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PubMed1993

Plasma lactate accumulation and distance running performance. 1979.

Laboratory and field assessments were made on eighteen male distance runners. Performance data were obtained for distances of 3.2, 9.7, 15, 19.3 km (n = 18) and the marathon (n = 13). Muscle fiber composition expressed as percent of slow twitch fibers (%ST), maximal oxygen consumption (VO2max), running economy (VO2 for a treadmill velocity of 268 m/min), and the VO2 and treadmill velocity corresponding to the onset of plasma lactate accumulation (OPLA) were determined for each subject. %ST (R > or equal to .47), VO2max (r > or equal to .83), running economy (r > or equal to .49), VO2 in ml/kg min corresponding to the OPLA (r > or equal to .91) and the treadmill velocity corresponding to OPLA (r > or equal to .91) were significantly (p < .05) related to performance at all distances. Multiple regression analysis showed that the treadmill velocity corresponding to the OPLA was most closely related to performance and the addition of other factors did not significantly raise the multiple R values suggesting that these other variables may interact with the purpose of keeping plasma lactates low during distance races. The slowest and fastest marathoners ran their marathons 7 and 3 m/min faster than their treadmill velocities corresponding to their OPLA which indicates that this relationship is independent of the competitive level of the runner. Runners appear to set a race pace which allows the utilization of the largest possible VO2 which just avoids the exponential rise in plasma lactate.

Anaerobic Threshold↗
PubMed1995

Cardiovascular responses to exercise in sprinters and distance runners.

The purpose of this study was to examine the cardiovascular responses of sprinters and distance runners to isometric (IE) and dynamic exercise (DE). Normotensive males were selected and grouped according to prior running performance: sprinter (N = 6) or distance runner (N = 6). Each subject completed an incremental DE (cycle ergometry) test (6-min stages) at 20%, 40%, and 60% of VO2peak, and 3 min of isometric handgrip at 30% of MVC. Blood pressure (BP), heart rate (HR), cardiac output (Q), oxygen uptake, and blood lactate were measured, while mean arterial blood pressure (MABP), cardiac index (CI), and systemic vascular resistance (SVR) were calculated during each stage of DE. BP and HR were measured during each minute of IE. Muscle biopsies of the vastus lateralis revealed a significant difference in capillary density (capillaries per mm2 and capillaries per fiber) between the sprinters and distance runners (323 +/- 23 vs 409 +/- 27 and 2.2 +/- 0.2 vs 3.2 +/- 0.3, P < 0.05) and for the percentage of Type I fibers (46.4 +/- 4% vs 64.8 +/- 7%, P < 0.05). The IE challenge elicited a greater BP response at minute 3 in the sprinters, which was associated with a greater HR response. During DE, there were no significant differences in BP or HR between the groups. However, at 60% of VO2peak, the distance runners had a significantly higher cardiac index and a lower systemic vascular resistance than the sprinters (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2004

Effects of running distance and training on Ca2+ content and damage in human muscle.

PURPOSE: Muscle damage and soreness are well-known adverse effects of running, especially when covering distances in excess of habitual running activity. Loss of Ca homeostasis is hypothesized to initiate the development of exercise-induced muscle damage. We tested the hypothesis that the Ca content of vastus lateralis muscle increases after a 10- or 20-km run and studied the relations between Ca accumulation and running distance, endurance training, and fiber type distribution. METHODS: Twenty-four healthy young men and women were divided into two groups who ran either 10 or 20 km. Muscle biopsies and blood samples were collected before, immediately after, and in the days after the run. RESULTS: : The Ca content in muscle biopsies increased from 0.70 +/- 0.02 to 0.93 +/- 0.04 micromol x g wet weight after the 20-km run (P < 0.001) and was still significantly elevated at 4 and 48 h after the run. In the 10-km runners, however, no significant increase in Ca was found (0.81 +/- 0.03 vs 0.91 +/- 0.06 micromol x g wet weight, P = 0.08). Plasma levels of lactate dehydrogenase and creatine kinase increased after both running distances, the increase being greatest after the 20-km run. Eight of the 10-km runners completed an endurance-training program and subsequently repeated the 10-km run. The response to a new 10-km run with regard to muscle Ca content and parameters of muscle damage was essentially unchanged by training. CONCLUSIONS: The degree of muscle damage depends on running distance, and a significant Ca accumulation in muscle is seen after 20 km. Ten weeks of endurance training does not influence Ca homeostasis and muscle damage after 10-km running.

