scholarly journals Relationship between retinal vessel tortuosity and oxygenation in sickle cell retinopathy

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Maziyar M. Khansari ◽  
Sarah L. Garvey ◽  
Shayan Farzad ◽  
Yonggang Shi ◽  
Mahnaz Shahidi
Keyword(s):  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Sickle Cell ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Morphological Changes ◽  
Retinal Vessel ◽  
Mixed Model Analysis ◽  
Vessel Tortuosity ◽  
Fellow Eyes

Abstract Background Reduced retinal vascular oxygen (O2) content causes tissue hypoxia and may lead to development of vision-threatening pathologies. Since increased vessel tortuosity is an early sign for some hypoxia-implicated retinopathies, we investigated a relationship between retinal vascular O2 content and vessel tortuosity indices. Methods Dual wavelength retinal oximetry using a commercially available scanning laser ophthalmoscope was performed in both eyes of 12 healthy (NC) and 12 sickle cell retinopathy (SCR) subjects. Images were analyzed to quantify retinal arterial and venous O2 content and determine vessel tortuosity index (VTI) and vessel inflection index (VII) in circumpapillary regions. Linear mixed model analysis was used to determine the effect of disease on vascular O2 content, VTI and VII, and relate vascular O2 content with VTI and VII. Models accounted for vessel type, fellow eyes, age and mean arterial pressure. Results Retinal arterial and venous O2 content were lower in SCR (O2A = 11 ± 4 mLO2/dL, O2V = 7 ± 2 mLO2/dL) compared to NC (O2A = 18 ± 3 mLO2/dL, O2V = 13 ± 3 mLO2/dL) subjects (p < 0.001). As expected, O2 content was higher in arteries (15 ± 5 mLO2/dL) than veins (10 ± 4 mLO2/dL) (p < 0.001), but not different between eyes (OD: 12 ± 5 mLO2/dL; OS:13 ± 5 mLO2/dL) (p = 0.3). VTI was not significantly different between SCR (0.18 ± 0.07) and NC (0.15 ± 0.04) subjects, or between arteries (0.18 ± 0.07) and veins (0.16 ± 0.04), or between eyes (OD: 0.18 ± 0.07, OS:0.17 ± 0.05) (p ≥ 0.06). VII was significantly higher in SCR (10 ± 2) compared to NC subjects (8 ± 1) (p = 0.003). VII was also higher in veins (9 ± 2) compared to arteries (8 ± 5) (p = 0.04), but not different between eyes (OD: 9 ± 2; OS: 9 ± 2) (p = 0.2). There was an inverse linear relationship between vascular O2 (13 ± 5 mLO2/dL) content and VII (9 ± 2) (β = −0.5; p = 0.02). Conclusions The findings augment knowledge of relationship between retinal vascular oxygenation and morphological changes and potentially contribute to identifying biomarkers for assessment of retinal hypoxia due to SCR and other retinopathies.

Validation of Innovative Techniques for Monitoring Nociception during General Anesthesia

2017 ◽  
Vol 127 (2) ◽  
pp. 272-283 ◽  
Author(s):  
Sandra Funcke ◽  
Sven Sauerlaender ◽  
Hans O. Pinnschmidt ◽  
Bernd Saugel ◽  
Kai Bremer ◽  
...  
Keyword(s):  
Heart Rate ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Bispectral Index ◽  
Mixed Model ◽  
Nociceptive Response ◽  
Pupillary Dilatation ◽  
Mixed Model Analysis ◽  
Receiver Operating Characteristic Curves ◽  
Prediction Probability

