No Tillage With Plastic Re-mulching Maintains High Maize Productivity via Regulating Hydrothermal Effects in an Arid Region

Plastic is a valuable mulching measure for increasing crop productivity in arid environments; however, little is known about the main mechanism by which this valuable technology actuates spatial–temporal changes in soil hydrothermal effect. So a 3-year field experiment was conducted to optimize soil hydrothermal effect of maize field with three plastic mulched management treatments: (1) no tillage with plastic re-mulching (NM), (2) reduced tillage with plastic mulching (RM), and (3) conventional tillage with annual new plastic mulching (CM). The results showed that NM treatment increased soil water content by 6.6–8.4% from maize sowing to seedling stage, than did CM, and it created a good soil moisture environment for sowing of maize. Also, NM had greater soil water content by 4.8–5.6% from maize silking to early-filling stage than had CM, and it made up for the abundant demand of soil moisture for the vigorous growth of maize filling stage. The NM treatment increased water consumption (WC) before maize big-flare stage, decreased WC from big-flare to early-filling stage, and increased WC after early-filling stage. So NM treatment effectively coordinated water demand contradiction of maize at entire growing season. NM decreased soil accumulated temperature (SAT) by 7.0–13.0% at maize sowing to early-filling stage than did CM, but NM had little influence on the SAT during filling stage. In particular, the treatment on NM had smaller absolute values of air–soil temperature differences than RM and CM treatments during maize filling stage, indicating that NM treatment maintains the relative stability of soil temperature for ensuring grain filling of maize. The NM treatment allowed the maize to grow in a suitable hydrothermal status and still maintained high yield. In addition, NM treatment obtained higher net income and rate of return by 6.4–11.0% and 44.1–54.5%, respectively, than did CM, because NM treatment mainly decreased the input costs for plastic and machine operations. Therefore, the NM treatment can be recommended as a promising technique to overcome simultaneous heat stress and water shortage in arid environments.

An Integrated and Automated Tool for Quantification of Biomechanics in Fetal and Neonatal Echocardiography

ObjectivesTo show simultaneous quantification of flow and mechanics of cardiac function from fetal and neonatal echocardiograms using an integrated set of automated, physics-based, echocardiography analysis methods.BackgroundQuantifying ventricular biomechanics from fetal and neonatal echocardiograms presents unique and significant challenges. Existing analysis tools are designed for adults and cannot accurately assess fetal subjects.MethodsWe used in-house developed analysis algorithms to quantify ventricular biomechanics from four-chamber B-mode and color Doppler routine examinations recordings for three hypoplastic left heart (HLHS) patients at 33-weeks’ gestation and first week post-birth along with age-matched controls. Chamber morphology, tissue motion, atrioventricular valve inflow, global longitudinal strain, and hemodynamic flow parameters were measured.ResultsPrenatal cardiac output differed between control (LV:157 ± 139 mL/min, RV:257 ± 218 mL/min) and HLHS subjects (410 ± 128 mL/min). This difference persisted for control (LV:233 ± 74 mL/min, RV:242 ± 140 mL/min) and HLHS subjects (637 ± 298 mL/min) after birth. Peak global longitudinal strain measurements did not differ in utero between control (LV: 12.2 ± 4.1%, RV:12.1 ± 4.9%) and HLHS subjects (RV:12.7± 4.2%). After birth, myocardial contraction increased for the control (LV:15.4 ± 2.8%, RV:22.9 ± 6.9%) and HLHS subjects (14.4 ± 6.2%). Postnatal early filling mitral flow velocity for the control subjects (LV:58.8 ± 17.6 cm/s) and early-filling tricuspid flow of the HLHS subjects (64.8 ± 23.7cm/s) were similar, while the late filling velocity decreased for the control subject LV (33.5 ± 8.1 cm/s) compared to the HLHS subjects (66.9 ± 23.0 cm/s). Importantly, flow energy loss in the fetal HLHS hearts was increased (0.35 ± 0.19 m3/s2) compared to the control subjects (LV:0.09 ± 0.07 m3/s2, RV:0.17 ± 0.12 m3/s2), and further increased postnatally for the HLHS subjects (0.55 ± 0.24 m3/s2) compared to the control subjects (LV:0.23 ± 0.20 m3/s2, RV:0.09 ± 0.06 m3/s2).ConclusionsWe demonstrate the feasibility of integrated quantitative measurements of fetal and neonatal ventricular hemodynamics and biomechanics using only four-chamber B-mode and color Doppler recordings.Short AbstractWe integrated novel echocardiogram analysis methods to quantify ventricular flow and mechanics using apical long-axis B-mode and color Doppler imaging from fetal and neonatal subjects. Three hypoplastic left heart patients (HLHS) imaged at 33-weeks gestation and again in the first postnatal week, along with age-matched controls, were evaluated. For the first time, we show quantified hemodynamics from fetal echocardiography using flow reconstruction, flow energy loss, and intraventricular pressure, as well as global strain and strain rate. These tools are capable of longitudinal analysis of ventricle maturation, flow dynamics, and quantified measurements from routine examinations of complex congenital heart disease.

