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PubMed1995

The effect of knee and foot position on the electromyographical activity of the superficial quadriceps.

Isometric quadriceps exercises are used early in knee rehabilitation. Varying knee or foot position is hypothesized to selectively activate specific quadriceps muscles. This study examined the activities of the vastus medialis oblique, vastus lateralis, and rectus femoris during isometric contractions at 90 degrees, 150 degrees, and 175 degrees knee angles with internally rotated, neutral, and externally rotated foot positions. Subjects performed three perceived maximal isometric contractions at each knee angle/foot position while electromyographic activity (EMG) was collected. Statistical analysis consisted of a three-way repeated measures multiple analysis of variance, with post hoc analysis as was appropriate. Although no significant differences were detected among foot positions for the rectus femoris at 90 degrees, this knee angle produced significantly greater EMG activity for the neutral position compared with 150 degrees or 175 degrees. The 90 degrees angle was also superior to 175 degrees for the externally rotated position. The results for both the vastus medialis and vastus lateralis were similar, with the 90 degrees angle producing greater EMG activity than 175 degrees in the externally rotated position. In addition, the neutral position produced significantly more activity than the internally rotated position at 90 degrees. At 150 degrees, the neutral position was superior to the externally rotated position. Finally, at the 175 degrees knee angle, the highest level of EMG activity was with the foot internally rotated. Considering the combination of effects for EMG activity across all muscles tested, the 90 degrees knee angle with a neutral foot position may provide the most effective condition for rehabilitation of all muscles tested.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Evidence for genetic basis of seasonal differences in antibody formation between two mouse strains.

In order to confirm the presence of an acrophase difference based upon genotype in the seasonal expression of an immune competence end point, splenic plaque-forming cell (PFC) response to sheep red blood cells (SRBC), female B6C3F1 and CD1 mice were concurrently studied for PFC response during two studies performed in each season for 1 year. Mice were multiply housed, fed ad libitum, and standardized to light (06:00-18:00); dark (18:00-06:00). For each strain and study, subgroups were either naive (n = 10), received a vehicle (n = 10) or Cytoxan (n = 5). Challenge with SRBC occurred in early afternoon 4 days before harvesting of spleens and PFC assay. All other procedures were performed early in the daily light span. Analysis of variance and single cosinor analysis revealed a significant seasonal time effect for PFC in naive mice of both strains. Antibody formation was greatest in spring for CD1 mice and in summer for the B6C3F1 mice. These acrophases were consistent with earlier results for both strains and show the phenomena to be reproducible and genetically based.

Analysis of Variance↗
PubMedDate not supplied

A multimethod assessment of social intervention effects on narcotics use and property crime.

Log-linear modeling, structural equation modeling, repeated measures analysis of variance, and time series analysis are discussed for their utility in evaluating the temporal effects of social interventions. Methods are illustrated by applications examining the independent and joint temporal effects of methadone maintenance treatment and legal supervision on narcotics use and property crime among narcotics addicts. Convergent results from a multimethod assessment of the issue show that methadone maintenance has long-term and short-term suppressive effects on narcotics use and property crime. More complicated but complementary findings have been found in evaluating the effectiveness of legal supervision.

Analysis of Variance↗
PubMed1999

Variation in movement traces of the kinematic center of the temporomandibular joint.

AIM: The purpose of this study was to compare the variation in movement traces of the kinematic center of the temporomandibular joint with that of 4 nearby condylar reference points. METHODS: Jaw movement recordings were made with an optoelectronic jaw movement recording system. Four asymptomatic participants performed 14 to 18 open-close mandibular movements. The movements were performed with deliberate alterations of the rotation/translation ratio during opening. The kinematic center of the condyle and 4 nearby condylar points (the corner points of a square placed in the condylar sagittal plane, centered around the kinematic center, and with an edge length of 10 mm) were used as reference points. The standard deviations in the downward displacements at the halfway point in the mandibular opening of these reference points were calculated as a quantification of the variation in the movement tracings of these points. RESULTS: The movement traces of the kinematic center showed the smallest variation in comparison to the traces of the 4 nearby reference points (2-way analysis of variance and subsequent contrast analysis; P = 0.0026). CONCLUSION: In comparison to 4 nearby condylar reference points, the movement traces of the kinematic center show the lowest sensitivity to variations in the way mandibular movements are performed.

Adult↗
PubMed1979

The ultradian pulsatile release of gonadotropins in normal female subjects.

