Percentage Of Absolute Difference Research Articles

Assessment water productivity of barley varieties under water stress by AquaCrop model

Drought is the major a biotic stress that reduces plant growth and crop productivity worldwide. AquaCrop model is one of the most widely used simulation models, which simulates the growth, yield and water productivity of the crops. Field experiment was carried out in the Experimental Research Station of Nubaria, during two seasons of 2016/2017 and 2017/2018. The study to assess water productivity of Mediterranean barley (Egyptian, Tunisian, Algerian and Morocco) varieties grown under water stress condition (40% of water holding capacity) compared to normal one (75% of water holding capacity) by AquaCrop model. Deviations (%) between observed under normal irrigation water and observed water deficit (stress), AquaCrop model normal and AquaCrop model stress, data obtained were (2.36, 1.84, 2.25 and 1.59%) for Egyptian barley varieties, respectively. For Tunisian barley varieties, deviations (%) were (2.06, 1.59, 2.78 and 3.62%), respectively. For Algerian barley varieties, were (2.12, 1.66, 2.88 and 3.71%), respectively. The percentage of absolute difference between the percentage of variation in the case of water stress and the case without water stress treatment was 5.36% under Egyptian varieties, followed by Morocco varieties (12.78%). Egyptian varieties are the least tolerant of water stress treatment where the percentage difference in the absolute difference between the cases is equal to 25%.

LO82: Normal bedside ultrasound of growth plates in healthy children

Introduction: The diagnosis of Salter-Harris Type 1 fractures in the Emergency Department (ED) is primarily clinical, as radiographs are usually unrevealing. We hypothesize that bilateral asymmetry of the growth plate, detected using bedside ultrasound (US), could improve the accuracy of this diagnosis in the ED. This study seeks to determine growth plate size according to age, and to establish normal variation in bilateral symmetry of growth plate cartilage, for the ulna, radius, tibia, and fibula, using bedside US in normal healthy children. Methods: This prospective observational study was conducted in a convenience sample of children ages 0-17 during planned visits to an elementary school, high school, and an outpatient pediatric clinic. A sample size of 177 was determined with a linear regression model using previously published data on the subject. The study was approved by the hospital and universitys ethics board. After a medical questionnaire with a research nurse, the participants underwent ultrasound evaluation of bilateral ulnae, radii, fibulae, and tibiae, to obtain still images of the physes from two orthogonal views. The evaluations were performed by 3 medical residents, 1 medical student, and by the supervising emergency physician. All ultrasonographers were EDE1 certified and specifically trained for growth plate imagery. The still images were evaluated ulteriorly and measurements taken of the physeal cartilage. Ten percent of the patients had their images re-evaluated by the supervising physician to determine inter-rater reliability. Results: A total of 227 patients were recruited. The median age was 8 years old with an interquartile range of (3;14). Mean growth plate size by age was determined, confirming decreasing growth plate size with advancing age for all articulations. The percentage of absolute difference between right and left, for all growth plates together, was a mean of 17% with a 95% CI of 16-19%. The overall inter-rater reliability was excellent at 0.84. Conclusion: This study establishes a reproducible technique of measuring growth plates with ultrasound. We suspect that increased asymmetry at the growth plate, beyond this established normal variation, may signify a physis widening or hematoma consistent with a Salter-Harris Type 1 fracture; this will be evaluated in a second study.

Dr. Liver: A preoperative planning system of liver graft volumetry for living donor liver transplantation

