s impression, although there were individual discrepancies, were in general agreement. The performances were analyzed regarding physical parameters such as tempo, dynamics, agogics, intonation, vibrato, and so on. The relationships between the expressive intention of the singers and measured physical parameters were revealed.

When is a serum iron really a serum iron? The status of serum iron measurements

Although serum iron determinations play an important role in the diagnostic process, the accuracy of routine methods is suspect. The poor performance of currently used methods is well documented in the quarterly College of American Pathologists survey reports. Compared with the 1990 method of the International Committee for Standardization in Haematology (ICSH), the 1978 ICSH Reference Method shows a +3.4% bias and the standard method of the National Committee for Clinical Laboratory Standards shows a -17.8% bias for iron results. All routine methods checked--DuPont aca, Abbott TDx, Kodak Ektachem (except one lot), BM/Hitachi 717, and Synermed--show a negative bias over the entire analytical range, a significant negative intercept, and extremely poor correlation with the 1990 ICSH method for iron values < 750 micrograms/L. Individual discrepancies of several hundred percent were observed. Imprecision of the methods is not the reason for these discrepancies. We question whether most routine methods measuring low iron concentrations provide results sufficiently reliable for confirmation of iron deficiency.

LSC standardization of 45Ca by the CIEMAT/NIST efficiency tracing method

A commercial solution of 45CaCl 2 and two organic compounds, 45Ca-2-ethylhexadecanoate and 45Ca-HDEHP complex, synthesized in the laboratory, have been used to produce appropriate sources for LSC measurements. A toluene-based scintillator and three commercial cocktails (Hisafe II, Ultima Gold and Instagel) were used for measuring the samples. Their concentration quenching, time stability, and spectral behaviour were studied over a 30-day period. The stable samples were used to standardize the radioactive solutions by the CIEMAT/NIST efficiency tracing method. Experimental quench curves for 3H were measured with each scintillator to cover the range of figure of merit between 1 and 4, corresponding to 3H equivalent efficiency between 52 and 12%. Experimental and computed efficiencies were in good agreement, with individual discrepancies lower than 0.6% in all cases; high efficiency values, better than 95%, were obtained with unquenched samples. A combined uncertainty of 0.4% was obtained for the activity concentration estimation of each radioactive solution.

Influences on Measurement of Cellular Proliferation by Histology and Flow Cytometry in Mammary Carcinomas LabeledIn Vivowith Bromodeoxyuridine

Field-selection procedures strongly influence histologically determined bromodeoxyuridine (BrdU) labeling indices (HLIs): For a series of 52 breast carcinomas, "high-labeling" fields had mean 2,000-cell HLIs that were, on average, more than double those for random fields, but the ratio was extremely variable. Although there may be a priori reasons for preferring particular field-sampling techniques, nonstandardized kinetic data from different laboratories will be uninterpretable and therefore of limited clinical application. Also, if heterogeneity of tumor cell proliferation is neglected, it is possible that incomplete or even misleading data may be gained. Total flow cytometric BrdU labeling indices (TLIs) were not, on average, higher or lower than HLIs for the same cases, but individual discrepancies could be pronounced. The best correlation of flow cytometric LIs with HLIs was obtained for aneuploid carcinomas with a restricted labeling index derived for aneuploid (presumptively neoplastic) cells only. Although flow cytometric analysis avoids the statistical problems associated with accurately determining a small percentage from relatively few cells, it lacks precise definition of the character of the cells counted, but even histologic methods are not entirely free of this difficulty.

Information in powder pattern indexing

A criterion to estimate the reliability of powder pattern indexings, based upon information theory principles, is proposed. It takes account of the individual discrepancies between computed and observed line positions, of the unit-cell volume and of the systematic extinction rules due to the lattice type. The resulting figure is in fact the information quantity conveyed by the set of indices assigned to the given experimental lines.

How Are the Player's Ideas Conveyed to the Audience?

Psychological experiments and analyses have been done to investigate quantitatively how the ideas of a musician are conveyed to the audience. The musician performed 1 minute of the beginning of the first movement of Mendelssohn's Violin Concerto with 10 different nuances: weak, powerful, bright, sad, sophisticated, beautiful, dreamy, fashionable, simple, and deep. Sixteen listeners, including the violinist, were asked to give their impressions of each of the 10 performances by the semantic differential method. The data obtained were analyzed by Kruskal's multidimensional scaling technique. The results revealed that, on the whole, the player's intention and the listener's impression, although there were individual discrepancies, were in general agreement.

Prediction of Energy Intakes of Residents in Homes for the Elderly

AN EQUATION to predict intake in institutionalised elderly, derived from data collected in W. Yorkshire, was tested in two homes for the elderly in Shropshire by comparing observed with predicted intakes. On average, observed and predicted intakes differed by only about 2%, although there were substantial individual discrepancies. Observed intakes of iron, folate, and vitamins A and D were below recommended intakes for these nutrients.

