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At least 703 records · Page 39Linked to original sources
PubMed2004

[The measurement of wrist kinematics in children 4 to 16 years old and the comparison of the scapholunate distance with adult values].

OBJECTIVES: We sought to determine the position and values of the kinematic indices of the wrist (center of rotation, carpal height, carpal-ulnar distance), the third metacarpal length, and the scapholunate distance for children and compared the results with those reported for adults. METHODS: The study included 41 children (24 girls, 17 boys; age range 4 to 16 years) who presented with wrist and/or forearm injuries, and whose radiographs of the other wrist had been obtained for comparison. The children were divided into six age groups separated by 2-year intervals regardless of gender or the side of the wrists involved. Measurements were made on standard posteroanterior radiographs of healthy wrists and the mean values obtained were statistically analyzed. RESULTS: The carpal height, carpal-ulnar distance and the third metacarpal length were significantly different in all age groups. The ratios of the carpal height and the carpal-ulnar distance to the third metacarpal length were similar both in the age groups and to those reported for the adult values. However, the scapholunate distance exhibited significant differences between the age groups and from the standard adult value. CONCLUSION: The adult values given for the ratios of the carpal height and the carpal-ulnar distance to the third metacarpal length can be adopted as standard values for children. However, determination of the scapholunate dissociation in children should not be based on the normal range given for adults.

Adolescent↗
PubMed2004

Internipple distance and internipple index.

OBJECTIVE: To determine the internipple distance and internipple index in Chinese children. METHODS: The internipple distance and chest circumference were measured in 3,290 healthy Chinese children (1,715 males and 1,575 females) aged birth to 18 years seen at the Asian Medical Centre. The internipple distance and chest circumference were obtained at the end of expiration whenever possible, with a standard nonstretch tape measure graduated in millimeters with the arms hanging relaxed alongside the body. Patients under two years of age were measured supine and those over two years of age standing. The internipple distance was measured between the centers of both nipples, and the chest circumference was measured across the internipple line. The internipple index was calculated according to the formula: internipple distance (cm) multiplied by 100 and divided by chest circumference (cm). RESULTS: The internipple distance and chest circumference increased with age. The internipple index was highest in the neonatal period (26.4 +/- 1.6 for males and 26.3 +/- 2 for females), and decreased steadily until the age of four years (23.8 +/- 1.2 for males and 23.8 +/- 1.4 for females), and thereafter was relatively constant through the age of 18 years in males and the age of 11 years in females. In females, the internipple index decreased gradually from the age of 11 years to 18 years. CONCLUSIONS: While internipple index is a more practical way to assess nipple placement, there are ethnic differences in the internipple index. Proper reference standards should be used in the assessment whether the nipples are closely or widely spaced.

Adolescent↗
PubMed1992

Lateral phoria at distance: contributions of accommodation.

Lateral heterophoria at distance often is cited as an index of tonic vergence, yet recent research has shown that vergence in darkness is more convergent than most measures of phoria. Two experiments were conducted to investigate the possible role of accommodation in this discrepancy. Experiment I compared measures of distance phoria of 19 young adults with measures of vergence and accommodation of the same subjects. Dark vergence was found to be correlated with but significantly more convergent than distance phoria. Hierarchical regression analysis showed that individual measures of phoria were related to subjects' negative accommodation (from the dark focus to the distant target) as well as to dark vergence. Experiment II tested 13 young adults to evaluate three simple models of the influence of accommodation on distance phoria. Distance phoria was predicted best by a model that included the subjects' negative accommodation, accommodative vergence, and dark vergence. These findings support the hypothesis that distance phoria is influenced by accommodation for the fixation target. Dark vergence is a simpler index of tonic vergence.

Accommodation, Ocular↗
PubMed2006

Intercondylar distances of the human temporomandibular joints.

