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PubMed1988

Between and within subject variation of the first phase insulin response to intravenous glucose.

Eight normal subjects underwent two intravenous glucose tolerance tests to determine the between and within subject variation of the first phase insulin response. Variability was represented by the coefficient of variation. The between subject variation for the incremental 0-10 min insulin area was 58%, and the within subject variation was 22% (median value), range 3-55%. The variation of the first phase response expressed in four different ways was compared. The total and incremental (above fasting levels) 0-10 min areas provided less variable results (variation 52 and 58%) than the 1 + 3 min insulin levels (variation 72%) or mean of the incremental 3-5 min insulin levels (variation 66%). The ratio of the incremental 0-10 min insulin to glucose areas was as variable (variation 53%) as the insulin responses alone. The variability of insulin responses to intravenous glucose severely limits their value as early predictors of B-cell failure.

Adult↗

PubMed2003

Respiratory variations in the reflection mode photoplethysmographic signal. Relationships to peripheral venous pressure.

Photoplethysmography (PPG) is a non-invasive optical way of measuring variations in blood volume and perfusion in the tissue, used in pulse oximetry for instance. Respiratory-induced intensity variations (RIIVs) in the PPG signal exist, but the physiological background is not fully understood. Respiration causes variations in the blood volume in the peripheral vascular bed. It was hypothesised that the filling of peripheral veins is one of the important factors involved. In 16 healthy subjects, the respiratory synchronous variations from a PPG reflection mode signal and the peripheral venous pressure (PVP) were recorded. Variations of tidal volume, respiratory rate and contribution from abdominal and thoracic muscles gave significant and similar amplitude changes in both RIIV and the respiratory variation of PVP (p<0.01). The highest amplitudes of both signals were found at the largest tidal volume, lowest respiratory rate and during mainly thoracic breathing, respectively. The coherence between PVP and RIIV signals was high, the median (quartile range) being 0.78 (0.42). Phase analysis showed that RIIV was usually leading PVP, but variations between subjects were large. Although respiratory-induced variations in PVP and PPG showed a close correlation in amplitude variation, a causal relationship between the signals could not be demonstrated.

Adult↗

PubMed2000

Variability of tear protein levels in normal young adults: between-day variation.

BACKGROUND: An adequate knowledge of physiological variation is important for valid comparative studies of tear proteins. The aim of this study was to investigate the between-day variation of the human tear protein levels, including the total protein concentration (TPC) and the levels of major protein fractions. Two sampling methods, the yawn and the eye-flush methods, were used and compared. METHODS: TPC was determined by the Bradford method. The major protein fractions were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and their levels were determined by scanning densitometry after SDS-PAGE. The tear protein levels were monitored for 3 days. RESULTS: The between-day differences in the levels of TPC and the individual protein fractions were not statistically significant in either sampling method, but the variations of some proteins were large and would be clinically significant. Different variations were observed in different proteins. The variations in serum albumin were large, up to 61% and 113% in the yawn and eye-flush methods respectively. The variations in lactoferrin, tear-specific prealbumin and lysozyme were relatively small in the yawn method. The variations in protein levels obtained by the eye-flush method were generally higher than by the yawn method. CONCLUSION: Although the between-day differences in tear protein levels were not statistically significant, the variations in some proteins would be large in magnitude. The variability of tear protein levels obtained by the eye-flush method was larger than that by the yawn method. Therefore, caution should be taken if the eye-flush method is used for sampling tears for quantitative analysis of tear proteins, although it is easier to collect tear samples using this method. The results will be useful to exclude normal variation in tear protein levels when comparing pre- and post-therapeutic tear protein levels in eyes treated for tear-related abnormalities.

Adult↗

PubMed1993

Prediction of the antidepressant response to total sleep deprivation of depressed patients: longitudinal versus single day assessment of diurnal mood variation.