With an original statistical study which employes the analysis of variance and the harmonic analysis, the authors evaluated the levels of LH and FSH obtained from 5 female patients of the infertility clinic. These subjects, apparently free from endocrine disorders, underwent a 7-hour test consisting of samples obtained at 20 minute intervals. By a double-antibody RIA method, we assayed LH and FSH in quintuplicate or triplicate in each sample and counted the tubes twice consecutively. In all subjects for LH and in 3 subjects for FSH we detected a real ultradian pulsatile release of the hormone. Period and amplitude of the LH fluctuations vary according to the phase of the menstrual cycle (follicular phase: short period and low amplitude; luteal phase: long period and high amplitude). No change in amplitude was observed for FSH, while the period in two cases varied in accordance with LH. In two cases we found multiple periods in the fluctuations of one hormone during the same test.

Adult↗
PubMed2004

[A research on the public health index related to the comprehensive assessment on floods].

OBJECTIVE: To develop a public health index related to the comprehensive assessment on the impact caused by floods. METHODS: A Analytic hierarchy process (AHP) theory was used to establish the initial evaluation system on the impact of floods. Modified-Delphi process was used to screen and determine the indicators and their weights while synthetical scored method was used to establish the comprehensive assessment model. Percentile was used to differentiate the degree of floods. Finally, analysis of variance (ANOVA) and correlation analysis were used to test the differentiability of the model for different degree of floods and the independence of these indicators. RESULTS: The model of comprehensive assessment on the impact of floods was set up, including six first-ranking indicators and twenty-four sub-indicators. The values of comprehensive assessment were divided into five grades by the percentiles. Verified results indicated that there were significant difference among the five grades (F = 76.11, P < 0.01) and all indicators were independent. CONCLUSION: An index of comprehensive assessment on the impact of floods was established, which could be used to evaluate the impact of floods and to differentiate the degree of flood, which seemed to have the characteristic of reliability, comprehensiveness and practicability.

Analysis of Variance↗
PubMed2005

Anemia in rheumatoid arthritis: association with polymorphism in the tumor necrosis factor receptor I and II genes.

OBJECTIVE: To investigate whether polymorphisms in the tumor necrosis factor receptor I (TNFRSF1A) and receptor II (TNFRSF1B) genes are associated with the anemia observed in rheumatoid arthritis (RA). METHODS: We studied a group of Caucasian patients (n = 160) with established RA on whom longitudinal data of hemoglobin (Hb) levels over 5 years were recorded. A second group of patients (n = 102) with early RA was used for a confirmation study. Polymerase chain reaction restriction fragment length polymorphism analysis was used to genotype patients for the A36G polymorphism in the TNFRSF1A gene, and the T676G polymorphism in TNFRSF1B. Serum levels of ferritin were determined by ELISA and used to differentiate between iron deficiency anemia (IDA) and anemia of chronic disease (ACD). Data were analyzed by Kruskal-Wallis analysis of variance and logistic regression analysis. RESULTS: The TNFRSF1A GG genotype was associated with lower 5-year mean area under the curve Hb levels compared with other genotypes (p = 0.01). Analysis of anemic status showed an increased frequency of anemia in patients carrying a G allele, with the highest frequency in GG homozygotes. The TNFRSF1A GG genotype was significantly associated with IDA in established RA (OR 4.3, p = 0.01), and this was confirmed in a group of patients with early RA (OR 4.8, p = 0.04). Analysis of the combined groups also showed a weak association of the G allele with ACD (OR 2.2, p = 0.04). No association was found between TNFRSF1B variants and anemia when the cohorts were analyzed separately, but an association between carriage of the T allele and ACD was found when the 2 groups were combined (OR 11.5, p = 0.01). CONCLUSION: Our data suggest that polymorphisms within the TNFRSF1A and TNFRSF1B genes are associated with IDA and/or ACD in patients with RA.

Age Distribution↗
PubMedDate not supplied

How significant is the difference between drug doses influencing the threshold for electroconvulsions?