Background and ObjectiveManual tracing of the right and left liver lobes from computed tomography (CT) images for graft volumetry in preoperative surgery planning of living donor liver transplantation (LDLT) is common at most medical centers. This study aims to develop an automatic system with advanced image processing algorithms and user-friendly interfaces for liver graft volumetry and evaluate its accuracy and efficiency in comparison with a manual tracing method. MethodsThe proposed system provides a sequential procedure consisting of (1) liver segmentation, (2) blood vessel segmentation, and (3) virtual liver resection for liver graft volumetry. Automatic segmentation algorithms using histogram analysis, hybrid level-set methods, and a customized region growing method were developed. User-friendly interfaces such as sequential and hierarchical user menus, context-sensitive on-screen hotkey menus, and real-time sound and visual feedback were implemented. Blood vessels were excluded from the liver for accurate liver graft volumetry. A large sphere-based interactive method was developed for dividing the liver into left and right lobes with a customized cutting plane. The proposed system was evaluated using 50 CT datasets in terms of graft weight estimation accuracy and task completion time through comparison to the manual tracing method. The accuracy of liver graft weight estimation was assessed by absolute difference (AD) and percentage of AD (%AD) between preoperatively estimated graft weight and intraoperatively measured graft weight. Intra- and inter-observer agreements of liver graft weight estimation were assessed by intraclass correlation coefficients (ICCs) using ten cases randomly selected. ResultsThe proposed system showed significantly higher accuracy and efficiency in liver graft weight estimation (AD = 21.0 ± 18.4 g; %AD = 3.1% ± 2.8%; percentage of %AD > 10% = none; task completion time = 7.3 ± 1.4 min) than the manual tracing method (AD = 70.5 ± 52.1 g; %AD = 10.2% ± 7.5%; percentage of %AD > 10% = 46%; task completion time = 37.9 ± 7.0 min). The proposed system showed slightly higher intra- and inter-observer agreements (ICC = 0.996 to 0.998) than the manual tracing method (ICC = 0.979 to 0.999). ConclusionsThe proposed system was proved accurate and efficient in liver graft volumetry for preoperative planning of LDLT.

Validation of electronic sphygmomanometers against mercury sphygmomanometers at high altitude in Tibet

Objective: Studies at normal altitude generally showed that electronic sphygmomanometers (ES) yielded different readings from mercury sphygmomanometers (MS) but could be used as a substitute. Little is known about the performance of ES at high altitude, necessitating this validation study. Design and methods: In Dangxiong County in Tibet, 4300 m above sea level, a well-trained cardiologist measured the systolic (SBP) and diastolic blood pressure (DBP) of 129 adults (80 men, aged between 19 and 69, mean age 38) 3 times in a quiet roomwith proper room temperature. An ES (Omron HEM-759P) was connected with the MS by an air control valve and the bulb assembly served as the pressure source, allowing simultaneous measurement of BP using the 2 instruments. Results: Mean SBP measured by ES (124.67 ± 20.39 mm Hg) was significantly higher than by MS (118.91 ± 20.56 mm Hg) (5.76 mm Hg, p < 0.001) while DBPmeasured by ES (76.54±12.63mmHg) and byMS (76.95± 13.86mmHg) has no significant difference (− 0.42mmHg, p=0.228). Difference in SBP measured by ES and MS was more pronounced in men (6.84 mm Hg) than in women (4.00 mm Hg) (p = 0.002); and for DBP, no gender difference was found (− 0.93 mm Hg vs. 0.42 mm Hg, P=0.58). The Pearson's correlation coefficients betweenMSand ES were 0.974 for SBP (p < 0.001) and 0.961 for DBP (p < 0.001). The percentages of absolute differences between ES andMS in categories≤ 5 mm Hg, ≤ 10 mm Hg and ≤ 15 mm Hg for SBP were 50.4%, 82.2% and 96.1% respectively; and 86.7%, 99.2% and 100% for DBP respectively. Bland–Altman plots showed good consistency between MS and ES for both SBP and DBP measurements. Conclusion: To our knowledge, the first validation study conducted at high altitude demonstrated comparable differences between ES andMS as those at normal altitude. More studies are needed to firmly establish the usability of ES in high altitude.