In a sample which included subjects of the Croatian population we made measurements of intercondylar distances between the temporomandibular joints in radiographs. A total of 101 subjects of both sexes ranging in age from 20 to 80 years, mostly residents in Zagreb, were evaluated. We measured the intercondylar distances from the condyle centers in the postero-anterior cranial radiographs which had previously been examined and traced on acetate paper. The measuring points were digitized prior to measurements. A special system of coordinates was devised for each radiograph. The results of our measurements were assessed by ANOVA analysis. The intercondylar distance between the two temporomandibular joints was within the range of 110 and 145 mm, with the mean of 126 mm. In men the intercondylar distance was within the range of 116 and 145 mm, with the mean of 130.2 mm. In women the distance ranged from 110 to 138 mm, with the mean of 123.5 mm. There was a significant difference between the two sexes. From a review of the literature, it is apparent that the results of our measurements do not support the results of similar studies assessed by a number of researchers in other countries. The intercondylar distance in the Croatian sample was 5.25% larger than the maximal values of the same parameters in other populations suggesting larger craniofacial skeletons. The development of this radiographic assessment method should improve evaluation of subjects seeking treatment.

Adult↗
PubMed2006

Association between genetic sequence homology of Porcine reproductive and respiratory syndrome virus and geographic distance between pig sites.

The objective of this study was to investigate whether geographic distance was correlated with genetic homology among isolates of Porcine reproductive and respiratory syndrome virus (PRRSV) from a single pork-producing company. We analyzed geographic distance, temporal distance, and percentage similarity in the PRRSV nucleotide sequence among 62 farms, applying the Mantel test for correlation between distance matrices and PRRSV sequencing. Genomic similarity had a significant (P < 0.01) negative (rM = -0.217) correlation with geographic distance. These findings indicate that, under the conditions of this study, the greater the distance between farms, the less the genetic homology among PRRSV isolates.

Animals↗
PubMed2006

The influence of distance on registration in ISO-C-3D navigation: a source of error in ISO-C-3D navigation.

Computer-assisted treatments have become increasingly common. Consequently, there is an increased desire for navigation methods with simplified workflow. Anatomic-based pair-point registration is often mentioned as a source of error. Alternatively, the use of preoperatively implanted markers for registration remains complex. The self-acting registration of Iso-C-3D at the moment of data acquisition can reduce essential errors. The aim of this study was to evaluate the effect of reference placement on accuracy, and to determine the maximum acceptable distance between the reference and a given isocentre. This study demonstrates the interdependence of the reference distance on the region of interest (ROI). The mean error of registration amounts to 0.04 mm (0.04-0.05 mm) up to a distance of 200 mm and beyond 0.25 mm (0.24-0.26) for distances beyond 200 mm. The accuracy was significantly lower (p<0.0001) with a distance more than 200 mm. For optimal accuracy when utilizing navigation for pelvic and long bone surgery, the reference base should not been placed at a distance more than 200 mm from the isocentre of interest.

Humans↗
PubMed1995

[Experimental studies on influence of alignment errors on measurement in a corneal topographic system--relationship between degree of measurement error and working distance].

To evaluate the influence of alignment errors in focusing on the results of measurements in corneal topography, we experimented using polymethyl-methacrylate balls with definite radii of curvature as test objects. We used 3 different corneal topographic systems with different working distances to clarify the relationship between the degree of errors and the working distance. We determined the refractive power of the test balls by the topographic systems and studied changes in the values as the balls were slightly displaced from the alignment position axially, or horizontally. The test balls were set on the stage with a micrometer so that the distance of displacement could be determined precisely. When the test balls were placed precisely in alignment, there was no significant relationship in the magnitude of measurement errors with working distance of the topographical systems. When the test balls were displaced axially, the measurement values decreased as the balls come near from the alignment position and increased as they moved away from the alignment position. The magnitude of the measurement errors caused by back and forth displacement of the object became larger as the working distance of the topographic system became shorter. There was no specific relationship between the degree of measurement errors and the working distance when the balls were displaced horizontally.

Cornea↗
PubMed1994

[Orbital measurements in Zairian children. Inner canthal, outer orbital, inter-pupillary distances and proptosis].

