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PubMed1990

The relationship between task complexity and decision-making consistency.

The purpose of this study was to examine the relationship between task complexity and decision-making consistency using a normative decision model. The Decision Analytic Questionnaire (DAQ), an instrument designed to measure nurses' decision making under increasingly uncertain and complex conditions, was administered to a stratified random sample of 101 paid volunteer medical-surgical nurses drawn from three public teaching hospitals. Probit analysis was used to construct a profile of the decision maker whose decisions coincided with those of the model. Results indicated that nurses made clinical decisions that coincided with those recommended by a normative decision model but that agreement diminished as task complexity increased (p less than .005). The results also indicated that consistency was task specific, that predictive variables were a function of decision task and that more predictor variables were needed to explain consistency as task complexity increased.

Clinical Competence↗

PubMed1987

Variance estimators for attributable fraction estimates consistent in both large strata and sparse data.

A number of variance formulae for the attributable fraction have been presented, but none is consistent in sparse data, such as found in individually matched case-control studies. This paper employs Mantel-Haenszel estimation to derive variance estimators for attributable fractions that are dually consistent, that is, consistent in both sparse data and large strata. The method may also be applied using conditional maximum likelihood. Extensions of these estimators to situations involving effect modification and preventive exposures are also derived. Examples of applications to individually matched case-control studies are given.

Analysis of Variance↗

PubMed1993

A self-consistent method for the analysis of protein secondary structure from circular dichroism.

A self-consistent procedure for estimating the secondary structure content from circular dichroism spectra of proteins is presented. In this method the spectrum of the protein to be analyzed is included in the basis set and an initial guess is made for the unknown structure as a first approximation. The resulting matrix equation is solved using the singular value decomposition algorithm and the initial guess is replaced by the solution. The process is repeated until self-consistency is attained. The best features of the variable selection and the locally linearized methods are incorporated in this procedure. We have applied this method to examine the inconsistencies in the CD data, to compare the predictions with different ranges and resolutions of the CD data, and to compare different assignments of secondary structures from X-ray structure analyses in the context of secondary structure predictions. The results are compared using the root mean square differences and correlation coefficients. The results obtained are as good as or better than the previous analyses. For most of the proteins considered the self-consistent solutions obtained with different initial guesses were similar. We find the Kabsch and Sander protein crystal structure analysis to be most suitable for our prediction method.

Circular Dichroism↗

PubMed1995

Consistency of liking and appropriateness ratings and their relation to consumption in a product test of ice cream.

The consistency of hedonic responses to three brands of vanilla ice cream over 5 weeks was examined using two procedures. Respondents (n = 40) came to the test after their usual lunch and rated their liking for ice creams side-by-side (three samples in one session) and after ad libitum consumption (one sample at a time). The quantity of ice cream consumed in ad libitum procedure was recorded. Respondents also assessed the appropriateness of the three samples of vanilla ice cream to ten usage situations, including "as a dessert" which was the context in the test situation. The consistency of hedonic responses was low over replicates (r = 0.03 to 0.48). In the side-by-side condition, only 48% of the liking responses in replicates were within one point (not at all = 1, extremely = 9), and 63% in the after-consumption condition. Some respondents ate more of all brands than other subjects did in both replicates, unrelated to differences in liking. The appropriateness ratings of brands were similar but the ratings of appropriateness "as a dessert" differentiated the brands. In the after-consumption condition the ratings of liking and appropriateness, together with consumption measures, appeared to be slightly more consistent at the individual level than those made in the side-by-side situation.

Adult↗

PubMed1994

Predicting protein mutant energetics by self-consistent ensemble optimization.

In this paper we present a self-consistent ensemble optimization (SCEO) theory for efficient conformational search, which we have applied to predicting the effects of mutations on protein thermostability. This approach takes advantage of a statistical mechanical self-consistency condition to home in iteratively on the global minimum structure. We employ a fast potential of mean-force approximation to cut computation time to a few minutes for a typical protein mutation, with only linear time-dependence on the size of the prediction problem. Rather than seeking a single, static structure of minimum energy, the new method optimizes an ensemble of many conformations, seeking to predict the most likely ensemble for the native state at a desired temperature. Testing this approach with a simple physical model focusing entirely on steric interactions and side-chain rearrangement, we obtain robustly convergent prediction of core side-chain conformation, and of hydrophobic core mutations' effects on protein stability. Self-consistent ensemble optimization is superior to simulated annealing in its speed and convergence to the global minimum, and insensitive to starting conformation. In calculations on lambda repressor protein, structural predictions for an eight-residue molten-zone had side-chain r.m.s. error of 0.49 A for the wild-type protein. Evaluation of the method's mutant structure predictions should become possible, as structures of these mutant repressors are solved. Predicted energies for a series of nine hydrophobic core mutants correlated with measured free energies of unfolding with a coefficient of 0.82.