Abstract Background This study compares the analgesic indices Analgesia Nociception Index (heart rate variability), Surgical Pleth Index (photoplethysmography), and pupillary dilatation, to heart rate, mean arterial pressure, and bispectral index, with regard to diagnostic accuracy and prediction probability for nociceptive response. The primary endpoint was the correlation between Δ values and the remifentanil dose administered. Methods We anesthetized 38 patients with propofol and increasing doses of remifentanil and applied standardized tetanic and intracutaneous electrical painful stimulations on each analgesic level. Baseline and Δ values of the Analgesia Nociception Index, the Surgical Pleth Index, pupillary dilatation, heart rate, mean arterial pressure, and bispectral index and their relation to remifentanil doses were analyzed by receiver operating characteristic curves, prediction probability (PK), and mixed-model analysis. Results Under propofol sedation, sensitivity and specificity of the Analgesia Nociception Index (PK = 0.98), the Surgical Pleth Index (PK = 0.87), and pupillary dilatation (PK = 0.98) for detecting both painful stimulations were high compared to heart rate (PK = 0.74), mean arterial pressure (PK = 0.75), and bispectral index (PK = 0.55). Baseline values had limited prediction probability toward the nociceptive response (Analgesia Nociception Index: PK = 0.7; Surgical Pleth Index: PK = 0.63; pupillary dilatation: PK = 0.67; and bispectral index: PK = 0.67). The remifentanil dose had an effect (P &lt; 0.001) on all parameters except for bispectral index (P = 0.216). Conclusions The Analgesia Nociception Index, the Surgical Pleth Index, and pupillary dilatation are superior in detecting painful stimulations compared to heart rate and mean arterial pressure but had limited predictive value. These effects are attenuated by increasing dosages of remifentanil. Our data confirm that bispectral index is not a marker of analgesia.

scholarly journals Reducing Aggression by Developing Emotional and Inhibitory Control

2021 ◽  
Vol 18 (10) ◽  
pp. 5263
Author(s):  
Miriam Romero-López ◽  
María Carmen Pichardo ◽  
Ana Justicia-Arráez ◽  
Judit Bembibre-Serrano
Keyword(s):  
Psychosocial Development ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Generalized Linear Mixed Model ◽  
Emotional Control ◽  
Control Group ◽  
Post Intervention ◽  
Mixed Model Analysis ◽  
Intervention Measures ◽  
Experimental Group

The objective of this study is to measure the effectiveness of a program on improving inhibitory and emotional control among children. In addition, it is assessed whether the improvement of these skills has an effect on the reduction of aggressive behavior in pre-school children. The participants were 100 children, 50 belonging to the control group and 50 to the experimental group, aged between 5 and 6 years. Pre-intervention and post-intervention measures of inhibitory and emotional control (BRIEF-P) and aggression (BASC) were taken. A Generalized Linear Mixed Model analysis (GLMM) was performed and found that children in the experimental group scored higher on inhibitory and emotional control compared to their peers in the control group. In addition, these improvements have an effect on the decrease in aggressiveness. In conclusion, preventive research should have among its priorities the design of such program given their implications for psychosocial development.

scholarly journals Methods to Assess Fat Mass in Infants and Young Children: A Comparative Study Using Skinfold Thickness and Air-Displacement Plethysmography

Life ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 75
Author(s):  
Stefanie M. P. Kouwenhoven ◽  
Nadja Antl ◽  
Jos W. R. Twisk ◽  
Berthold V. Koletzko ◽  
Martijn J. J. Finken ◽  
...  
Keyword(s):  
Young Children ◽  
Fat Mass ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Correlation Coefficients ◽  
Skinfold Thickness ◽  
Limited Information ◽  
Air Displacement Plethysmography ◽  
Mixed Model Analysis ◽  
Infants And Young Children

Background: Traditionally, fat mass is estimated using anthropometric models. Air-displacement plethysmography (ADP) is a relatively new technique for determining fat mass. There is limited information on the agreement between these methods in infants and young children. Therefore we aimed to longitudinally compare fat mass percentage values predicted from skinfold thicknesses (SFTs) and ADP in healthy infants and young children. Methods: Anthropometry and body composition were determined at the ages of 1, 4, and 6 months and 2 years. We quantified the agreement between the two methods using the Bland–Altman procedure, linear mixed-model analysis, and intra-class correlation coefficients (ICC). Results: During the first 6 months of life, fat mass% predicted with SFT was significantly different from that measured with ADP in healthy, term-born infants (n = 245). ICCs ranged from 0.33 (at 2 years of age) and 0.47 (at 4 months of age). Although the mean difference (bias) between the methods was low, the Bland–Altman plots showed proportional differences at all ages with wide limits of agreement. Conclusions: There is poor agreement between ADP and SFTs for estimating fat mass in infancy or early childhood. The amount of body fat was found to influence the agreement between the methods.