Measurements of outer orbital distance, inner canthal distance and of interpupillary distance and proptosis were performed on 95 healthy Zairian subjects. The subjects were aged from 2 1/2 to 18 years. There were 47 boys (mean age +/- SD, 9.74 +/- 4.4 years) and 48 girls (mean age +/- SD, 9.07 +/- 4.1 years). No statistically significant difference was found between the two sexes for the mean age. Subjects were divided in four age groups: the first age group included children aged from 2 1/2 to 6 years (mean age +/- SD, 4.62 +/- 1.31 years), the second age group included children aged from 7 to 10 years (mean age, 8.32 +/- 1.22 years), the third included subjects aged from 11 to 14 years (mean age +/- SD, 12 +/- 1.06 years) and the fourth included subjects aged from 15 to 18 years (mean age +/- SD, 17 +/- 3 years). The measurements were performed with the Hertel exophthalmometer for the proptosis and the outer orbital distance, with the pupillometer model PD-2 meter for the interpupillary distance; with a ruler for the inner canthal distance. The mean +/- SD inner canthal was 27.4 +/- 2.7 mm for the first age group, 29.7 +/- 3.1 mm for the second age group, 30 +/- 2.4 mm for the third age group and 32.2 +/- 3.1 mm for the fourth age group. The mean +/- SD outer orbital was 100.0 +/- 4.4 mm for the first age group, 106.5 +/- 4.6 mm for the second age group, 111.7 +/- 6.8 mm for the third age group and 118.5 +/- 6.4 mm for the fourth age group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

Interuncal distance as a measure of hippocampal atrophy: normative data on axial MR imaging.

PURPOSE: To assess the effects of age and gender on the interuncal distance measured from MR images. METHODS: High-field strength MR images (axial) of 75 volunteers, 21-82 years old and free of neurologic disorders, were used to measure the interuncal distance. RESULTS: The interuncal distance increased with age (r = 0.66, P < .0001). The mean (SD) interuncal distance for all subjects was 21.4 (4) mm with a range of 12 to 29 mm. CONCLUSIONS: The interuncal distance in healthy subjects is unlikely to exceed 30 mm. Our data may be of clinical significance in view of a previous report stating that the interuncal distance may be enlarged in pathologic hippocampal degeneration, such as in patients with Alzheimer disease.

Adult↗
PubMed1993

[Predicting the difficulty of laryngoscopy using the distance between the lower border of the mandible and the thyroid notch].

We examined the relationship between the degree of difficulty in visualization of the larynx and the distance from the lower border of the mandible to the thyroid notch (M-T distance). Patients were examined and the M-T distance was measured with their neck fully extended during preoperative period. Difficulty of laryngoscopy was graded as reported previously. Five hundred sixty one patients were assessed, and those with obvious neck and head pathology were excluded. There were 440 cases (78.4%) in grade 1, 116 cases (20.7%) in grade 2 and only 5 cases (0.9%) in grade 3. There were no grade 4 cases. The M-T distance was 5.4 +/- 0.6 cm in grade 1, 4.6 +/- 0.7 cm in grade 2 and 3.6 +/- 0.7 cm in grade 3. These were significantly different with each other (P < 0.05). If the M-T distance is 4.5 cm or less, the difficulty in visualization of laryngoscope increases. Therefore, in the case in which the M-T distance is 4.5 cm or less, we recommend further examination and preparation for difficult laryngoscopy.

Forecasting↗
PubMed1997

Does distance between home and transplantation center adversely affect patient outcomes after heart transplantation?