The relationship between diurnal variation of mood and the clinical response to total sleep deprivation (TSD) was investigated in 43 depressed patients. The question asked was whether the propensity to produce diurnal variations of mood or the actual mood course on the day before TSD determines the clinical response to TSD. Patients rated their mood three times daily during an experimental period of 56 days. The frequency as well as the amplitude of daily mood changes were assessed during this period. For each patient six TSDs were scheduled: two after days with a positive mood course, two after a negative mood course, and two after days without a diurnal change of mood. This strategy allowed comparisons of TSD responses within patients. Moreover, longitudinally and retrospectively assessed diurnal variation were compared with each other. It was found that patients vary largely in the occurrence of diurnal variations of mood. The propensity to produce diurnal variations either in terms of frequency or amplitude was positively correlated with the response to TSD. Within patients no differences were found in responses to TSDs applied after days with diurnal variations (positive or negative) or without diurnal variations. A second aim was to get more insight into the mechanism relating diurnal variations of mood and the TSD response. Therefore, the interrelatedness of various measures of diurnal variations, such as amplitudes and frequencies of positive or negative diurnal mood changes, was studied, as well as the relationships of these variables with TSD responses. On the basis of the strong interrelatedness it is suggested that they all reflect the same underlying mechanism, to be symbolized by an oscillator, producing positive daily fluctuations of mood.

Adult↗

PubMed1976

Daily variation of lipids and hormones in sera of healthy subjects.

The physiological day-to-day variation of selected hormone and lipid concentration values in sera of healthy subjects was studied. We drew blood specimens from 14 healthy volunteers, aged 22 to 40 years, (8 male and 6 female) at 0800 h on six separate days over a ten day interval. On one occasion all the twelve specimens from each subject (6 days X 2 replicates) were assayed for the hormones: thyroxine and cortisol; and the lipips: cholesterol and triglyceride which were analyzed by enzymatic methods. The assays were performed on one occasion in order to eliminate the batch-to-batch analytical variation which would tend to blur the physiological day-to-day variation. Using an analysis of variance technique, the total variation was separated into the physiological intraindividual day-to-day variation, the biological inter-individual variation, and the within-batch analytical variation. The mean physiological day-to-day variations in terms of percent coefficient of variation were 7.5% for thyroxine, 26.6% for cortisol, 4.8% for cholesterol, , and 25.0% for triglycerides.

Adult↗

PubMed1996

Methods for investigating the sensitivity of joint resultants to body segment parameter variations.

Two methods are presented for determining the sensitivity of joint resultants to variations in body segment parameters (BSPs) when solving inverse dynamics problems: the exact sampling method (ESM), and the approximate variational method (AVM). These methods are illustrated by applying them to a single segment in fixed-axis rotation. The results indicate that (a) the AVM provides first-order (linear) approximations to the total variations in joint resultants obtained when using the ESM, (b) the ESM should be used when BSP variations become large and higher-order terms in these variations can no longer be ignored as negligible in the BSP-dependent expansions for the joint resultants, (c) small percent variations in BSPs can propagate into considerably larger percent variations in the joint resultants obtained when solving inverse dynamics problems, and (d) if BSP variations are sufficiently small to allow nonlinear terms in these variations to be ignored as negligible, the AVM is much simpler and easier to use than the ESM.

Algorithms↗

PubMed1989

Urethral pressure variations diagnosed by multiple urethral pressure transducers. A common phenomenon in women suffering from urinary incontinence.

The prevalence of urethral pressure variations (variation of urethral pressure greater than 15 cm H2O) was investigated, with the use of a data-based multitransducer catheter, in female patients suffering from urinary incontinence. Urethral pressure variations were diagnosed in 45 (63%) of 71 patients. This prevalence was greater than in previous studies, possibly for methodological reasons; the urethral pressure was simultaneously measured by five urethral microtransducers, thereby registering all variations in maximal urethral pressure. The present method also showed that urethral pressure variations were simultaneously present in different urethral sites, but that the amplitude of variation differed between the different points of registration. In most cases, urethral pressure variations were already apparent at the start of urethrocystometry. Voluntary holding, in an effort to inhibit the desire to void, can cause these variations in urethral pressure. Hence urethral pressure variations may be a normal physiological phenomenon.

Female↗

PubMedDate not supplied

Sources of variation in the mutagenic potency of complex chemical mixtures based on the Salmonella/microsome assay.