Amino Acid Sequence↗

PubMed1990

Dietary fat and cancer: consistency of the epidemiologic data, and disease prevention that may follow from a practical reduction in fat consumption.

International variations and national time trends in disease rates suggest major associations between dietary fat and several important cancers. In contrast, case-control and cohort studies of dietary fat in relation to the same cancers generally report weak associations, or have failed to detect any association with fat intake. This study was undertaken in an attempt to understand the apparent discrepancy between these observations. The results provide an insight into the magnitude of cancer risk reduction that may follow from a practical reduction in dietary fat. Regression analyses of international variations in cancer incidence rates were used to estimate relative risks (RR) as a function of fat intakes for both males and females. These analyses focused on cancers of the breast, colon, rectum, ovary, and endometrium in females, and colon, rectum, and prostate cancers in males. Ages 55-69 and 30-44 were considered in order to compare RR estimates between an older and younger age group, and between post- and pre-menopausal women. Corresponding RR estimates were also calculated, based on the regression of changes in disease rates from the mid-1960s to 1980 on changes in dietary fat, using data from several countries. A strong degree of consistency with the RR estimates from international comparisons was observed. The international regression analyses were also used to project changes in cancer rates among Japanese migrants to the United States. A high level of consistency with the observed disease-rate changes was noted. Similarly, the international data analyses were used to project RRs for the fat intake categories used in specific case-control and cohort studies, while acknowledging measurement error in individual dietary assessment. Although certain exceptions are noted, considerable consistency was found between the aggregate and analytic data results, leaving open the strong possibility that a practical reduction in dietary fat could result in a major reduction in the incidence of several prominent cancers in the United States and in other nations having high fat consumption.

Adult↗

PubMed1979

Comparison of consistency of meningiomas and CT appearances.

Computed tomograms of meningiomas in which the consistency of the tumour had been specifically noted at surgery were reviewed. Those showing diffuse calcification or evidence of marked cystic or necrotic changes were excluded, leaving 77 tumours of which 46 were hard and 31 soft. Ninety per cent of the hard tumours were of increased attenuation; the other 10% were isodense with brain. Forty-nine per cent of the soft meningiomas were of high attenuation, but 35% were isodense and 16% were of lower than brain attenuation. There was a greater incidence of marked intracerebral oedema around the hard tumours. All hypodense tumours enhanced to greater than brain attenuation; mean enhancement was relatively less in the tumours of high plain scan attenuation regardless of consistency and there was no relationship between degree of enhancement and either the consistency or with the amount of vascularity as estimated by the surgeon or histologist.

Adolescent↗

PubMed1989

Internal consistency of a diagnostic interview for children: the Child Assessment Schedule.

The purpose of this study was to evaluate the internal consistency of the content scales of the Child Assessment Schedule (CAS). A total of 116 psychiatric patients with a mean age of 10 years were administered the interview, and 92 parents were administered the parent version. Coefficient alpha was calculated for each of the 11 content scales. High internal consistency was demonstrated for school, friends, worries, mood, physical complaints, and expression of anger. More moderate but acceptable alphas were observed for the family, fears, and self-image scales. The same general pattern of results was observed for both the child and parent interviews. Additional analyses revealed that the number of items in the CAS could be reduced up to 30% without sacrificing internal consistency. These results indicate that 9 of the scales yield reliable scores.

Child↗

PubMed1990

Esophageal function in humans. Effects of bolus consistency and temperature.

