Percentage Of Mean Value Research Articles

Accuracy of continuity equation in aortic stenosis and irregular heart rhythm (5–10 beats average)

Abstract Introduction Continuity equation is the cornerstone of aortic valve area (AVA) calculation in patients with aortic stenosis (AS). In patients with irregular rhythms (IR) - especially atrial fibrillation (AF)-, values of velocity-time integral (VTI) at left ventricular outflow tract (LVOT) and aortic valve (AV) vary between heart beats. The usual recommendation is to average the measurements of 5 or 10 beats in both locations. However, original papers describing continuity equation, from which that recommendation arises (refs 1 & 2), only included 3 and 2 AF patients, respectively. To our knowledge, there are not clinical studies to support this procedure and its accuracy has not been established. In contrast, in a previous study our team had evaluated the accuracy of the double envelope technique to assess both LVOT and AV VTI in the same beat, with a 7.8% (CI 95%: 5.8–10.3) difference (error) in the estimation of AVA when compared to pulsed wave of LVOT in patients with stable sinus rhythm. Purpose To evaluate how dispersion in VTIs due to IR impacts on variability of AVA calculations. Methods For each patient, we recorded multiple measurements of VTI in both LVOT and AV (mean 36.8 beats, range 29–47) per patient and location). Reference AVA was estimated using the average of all these measurements. To estimate the accuracy of averaging 5 or 10 heart beats, we created a computer code which simulated the AVA calculation using random samples of these measurements, and calculated the difference between true AVA and that obtained in the simulation (expressed as percentage of the true value). The process was iterated 10,000 times to obtain the distribution of differences and to estimate its mean value. Data handling and graphic representation was performed with Python 3.9.6 and Pyodbc, Pandas, NumPy, Matplotlib and Seaborn libraries. Results We included data from 8 patients with AS and IR (Age: 71 to 89, mean 82.5 years; Aetiology: degenerative (100%); Sex: 3 males / 5 females; Rhythm: AF [7], atrial flutter [1]; Severity: severe [3], moderate [4], mild [1]). Mean difference in AVA calculations was 8.2% (range: 5.1–13.5%). With 10 beats, mean difference was 5.7% (range: 3.6–9.5%). Figute 1 shows violin plot with distribution in each patient of recorded VTIs at both AV (left) and LVOT (right). To ease visualization, data are expressed as percentage of mean values. Fig 2 shows how that variability results in inaccuracy of AVA calculations with 5 (left) or 10 beats (right). Note that in many cases, possible results are located on both sides of the severity threshold of 1 cm2 (red line). Conclusion AVA assessment using 5 beats average results in a mean difference (error) of 8.2%, which can be reduced to a mean of 5.7% using 10 beats. These differences are comparable with the previously observed with the double envelope technique (7.8%). Funding Acknowledgement Type of funding sources: None.

Genetic variability and correlation analysis in indigenous germplasm of okra (Ablemoschus esculentus L. Moench)

An experiment was undertaken to evaluate the genetic variability, coefficient of variation, heritability, genetic advance and correlation coefficient among indigenous okra accessions based on morphological parameters. Ten okra accessions collected from different parts of Garo Hills regions of Meghalaya were planted during 2019 at NEHU Tura campus, Meghalaya in random block design with three replications. The Analysis of variance exhibited significant differences among the accession for different characters evaluated. The phenotypic coefficient of variance (PCV) was predominantly superior to their corresponding genotypic coefficient of variance resulting the role of environmental aspects. A high heritability in relation with high genetic advance as the percentage of mean value was observed for plant height. The Correlation studies between various quantitative characters exhibited significant association between parameters. Plant height, number of fruits per plant showed highly positive significant association with fruit yield per plant both at phenotypic and genotypic level. On the basis of mean performance for fruit yield and its component characters from the present investigation 5 superior okra germplasm lines namely T-4, T-6, T-7, T-8 and T-10 were selected as superior and most promising genotypes for the crop improvement programmed in okra.