Twenty laboratories worldwide participated in a collaborative trial sponsored by the International Programme on Chemical Safety on the mutagenicity of complex mixtures as expressed in the Salmonella/microsome assay. The U.S. National Institute of Standards and Technology provided homogeneous reference samples of urban air and diesel particles and a coal tar solution to each participating laboratory, along with samples of benzo[a]pyrene and 1-nitropyrene which served as positive controls. Mutagenic potency was characterized by the slope of the initial linear component of the dose-response curve. Analysis of variance revealed significant interlaboratory variation in mutagenic potency, which accounted for 57-96% of the total variance on a logarithmic scale, depending on the sample, strain and activation conditions. Variation among replicate extractions of organic material (required for the air and diesel particles) and among replicate bioassays within the same laboratory was also appreciable. The average potencies for air and diesel particles in laboratories using Soxhlet extracts were not significantly different from those in laboratories using sonication, although there was larger interlaboratory variation for the Soxhlet method. Repeatability (which approximates the coefficient of variation within laboratories) ranged from 18 to 40% for air and diesel particles extracted using sonication, depending on the strain and activation conditions. Repeatability of Soxhlet-extracted air and diesel particles, however, ranged from about 37 to 89% including outliers and from about 11 to 31% excluding outliers. Repeatability of the coal tar sample and the 2 positive controls was in the range 18-34%. Reproducibility (which approximates the coefficient of variation between laboratories) was generally at least twice repeatability, and exceeded 100% for Soxhlet-extracted air and diesel particles, as well as 1-nitropyrene. Reanalysis of the data omitting observations of more than 1500 revertants/plate generally had little effect on these results. Elimination of outlying observations had limited impact, with the exception of Soxhlet-extracted air and diesel particles. In this case, reproducibility of bioassay results was notably improved, due largely to the omission of results for replicate extractions which varied more than 5-fold within one laboratory. Normalization of the log potency slopes for the mixtures by the corresponding slopes for benzo[a]pyrene tended to reduce this variation, although variation was increased after normalization by 1-nitropyrene. Adjustment for the percentage of organic matter extracted from the air and diesel particulate samples had little effect on variation for sonication-extracted particles, whereas variation was reduced for diesel particles and increased for air particles for Soxhlet.

Air Pollutants↗

PubMed1987

Estrogen and progesterone receptor assays in human breast cancer: sources of variation between laboratories.

The importance of cytosol preparation as a source of inter-laboratory variation in estrogen (ER) and progesterone (PR) receptor measurements was evaluated together with protein measurements and receptor assays for five laboratories in Sydney, Australia, using pooled, fragmented human breast cancer samples. Protein measurement was only a minor source of variation between the laboratories with a CV of 13%. For ER measurements, sources of variation due to either assay or cytosol preparation methods contributed 40 and 39% CV each. However, the variation due to assay method was reduced to 25% CV when the results from one laboratory with a known effect of a different ER assay protocol were excluded, suggesting that assay standardization could readily reduce this source of variation. In contrast, the source of a large cytosol error (39% CV) could not be identified. Variations in PR results were similar to ER, but the sources could not be accurately estimated. It is concluded that cytosol preparation as well as assay methods were major sources of between laboratory variation and need to be further investigated and standardized. This approach should reduce these sources of variation since it was found that the within laboratory cytosol and assay variations were only 13 and 18% CV, respectively, for the ER measurements.

Breast Neoplasms↗

PubMed1994

Free oxygen radicals contribute to platelet aggregation and cyclic flow variations in stenosed and endothelium-injured canine coronary arteries.

OBJECTIVES: The purpose of this study was to test the hypothesis that free oxygen radicals contribute to platelet aggregation and cyclic flow variations in stenosed and endothelium-injured coronary arteries. BACKGROUND: Although free oxygen radicals, such as superoxide anion and hydrogen peroxide, have been shown to alter platelet function in vitro, the potential role of free oxygen radicals has not been fully described in an in vivo model of coronary artery thrombosis. METHODS: Cyclic flow variations were produced in dogs by an external constrictor placed at the site of the left anterior descending coronary artery with injured endothelium. Blood flow in this artery was monitored by a pulsed Doppler flow probe. If cyclic flow variations were observed during postoperative days, dogs intravenously received superoxide dismutase plus catalase. In anesthetized dogs that did not develop an episode of cyclic flow variations, the effect of intracoronary infusion of xanthine plus xanthine oxidase or hydrogen peroxide on arterial blood flow velocity was studied. In platelet studies, the effect of free oxygen radicals and radical scavengers on platelet aggregation was examined. RESULTS: In conscious dogs with cyclic flow variations, superoxide dismutase plus catalase significantly reduced cyclic flow variations (n = 7), whereas saline infusion had no effect (n = 7). The infusion of xanthine plus xanthine oxidase or hydrogen peroxide significantly induced cyclic flow variations in four of six dogs or in five of seven dogs, respectively. In vitro platelet studies showed that xanthine plus xanthine oxidase or hydrogen peroxide significantly enhanced platelet aggregation, and superoxide dismutase or catalase significantly inhibited such aggregation. CONCLUSIONS: Reduction of free radical formation decreases platelet aggregation and may eliminate cyclic flow variations, whereas promotion of free radical generation enhances platelet aggregation and may induce cyclic flow variations. Thus, free oxygen radicals are an important mediator in this model.

