scholarly journals Among-Strain Variation in Resistance of Paramecium caudatum to the Endonuclear Parasite Holospora undulata: Geographic and Lineage-Specific Patterns

2020 ◽  
Vol 11 ◽  
Author(s):  
Jared Weiler ◽  
Giacomo Zilio ◽  
Nathalie Zeballos ◽  
Louise Nørgaard ◽  
Winiffer D. Conce Alberto ◽  
...  
Keyword(s):  
Intraclass Correlation ◽  
Natural Populations ◽  
Correlation Coefficients ◽  
Infection Prevalence ◽  
Post Inoculation ◽  
Paramecium Caudatum ◽  
Geographical Scale ◽  
Neutral Marker ◽  
The Difference ◽  
Available Information

Resistance is a key determinant in interactions between hosts and their parasites. Understanding the amount and distribution of variation in this trait between strains can provide insights into (co)evolutionary processes and their potential to shape patterns of diversity in natural populations. Using controlled inoculation in experimental mass cultures, we investigated the quantitative variation in resistance to the bacterial parasite Holospora undulata across a worldwide collection of strains of its ciliate host Paramecium caudatum. We combined the observed variation with available information on the phylogeny and biogeography of the strains. We found substantial variation in resistance among strains, with upper-bound values of broad-sense heritability >0.5 (intraclass correlation coefficients). Strain estimates of resistance were repeatable between laboratories and ranged from total resistance to near-complete susceptibility. Early (1 week post inoculation) measurements provided higher estimates of resistance heritability than did later measurements (2–3 weeks), possibly due to diverging epidemiological dynamics in replicate cultures of the same strains. Genetic distance (based on a neutral marker) was positively correlated with the difference in resistance phenotype between strains (r = 0.45), essentially reflecting differences between highly divergent clades (haplogroups) within the host species. Haplogroup A strains, mostly European, were less resistant to the parasite (49% infection prevalence) than non-European haplogroup B strains (28%). At a smaller geographical scale (within Europe), strains that are geographically closer to the parasite origin (Southern Germany) were more susceptible to infection than those from further away. These patterns are consistent with a picture of local parasite adaptation. Our study demonstrates ample natural variation in resistance on which selection can act and hints at symbiont adaptation producing signatures in geographic and lineage-specific patterns of resistance in this model system.

scholarly journals Heritable variation in resistance to the endonuclear parasite Holospora undulata across clades of Paramecium caudatum

2020 ◽  
Author(s):  
Jared Weiler ◽  
Giacomo Zilio ◽  
Nathalie Zeballos ◽  
Louise Noergaard ◽  
Winiffer D. Conce Alberto ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Natural Populations ◽  
Infection Prevalence ◽  
Post Inoculation ◽  
Paramecium Caudatum ◽  
Heritable Variation ◽  
Natural Genetic Variation ◽  
Geographical Scale ◽  
Neutral Marker ◽  
The Difference

AbstractResistance is a key determinant in interactions between hosts and their parasites. Understanding the amount and distribution of genetic variation in this trait can provide insights into (co)evolutionary processes and their potential to shape patterns of diversity in natural populations. Using controlled inoculation in experimental mass cultures, we investigated the quantitative genetic variation in resistance to the bacterial parasite Holospora undulata across a worldwide collection of strains of its ciliate host Paramecium caudatum. We combined the observed variation with available information on the phylogeny and biogeography of the strains. We found substantial variation in resistance among strains (with broad-sense heritability > 0.5), repeatable between laboratories and ranging from total resistance to near-complete susceptibility. Early (one week post inoculation) measurements provided higher estimates of resistance heritability than did later measurements (2-3 weeks), possibly due to diverging epidemiological dynamics in replicate cultures of the same strains. Genetic distance (based on a neutral marker) was positively correlated with the difference in resistance phenotype between strains (r = 0.45), essentially reflecting differences between highly divergent clades (haplogroups) within the host species. Haplogroup A strains, mostly European, were less resistant to the parasite (49% infection prevalence) than non-European haplogroup B strains (28%). At a smaller geographical scale (within Europe), strains that are geographically closer to the parasite origin (Southern Germany) were more susceptible to infection than those from further away. These patterns are consistent with a picture of local parasite adaptation. Our study demonstrates ample natural genetic variation in resistance on which selection can act and hints at symbiont adaptation producing signatures in geographic and lineage-specific patterns of resistance in this model system.