Factors influencing the occurrence of high ultimate pH in three muscles of lamb carcasses in Australia

2014 ◽  
Vol 54 (10) ◽  
pp. 1853 ◽  
Author(s):  
N. G. McPhail ◽  
J. L. Stark ◽  
A. J. Ball ◽  
R. D. Warner
Keyword(s):  
Mixed Model ◽  
Linear Mixed Model ◽  
Rectus Femoris ◽  
Carcass Weight ◽  
Mixed Model Analysis ◽  
Factors Influencing ◽  
South Wales ◽  
Generalised Linear Mixed Model ◽  
Processing Plants ◽  
Few Data

Chilled lamb meat exported from Australia has, on occasions, been rejected by importing countries due to greening, after only 6 weeks of storage time. Greening is known to be more prevalent in high ultimate pH (pHu) beef meat (>5.9). There are few data available for lamb carcasses in Australia on the occurrence of high pHu meat, which may have an impact on the understanding and control of quality and greening during storage. The aim of this project was to determine the prevalence of, and influencing factors for, high pHu meat in a range of muscle types in lamb carcasses in Australia. Muscle pHu data were collected from a total of 1614 carcasses from 78 lots at four lamb processing plants in Victoria and New South Wales in autumn and spring of 2013. The pHu of the knuckle (rectus femoris), rack (longissimus) and blade (infraspinatus) was measured and data on carcass and lot characteristics were recorded. Data were subjected to restricted maximum likelihood and generalised linear mixed model analysis. The mean pHu of the knuckle, rack and shoulder were 6.06, 5.79 and 6.12 respectively, and the main factors influencing muscle pHu and occurrence of dark-cutting were breed, season, electrical stimulation and carcass weight. Merino lambs had a higher pHu in the blade and knuckle than did other breeds (P < 0.05, P < 0.01 respectively). Lambs processed in autumn had a higher predicted pHu in the blade and knuckle and a higher percentage dark-cutting (DC; pHu >6.0) for those muscles, than did those processed in spring (P < 0.05). Carcasses that had been electrically stimulated had a higher %DC and a higher pHu in all three muscles (P < 0.05). Carcass weight had a significant effect on the pHu of all three muscles (P < 0.001), with heavier carcasses having a lower pHu and lower %DC. The pHu of the rack was not a reliable predictor for the pHu in other muscles of the lamb carcass. In conclusion, the high occurrence of DC in the muscles, particularly the blade and knuckle, suggests that these muscles may be at risk for producing greening in the vacuum bag during storage.

Size-related boldness is not altered by stomach flushing in a terrestrial salamander

2021 ◽  
pp. 1-6
Author(s):  
Sebastiano Salvidio ◽  
Andrea Costa ◽  
Fabrizio Oneto
Keyword(s):  
Body Condition ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Animal Personality ◽  
Model Analysis ◽  
Mixed Model Analysis ◽  
Linear Mixed Model Analysis ◽  
Before And After ◽  
Trophic Strategy ◽  
The Relationship

Abstract Animal personality is a relatively neglected field in amphibian research. In this study we assessed the influence of stomach flushing, a non-lethal technique used in amphibian dietary studies, on the boldness behaviour of the cave salamander Speleomantes strinatii. The time of emergence from a shelter located in an unfamiliar environment (a proxy for individual boldness) was measured in 26 cave salamanders before and after stomach flushing, while 14 non-flushed salamanders were tested as controls. Boldness was a repeatable behaviour for salamanders and larger individuals emerged from their shelter more rapidly than smaller ones. Linear mixed model analysis showed that flushing, sex and body condition had no effect on this behaviour. These findings are promising in the framework of the study of salamander personality. In particular, our results will be useful when exploring the relationship between individual trophic strategy and boldness, aggression or exploration behaviours in terrestrial salamanders.