Animals↗

PubMed2005

Intra- and inter-speaker variations of formant pattern for lateral syllables in Standard Chinese.

Speech variation of speakers is a crucial issue for speaker recognition and identification, especially for forensic practice. Greater intra-speaker variation is one main reason for incorrect speaker identification in real forensic situations. Understanding the stability of acoustic parameters and their variation in speech is therefore significant for the evaluation of effective parameters for speaker identification. In this paper, all vowels in Standard Chinese including five monophthongs, eight diphthongs and four triphthongs were combined with lateral /l/. Finally, 15 lateral syllables with different tones for 10 speakers were selected and acoustically analyzed. Central frequencies of the first four formants for each syllable were measured for quantitative comparison of intra- and inter-speaker variation in order to provide a general idea of speaker variation in Standard Chinese, and finally serving for forensic application. Results show that the overall intra-speaker variation is less than the inter-speaker variation in great extent under laboratory condition though occasionally they are contrary. This supports the basis for forensic speaker identification, that is, intra-speaker variation should be less than inter-speaker variation in many acoustic features, and further validates the probability and reliability of forensic speaker identification.

Adult↗

PubMed2006

Diel mercury-concentration variations in streams affected by mining and geothermal discharge.

Diel variations of concentrations of unfiltered and filtered total Hg and filtered methyl Hg were documented during 24-h sampling episodes in water from Silver Creek, which drains a historical gold-mining district near Helena, Montana, and the Madison River, which drains the geothermal system of Yellowstone National Park. The concentrations of filtered methyl Hg had relatively large diel variations (increases of 68 and 93% from morning minima) in both streams. Unfiltered and filtered (0.1-microm filtration) total Hg in Silver Creek had diel concentration increases of 24% and 7%, respectively. In the Madison River, concentrations of unfiltered and filtered total Hg did not change during the sampling period. The concentration variation of unfiltered total Hg in Silver Creek followed the diel variation in suspended-particle concentration. The concentration variation of filtered total and methyl Hg followed the solar photocycle, with highest concentrations during the early afternoon and evening and lowest concentrations during the morning. None of the diel Hg variations correlated with diel variation in streamflow or major ion concentrations. The diel variation in filtered total Hg could have been produced by adsorption-desorption of Hg2+ or by reduction of Hg(II) to Hg0 and subsequent evasion of Hg0. The diel variation in filtered methyl Hg could have been produced by sunlight- and temperature-dependent methylation. This study is the first to examine diel Hg cycling in streams, and its results reinforce previous conclusions that diel trace-element cycling in streams is widespread but often not recognized and that parts of the biogeochemical Hg cycle respond quickly to the daily photocycle.

Environmental Monitoring↗

PubMed2001

Physiological variation in insects: hierarchical levels and implications.

Variation, and in particular regular pattern in that variation, forms the foundation for evolutionary physiology. Nonetheless, with the exception of seemingly good fits between the tolerances of animals and the environments they live in, this variation is often not well explored. Here, three examples of different forms of such variation (both large- and small-scale) in a range of physiological traits in insects are explored. In the first example, I show that at global, regional, and local scales, variation in insect upper lethal temperatures is far less variable than variation in lower lethal temperatures, and that upper and lower tolerances are partially decoupled. Second, I demonstrate that variation in upper and lower lethal limits, desiccation resistance and tolerance, and respiration rate are often partitioned at taxonomic levels above that of the species. In other words, there is considerable phylogenetic constraint in the evolution of the responses of insects to the environment. These findings suggest that several ideas regarding insect physiological adaptations might have to be re-examined. They also suggest that approaches using both "raw" and corrected data should be adopted where possible. Finally, I demonstrate that there is considerable intra-individual variation in the characteristics of insect discontinuous gas exchange cycles. This is perhaps well-known to researchers in the field, but the implications thereof for arguments in favour of the adaptive nature of these regular cycles have not been carefully examined. Together, these findings suggest that there is still much to be learned about variation in insect physiological traits.