scholarly journals Assessment of reliability and validity of the 5-scale grading system of the point-of-care immunoassay for tear matrix metalloproteinase-9

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Minjeong Kim ◽  
Ja Young Oh ◽  
Seon Ha Bae ◽  
Seung Hyeun Lee ◽  
Won Jun Lee ◽  
...  
Keyword(s):  
Matrix Metalloproteinase ◽  
Calibration Curve ◽  
Point Of Care ◽  
Interobserver Reliability ◽  
Intraclass Correlation ◽  
Reliability And Validity ◽  
Correlation Coefficients ◽  
Grading System ◽  
Intraclass Correlation Coefficients ◽  
The Difference

AbstractWe evaluated the reliability and validity of the 5-scale grading system to interpret the point-of-care immunoassay for tear matrix metalloproteinase (MMP)-9. Six observers graded red bands of photographs of the readout window in MMP-9 immunoassay kit (InflammaDry) two times with 2-week interval based on the 5-scale grading system (i.e. grade 0–4). Interobserver and intraobserver reliability were evaluated using intraclass correlation coefficients. The interobserver agreements were analyzed according to the severity of tear MMP-9 expression. To validate the system, a concentration calibration curve was made using MMP-9 solutions with reference concentrations, then the distribution of MMP-9 concentrations was analyzed according to the 5-scale grading system. Both intraobserver and interobserver reliability was excellent. The readout grades were significantly correlated with the quantified colorimetric densities. The interobserver variance of readout grades had no correlation with the severity of the measured densities. The band density continued to increase up to a maximal concentration (i.e. 5000 ng/mL) according to the calibration curve. The difference of grades reflected the change of MMP-9 concentrations sensitively, especially between grade 2 and 4. Together, our data indicate that the subjective 5-scale grading system in the point-of-care MMP-9 immunoassay is an easy and reliable method with acceptable accuracy.

scholarly journals Reproducibility and reliability of three-dimensional soft tissue landmark identification using three-dimensional stereophotogrammetry

2016 ◽  
Vol 86 (6) ◽  
pp. 1004-1009 ◽  
Author(s):  
Asli Baysal ◽  
Ahmet Oguz Sahan ◽  
Mehmet Ali Ozturk ◽  
Tancan Uysal
Keyword(s):  
Soft Tissue ◽  
Statistical Significance ◽  
Intraclass Correlation ◽  
Three Dimensional ◽  
Correlation Coefficients ◽  
Intraclass Correlation Coefficients ◽  
Paired Samples ◽  
Landmark Identification ◽  
The Difference ◽  
Intraexaminer Reliability

ABSTRACT Objective: To evaluate the intraexaminer repeatability and interexaminer reproducibility of soft tissue landmarks on three-dimensional (3-D) stereophogrammetric images. Materials and Methods: Thirty-four stereophotogrammetric images were taken and 19 soft tissue points were identified. The images were obtained using the 3-DMD Face (3-DMD TM Ltd, Atlanta, Ga) system. Two examiners marked 34 images manually with a mouse-driven cursor 4 weeks apart. Intraexaminer marking differences were calculated and classified as <0.5 mm, 0.5–1 mm, and >1 mm. Intraclass correlation coefficients were calculated for intraexaminer reliability. A paired-samples t-test was used to evaluate the difference between the examiners. Interexaminer reproducibility was evaluated by kappa analysis. Statistical significance was set at P < .05. Results: Only one landmark (labiale superior) had an intraexaminer marking difference less than 0.5 mm. Existing landmarks had an intraexaminer difference less than 1 mm, but higher than 0.5 mm. The intraclass correlation coefficients (ICCs) indicated good intraexaminer repeatability for both observers. The ICC range for examiners 1 and 2 was 0.986–1.000 and 0.990–1.000, respectively. Kappa scores showed good interexaminer agreement, especially on the z-axis. Conclusions: Except labiale superior, the soft tissue landmarks used in this study were shown to have moderate reproducibility, but the difference between the landmarks was less than 1 mm, and they had clinically acceptable reproducibility.

scholarly journals Noninvasive quantitative estimation of hepatic steatosis by ultrasound: a comparison of the hepato-renal index and ultrasound attenuation index.