BACKGROUND: The emergence of heart transplantation referral centers, in an era of cost-conscious managed care programs, frequently leads to long-distance patient consultation and care. The purpose of this project was to review one center's experience regarding the effect of long distances from home to transplantation hospital on outcomes. METHODS: Three hundred twelve adult, noninternational, transplant recipients surviving at least 3 months were assessed for 10 events: rejection episodes, number of endomyocardial biopsies, emergency department visits, hospital admissions, return to full-time work or school, infections, coronary allograft vasculopathy, malignancies, retransplantation, and death. Presence of a locally involved physician was also determined. Distance from the transplantation center was analyzed in three discrete groups: 0 to 150 miles (n = 207), 151 to 300 miles (n = 69), and >300 miles (n = 36). RESULTS: There were no differences among the groups in mean length of follow-up (40.6, 36.9, 39.0 months, p = 0.27) or number of biopsies (20.5 +/- 0.16, 18.3 +/- 1.1, 18.0 +/- 1.1, p = 0.07). As the distance increased from the transplantation center, there was no greater incidence of adverse outcomes. Cellular rejection was the same among the groups (45%, 45%, 36%, p = 0.58). Likewise, emergency department visits and hospital admissions also did not vary: (9.7%, 5.8%, 8.3%, p = 0.61) and (22.2%, 13.0%, 16.7%, p = 0.23, respectively). There were no differences in the incidence of coronary vasculopathy (9.2%, 11.6%, 13.9%, p = 0.63). More importantly, the three groups did not differ in death/retransplantation rates (3-year survival, 84.5, 94.0 and 86.9, p = 0.14). Patients cared for by a local physician in addition to their transplant cardiologist had better survival rates than patients without a local physician (3-year survival rate, 90.7 vs 72.6, p = 0.0008). CONCLUSIONS: Long-distance management of heart transplant recipients is successful and is not associated with an increase in adverse outcomes. By itself, distance should not represent a contraindication to transplantation. Patients should be encouraged to maintain contact with a local physician, in addition to the regularly scheduled visits at the transplantation center.

Adolescent↗
PubMed1997

Electronic communication with patients. Evaluation of distance medicine technology.

OBJECTIVE: To evaluate controlled evidence on the efficacy of distance medicine technologies in clinical practice and health care outcome. DATA SOURCES: Systematic electronic database and manual searches (1966-1996) were conducted to identify clinical trial reports on distance medicine applications. STUDY SELECTION: Three eligibility criteria were applied: prospective, contemporaneously controlled clinical trial with random assignment of the intervention; electronic distance technology application in the intervention group and no similar intervention in the control group; and measurement of the intervention effect on process or outcome of care. DATA EXTRACTION: Data were abstracted by independent reviewers using a standardized abstraction form and the quality of methodology was scored. Distance technology applications were described in 6 categories: computerized communication, telephone follow-up and counseling, telephone reminders, interactive telephone systems, after-hours telephone access, and telephone screening. DATA SYNTHESIS: Of 80 eligible clinical trials, 61 (76%) analyzed provider-initiated communication with patients and 50 (63%) reported positive outcome, improved performance, or significant benefits, including studies of computerized communication (7 of 7), telephone follow-up and counseling (20 of 37), telephone reminders (14 of 23), interactive telephone systems (5 of 6), telephone access (3 of 4), and telephone screening (1 of 3). Significantly improved outcomes were demonstrated in studies of preventive care, management of osteoarthritis, cardiac rehabilitation, and diabetes care. CONCLUSIONS: Distance medicine technology enables greater continuity of care by improving access and supporting the coordination of activities by a clinician. The benefits of distance technologies in facilitating communication between clinicians and patients indicate that application of telemedicine should not be limited to physician-to-physician communication.

Communication↗
PubMed1998

Effect of source of cattle and distance transported to a commercial slaughter facility on carcass bruises in mature beef cows.