scholarly journals Maximin Efficiencies under Treatment-Dependent Costs and Outcome Variances for Parallel, AA/BB, and AB/BA Designs

2018 ◽  
Vol 2018 ◽  
pp. 1-15
Author(s):  
Math J. J. M. Candel
Keyword(s):  
Mixed Model ◽  
Linear Mixed Model ◽  
Optimal Allocation ◽  
Power Level ◽  
Equal Treatment ◽  
Small Samples ◽  
Asymptotic Results ◽  
Crossover Designs ◽  
Mixed Model Analysis ◽  
Intraclass Correlations

If there are no carryover effects, AB/BA crossover designs are more efficient than parallel (A/B) and extended parallel (AA/BB) group designs. This study extends these results in that (a) optimal instead of equal treatment allocation is examined, (b) allowance for treatment-dependent outcome variances is made, and (c) next to treatment effects, also treatment by period interaction effects are examined. Starting from a linear mixed model analysis, the optimal allocation requires knowledge on intraclass correlations in A and B, which typically is rather vague. To solve this, maximin versions of the designs are derived, which guarantee a power level across plausible ranges of the intraclass correlations at the lowest research costs. For the treatment effect, an extensive numerical evaluation shows that if the treatment costs of A and B are equal, or if the sum of the costs of one treatment and measurement per person is less than the remaining subject-specific costs (e.g., recruitment costs), the maximin crossover design is most efficient for ranges of intraclass correlations starting at 0.15 or higher. For other cost scenarios, the maximin parallel or extended parallel design can also become most efficient. For the treatment by period interaction, the maximin AA/BB design can be proven to be the most efficient. A simulation study supports these asymptotic results for small samples.

scholarly journals Which Test of Divergent Thinking Is Best?

2016 ◽  
Vol 3 (1) ◽  
pp. 4-18 ◽  
Author(s):  
Mark A. Runco ◽  
Ahmed M. Abdulla ◽  
Sue Hyeon Paek ◽  
Fatima A. Al-Jasim ◽  
Hanadi N. Alsuwaidi
Keyword(s):  
Divergent Thinking ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Mixed Model Analysis ◽  
Demographic Questionnaire ◽  
Problem Generation ◽  
Behavior Scale ◽  
Realistic Problem ◽  
Post Hoc ◽  
Better Than

AbstractDivergent thinking (DT) tests are probably the most commonly used measures of creative potential. Several extensive batteries are available but most research relies on one or two specific tests rather than a complete battery. This may limit generalizations because tests of DT are not equivalent. They are not always highly inter-correlated. Additionally, some DT tests appear to be better than others at eliciting originality. This is critical because originality is vital for creativity. The primary purpose of the present study was to determine which test of DT elicits the most originality. Seven measures of DTwere administered on a sample of 611 participants in eight Arabic countries. The tests were Figural, Titles, Realistic Presented Problems, Realistic Problem Generation, Instances, Uses, and Similarities. The Quick Test of Convergent Thinking, Runco’s Ideational Behavior Scale, and a demographic questionnaire were also administered. A linear mixed model analysis confirmed that the originality scores in the DT tests differed by test. Post-hoc tests indicated that the Titles and Realistic Problem Generation tests produced the highest mean originality scores, whereas the Realistic Presented Problems test produced the lowest mean originality scores. These differences confirm that research using only one DT test will not provide generalizable results.