We determined the effect of increased bolus consistency on esophageal motor function in 11 healthy volunteer subjects. Further, we sought to define the esophageal response to boluses with a wide range of temperatures in nine healthy volunteers. Intraluminal pressure events were measured with an infused catheter system, and lower esophageal sphincter pressure was monitored continuously with a Dent sleeve. Boluses (10 swallows each) consisting of 5 ml of a solid suspension (yogurt), 5 cm3 of a soft solid (gelatin), and 5 ml of water were given in a randomized order. In a separate study, boluses with temperatures of 1 degree C, 5 degrees C, 10 degrees C, 15 degrees C, room temperature, 30 degrees C, 40 degrees C, 50 degrees C, and 60 degrees C were given in a randomized fashion. Compared to the water bolus, the solid boluses elicited a significant (P less than 0.05) reduction in peristaltic wave velocity, which was accompanied by significant (P less than 0.05) increments in the durations of wave contraction and lower esophageal sphincter relaxation. The magnitude of the response elicited by the solid boluses was comparable to that noted with boluses of high viscosity suggesting that the esophagus response to increments in bolus viscosity and consistency in a similar fashion. Alterations in bolus temperature did not elicit any significant changes in the parameters of esophageal peristalsis. It is concluded that bolus temperature does not have a significant role in the modulation of human esophageal peristalsis except under conditions that cause a change in esophageal wall temperature.

Adult↗

PubMed1976

Identification of consistent responding to auditory stimuli by a functionally "deaf" autistic child.

Although the severity of autistic children's unresponsiveness to external stimulation has been frequently reported, little empirical work has been conducted to specifically describe the nature of their unresponsiveness. The child who participated in this experiment was at varying times reported to be deaf, hard of hearing, or functionally deaf; and at other times was reported to have normal hearing. In this experiment, we measured his responses to systematically presented auditory stimuli in order to determine if there was any pattern to his responding. Two types of auditory stimuli were used: (a) white noise, consisting of most of the frequencies within the human range of hearing, and (b) the sound of a candy machine delivering candy. The results showed the following. (1) There was consistent responding to both the white noise and the candy feeder. (2) The thresholds for responding to the white noise were always consistent on a given day, but varied from day to day. (3) Responding to the candy machine stimulus always occurred at sound levels which were well below the threshold for the white noise. These results are discussed in terms of their implications for understanding autism, and in particular in terms of understanding the lack of speech development in mute autistic children.

Acoustic Stimulation↗

PubMed1990

Effects of body position and bolus consistency on the manometric parameters and coordination of the upper esophageal sphincter and pharynx.

The development of a solid-state intraluminal sphincter transducer has alleviated many of the problems associated with manometric studies of the upper esophageal sphincter (UES) and pharynx (P). We used this technology to study the effect of position (upright vs. supine) on resting UES pressures and the pressure dynamics of the UES/P complex during both wet and dry swallows in 11 normal volunteers and the effects of foods of different consistencies on the UES/P swallow dynamics in 10 normal volunteers. The UES/P coordination parameters were defined as the 15 time intervals that can be measured between any 2 of 6 pertinent points: the beginning, peak, and end of the pharyngeal contraction and the beginning, nadir, and end of the UES relaxation. Data from both the circumferential transducer used to measure sphincter pressures and a standard microtransducer used to measure pharyngeal pressures were collected on-line by an Apple IIe microcomputer and analyzed by programs written in our laboratory. Significant changes in swallow coordination were measured between upright and supine swallows of the same bolus size, between wet and dry swallows in the same position, and among foods of varying consistencies. Resting UES pressure was unchanged by position and pharyngeal contraction pressure was unchanged by bolus size or consistency.

Adult↗

PubMedDate not supplied

The inter-rater reliability and internal consistency of a clinical evaluation exercise.

OBJECTIVE: To assess the internal consistency and inter-rater reliability of a clinical evaluation exercise (CEX) format that was designed to be easily utilized, but sufficiently detailed, to achieve uniform recording of the observed examination. DESIGN: A comparison of 128 CEXs conducted for 32 internal medicine interns by full-time faculty. This paper reports alpha coefficients as measures of internal consistency and several measures of inter-rater reliability. SETTING: A university internal medicine program. Observations were conducted at the end of the internship year. PARTICIPANTS: Participants were 32 interns and observers were 12 full-time faculty in the department of medicine. The entire intern group was chosen in order to optimize the spectrum of abilities represented. Patients used for the study were recruited by the chief resident from the inpatient medical service based on their ability and willingness to participate. INTERVENTION: Each intern was observed twice and there were two examiners during each CEX. The examiners were given a standardized preparation and used a format developed over five years of previous pilot studies. MEASUREMENTS AND MAIN RESULTS: The format appeared to have excellent internal consistency; alpha coefficients ranged from 0.79 to 0.99. However, multiple methods of determining inter-rater reliability yielded similar results; intraclass correlations ranged from 0.23 to 0.50 and generalizability coefficients from a low of 0.00 for the overall rating of the CEX to a high of 0.61 for the physical examination section. Transforming scores to eliminate rater effects and dichotomizing results into pass-fail did not appear to enhance the reliability results. CONCLUSIONS: Although the CEX is a valuable didactic tool, its psychometric properties preclude reliable assessment of clinical skills as a one-time observation.