Accuracy of analytic semiclassicalT-matrix elements

The accuracy of two different semiclassical methods of evaluating T-matrix elements by stationary-phase techniques are reported. Their predictions are compared to quantal results for the far-red-wing emission spectrum of Rb collisionally broadened by Xe perturbers. One method is based on the direct use of uniform semiclassical wave functions in the overlap integral of the T-matrix elements. It is shown to give very accurate results (generally to within 3% of quantal values) for both classically allowed and classically forbidden transitions, whether they are near to or far from the classical singularity associated with the collisional turning points. The other semiclassical method is based on a cubic expansion of the phases of the semiclassical wave functions. If simple semiclassical amplitudes and phases are used in the resulting expression, individual T-matrix elements can have significant errors. However, the sum over angular momenta tends to compensate for the individual discrepancies so that the final differential intensity is generally within 10% of quantal values, except for narrow spikes due to the turning-point singularities. The use of uniform semiclassical amplitudes and phases removes these spikes and reduces the error in the total differential intensity given by the cubic expression to only a few percent.

The analytical reliability of the zirconyl phosphate method of plasma carcinoembryonic antigen.

We evaluated the analytical reliability of the carcinoembryonic antigen (CEA) method of Hansen. Our experience is based on performing over 23,000 CEA assays in more than 10,000 clinical samples. The sensitivity of the assay is 0.5 ng/ml. The precision must be defined as a function of concentration. In the range 2.6 to 12 ng/ml the coefficient of variation is 4.96 to 7.39%. Long-range studies of the reproducibility of the standard curve, over a period of several years and including 435 standard curves, have shown an overall mean B/Bo of 31.45% which is close to the theoretical optimal of 33%. The long-term 90 and 50% intercepts are 0.55 +/- 0.15 and 7.11 +/- 1.0, respectively. Interlaboratory surveys show good agreement between the means of the survey group and the target values but rather large individual discrepancies. The CEA method studied here is sensitive and reproducible in intralaboratory studies but less so in interlaboratory comparisons. The reagents have performed uniformly and close to specifications over an extended period of time.

A photometric study of the Orion OB 1 association. III - Subgroup analyses

The four principal subgroups of the association are examined in detail using individual distances and reddening values determined for their B-type members from uvbyfl data presented in the previous papers of this series. Subgroup la appears not to show a spread in age as suggested by a previous study; nor does it show a systematic distance increase with right ascension when fainter members are considered, although such a trend in declination indicates a possible connection of this subgroup with the A Orionis clustering to the north. An eastwardly increase in distance is found for subgroup ib, in agreement with previous studies, but the reddening law for the east Belt appears normal. Tile small subclusterings in the vicinity of the Orion Nebula appear not to differ in evolutionary state, but their ages are considerably greater than those of stars in the nebula and its associated cluster. Both uniform differences and large individual discrepancies in the m0 index, similar to those found in a study of the Upper Scorpius region of the association Sco OB 2, have been found for the young stars surrounding the Orion Nebula. They appear to be a result of several effects connected with line and/or continuum anomalies and mechanisms associated with local absorption. Several pre-main-sequence candidates are found among the late B- and A-type stars in the nebula region, and the lower main-sequence turnup occurs at approximately spectral type A0, beyond which the A- and F-type stars define a uniform sequence running parallel to the main sequence, but above it by about 1.3 mag. A clear gap in the F-star sequence is found in the range 0.21 &lt; (b - Y)o &lt; 0.26, indicating possible implications for the theory of convection in stellar envelopes of pre-main-sequence stars. Tile distribution of reddened B stars in the northern and southern sections of the association is indicative of absorption by circumstellar remnant dust for stars near the pre-main-sequence turnup. New age estimates for the association subgroups, made using intrinsic colors of their bluest main-sequence stars, are in substantial agreement with earlier determinations, but the accuracy can be improved by correcting for rotational-velocity effects if and when rotating models for higher mass stars become available. Subject headings: clusters: associations - nebulae: Orion Nebula - photometry - stars: early-type - stars: evolution - stars: pre-main-sequence

102: Study of serum GH by radioreceptor assay in normal and constitutionally short children

A growth hormone radioreceptor assay (RRA) was developed using the 100,000 g pellet from pregnant cortisone-treated rabbit liver homogenate, the 125 I hGH binding being specifically and completely displaced by unlabelled hGH. Sensitivity was 0.2 ng. Comparing the GH levels found by this method and by radioimmunoassay in normal sera, the mean RRA/RIA ratio was 0.84 ± SEM 0.07 (range 0.70/0.93). In 11 out of 16 primordial dwarfs the RRA/RIA ratio was in the normal range; it was lower in 2 and higher in 3. But in a number of samples from primordial dwarfs the curve of displacement of labelled GH from the receptor did not parallel the standard curve. This phenomenon was not due to anti-hGH antibodies, it was not induced by addition of insulin and was not modified when variable amounts of hGH were added to these sera. It may be concluded 1/ that serum levels of GH estimated by RRA are generally lower than by RIA; 2/ that individual discrepancies are found in primordial dwarfs; 3/ that the serum from certain primordial dwarfs modifies the affinity of GH for the receptors.