In this study, three computational methods (log-probit, one-way analysis of variance and linear regression analysis) were applied to statistically determine and compare a minimal dose of the antiepileptic drug--levetiracetam (LEV), which significantly increased the threshold for maximal electroconvulsions in mice. Results analyzed with log-probit method revealed that such a dose for LEV was 50 mg/kg. In contrast, one-way ANOVA indicated that the minimal dose of LEV, fulfilling the criterion of the significant increment in the threshold for electroconvulsions, was 100 mg/kg. Moreover, linear regression analysis allowed for the determination of threshold increasing doses by 20% (TID20) and 50% (TID50) for LEV, which amounted to 44 mg/kg and 150 mg/kg. This comparative study demonstrated distinct differences between the electroconvulsive threshold-influencing doses of LEV calculated with these three methods, and only statistical evaluation of data using one-way ANOVA provided the most adequate determination of statistical significance. The application of log-probit method and linear regression analysis in the search for significant drug-dose effects should be substantially restricted to specific experimental conditions.

Analysis of Variance↗
PubMed1983

Determinants of community placement of institutionalized mentally retarded persons.

A systematic examination of the decision process used when deinstitutionalizing mentally retarded persons was undertaken to determine what criteria, if any, institutional review teams employed when making placement recommendations. A multivariate analysis of variance and a discriminant analysis revealed that demographic and Adaptive Behavior Scale (ABS) measures varied significantly with placement recommendations for skill development homes, group homes, small intermediate facilities, and large intermediate facilities. In general, higher functioning residents were placed in less restrictive settings. Specific differences among residents placed in skill development homes and group homes were examined. Implications for preparing institutionalized residents for community placement were drawn and directions for future research outlined.

Adaptation, Psychological↗
PubMed1994

[Use of macroalgae for the evaluation of organic pollution in the Preto river, northwest of São Paulo State].

The Preto River, located in the northwest of São Paulo State, receives a total wastewater load of 15.150 kg DBO day-1, from which 13.685 kg DBO day-1 (90.5%) corresponds to domestic sewage, and the city of São José do Rio Preto contributes with 12.400 kg DBO day-1 (90% of domestic sewage). During the period from August 1990 through January 1991, monthly sampling was carried out to evaluate the use of macroalgae as bioindicator of organic pollution. Five sampling sites were established along the main river and the following variables were analised: temperature, conductance, turbidity, dissolved oxygen, BOD, COD, total and fecal coliforms, and composition and abundance of macroalgal communities. Data were submitted to analysis of variance, correlation coefficient, cluster analysis (four different approaches) and converted to biological indices (species deficit, relative pollution, saprobity, diversity and uniformity indices). A wide range in water quality was found (particularly for conductance, oxygen, BOD and COD) among the sampling sites, which were classified into three groups (polluted, moderately polluted and unpolluted/weakly polluted). As regards the occurrence and abundance of macroalgae the Rhodophyta were found only in unpolluted or weakly polluted sites, whereas Cyanophyta occurred mostly under high pollution load; the Chlorophyta species were observed under a wide range of conditions. Among the biological indices, saprobity was the most sensitive and correlated to all water variables and the other indices. Cluster analyses showed that the composition of macroalgal communities was consistent with the levels of organic pollution in the Preto River.

Analysis of Variance↗
PubMed1995

Reassessment of circadian profile of blood pressure and heart rate in diabetic patients with autonomic neuropathy.

Previous studies have shown that the normal circadian blood pressure fall is absent in patients with diabetic autonomic neuropathy, while the reported rise in blood pressure during the night in the same patients is controversial. This study analyzed the circadian profile in 19 diabetic patients with established autonomic neuropathy. Twenty-four hour ambulatory systolic blood pressure, diastolic blood pressure, mean arterial pressure, and heart rate were recorded every 20 minutes during the day and every 60 minutes at night in 29 patients, 19 with diabetic autonomic neuropathy and 10 nondiabetic hypertensive patients as controls. Twelve diabetic patients with autonomic neuropathy with unknown hypertension were found to have hypertension based on 24 hour ambulatory blood pressure monitoring. Repeated measured analysis of variance (ANOVA) and trend analysis indicated that the linear systolic blood pressure increased from night to morning to afternoon while mean arterial pressure and diastolic blood pressure increased from night to morning but decreased from morning to afternoon. In practice, the early morning rise in systolic blood pressure in diabetic neuropathy is not different from that in normal or hypertensive patients and requires appropriate treatment. The absence of the nocturnal rise in the blood pressure revealed a subgroup of patients with diabetic neuropathy which demonstrated no fatal cardiovascular or renal events over 18 to 24 months of follow-up.

Aged↗
PubMed2000

Statistical examination of hair color as a potential biasing factor in hair analysis.