Analysis of Variance↗
PubMed1981

Estimation of inter-electrode distance for body surface mapping: application of Fourier analysis to potential distribution due to the epicardial breakthrough.

For the purpose of determining an appropriate distance of lead points for constructing body surface maps, Fourier analysis was performed on potential distribution reflecting the epicardial breakthrough, and inter-electrode distance necessary for sampling of harmonics contributing to the body surface potential distribution was determined by application of sampling theorem. Potential distribution was simultaneously recorded with an interval of 4 mm for 250 msec along the vertical (head to foot) and horizontal (right to left) line crossing a second-minimum appearing on the chest surface of a healthy adult, and the data obtained from 9.6 cm along the respective lines underwent Fourier transform. Relative contribution of the second harmonics to the original wave forms increased with time lapse after QRS initiation, in accordance with reductions of the first harmonics component, and attained the maximum (32.5% of total power spectrum without d-c component) at the instant of occurrence of the second-minimum. A similar tendency was observed among higher harmonics, but their contribution was comparatively low (within 10%). Inter-electrode distance determined by sampling theorem was 4.8 cm for the first harmonics and 2.4 cm for the second harmonics. In conclusion it is proposed that placement of electrodes with an inter-electrode distance of 2.4 cm is necessary for acquiring clinically important data on the epicardial breakthrough.

Electrocardiography↗
PubMed1995

Technical note: measuring the coracoclavicular distance with ultrasound--a new technique.

The distance between the clavicle and the coracoid process of the scapula is frequently assessed during the radiographic investigation of the acromioclavicular joint. This study defines an ultrasound technique (5 MHz real time linear array) for measuring the coracoclavicular distance, and determines its reliability and validity. A new ultrasonic technique was performed on 49 healthy subjects who had volunteered to participate in the study, having given signed, informed consent. The measuring endpoints for the coracoclavicular distance were the superior border of the clavicle and the superior border of the coracoid process. Three replicate scans were performed on each shoulder. The ultrasound measurements for 19 of the subjects were compared with the measurement obtained from a normal shoulder radiograph (which had previously been requested on clinical grounds). The data were subjected to analysis of variance (ANOVA) and the limits of agreement method of analysis. The mean difference between the radiograph and ultrasound measurements was 0.38 mm. The limits of agreement (95% confidence intervals) were -0.57 (-0.97, -0.17) and 1.33 (0.93, 1.73). Intraoperator and interoperator reliability were evaluated with a multifactor ANOVA and gave p = 0.7 for intraoperator reliability and p = 0.5 for interoperator reliability. The mean of the coefficients of variation for the two operators was 1.84%. The average range for repeated trials (same operator, same subject) was 1.35 mm. The maximum differences in the averages for each operator was 1.2 mm. The ultrasound technique described is a reliable, accurate and valid technique for evaluating the coracoclavicular distance and may usefully supplement the routine radiographic examination of the shoulder in patients presenting for radiographic examination of the acromioclavicular joint.

Acromioclavicular Joint↗
PubMed2006

Study of scattered radiation for in-air calibration by a multiple-distance method using ionization chambers and an HDR 192Ir brachytherapy source.

The aim of this study is to estimate the room-scatter correction when measuring air kerma rate of an HDR 192Ir brachytherapy source by in-air calibration. The variation in scattered radiation due to the specially designed jig and from the room walls was also studied. Two therapy ion chambers of volume 0.1 cm3 and 0.6 cm3 were used in the present study. Air kerma was measured by placing the source at several distances between 10 cm and 20 cm from the chamber. The scatter radiation was determined by superimposing the theoretically derived model curve of known scatter (based on the inverse square law) over the plot of measured air kerma strength values. The scatter radiation was estimated in terms of percentage of the primary radiation at 10 cm measurement distance. The scatter estimated by the 0.6 cm3 chamber at two positions was 0.33% and 0.59%, respectively. Similarly the scatter estimated at two other positions by the 0.1 cm3 chamber was 0.58% and 1.11%. This variation in scatter with position as well as with the chamber was due to the varying scatter contribution from components of the measurement set-up. The scatter radiation becomes constant at a distance greater than 100 cm from the walls of the room. We conclude that a fixed chamber with changing source positions should be used in multiple-distance measurement of air kerma rate when using a measurement jig.