Clinical Competence↗

PubMed2001

Accuracy and consistency of respiratory inductive plethysmography for overnight tidal volume measurement.

To validate the accuracy and consistency of respiratory inductive plethysmography (RIP) in measuring tidal volume after an overnight sleep, tidal volumes of 18 patients with suspected sleep-disordered breathing and 8 normal volunteers were measured simultaneously with RIP (VTRIP) and with an ultrasonic airflow meter (VTUFM) before and after an unstrained overnight sleep on supine and lateral decubitus. The bias of the VTRIP was expressed as (VTRIP-VTUFM)/ VTUFM.100%, limits of agreement between VTRIP and VTUFM was measured by averaged bias +/- 2 s. Results showed that in normal subjects, the bias of RIP before and after overnight sleep was precise and consistent in both supine (0.7% and -1.6%) and lateral decubitus (3.7% and -0.56%). In these patients, the bias of RIP before and after sleep in supine also remained small (1.9% and 1.7%), but it became larger in lateral decubitus (24.5% and 20.4%) and 11.5% exceeded the limits of agreement observed in the evening. The patients' body mass indices (BMI) were higher than those of normal subjects (median 34.2 vs. 27.8 kg/m2). Pooled data showed that the bias of VTRIP in the morning on lateral decubitus but not on supine was correlated to BMI (Spearman R = 0.32, n = 52, P = 0.02). Thus, we were led to conclude that the accuracy of VTRIP overnight was precise and consistent in normal subjects, but the deviation of VTRIP measured on lateral decubitus in patients especially in those with excessive obesity was greater, thus, the method should not be used for quantitative determination.

Adult↗

PubMed2001

[German instrument for the assessment of quality of life in skin diseases (DIELH). Internal consistency, reliability, convergent and discriminant validity and responsiveness].

BACKGROUND AND OBJECTIVE: Performance and psychometric testing of the German Instrument for the Assessment of Quality of Life in Skin Diseases (DIELH). PATIENTS/METHODS: The instrument consisting of 36 questions (maximum skore 180, 7 domains) was used in 836 outpatients and quality assessments (validity, reliability, responsiveness) were performed. RESULTS: The total skore had a mean of 54 pts. (STD 31, range 0-157) and was normally distributed. Women reported a higher impact on quality of life (median 56 vs. 49, p < 0.001). In terms of discriminant validity significant differences between diagnostic groups were observed with high scorings for patients with eczema, psoriasis, urticaria, and acne (p < 0.001). Tests for internal consistency (Cronbach's alpha 0.71-0.92) and reliability (r = 0.73-0.86) revealed valid results. The DIELH correlated well with the DLQI (r = 0.78, p < 0.001) and moderately with 3 domains of the SF 36 (r = 0.25-0.30, p < 0.01). Changes in the quality of life after 4 weeks were consistent with the corresponding changes of the skin condition and partially significant. CONCLUSIONS: In the use within a large patient sample the DIELH proved to be feasible, valid, reliable, and responsive.

Adolescent↗

PubMed2002

Learned perceptual associations influence visuomotor programming under limited conditions: kinematic consistency.

Previous findings have suggested that visuomotor programming can make use of learned size information in experimental paradigms where movement kinematics are quite consistent from trial to trial. The present experiment was designed to test whether or not this conclusion could be generalized to a different manipulation of kinematic variability. As in previous work, an association was established between the size and colour of square blocks (e.g. red = large; yellow = small, or vice versa). Associating size and colour in this fashion has been shown to reliably alter the perceived size of two test blocks halfway in size between the large and small blocks: estimations of the test block matched in colour to the group of large blocks are smaller than estimations of the test block matched to the group of small blocks. Subjects grasped the blocks, and on other trials estimated the size of the blocks. These changes in perceived block size were incorporated into grip scaling only when movement kinematics were highly consistent from trial to trial; that is, when the blocks were presented in the same location on each trial. When the blocks were presented in different locations grip scaling remained true to the metrics of the test blocks despite the changes in perceptual estimates of block size. These results support previous findings suggesting that kinematic consistency facilitates the incorporation of learned perceptual information into grip scaling.