We review eight different data sets in this paper for the purposes of assessing the possibility that reported color of hair can produce a systematic bias in the interpretation of hair assays. We review studies or data sets that include heroin and its metabolites, cocaine and its metabolites, MDMA and its analogs, and amphetamine and methamphetamine. The studies have utilized a variety of different degrees of color categorization, ranging from the simple dichotomy of brown and black, to a high of 12 categories. The mean number of categories reported approaches 6 (mean = 5.875). There are a total of 2791 data points in this analysis. We utilize two major statistical techniques for assessing significance; one-way analysis of variance, and Tukey's Honestly Significant Difference procedure. In circumstances were only dichotomous contrasts are possible, one-way analysis of variance is used. In contrasts involving three or more categorical groups, Tukey's procedure is used. In circumstances where the homogeneity of group variances is not sustained by the Levene statistic, we use the Tamahane procedure, allowing an assessment that assumes unequal variances. The analysis of this data fails to discern a significant color effect. We speculate that it may be that variance is large in many domains affecting analyte recovery from hair. In large groups these variations tend to regress towards a typical or mean value. Thus the data here show that while there are group or aggregate differences in these 'typical' values, they are not great when considered in relation to the within-group variations which exist for those values. It is our view that color may play a role in the accumulation of drugs in hair, however it is likely to account for only a very small part of the complex process of drug accumulation.

Bias↗
PubMed2002

Selecting the best method to evaluate bronchodilation when analysing bronchodilator studies.

Changes in lung function (that is, FEV(1)) are commonly expressed as a percentage of the predicted value. The question is whether this parameter is best suited for statistical analysis. A total of 2199 bronchodilation tests were selected and pre- and post-dilator FEV(1), age, height and sex extracted. Predicted FEV(1) values, the difference between pre- and post-dilator FEV(1) and the change as percentage of predicted or baseline FEV(1) were calculated. The latter parameters were subjected to analysis of variance and pre- and post-dilator FEV(1) to analysis of covariance. The statistical power of these four approaches and the residual structure were used to select the best approach. Analysis of variance of the change as percentage of predicted and covariance analysis of pre- and post-dilator FEV(1) offers the best performance. The residuals of the analysis of variance showed a funnel shaped structure. The latter causes residual heterogeneity, resulting in a loss of power and deviations between the actual and nominal alpha-level. This is not taken into account when calculating sample sizes using the standard equations, which implicitly assume lack of these problems. Analysis of covariance does not suffer from these problems. The best way to evaluate bronchodilation in trials is to use analysis of covariance.

Age Factors↗
PubMed1996

Effects of adrenaline infusion on the interstitial environment of subcutaneous adipose tissue as studied by microdialysis.

1. Adrenaline was infused at a rate of 25 ng min-1 kg-1 into seven healthy volunteers and its effects on adipose tissue were studied by microdialysis. 2. Adrenaline infusion led to a rapid rise in plasma adrenaline concentration from a basal value of 0.15 +/- 0.03 nmol/l to a peak value of 1.82 +/- 0.15 nmol/l within 30 min (analysis of variance: P < 0.001). Plasma noradrenaline levels increased from the basal value of 1.48 +/- 0.21 nmol/l to 1.78 +/- 0.20 nmol/l within 30 min of infusion (analysis of variance: P < 0.05). Once the infusion was stopped the plasma adrenaline and noradrenaline levels returned to basal values within 15 min. 3. The arterialized blood glycerol concentration increased from the basal value of 47 +/- 6 mumol/l to 101 +/- 8 mumol/l (analysis of variance: P < 0.001), and the interstitial glycerol concentration increased from 181 +/- 17 mumol/l to 350 +/- 47 mumol/l (analysis of variance: P < 0.001) within 30 min of adrenaline infusion. Thereafter the concentrations declined gradually towards basal values. When the infusion was discontinued the levels declined further, below the basal value. 4. Adrenaline infusion caused a significant increase in the plasma glucose and blood lactate concentration (analysis of variance: P < 0.001 and P < 0.001), but no such effect was observed in the interstitial concentrations. 5. The basal dialysate concentrations of adrenaline and noradrenaline were 43 +/- 37 pmol/l and 1170 +/- 430 pmol/l respectively. There were difficulties in estimating the absolute interstitial concentrations of adrenaline and noradrenaline which are discussed. The dialysate adrenaline concentration increased to a peak value of 112 +/- 48 pmol/l (analysis of variance: P < 0.05) within 30 min. The dialysate noradrenaline concentration increased to a peak value of 2830 +/- 1470 pmol/l, but the rise was not significant. 6. These results show that the interstitial concentrations of metabolites and hormones can be significantly different from those of blood and plasma and these differences reflect tissue specialization.