Brachytherapy↗
PubMed2005

Three-dimensional display with a long viewing distance by use of integral photography.

We developed a technique of three-dimensional (3-D) display for distant viewing of a 3-D image without the need for special glasses. The photobased integral photography (IP) method allows precise 3-D images to be displayed at long viewing distances without any influence from deviated or distorted lenses in a lens array. We calculate elemental images from a referential viewing area for each lens and project the corresponding result images to photographic film through each lens. We succeed in creating an image display that appears to have three dimensionality even when viewed from a distance, with an image depth of 5.7 m or more in front of the display and 3.5 m or more behind the display. To the best of our knowledge, the long-distance IP display presented here is technically unique because it is the first report of generation of an image with such a long viewing distance.

Data Display↗
PubMed2006

Probe beam size effect on the measurement of the distance between the probe beam and the sample in photothermal deflection.

A distance-scan method to determine the distance between the probe beam and sample, which is not easily measured exactly, in photothermal deflection (PD) was reported, with which the distance and thermal diffusivity of the deflecting medium can be simultaneously measured. Probe beam size effect (PBSE) on PD phase signal was quantitatively analyzed to clearly show its physical meaning. The measured distance was experimentally verified as correct and reliable, and the measured thermal diffusivities of N2 and CO2 are in good agreement with the literature values. They could not be precisely measured by phase signal without considering the PBSE.

Journal Article↗
PubMed2004

Upper-body power as measured by medicine-ball throw distance and its relationship to class level among 10- and 11-year-old female participants in club gymnastics.

The purpose of this study was to determine whether or not a relationship existed between upper-body power and class level among female club gymnasts. Sixty female gymnasts between the ages of 10 and 11 and between class levels 5 and 8 participated in the study. The distance of a medicine-ball throw was used to measure upper-body power. Three types of throws--overhead forward throw, overhead backward throw, and chest pass--were performed with a 6-lb rubber medicine ball. The mean distances of 2 trails were calculated and categorized into age group and class level. An analysis of variance design was used to determine the relationship between mean throw distances and throw type, age, and class level. No significant differences were found between mean throw distances and throw type, age, or class level. The results of this study show no relationship between upper-body power of female gymnasts and throw type, age, and class level.

Analysis of Variance↗
PubMed2005

Normal-modes-based prediction of protein conformational changes guided by distance constraints.

Based on the elastic network model, we develop a novel method that predicts the conformational change of a protein complex given its initial-state crystal structure together with a small set of pairwise distance constraints for the end state. The predicted conformational change, which is a linear combination of multiple low-frequency normal modes that are solved from the elastic network model, is computed as a response displacement induced by a perturbation to the system Hamiltonian that incorporates the given distance constraints. For a list of test cases, we find that the computed response displacement overlaps significantly with the measured conformational changes, when only a handful of pairwise constraints are used (</=10). The performance of this method is also shown to be robust against different choices of pairwise distance constraints and errors in their values. This method, if supplied with the experimentally derived distance constraints (for example, from NMR or other spectroscopic measurements), can be applied to the analysis of protein conformational changes toward transient states.

Algorithms↗
PubMed2005

A non-Gaussian distribution quantifies distances measured with fluorescence localization techniques.

When single-molecule fluorescence localization techniques are pushed to their lower limits in attempts to measure ever-shorter distances, measurement errors become important to understand. Here we describe the non-Gaussian distribution of measured distances that is the key to proper interpretation of distance measurements. We test it on single-molecule high-resolution colocalization data for a known distance, 10 nm, and find that it gives the correct result, whereas interpretation of the same data with a Gaussian distribution gives a result that is systematically too large.

DNA↗
PubMed2006

Three-color alternating-laser excitation of single molecules: monitoring multiple interactions and distances.