OBJECTIVE: To determine the effect of source of cattle and distance cattle were transported to a commercial slaughter facility on prevalence and severity of carcass bruises in mature beef cows. DESIGN: Epidemiologic investigation. SAMPLE POPULATION: Carcasses from 3,955 beef cows from 11 states assembled in 89 procurement lots. PROCEDURE: Each carcass was scored for bruise severity and location. Source of cattle was categorized. Distance from source to slaughter facility was determined. An ANCOVA was used to determine effects of variables on carcass bruises. RESULTS: Mature beef cows marketed through livestock auctions conducting first-point testing for brucellosis, especially when transported longer distances (> 325 km) to slaughter facilities, had a greater number and severity of carcass bruises than cows originating from ranches or livestock auctions not conducting first-point testing. There was an increase in number of rib bruises in cows originating from livestock auctions not conducting first-point testing. Prevalence and severity of bruises were not significantly affected by transportation distance between cows originating from auctions not conducting first-point testing and cows originating from ranches. CLINICAL IMPLICATIONS: A strong association existed between handling for brucellosis testing prior to sale for slaughter and distance transported to slaughter facility with carcass bruises in mature beef cows. Bruises are major quality defects that decrease carcass value and slaughter-cow prices. Repeated handling and restraint as well as long-distance transport are issues to consider regarding the responsibility of the livestock industry to provide for the safety and well-being of cattle sold for slaughter.

Abattoirs↗
PubMed1976

Muscle fiber composition and enzyme activities of elite distance runners.

Muscle biopsies were obtained from the gastrocnemius of 14 elite distance runners, 18 middle distance runners, and 19 untrained men. The middle distance runners were all highly trained, but had significantly slower performance times than the elite runners at distances greater than 3 miles. Fiber composition and mean cross-sectional areas were determined from muscle sections incubated for histochemical activity. A portion of the specimen was used to determine succinate dehydrogenase (SDH), lactate dehydrogenase (LD/Y and phosphorylase activities. All subjects were tested for maximal oxygen uptake on a treadmill. As previously demonstrated by others, the elite runners' muscles were characterized by a high percentage (79%) of slow twitch (ST) fibers. On the average, the crosssectional area of their ST fibers was found to be 22% larger than the FT fibers (P less than 0.05). SDH activity of whole muscle homogenates from elicte and middle distance runners was 3.4- and 2.8- fold greater, respectively, than that measured in the untrained men. Since the LDH and phosphorylase activities were similar for the runners and untrained men, it appears that training for distance running has little influence on the enzymes of glycogenolysis.

Glycolysis↗
PubMed1998

Isonymy and isolation by distance in Germany.

The isonymy structure of Germany was studied using the surname distributions of 5,150,310 private telephone users selected from 39,000,000 users registered in a 1996 commercial CD-ROM, which contains all telephone users in the country. The users were distributed in 106 towns selected on a geographic basis. Germany was subdivided into 50 adjacent rectangles, each 115 x 80 km, and at least the largest town in the rectangle was selected for study; the private telephone users in that district were downloaded from the CD-ROM and included in the analysis. The shortest distance between nearest neighbor towns was 10.7 km (Travemunde and Lübeck), and the largest distance was 69.8 km (Meppen and Osnabruck). The number of different surnames found in the whole analysis was 462,526. Lasker's distance, the negative value of the logarithm of isonymy between localities, was found to be linearly and significantly correlated with geographic distance (r = 0.51 +/- 0.010). A dendrogram was built with the matrix of isonymy distances, using UPGMA. This method separates the German towns into two main clusters, one in the southern half of the country and the other in the northern half. Within each cluster small subclusters with specific geographic distributions could be delimited. The two main clusters correspond fairly well to the north-south division of German sublanguages (Nieder- and Mitteldeutsch in the north vs. Frankisch-Alemannisch in the south). The other clusters are related to minor sublanguages. Comparisons with the results of a previous analysis of Switzerland's structure are given. From the present analysis isolation by distance emerges clearly, although it is less strong than in Switzerland and indicates that Germany has a fairly homogeneous isonymy structure. The random component of inbreeding estimated from isonymy indicates that eastern Germany is on average more inbred than western Germany.

CD-ROM↗
PubMed1998

Extraction of geometrically similar substructures: least-squares and Chebyshev fitting and the difference distance matrix.