Appetite-stimulating effect of gabapentin vs mirtazapine in healthy cats post-ovariectomy

2020 ◽  
Vol 22 (12) ◽  
pp. 1176-1183
Author(s):  
Marco Fantinati ◽  
Julien Trnka ◽  
Amélia Signor ◽  
Séverine Dumond ◽  
Géraldine Jourdan ◽  
...  
Keyword(s):  
Placebo Group ◽  
Food Intake ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Repeated Measure ◽  
Mixed Model Analysis ◽  
Treatment Groups ◽  
Significant Difference ◽  
Post Hoc ◽  
Difference Test

Objectives The aim of the study was to evaluate the appetite-stimulating effect of gabapentin by comparing it with mirtazapine in healthy cats in the first 8 h after ovariectomy surgery. Methods This double-masked, placebo-controlled, prospective clinical trial included 60 healthy cats presented to the hospital for ovariectomy: 20 received gabapentin, 21 received mirtazapine and 19 received a placebo immediately before and 6 h after surgery. Food was offered at 2, 4, 6 and 8 h post-ovariectomy. After each meal, food intake was measured. Data were analysed using repeated-measure ANOVA and a linear mixed-model analysis. Post-hoc Tukey’s honest significant difference test was performed for multiple comparisons. Results Food intake increased in both treatment groups vs placebo. No statistically significant difference was found between cats treated with gabapentin or mirtazapine. Conclusions and relevance Cats receiving gabapentin ate more than cats in the placebo group. Thirty percent of cats in the gabapentin group covered their resting energy requirements, while none of the cats in the placebo group did. Gabapentin and mirtazapine produced similar effects on food intake.

scholarly journals Associations of Retinal Microvascular Diameters and Tortuosity With Blood Pressure and Arterial Stiffness

Hypertension ◽  
2019 ◽  
Vol 74 (6) ◽  
pp. 1383-1390 ◽  
Author(s):  
Robyn J. Tapp ◽  
Christopher G. Owen ◽  
Sarah A. Barman ◽  
Roshan A. Welikala ◽  
Paul J. Foster ◽  
...  
Keyword(s):  
Blood Pressure ◽  
United Kingdom ◽  
Mean Arterial Pressure ◽  
Arterial Stiffness ◽  
Arterial Pressure ◽  
Retinal Vessel ◽  
Vessel Diameter ◽  
Automated Image Analysis ◽  
Stiffness Index ◽  
Arterial Stiffness Index

To examine the baseline associations of retinal vessel morphometry with blood pressure (BP) and arterial stiffness in United Kingdom Biobank. The United Kingdom Biobank included 68 550 participants aged 40 to 69 years who underwent nonmydriatic retinal imaging, BP, and arterial stiffness index assessment. A fully automated image analysis program (QUARTZ [Quantitative Analysis of Retinal Vessel Topology and Size]) provided measures of retinal vessel diameter and tortuosity. The associations between retinal vessel morphology and cardiovascular disease risk factors/outcomes were examined using multilevel linear regression to provide absolute differences in vessel diameter and percentage differences in tortuosity (allowing within person clustering), adjusted for age, sex, ethnicity, clinic, body mass index, smoking, and deprivation index. Greater arteriolar tortuosity was associated with higher systolic BP (relative increase, 1.2%; 95% CI, 0.9; 1.4% per 10 mmHg), higher mean arterial pressure, 1.3%; 0.9, 1.7% per 10 mmHg, and higher pulse pressure (PP, 1.8%; 1.4; 2.2% per 10 mmHg). Narrower arterioles were associated with higher systolic BP (−0.9 µm; −0.94, −0.87 µm per 10 mmHg), mean arterial pressure (−1.5 µm; −1.5, −1.5 µm per 10 mmHg), PP (−0.7 µm; −0.8, −0.7 µm per 10 mmHg), and arterial stiffness index (−0.12 µm; −0.14, −0.09 µm per ms/m 2 ). Associations were in the same direction but marginally weaker for venular tortuosity and diameter. This study assessing the retinal microvasculature at scale has shown clear associations between retinal vessel morphometry, BP, and arterial stiffness index. These observations further our understanding of the preclinical disease processes and interplay between microvascular and macrovascular disease.

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