We introduce three-color alternating-laser excitation (3c-ALEX), a fluorescence resonance energy transfer (FRET) method that measures up to three intramolecular distances and complex interaction stoichiometries of single molecules in solution. This tool extends substantially the capabilities of two-color ALEX, which employs two alternating lasers to study molecular interactions (through probe stoichiometry S) and intramolecular distances (through FRET efficiency E), and sorts fluorescent molecules in multi-dimensional probe-stoichiometry and FRET-efficiency histograms. Probe-stoichiometry histograms allowed analytical sorting, identification, and selection of diffusing species; selected molecules were subsequently represented in FRET-efficiency histograms, generating up to three intramolecular distances. Using triply labeled DNAs, we established that 3c-ALEX enables 1), FRET-independent analysis of three-component interactions; 2), observation and sorting of singly, doubly, and triply labeled molecules simultaneously present in solution; 3), measurements of three intramolecular distances within single molecules from a single measurement; and 4), dissection of conformational heterogeneity with improved resolution compared to conventional single-molecule FRET. We also used 3c-ALEX to study large biomolecules such as RNA polymerase-DNA transcription complexes, and monitor the downstream translocation of RNA polymerase on DNA from two perspectives within the complex. This study paves the way for advanced single-molecule analysis of complex mixtures and biomolecular machinery.

Base Sequence↗
PubMed2006

Distance measurements by fluorescence energy homotransfer: evaluation in T4 lysozyme and correlation with dipolar coupling between spin labels.

We demonstrate the feasibility and practical limitations of using steady-state anisotropy to determine distances from fluorescence homotransfer in the context of a protein of known crystal structure. Eight double mutants of T4 lysozyme spanning the distance range between 20 A and 50 A were labeled with a methanethiosulfonate derivative of fluorescein. The measured distances in liquid solution are in agreement with those determined from dipolar coupling between spin labels in the frozen state. They can be interpreted in the context of the crystal structure after accounting for the probe linking arm. Overall, the results establish the necessary calibration for this spectroscopic ruler. The measurement of similar distance trends using independent probes sets the stage for the complementary use of homotransfer and dipolar coupling in the determination of static structures and detection of conformational changes.

Anisotropy↗
PubMed1986

Ano-genital distance as a factor in determining puberty acceleration in mice.

The daily exposure of newly born female mice to the urine of lactating mice with a small ano-genital distance accelerated the onset of first oestrus while the urine from donors with a large ano-genital distance was without effect in advancing puberty. The rate of growth of the mice exposed to the urine of lactating mothers was greater than that of a control sample but it was only those mice exposed to the urine of lactating females with a small ano-genital distance which continued to grow, after the cessation of treatment at 21 days of age, at a faster rate. There was no difference in the mass of the uterus when the mice were killed when adult but there were significant age-dependent differences in the mass of the ovaries and adrenal glands. The mice exposed to the urine from lactating mothers (with both large and small ano-genital indices) had smaller ovaries than the control mice while the adrenal glands of mice exposed to the urine of lactating mothers with a large ano-genital index were of greater mass than those of the control mice and mice exposed to mothers with a small ano-genital distance. Exposure to the urine of lactating mothers had no effect on the subsequent activity of the mice when tested in an automated activity recorder. The results confirm that urine from lactating mothers accelerates the onset of puberty and suggests that the effects are restricted to the urine from mothers with a small ano-genital index.

Anal Canal↗
PubMed2005

Lifting strengths in different horizontal distances of objects to be lifted.

This study recruited eleven healthy males and thirteen healthy females to examine their maximum two-handed isometric back lifting strength, upper-body lifting strength, arm lifting strength and shoulder lifting strength in three different horizontal distances of objects to be lifted (toes were anterior to, aligned with, and posterior to the exerted handle). The results showed that human lifting strength decreased significantly as the toe position shifted from anterior of the vertical plane of the exerted handle to posterior of the vertical plane of the exerted handle. The strength order relationship between back lifting strength and upper-body lifting strength was dependent on the horizontal distance of objects to be lifted. This study also observed that the effects of the horizontal distance of objects to be lifted on human lifting postural angles for the four assessed lifting types mainly occurred in the upper extremities. This study recommends that practitioners should not overlook the effects of the horizontal distance of objects to be lifted on lifting strength when evaluating workers' lifting strength for screening purposes.