Journal Article↗

PubMed2000

No seasonal variation of insulin sensitivity and glucose effectiveness in men.

Insulin resistance is of pathogenetic importance for the development of non-insulin-dependent diabetes mellitus (NIDDM). However, not much is known about the variation in insulin sensitivity in the individual over longer periods. Consequently, we measured insulin sensitivity (Si) and glucose effectiveness (Sg) in healthy young men (N = 10) 5 times over a period of 15 months using a frequently sampled intravenous glucose tolerance test (FSIVGTT) with minimal-model analysis (study of seasonality). The maximal aerobic capacity (V(O2)max), fat-free mass, body mass index (BMI), and 24-hour ambulatory blood pressure (BP) were also assessed. Furthermore, we performed a study designed to evaluate the day-to-day variation in Si and Sg (study of day-to-day variation). Here, we studied Si and Sg in healthy young men (n = 8) within 2 weeks. In the study of seasonality, the coefficient of variation (CV) for Si was 24.0%, whereas the CV for Sg was 26.0%. Anticipating a seasonal variation in Si following a sine curve with a cycle length of 1 year and an unknown phase and amplitude, we tested this hypothesis with a multiple linear regression model that allows for different levels of Si between individuals, and failed to detect any impact due to this. Si (mean +/- SD, 1.17 +/- 0.28 x 10(-4) x min(-1) x pmol/L(-1), P = .38), Sg (0.023 +/- 0.006 min(-1), P= .71), fasting insulin (21.2 +/- 7.3 pmol/L, P= .98), V(O2)max (3.8 +/- 0.6 L/min, P= .13), and fat-free mass (64.9 +/- 2.5 kg, P = .92) were constant over time. In the study of day-to-day variation, we found a CV for Si of 17.3% and a CV for Sg of 23.3%. In conclusion, we found that the variations in Si and Sg were slightly higher than those found in studies performed to establish the day-to-day variation. However, no significant seasonal variation in Si and Sg was evident in this group of healthy young lean caucasian men. Consequently, indices of Si and Sg obtained at different times of the year appear comparable.

Adult↗

PubMed1999

Long-term variations of man-made radionuclide concentrations in a bio-indicator Mytilus galloprovincialis from the French Mediterranean coast.

Results from a 14-year monitoring (1984-1997) of man-made radionuclide (137Cs and 106Ru) levels in Mytilus galloprovincialis collected monthly on the French Mediterranean coast are presented. In this area sources of man-made radionuclides are on the one hand atmospheric fallout from both the past nuclear testings and the Chernobyl accident and on the other hand discharges from nuclear installations located on the Rhône River banks, especially those from the spent nuclear fuel reprocessing plant in Marcoule. Long-term variations of radionuclide concentrations in Mytilus demonstrated seasonal variations which are linked to the reproductive cycle of these organisms as well as to variations in land-based inputs of man-made radionuclides. A comparative study of these seasonal variations has been carried out with the aid of spectral analysis. Due to differences in released activities and discharge patterns, flow rates appear to govern mainly the 137Cs variations in the Rhône waters, whereas 106Ru variations are driven by the discharges. In the area under the influence of the Rhône outflow, 137Cs variations in mussels are characterized by seasonal variations which are themselves inversely correlated with variations of 137Cs concentrations in Rhône waters. This cyclic component seems to be closely linked to the mussel reproductive cycle. The possible influence of other parameters is discussed.

Animals↗

PubMed1997

The role of the ostiomeatal unit anatomic variations in inflammatory disease of the maxillary sinuses.