2016 ◽  
Vol 18 (4) ◽  
pp. 431 ◽  
Author(s):  
Heon-Ju Kwon ◽  
Kyoung Won Kim ◽  
Jin-Hee Jung ◽  
Sang Hyun Choi ◽  
Woo Kyoung Jeong ◽  
...  
Keyword(s):  
Hepatic Steatosis ◽  
Interobserver Agreement ◽  
Quantitative Estimation ◽  
Statistical Significance ◽  
Characteristic Curve ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Ultrasound Attenuation ◽  
Attenuation Index ◽  
The Difference

Aims: To compare the accuracy of the ultrasound attenuation index (USAI) and hepato-renal index (HRI) for the diagnosis of hepatic steatosis (HS). Material and methods: Two hundred and twenty-four potential living hepatic donors underwent US and subsequent US-guided liver biopsy. The USAI was calculated from US images with an 8 MHz transducer and HRI was measured on sagittal images with a clear visualization of both the liver and kidney. Using histological degrees of HS as the reference standard, we compared the performance of USAI and HRI for diagnosing HS ≥ 5% and ≥ 30% by receiver operating characteristic curve analysis. The interobserver agreement was evaluated by using intraclass correlation coefficients (ICCs) or Bland–Altman statistics. Results: Histologic degree of HS was 0–70% (median, 5%). HRI showed a tendency towards higher accuracy than USAI for diagnosing HS ≥ 5% (the area under the ROC curve, 0.856 vs. 0.820; p= 0.279) and ≥ 30% (0.937 vs. 0.909; p = 0.378) without statistical significance. There was an excellent interobserver agreement for both USAI and HRI (ICC = 0.931 and 0.973, respectively). According to the Bland–Altman method, the 95% limits of difference between two readers for HS were −8.5% to 6.6% by USAI and −4.8% to 6.2% by HRI. Most patients would have the difference of calculated HS by USAI (74.0%) and HRI (96.0%) from different operators within a range of ±5%. Conclusions: Although statistically insignificant, HRI was superior to USAI for the diagnosis and quantitative estimation of HS in terms of diagnostic performance, including accuracy and reproducibility.

scholarly journals Reliability of Measuring the Cervical Sagittal Translation Mobility with a Simple Method in a Clinical Setting

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Yvonne Severinsson ◽  
Lena Elisson ◽  
Olle Bunketorp
Keyword(s):  
Clinical Setting ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Practical Method ◽  
Systematic Difference ◽  
Reference Plane ◽  
Rank Test ◽  
Rater Agreement ◽  
Simple Method ◽  
The Difference

Introduction. The cervical sagittal translation mobility is related to neck pain. A practical method for measuring the specific cervical mobility is needed. The aim was to describe a simple method for measuring the cervical sagittal translation mobility and to evaluate its reliability in a clinical setting.Method. The head protraction and retraction ranges of thirty healthy seated subjects were measured from a dorsal reference plane by two physiotherapists utilizing a tape measure. A standard inclinometer/goniometer was used to minimize angular movements of the head during the translational movements. The measurements were made twice for each subject with a two-hours interval between each measurement. The inter-rater and intra-rater agreements were evaluated with intraclass correlation coefficients (ICCs) and with the distribution of the difference of the measurements. The systematic differences were analysed with the Wilcoxon signed rank test.Results. The intra-rater agreement was good. The inter-rater agreement was moderate in the first measurement and good in the second. A systematic difference was noted between raters in the first measurement but not in the second, possibly indicating a learning effect.Discussion. The method used in the study is simple and reliable and can be recommended for clinical use.

scholarly journals Thumb Proprioception in Hypermobile and Non-Hypermobile Adults: An Observational Study

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Leon Fonseka ◽  
Nicola Massy-Westropp ◽  
Steve Milanese ◽  
Arjun Burlakoti
Keyword(s):  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Joint Hypermobility ◽  
Angular Distance ◽  
Test Reliability ◽  
Joint Position ◽  
Convenience Sample ◽  
Intraclass Correlation Coefficients ◽  
The Difference ◽  
Design And Methods