The study on the association of blood pressure and relative factors with cholesterol and ABI and PWV in hypertensive patients

Objective: Studies at normal altitude generally showed that electronic sphygmomanometers (ES) yielded different readings from mercury sphygmomanometers (MS) but could be used as a substitute. Little is known about the performance of ES at high altitude, necessitating this validation study. Design and methods: In Dangxiong County in Tibet, 4300 m above sea level, a well-trained cardiologist measured the systolic (SBP) and diastolic blood pressure (DBP) of 129 adults (80 men, aged between 19 and 69, mean age 38) 3 times in a quiet roomwith proper room temperature. An ES (Omron HEM-759P) was connected with the MS by an air control valve and the bulb assembly served as the pressure source, allowing simultaneous measurement of BP using the 2 instruments. Results: Mean SBP measured by ES (124.67 ± 20.39 mm Hg) was significantly higher than by MS (118.91 ± 20.56 mm Hg) (5.76 mm Hg, p < 0.001) while DBPmeasured by ES (76.54±12.63mmHg) and byMS (76.95± 13.86mmHg) has no significant difference (− 0.42mmHg, p=0.228). Difference in SBP measured by ES and MS was more pronounced in men (6.84 mm Hg) than in women (4.00 mm Hg) (p = 0.002); and for DBP, no gender difference was found (− 0.93 mm Hg vs. 0.42 mm Hg, P=0.58). The Pearson's correlation coefficients betweenMSand ES were 0.974 for SBP (p < 0.001) and 0.961 for DBP (p < 0.001). The percentages of absolute differences between ES andMS in categories≤ 5 mm Hg, ≤ 10 mm Hg and ≤ 15 mm Hg for SBP were 50.4%, 82.2% and 96.1% respectively; and 86.7%, 99.2% and 100% for DBP respectively. Bland–Altman plots showed good consistency between MS and ES for both SBP and DBP measurements. Conclusion: To our knowledge, the first validation study conducted at high altitude demonstrated comparable differences between ES andMS as those at normal altitude. More studies are needed to firmly establish the usability of ES in high altitude.

The effect of heart rate variability on request for labour epidural analgesia

Maternal heart rate variability of 62 parturients were compared based on their choice of using (epidural group, 44 women) or not using (control, 18 women) epidural analgesia. Baseline heart rate variability and visual analogue scores were recorded when the cervix of the parturient dilated to 2-4 cm, and paired data were collected 1 h later. We found that parturients in the epidural group had greater heart rate variability at the beginning of labour. Multiple logistic regression analysis identified percentage of absolute difference in successive RR intervals exceeding 20 ms as the best indicator of choosing epidural analgesia. Almost all heart rate variability measures were unchanged 1 h later in both groups. We concluded that parturients who chose epidural analgesia had greater heart rate variability, and that percentage of absolute difference in successive RR intervals exceeding 20 ms could reflect their likelihood of requesting epidural analgesia at the beginning of labour.

The intra- and inter-operator variability of Echo-Doppler measurements for noninvasive pulmonary arterial pressure determination in congenital heart disease

Objective: This prospective study determines reproducibility of measurements derived from the pulmonary arterial (PA) blood flow velocity waveform in infants and children with congenital heart disease by performance of the Doppler echocardiographic examination by different echocardiographers. Additionally, the effect of respiration on reproductibility is investigation. Methods: In group I consisting of 44 consecutive patients (aged 0.1–16.2 years) admitted for echocardiography, the PA blood flow velocity waveform was independently determined by two equally experienced echocardiographers. To obtain intra-operator variability, one performed the examination again. In 38 mechanical ventilated patients (aged 0.2–15.6 years), PA blood flow velocity was examined twice by the same echocardiographer to investigate the effects of respiration on reproducibility (group II). Results: In both groups, no systematic difference between examinations could be shown for all Doppler measurements. In group I, the percentage of absolute difference between echocardiographers ranged from 6.0% to 26.4%. Maximal acceleration and deceleration were least reproducible. In group II, the percentage of absolute difference between successive PA bloodflow velocity waveform determinations ranged from 9.2% to 28.6%. No significant difference in reproducibility between respiratory phases was present for all Doppler measurements. Reproducibility was best in end-expiratory beats. Conclusions: reproducibility of measurements derived from the PA blood flow velocity waveform is low and might explain the conflicting results in non-invasive PA pressure determination. To overcome effects of respiration, selection of end-expiratory beats is reccommended.