OBJECTIVE: The purpose of the study was to determine the correlation between bony anatomic variations of the ostiomeatal unit (OMU) and chronic maxillary sinusitis. The study was based on the hypothesis that the mucosal contact caused by the variations represents the critical factor in increasing the risk of maxillary sinusitis. MATERIALS AND METHODS: Thin section high resolution computerised tomography (CT) examinations of the paranasal sinuses in 73 consecutive patients with 113 anatomic variations of the OMU were retrospectively reviewed. The following CT features were assessed: (1) Type of anatomic variations, (2) presence of a mucosal contact in the OMU and (3) presence of maxillary disease. Statistical evaluation was carried out using chi 2-test. RESULTS: The following bony anatomic variations were found: Concha bullosa (67 cases), abnormalities of the uncinate process (18 cases), Haller's cells (24 cases) and large ethmoidal bulla (four cases). Only 52 of the 113 anatomic variations were associated with ipsilateral maxillary disease (mucosal thickening, mucous retention cysts, polyps, retained secretions). Of 113 variations, 44 caused a mucosal contact, 35 of these were associated with maxillary abnormalities, while in nine cases there were no pathologic changes. Of 69 variations, 17 did not cause mucosal contact (P < 0.05). CONCLUSION: Our data shows that, in the presence of anatomic bony variations, a contact between the mucosal surface of the OMU is valuable in predicting the likelihood of a maxillary inflammatory disease.

Adolescent↗

PubMed2000

Variation in caries and treatment experience in 35-44-year-old Lithuanians.

Data summarising caries levels differ between countries and often conceal large variations. These differences may reflect variations at individual, group, social and other levels. Caries and treatment experience differences are found to be significantly related to a variety of clinical and non-clinical factors. Variation in caries within Lithuanian children has been reported and related to background-, behavior-, dental care- and other factors. Variation in general or related to any factors in adult Lithuanian population has not been studied. The aim of the present study was to estimate variation in caries and treatment experience and relate them to biological-, psychosocial-, health-related, behavioral- and dental care related aspects. The existing knowledge from other oral health studies was used to select the factors found of importance in relation to variations in caries scores. The study consisted of clinical and self-reported data collected from a stratified random sample of 382 individuals (attendance rate 50%). Two statistical approaches, a bivariate and a multivariate, were applied. The two dependent variables DMFT and DS were tested with a set of independent variables. The bivariate analysis revealed significant associations for approximately one half of all variables studied. For multivariate testing, a backward linear multiple regression was used. Forty-one percent of the variation in DS was explained and 48% in DMFT scores. Differences in scores were related to various factors in the two analyses. The strength and significance of a few relationships differed in both of the analyses. The multivariate testing revealed some strong and significant associations with independent variables which were found to be weak and non-significant (P>0.05) when tested bivariately and vice versa. Less than half of the variation could be explained in dental caries scores in 35-44-year-olds and not only dental care related factors were important. In both of the analyses, the varying degrees of strength (significance levels) give rise to a hypothesis that this incomplete explanation of the variation can be due to interrelated effects of different estimates.

Adult↗

PubMed1999

Short-term variations in oscillatory and spirometric lung function parameters of non-asthmatic adults.

Oscillatory respiratory resistance (Rrsfo) at 8 Hz was compared to flow-volume spirometry with regard to immediate, within-day, day-to-day and week-to-week variations in seven female and four male non-smoking, non-asthmatic volunteers. The lung functions were measured at 08:00, 12:00, 16:00 and 20:00 h on each of the four study days, i.e. two consecutive days in two consecutive weeks. During each visit there were three immediately repeated measurements of Rrsfo, followed by three spirometric recordings. The intra-subject coefficient of variation (Coeffvar) for the immediately repeated measurements was largest for Rrsfo (11.8%). When a simple reliability index (+/- 2 SD of the differences between the repeated measurements) was applied to the Rrsfo data, the Coeffvar reduced to 7.5%. In spirometry, the airflow parameters at defined lung volumes showed larger immediate variations (MEF50 = 5.6%, MEF25 = 8.3%, MMEF = 4.4%) than FEV1 (1.5%) and PEF (3.2%). The within-day variations were larger than the day-to-day or week-to-week variations, and the variations were largest in Rrsfo. A significant diurnal pattern was shown in spirometric parameters but not in Rrsfo. About 38% of the total variance in Rrsfo was due to variation within subjects, while the corresponding proportions in spirometric parameters were 1.8-18.4%. In conclusion, Rrsfo showed larger intrasubject variations than the spirometric parameters at all time intervals. Application of a simple reliability index and standardization of the time of day of the measurement reduced the variations and improved the quality of the Rrsfo data.

Adult↗