Aims and Background Hypermobility is a common presentation in the community and is reported related to higher rates of injury and musculoskeletal pain, however the mechanism underpinning this relationship remains unclear. Poor proprioception in hypermobile joints has been proposed as a potential mechanism. This study aims to determine if there is a difference in proprioceptive acuity, as measured by joint position reproduction, in adults with generalised joint hypermobility. Design and methods A convenience sample of 26 university students and staff (mean age 29.23 years, range 18-47) were recruited, of which 12 participants displayed generalised joint hypermobility, and 14 did not. A laser light, mounted to the dominant thumb, was used to test joint position reproduction sense by pointing to targets using a unilateral active-active position reproduction protocol. Results/Findings Test reliability across a range of targets was poor to good (intraclass correlation coefficients ranged from 0.1163 to 0.7256), indicating significant variability between participants. No significant differences was found in absolute angle of error between generalised joint hypermobility and non-generalised joint hypermobility participants. For direction of error in relation to the proprioceptive targets, only 30° thumb extension above horizontal was found to be significantly different between the hypermobile and non-hypermobile groups, with hypermobile participants tending to underestimate distance to target. Age and sex were not correlated to thumb proprioception. Application and Conclusion The difference found in direction of error and tendency to underestimate angular distance may be protective against straying into possibly injurious end-ranges; however, larger studies are recommended to confirm this.

scholarly journals Head Orientation in CBCT-generated Cephalograms

2009 ◽  
Vol 79 (5) ◽  
pp. 971-977 ◽  
Author(s):  
Lucia Cevidanes ◽  
Ana E. F. Oliveira ◽  
Alexandre Motta ◽  
Ceib Phillips ◽  
Brandon Burke ◽  
...  
Keyword(s):  
Intraclass Correlation ◽  
Three Dimensional ◽  
Correlation Coefficients ◽  
Dental Student ◽  
Head Orientation ◽  
Class Iii ◽  
Good Reliability ◽  
Mean Values ◽  
Lateral Cephalograms ◽  
The Difference

Abstract Objective: To determine the reliability of obtaining two-dimensional cephalometric measurements using two virtual head orientations from cone-beam computed tomography (CBCT) models. Materials and Methods: CBCT scans of 12 patients (6 class II and 6 class III) were randomly selected from a pool of 159 patients. An orthodontist, a dental radiologist, and a third-year dental student independently oriented CBCT three-dimensional (3D) renderings in either visual natural head position (simulated NHP) or 3D intracranial reference planes (3D IRP). Each observer created and digitized four CBCT-generated lateral cephalograms per patient, two using simulated NHP and two using 3D IRP at intervals of at least 3 days. Mixed-effects analysis of variance was used to calculate intraclass correlation coefficients (ICCs) and to test the difference between the orientations for each measure. Results: ICC indicated good reliability both within each head orientation and between orientations. Of the 50 measurements, the reliability coefficients were ≥0.9 for 45 measurements obtained with 3D IRP orientation and 36 measurements with simulated NHP. The difference in mean values of the two orientations exceeded 2 mm or 2° for 14 (28%) of the measurements. Conclusions: The reliability of both virtual head orientations was acceptable, although the percentage of measurements with ICC >0.9 was greater for 3D IRP. This may reflect the ease of using the guide planes to position the head in the 3D IRP during the simulation process.

scholarly journals Repeatability of OPD-Scan III and its agreement with Pentacam in measuring keratometry, astigmatism and axis in patients with cataract and moderate to high astigmatism

2020 ◽  
Author(s):  
YU Song ◽  
Panpan Li ◽  
Yuanyuan Tu ◽  
Ying Wu ◽  
Lili Huang ◽  
...  
Keyword(s):  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
High Accuracy ◽  
Wilcoxon Test ◽  
Spearman Correlation ◽  
Limits Of Agreement ◽  
Intraclass Correlation Coefficients ◽  
Bland Altman Method ◽  
The Difference ◽  
Cataract Patients

Abstract Purpose To assess accuracy of OPD-Scan III in measuring keratometry, astigmatism and axis in patients with cataract and moderate to high astigmatism Materials and Methods Measurements were taken with OPD-Scan III and Pentacam in cataract patients with keratometric astigmatism (KA) more than 0.75 D. Keratometry in the steepest axis (Ks) and flattest axis (Kf), KA and axis, which are power vector components of astigmatism (J0 and J45), were evaluated. Intraclass correlation coefficients (ICCs) were used to assess repeatability. The Wilcoxon test was used to assess differences, the Spearman correlation was used to assess correlations, and the Bland-Altman method was used to assess agreement. Results Seventy eyes of 63 patients were included to analyze the repeatability of the two devices. The ICCs of Ks, Kf, KA, axis, J0 and J45 were 0.991, 0.995, 0.946, 0.883, 0.946 and 0.892, respectively, with OPD-Scan III. Seven hundred and thirty-two eyes of 516 patients were included to analyze the difference, correlation and agreement of the two devices. There were significant differences between the two devices in terms of Ks, Kf, axis, J0 and J45 (all p < 0.01). There were significant correlations between the two devices in each parameter (all p < 0.01). The 95% limits of agreement (LOAs) for Ks, Kf, KA, astigmatic axis, J0 and J45 were (-0.34, 0.44) D, (-0.24, 0.38) D, (-0.46, 0.48) D, (-10.20, 12.92)°, (-0.24, 0.24) D, and (-0.27, 0.35) D respectively.The 95% LOAs for the degree of IOL caculated according to parameter measured by OPD-Scan III and Pentacam was (-0.32, 0.22) D. Conclusions OPD-Scan III has a high accuracy for measuring keratometry, but its accuracy for measuring astigmatism and axis is poor in eyes with moderate to high astigmatism.