Adipose Tissue↗
PubMed2002

A qualitative analysis of medication use variance reports.

BACKGROUND: This report of a process change utilized a qualitative approach to data analysis to improve medication use safety in a large hospital. The two goals were to design a strategy to analyze the qualitative data and to use that strategy to uncover previously unclassified medication use variance patterns that could be prevented. A multidisciplinary team performed the analysis in an effort to improve the quality and yield of the approach. METHODS: All medication use variance, incident, and event reports from Yale-New Haven Hospital during April-June 2000 were collected (N = 264). A 20% random sample of the reports was distributed to a five-member evaluation group (a pharmacist, two nurses, and two physicians) for independent qualitative analysis and coding. An initial coding framework was produced using a consensus process. This coding framework was applied to another sample, and the consensus and coding processes were repeated until no new domains were identified. RESULTS: Ten general medication use variance domains were determined. In addition, 21 subdomains among the various general domains were determined. DISCUSSION: Utilizing a multidisciplinary team and a qualitative strategy of analysis improved patient safety efforts. This combination led to the discovery of new variance domains, causes, and opportunities to intervene and ultimately prevent medication use variances. This analytic approach is widely applicable, adaptable, and dynamic. The design and results of this report improve on a strictly quantitative approach to medication use variance analysis. The approach employed by this report will be used to improve medication use safety within the Yale-New Haven Health System.

Adverse Drug Reaction Reporting Systems↗
PubMed2000

A multidisciplinary approach to talent identification in soccer.

The requirements for soccer play are multifactorial and distinguishing characteristics of elite players can be investigated using multivariate analysis. The aim of the present study was to apply a comprehensive test battery to young players with a view to distinguishing between elite and sub-elite groups on the basis of performance on test items. Thirty-one (16 elite, 15 sub-elite) young players matched for chronological age (15-16 years) and body size were studied. Test items included anthropometric (n = 15), physiological (n = 8), psychological (n = 3) and soccer-specific skills (n = 2) tests. Variables were split into separate groups according to somatotype, body composition, body size, speed, endurance, performance measures, technical skill, anticipation, anxiety and task and ego orientation for purposes of univariate and multivariate analysis of variance and stepwise discriminant function analysis. The most discriminating of the measures were agility, sprint time, ego orientation and anticipation skill. The elite players were also significantly leaner, possessed more aerobic power (9.0 +/- 1.7 vs 55.5 +/- 3.8 ml x kg(-1) x min(-1)) and were more tolerant of fatigue (P < 0.05). They were also better at dribbling the ball, but not shooting. We conclude that the test battery used may be useful in establishing baseline reference data for young players being selected onto specialized development programmes.

Adolescent↗
PubMed2002

Ovarian function and regulation of the hypothalamic-pituitary-ovarian axis after tubal sterilization.

OBJECTIVE: To assess the effects of laparoscopic tubal sterilization with Hulka or Filshie clip on ovarian function and regulation of the hypothalamic-pituitary-ovarian axis. STUDY DESIGN: Hormonal changes were evaluated in 33 women undergoing sterilization with Hulka (n = 16) or Filshie clips (n = 17). All participants were healthy, with regular menstrual cycles. The levels of estradiol, follicle-stimulating hormone, luteinizing hormone, sex hormone binding globulin, prolactin, testosterone and androstenedione were measured in one cycle immediately before and 3 and 12 months after sterilization on cycle days 3-7 and 20-24. Repeated measures analysis of variance, paired t test and nonparametric Friedman two-way analysis of variance were used for statistical analysis. RESULTS: The follicular phase estradiol values increased after sterilization. The highest values were observed three months after the procedure (204.8 +/- 119.1 pmol/L vs. 170.3 +/- 111.7 pmol/L) (P = .0407). The values declined to the presterilization level by 12 months (150.3 +/- 71.3 pmol/L). The luteal phase estradiol values did not change significantly. No change in any of the other hormones studied took place, with the exception of a slight increase in follicular phase luteinizing hormone levels (4.4 +/- 1.4 U/L in the first cycle, 5.1 +/- 1.3 U/L in the second cycle and 5.2 +/- 1.8 U/L in the third cycle) (P = .0553). CONCLUSION: Laparoscopic tubal sterilization increases follicular phase estradiol levels, but the change seems to be only temporary.

Adult↗

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