Genetic variability and correlation analysis in indigenous germplasm of okra (Ablemoschus esculentus L. Moench)

An experiment was undertaken to evaluate the genetic variability, coefficient of variation, heritability, genetic advance and correlation coefficient among indigenous okra accessions based on morphological parameters. Ten okra accessions collected from different parts of Garo Hills regions of Meghalaya were planted during 2019 at NEHU Tura campus, Meghalaya in random block design with three replications. The Analysis of variance exhibited significant differences among the accession for different characters evaluated. The phenotypic coefficient of variance (PCV) was predominantly superior to their corresponding genotypic coefficient of variance resulting the role of environmental aspects. A high heritability in relation with high genetic advance as the percentage of mean value was observed for plant height. The Correlation studies between various quantitative characters exhibited significant association between parameters. Plant height, number of fruits per plant showed highly positive significant association with fruit yield per plant both at phenotypic and genotypic level. On the basis of mean performance for fruit yield and its component characters from the present investigation 5 superior okra germplasm lines namely T-4, T-6, T-7, T-8 and T-10 were selected as superior and most promising genotypes for the crop improvement programmed in okra.

Genetic variability, heritability, trait associations and path coefficient analysis of maize (Zea mays L.) inbreed lines

Maize (Zea mays L.) is the first most vital cereal share for the productivity, but the second in its production area coverage next to tef, in Ethiopia. However, its development and productivity are influenced by biotic and abiotic factors. The absence of tolerant maize verities and or inbreed lines also another significant problem. Therefore, the present study was targeted to assess the magnitude of genetic variability, heritability and genetic advance of traits, to verify the genotypic and phenotypic associations between essential characteristics and determine the relationship of features with grain yield and direct and indirect effects using path coefficient analysis. The experiment was conducted at Pawe Agricultural Research Center using 23 inbred lines with RCB design with 3 replications. Results revealed that significant (P<0.01) variations were observed between inbred lines in yield and yield-related traits. Moderate to the high genotypic coefficient of variation, heritability and genetic advance as the percentage of mean values were recorded for plant height, ear height and grain yield. Plant height, ear height and number of ears were observed significant to highly significant positive phenotypic and genotypic associations with grain yield. In contrast, days to 50% anthesis and silk emergence, plant and ear aspects were showed negatively significant associations with grain yield at both genotypic and phenotypic levels. The highest grain yield was recorded from A7033 (8.3 t ha-1), CML197 (6 t ha-1) and CML202 (5.5 t ha-1) and these lines could be best female parents’ foe crop maize improvement programs.

Genetic variability of improved maize varieties (Zea mays L.) for acidic soil tolerance under contrasting environments in Assosa, Ethiopia

Maize is the second most widely grown food cereal crop cultivated in the world and consumed in various form of as part of diets of human and animals. However, its production and productivity is affected by biotic and abiotic stresses among which, soil acidity is the key factor. This field experiment was conducted to estimate the genetic variability of maize for yield and yield related traits, and determine the association of traits with grain yield at Assosa and Bambasi districts during the 2017main cropping season. The experiment consisted of limed and unlimed soil as main plots and 21 maize varieties as the sub-plots arranged in a split plot design with 3 replications. Highly significant (P<0.01) differences were observed among maize varieties in yield and yield related-traits at both locations. Moderate to high genotypic coefficient variation, heritability and genetic advance as the percentage of mean values were observed for stalk biomass, ear biomass, diameter and length, and grain yield at both locations. Highly significant phenotypic and genotypic correlations were observed between thousand seed weight and number of kernels per row, thousand seed weight and ear diameter, and number of kernels per row. The yield was highly significant and positively associated with above stalk biomass, ear biomass, thousand seed weight, and number of kernels per row at both locations at the genotypic and phenotypic level. The phenotypic and genotypic correlation and path coefficient analysis of harvesting index, above ground biomass, ear biomass, number of ears harvested per plot, number of rows per ear, and ear length and these traits also showed a direct effect on yield. The highest yield in t/ha was obtained from variety BH547 (3.04) and (7.35) at Assosa and Bambasi, respectively. Additionally, higher yield was recorded from SPRH1, BH661 and BH546 varieties at both locations. Therefore, farmers could use the above varieties in the acidic soil until other advanced varieties are developed, but the exact significant impact and duration of lime management in the acidic soil for maize needs further investigations.