In analysis, comparison and classification of conformations of proteins, a common computational task involves extractions of similar substructures. Structural comparisons are usually based on either of two measures of similarity: the root-mean-square (r.m.s.) deviation upon optimal superposition, or the maximal element of the difference distance matrix. The analysis presented here clarifies the relationships between different measures of structural similarity, and can provide a basis for developing algorithms and software to extract all maximal common well-fitting substructures from proteins. Given atomic coordinates of two proteins, many methods have been described for extracting some substantial (if not provably maximal) common substructure with low r.m.s. deviation. This is a relatively easy task compared with the problem addressed here, i.e., that of finding all common substructures with r.m.s. deviation less than a prespecified threshold. The combinatorial problems associated with similar subset extraction are more tractable if expressed in terms of the maximal element of the difference distance matrix than in terms of the r.m.s. deviation. However, it has been difficult to correlate these alternative measures of structural similarity. The purpose of this article is to make this connection. We first introduce a third measure of structural similarity: the maximum distance between corresponding pairs of points after superposition to minimize this value. This corresponds to fitting in the Chebyshev norm. Properties of Chebyshev superposition are derived. We describe relationships between the r.m.s. and minimax (Chebyshev) deviations upon optimal superposition, and between the Chebyshev deviation and the maximal element of the difference distance matrix. Combining these produces a relationship between the r.m.s. deviation upon optimal superposition and the maximal element of the difference distance matrix. Based on these results, we can apply algorithms and software for finding subsets of the difference distance matrix for which all elements are less than a specified bound, either to select only subsets for which the r.m.s.deviation is less than or equal to a specified threshold, or to select subsets that include all subsets for which the r.m.s. deviation is less than or equal to a threshold.

Algorithms↗
PubMed1998

Comparative assessment of distance processing and hemispheric specialization in humans and baboons (Papio papio).

This comparative study explored the ability to process distance and its lateralization in humans and baboons. Using a conditional matching-to-sample procedure in a divided-field format, subjects had to decide whether or not the distance between a line and a dot belonged to a short- or a long-distance category. Experiments 1, 2, and 4 demonstrated the ability of baboons to process and categorize distances. Moreover, humans showed better distance processing for right visual field/left hemisphere presentations than for left visual field/right hemisphere (LVF-RH) displays (Experiments 1-2). The same bias was found in baboons (Experiment 1), but in a weaker way. In Experiment 3, naive human individuals were tested and the difficulty of the discrimination was enhanced. There was a LVF-RH advantage which vanished with practice. Results are discussed by referring to theories (i.e., Kosslyn, 1987) of visuospatial processing for coordinate and categorical judgments.

Adult↗
PubMed1992

Apparent distance reduction with moving stimuli (Tandem Effect): evidence for an attention-shifting model.

When two vertical rods move through a horizontal window in close succession, the Tandem Effect can be observed. It consists of a spatial illusion (distance between the rods looking smaller than it actually is) and a temporal illusion (under certain conditions both rods are seen simultaneously in the window, though the first rod has left the window before the second rod enters it). We report six experiments that explored the distance-reduction illusion and tested an attentional model of the effect. It assumes that attention is initially focused on the first rod and then shifted to the second, when it enters the window. The percept of the pair of rods is integrated from the first rod's position at the beginning, and the second rod's position at the end, of the focus shift. Consequently their subjective distance will be smaller than their physical distance by the distance that they travel during the focus shift. Experiments 1 and 2 established the Tandem Effect as an empirical phenomenon and showed that its size depends on stimulus parameters such as window size and movement speed. Experiments 3-5 tested specific predictions from the attentional model. Experiment 6 examined a further illusion, the Fröhlich Effect, and showed that it can be subsumed under the model. The experiments produced some unexpected effects and some predictions from the model were only partly confirmed. It is shown that the main findings can be combined into two quantitative functions that describe the course of focusing. One implication is that visual attention does not "move" from one object to another; rather all attention shifts originate in the fovea. We discuss several alternative interpretations of our data and show that they are less satisfactory than the attentional model.

Adult↗