Association Learning↗

PubMed1997

Evaluation of a self-consistent method for calculating muscle parameters from a set of isokinetic releases.

A new method for calculating parameters describing the force-velocity relationship of the contractile element and the force-extension relationship of the series elastic element of skeletal muscle from a set of isokinetic release contractions is evaluated using experimental and numerical techniques. The method calculates from the set of isokinetic releases those force-velocity and force-extension relationships that give a self-consistent description of the data set. The self-consistent calculation method is applied to data obtained from the gastrocnemius medialis muscle of the rat, since for such an animal model both relationships can be independently derived from a set of isotonic release contractions. For the two animals studied, the force-velocity and force-extension relationships calculated by the self-consistent method were in good agreement with the ones derived from isotonic releases performed on the same muscle. The statistical properties of the estimates obtained by the calculation method were investigated using a Monte Carlo technique. The method was found to yield results which were biased by less than 2% and which possessed a coefficient of variation smaller than 5%. These findings indicate that the proposed calculation method can be a useful tool for determining the contractile properties of skeletal muscle as reflected in the force-velocity and force-extension relationships.

Animals↗

PubMed2000

Olfactory epithelium consisting of supporting cells and horizontal basal cells in the posterior nasal cavity of mice.

The olfactory epithelium of mice generally consists of olfactory cells, progenitors of olfactory cells (globose basal cells), supporting cells, and horizontal basal cells. However, in the dorsal fossa (the roof) of the posterior nasal cavity of mice, we found seven epithelial patches consisting of only non-neuronal cell types, i.e., supporting cells and horizontal basal cells, among the normal olfactory epithelium. The supporting cells occupied three or four layers in the apical to middle regions; in the basal region, horizontal basal cells were localized in a single row adjacent to the basement membrane. Bowman's gland ducts were also present in the epithelium. Neuronal cells (olfactory cells and globose basal cells) were totally absent. The ultrastructure of the supporting cells, horizontal basal cells, and Bowman's glands was essentially similar to that in the normal olfactory epithelium. In the early postnatal period (P1-P7), cell types in the epithelium were the same as those in the normal olfactory epithelium. From P10 to P21, olfactory cells and globose basal cells had disappeared from the olfactory epithelium. At this period, the number of TUNEL-positive cells was significantly higher than that in the surrounding olfactory epithelium; ultrastructurally, many apoptotic figures were observed. This suggests that the epithelium consisting of supporting cells and horizontal basal cells is generated by the apoptotic death of olfactory cells and globose basal cells during postnatal development.

Age Factors↗

PubMed2007

Maternal androgens in the pied flycatcher: timing of breeding and within-female consistency.

Maternal hormones can have substantial phenotypic effects in the progeny of many vertebrates. It has been proposed that mothers adaptively adjust hormone levels experienced by particular young to optimize their reproductive output. In birds, systematic variation in egg hormone levels has been related to different female reproductive strategies. Because in many bird species prospects of the offspring change seasonally and with brood number, strategic adjustment of yolk androgen levels would be expected. To test this idea, we induced pied flycatcher (Ficedula hypoleuca) females to nest twice during the same season by removing their first clutches shortly after clutch completion. We collected eggs of first and replacement clutches to measure yolk concentrations of androstenedione (A4) and testosterone (T) and captured the females that laid these clutches for phenotypic measurements. Although average egg androgen levels were remarkably consistent within females, hormone patterns differed considerably between first and replacement clutches. Eggs of replacement clutches were heavier with larger yolks compared to first clutches, but they contained on average lower levels of androgens. Within clutches, androgen concentration increased over the laying sequence in the first clutch, but decreased or remained more constant over the laying sequence in the replacement clutch. Mean yolk T, but not A4 levels, were negatively associated with laying date for both breeding attempts. Moreover, females in good body condition produced eggs containing lower levels of androgens than females in poor condition. Our results are consistent with the idea that differences in yolk androgen levels may be one mechanism underlying seasonal variation in reproductive success and it is possible that changes in egg androgen patterns may reflect a change in female reproductive strategy. High within-female consistency also highlights the possibility that there may be some underlying genetic variation in yolk androgen levels.

Androgens↗