Adult↗
PubMed2004

Body size and flight distance in stingless bees (Hymenoptera: Meliponini): inference of flight range and possible ecological implications.

We examined the spatial implications of maximum flight distance for several species of stingless bees. Data suggested that maximum flight distance in Meliponini is a function of body size, especially generalized wing size, which can be estimated through principal component analysis. For six species of stingless bees, flight distances and generalized wing sizes were highly correlated (r = 0.938). This indicates that species of Meliponini occupy an effectively larger area as body size increases, which has important implications in the spatial dynamics of local populations restricted to forest fragments. We also used the fitted linear regression model to estimate the maximum flight distance for 12 other species of Meliponini. The results of this research may provide insights for future studies of biological conservation.

Animals↗
PubMedDate not supplied

Dimensional stability of distances between posterior teeth in maxillary complete dentures.

The aim of this study was to assess the displacement of posterior teeth in maxillary complete dentures stored in water at 37 degrees C. Twenty acrylic resin-based maxillary complete dentures were constructed with the anterior teeth arranged in normal overlap and the posterior teeth in Angle class I. Metallic pins were placed on the labial cusp of the first premolars (PM), and on the mesiolabial cusp of the second molars (M). The final acrylic resin pressing was made in a metallic flask with aid of the RS tension system, and polymerized in a moist-hot cycle at 74 degrees C for 9 hours. The dentures were deflasked after cooling in their own polymerizing water or after cooling in polymerizing water plus bench storage for 3 hours, and stored in water at 37 degrees C for periods of 7, 30, and 90 days. Following deflasking and after each storage period tested, the PM-PM (premolar to premolar), M-M (molar to molar), LPM-LM (left premolar to left molar), and RPM-RM (right premolar to right molar) distances were measured with an STM Olympus microscope, with an accuracy of 0.0005 mm. Collected data were submitted to ANOVA and Tukey's test (5%). There was no statistically significant difference for the PM-PM, M-M, and LPM-LM distances after all storage periods when the flask cooling methods were considered. With exception of the RPM-RM distance after the 30-days water plus bench storage period, the other distances remained statistically stable.

Acrylic Resins↗
PubMed2006

The effects of interimplant distances on papilla formation and crestal resorption in implants with a morse cone connection and a platform switch: a histomorphometric study in dogs.

BACKGROUND: Implant esthetics have been the focus of attention for the last few years, and one of the most important points is the effect that interimplant distances can have on papilla formation and bone loss. The aim of this study was to evaluate the effect that distances of 1, 2, and 3 mm between implants after prosthetic restoration will have on crestal bone resorption (from the top of the implant to the bone crest [TI-BC]) and bone resorption (from the top of the implant to the first bone-to-implant contact TI-BIC) in two-stage implants used in a submerged and non-submerged protocol. METHODS: The mandibular bilateral premolars of seven dogs were extracted, and after 12 weeks, each dog received eight implants. The implants were placed so that three interimplant contact points were created, with 1-mm (group 1), 2-mm (group 2), and 3-mm (group 3) distances constructed on each side. The sides and the position of the groups were randomly selected. After 12 weeks, the implants received metallic prostheses with 5 mm between the contact point and the bone crest. After 8 weeks more, the animals were sacrificed. RESULTS: The TI-BC was 0.20 and 0.18 mm for group 1, 0.15 and 0.14 mm for group 2, and 0.15 and 0.15 mm for group 3 for non-submerged and submerged implants, respectively. At the proximal region, the TI-BC was 0.16 mm for non-submerged and 0.16 mm for submerged implants. The TI-BIC was 0.32 and 0.30 mm for group 1, 0.19 and 0.21 mm for group 2, and 0.30 and 0.24 mm for group 3 for non-submerged and submerged implants, respectively. At the proximal region, the TI-BIC was 0.26 mm for non-submerged and 0.25 mm for submerged implants. There was no statistical difference for any of the parameters (analysis of variance [ANOVA]). CONCLUSION: Distances of 1, 2, and 3 mm between implants do not result in statistically significant differences on TI-BC and TI-BIC around submerged or non-submerged implants with a Morse cone connection and a platform switch.

Alveolar Bone Loss↗