scholarly journals Validity and Reliability of an Alternative Method for Measuring Power Output During Six-Second All-out Cycling

2014 ◽  
Vol 30 (4) ◽  
pp. 598-603 ◽  
Author(s):  
Martin Watson ◽  
Daniele Bibbo ◽  
Charles R. Duffy ◽  
Philip E. Riches ◽  
Silvia Conforto ◽  
...  
Keyword(s):  
Power Output ◽  
Angular Displacement ◽  
Exercise Physiology ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Force Transducer ◽  
Systematic Bias ◽  
Validity And Reliability ◽  
Maximal Power Output ◽  
The Difference

In a laboratory setting where both a mechanically-braked cycling ergometer and a motion analysis (MA) system are available, flywheel angular displacement can be estimated by using MA. The purpose of this investigation was to assess the validity and reliability of a MA method for measuring maximal power output (Pmax) in comparison with a force transducer (FT) method. Eight males and eight females undertook three identical sessions, separated by 4 to 6 days; the first being a familiarization session. Individuals performed three 6-second sprints against 50% of the maximal resistance to complete two pedal revolutions with a 3-minute rest between trials. Power was determined independently using both MA and FT analyses. Validity: MA recorded significantly higher Pmaxthan FT (P< .05). Bland–Altman plots showed that there was a systematic bias in the difference between the measures of the two systems. This difference increased as power increased. Repeatability: Intraclass correlation coefficients were on average 0.90 ± 0.05 in males and 0.85 ± 0.08 in females. Measuring Pmaxby MA, therefore, is as appropriate for use in exercise physiology research as Pmaxmeasured by FT, provided that a bias between these measurements methods is allowed for.

Factors Affecting Cyclists’ Chances of Success in Match-Sprint Tournaments

2019 ◽  
Vol 14 (4) ◽  
pp. 472-477 ◽  
Author(s):  
Kathryn E. Phillips ◽  
Will G. Hopkins
Keyword(s):  
Elite Athlete ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Time Trial ◽  
Strongly Correlated ◽  
Factors Affecting ◽  
Female Head ◽  
Intraclass Correlation Coefficients ◽  
The Difference ◽  
Athlete Performance

Purpose: To further the understanding of elite athlete performance in complex race environments by examining the changes in cyclists’ performance between solo time trials and head-to-head racing in match-sprint tournaments. Methods: Analyses were derived from official results of cyclists in 61 elite international sprint tournaments (2000–2016), incorporating the results of 2060 male and 1969 female head-to-head match races. Linear mixed modeling of log-transformed qualification and finish ranks was used to determine estimates of performance predictability as intraclass correlation coefficients. Correlations between qualifying performance and final tournament rank were also calculated. Chances of winning head-to-head races were estimated adjusting for the difference in the cyclists’ qualifying times. All effects were evaluated using magnitude-based inference. Results: Minor differences in predictability between qualification time trial and final tournament rank were suggestive of more competitiveness among men in the overall tournament. Performance in the qualification time trial was strongly correlated with, but not fully indicative of, performance in the overall tournament. Correspondingly, being the faster qualifier had a large positive effect on the chances of winning a head-to-head race, but small substantial differences between riders remained after adjustment for time-trial differentials. Conclusions: The present study provides further insight into how real-world competition data can be used to investigate elite athlete performance in sports where athletes must directly interact with their opponents. For elite match-sprint cyclists, qualifying time-trial performance largely determines success in the overall tournament, but there is evidence of a consistent match-race ability that modifies the chances of winning head-to-head races.

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