A Trophic Comparison of Avifaunas

A trophic comparison of Avifaunas. Syst. Zool. 21:135–150. This paper presents an attempt to compare the passerine and near-passerine bird faunas of the six faunal regions on a trophic basis. Indices of similarity are calculated using: a) the importance (percentage of total species) of families in the areas, and b) the importance of different trophic roles in the areas. The importance values for trophic roles were calculated by multiplying the importance values of the families by indices for the importance of applicable trophic roles for each family and summing the values for each trophic role in each region. The faunal regions showed much higher similarity indices when compared on a trophic rather than a taxonomic basis. Also, the geographic patterns of taxonomic similarity are different from that for trophic similarity. High trophic similarity is related to the major ecological division “temperate” versus “tropical” rather than to the geographical proximity. An examination of the individual trophic roles reveals several facts. While some, such as gleaning invertebrates from foliage, have little variation in importance from region to region, others such as nectivory show high degrees of difference. Other roles with intermediate variability show individual discrepancies, such as the paucity of ground-feeding insectivores in the Australian region. Possible reasons for some of these phenomena are suggested. The families of birds that are specialists in or major contributors to the different trophic roles are surveyed to provide a number of examples of “ecological equivalence” between taxonomically remote groups. This ecological equivalence is often reflected in convergent moiphology and behavior patterns.

Quantitative comparison of passive motion and tendon reflex responses in biceps and triceps brachii muscles in hemiplegic or hemiparetic man.

The clinical impression that severe hyperreflexia is not consistently associated with severe spasticity in hemiplegia or hemiparesis due to vascular pathology was tested by objective measurement in 11 patients. The intensity of tendon reflex responses of the triceps and biceps brachii muscles was measured as the reflex sensitivity ratio (evoked twitch tension/stimulating hammer force). The degree of spasticity was measured as the threshold rate of elbow flexion or extension above which a myotatic response was elicited, determined by both a sudden increase in passive resistance and a burst of antagonist electromyographical activity. Rate thresholds were rank ordered for flexion data and for extension data with their corresponding reflex sensitivity ratios. Numerous individual discrepancies stood out. Correlation coefficients between rate thresholds and reflex sensitivities determined at two elbow angles were -0.52 and -0.35 during extension, and -0.47 and 0.03 during flexion. Differences in rate of stretch, differences in the sensory structures stimulated, and differences in the distortion of the organization of motor control may account for the difference in responses to the two tests.

Evaluation of some methods for serum total cholesterol

Toral serum cholesterol was analysed in samples by the methods of Huang 1, Abell 2 and Zak 3. Attention was paid to the level of bilirubin. In a group with normal ranges of bilirubin, the correlation of results was good. In a group of samples with normal and elevated concentrations of bilirubin, good agreement was obtained only between the methods of Huang and of Abell. In samples with bilirubin concentrations between 2.2 and 46 mg/100 ml, comparative results obtained with the methods of Huang and Abell, and Abell and Zak respectively did not show significant differences. In a group with individual discrepancies between results, no correlation was observed between these discrepancies and the level of bilirubin. One- and two-dimensional thin-layer chromatography did not show a separate fraction in cases where results according to Huang and to Abell were at variance.

Isomer ratios for some (n,γ) reactions

Isomer ratios were measured for capture of thermal and epi-cadmium neutrons by Se 80, Rh 103, Pd 108, Te 128 and Cs 133. These experimental values and all similar data in the literature are compared with a Fermi gas theory. In general the agreement between theory and experiment is satisfactory. However, a number of individual discrepancies do exist and indicate a need for more measurements.

Species difference in pancreatic lipolytic and amylolytic enzymes

The pancreatic content of lecithinase A in man is approximately 10–20 times that in the dog. In contrast, the pancreatic content of lipase is one-half and of amylase one-sixth that of the dog. The rabbit is similar to man in its pancreatic amylase and lipase content, and to the dog in its lecithinase A content. In man the serum lecithinase A increases during acute pancreatitis, paralleling more or less the elevations in serum amylase and lipase. Though individual discrepancies are noted, all three enzymes increase roughly proportionately. During acute pancreatitis in the dog, the serum lecithinase A increases but slightly, in sharp contrast to the elevations in serum amylase and lipase which are greater than in man. Submitted on July 12, 1962

Aerotriangulation on the AP/C

Aerotriangulation on the AP/C