Vertebral morphometry: repeat scan precision using the Lunar Expert-XL and the Hologic 4500A. A study for the 'WISDOM' RCT of hormone replacement therapy.

On radiation safety grounds there is concern about the morbidity attributable to routine radiographs of the spine for the identification of new fractures in large-scale trials of fracture prevention. However, the role of the potentially safer low-radiation-dose technique of vertebral morphometry performed by third generation dual-energy X-ray absorptiometry equipment requires evaluation for use in clinical trials. We have therefore investigated the short-term inter-scan imprecision as well as the imprecision attributable to different-day analyses by the same operator and differences in analyses by different operators. The volunteer subjects were participants in a pilot study for a randomized controlled trial of hormone replacement therapy (Women's International Study of long Duration Oestrogen after Menopause, WISDOM). Each subject had two morphometric X-ray analysis scans separated by 2-4 weeks. Exclusions were women with densitometrically defined osteoporosis, as defined by the WHO criterion, and women with a body mass index exceeding 30.9 kg/m2. On average, the women were 58.7 years of age and had bone mineral density values in the lumbar spine which were about 0.7 SD units higher than a reference US female age-matched population. Scans were assessed from vertebrae T7 through L4. In the study there were no clinically significant differences in performance between the Hologic QDR 4500A and the Lunar Expert XL equipment. Between-scan imprecision was significantly worse than imprecision attributable to reanalysis of the same scan by a different operator or the same operator after an interval. Vertebral level had an effect on measurement uncertainty, especially at the level of the diaphragm and at T7. Coefficients of variation, expressed as percentages of mean values, were better for absolute height measurements than for height ratios, ranging from 1.75% to 3.40% for the three heights measured on three separate machines and from 2.34% to 4.11% for the two height ratios. These results compared favorably with the equivalent figures from a parallel study of morphometry precision undertaken using standard lateral radiographs of the thoracic and lumbar spine (3.1-3.6% and 3.8-3.9%, respectively). We conclude that in trials of prevention therapy in women (or men) selected for not having osteoporosis, low-dose vertebral morphometry using the Hologic 4500A, the Lunar Expert XL or similar equipment is preferable on safety grounds to the classical technique based on standard radiographs, although conventional radiology may still be required in those with prevalent or incident deformities to exclude causes other than osteoporosis. The place of this low-dose technique in trials performed on patients with osteoporosis requires further study.

Methods for the quantitative analysis of lipids in cereal grains and similar tissues.

AbstractMethods are described for the extraction and quantification of total lipids in cereal grains and other similar tissues, and for the determination of all the major classes of acyl lipid found in these extracts. Total lipids, obtained by direct solvent extraction or after acid hydrolysis, are quantified as fatty acid methyl esters (FAME) by gas chromatography (g.c.), using heptadecanoate (17:0) as internal standard. Individual lipid classes are separated by thin‐layer chromatography; non‐polar lipids and glycolipids are measured as FAME by g.c., while phospholipids are determined from phosphorus distribution. Crude lipid extracts are used to avoid losses during purification, and methanolysis of lipid classes is always performed without extracting the lipids from silica gel in order to minimise autoxidation, handling losses and contamination. Corrections are described for minor losses during experimental procedures, and factors are given for conversion of weights of FAME or phosphorus into weights of original lipid. In the authors' laboratory the precision of routine determinations (variations expressed as percentage of mean values) are usually well within the limits: total lipids, 1.5%; major lipid classes, 1.5%; minor lipid classes, 5%.