Additional Heart Sounds—Part 1 (Third and Fourth Heart Sounds)

S3 is a low-pitched sound (25–50Hz) which is heard in early diastole, following the second heart sound. The following synonyms are used for it: ventricular gallop, early diastolic gallop, protodiastolic gallop, and ventricular early filling sound. The term “gallop” was first used in 1847 by Jean Baptiste Bouillaud to describe the cadence of the three heart sounds occurring in rapid succession. The best description of a third heart sound was provided by Pierre Carl Potain who described an added sound which, in addition to the two normal sounds, is heard like a bruit completing the triple rhythm of the heart (bruit de gallop). The following synonyms are used for the fourth heart sound (S4): atrial gallop and presystolic gallop. S4 is a low-pitched sound (20–30 Hz) heard in presystole, i.e., shortly before the first heart sound. This produces a rhythm classically compared with the cadence of the word “Tennessee.” One can also use the phrase “A-stiff-wall” to help with the cadence (a S4, stiff S1, wall S2) of the S4 sound.

Development and Evaluation of a New Spectral Disease Index to Detect Wheat Fusarium Head Blight Using Hyperspectral Imaging

Fusarium head blight (FHB) is a major disease threatening worldwide wheat production. FHB is a short cycle disease and is highly destructive under conducive environments. To provide technical support for the rapid detection of the FHB disease, we proposed to develop a new Fusarium disease index (FDI) based on the spectral data of 374–1050 nm. This study was conducted through the analysis of reflectance spectral data of healthy and diseased wheat ears at the flowering and filling stages by hyperspectral imaging technology and the random forest method. The characteristic wavelengths selected were 570 nm and 678 nm for the late flowering stage, 565 nm and 661 nm for the early filling stage, 560 nm and 663 nm for the combined stage (combining both flowering and filling stages) by random forest. FDI at each stage was derived from the wavebands of each corresponding stage. Compared with other 16 existing spectral indices, FDI demonstrated a stronger ability to determine the severity of the FHB disease. Its determination coefficients (R2) values exceeded 0.90 and the RMSEs were less than 0.08 in the models for each stage. Furthermore, the model for the combined stage performed better when used at single growth stage, but its effect was weaker than that of the models for the two individual growth stages. Therefore, using FDI can provide a new tool to detect the FHB disease at different growth stages in wheat.

P204 Recovery of left atrial function after restoration of sinus rhythm in patients with atrial fibrillation

Background Atrial fibrillation (AF) is associated with impaired mechanical function of the atria. The restoration of sinus rhythm (SR) leads to improvement of mechanics, however the onset of those changes is not established yet. Purpose To analyse changes in left atrial (LA) mechanical function after conversion to SR. Methods Forty patients (mean age 65 ± 12 years, 63% male) with nonvalvular AF underwent successful electrical cardioversion. Transthoracic echocardiography with speckle tracking analysis (STE) of LA was performed in AF and within 24 hours after cardioversion, in SR. We analysed standard parameters of left ventricle (LV) and LA. By the use of STE we assessed peak atrial longitudinal strain (PALS), time to PALS indexed to RR interval (TT-PALS/RR) and intra-atrial asynchrony. Results Heart rate during echocardiography was higher before cardioversion - median (IQR) 90 beats per minute (80-110) vs 61 (56-72); p < 0.0001. The mean LV ejection fraction in our study group was 48 ± 11%. We noticed significant improvement in LA STE measurements and in early diastolic (E’) mitral annular velocity. There were no significant changes in systolic (S’) mitral annular velocity and in the ratio of transmitral Doppler early filling velocity to E’ (E/E’). Detailed results are present in the table. Conclusions Speckle tracking measurements are able to detect early mechanical changes in LA even within 24 hours of SR. Atrial fibrillation Sinus rhythm p S" (cm/s) 6 (5-6.5) 6 (5-6.6) NS E" (cm/s) 10 (7.5-13) 9.5 (6.8-10.5) 0.0008 E/E" 8.2 (6.3-12.3) 9.3 (7.5-13) NS PALS (%) 9.9 ± 4.6 14.5 ± 6 <0.0001 TTP-PALS/RR (%) 51 (44-58) 42 (38-45) 0.0001 LA asynchrony 15 (11-19) 9 (8-14) 0.0007

P283 Post-reperfusion indicators of left ventricular diastolic function in patients with ST elevation myocardial infarction

Objective to study the effects of reperfusion on the formation of the type of diastolic dysfunction of the left ventricle in patients with ST elevation acute myocardial infarction (STEMI). Material and Methods The diastolic function of the LV was studied in 302 patients with STEMI using Pulse wave doppler with an estimate of transmitral flow and tissue doppler echocardiography. Depending on the effectiveness of reperfusion, the patients were divided into 3 groups: 1st group - 196 (65%) patients with successful reperfusion (with full ST-segment resolution); Group 2 - 76 (25%) patients with partial reperfusion (ST segment decline by more than 30%, but less than 70% from baseline), Group 3 - 30 (10%) patients with no reperfusion (an increase in the degree of elevation, the absence of dynamics or a decrease in ST elevation by less than 30% from baseline). Results According to the initial state of transmitral flow, patients of the three groups did not differ significantly. The maximum rate of early filling of the LV (E) in patients with the 1st, 2nd and 3rd groups was 58.0 ± 2.4, 56.0 ± 2.6 and 110.0 ± 2.2 cm / s, respectively. The integrated index of the LV diastolic function - the E/A ratio, which is the most important parameter for evaluating LV diastolic function, was equal to 0.83 ± 0.02, 0.79 ± 0.02, and 2.2 ± 0.02, respectively (p> 0.05). The integral of the rate of early filling of the LV (VTIE) was 9.8 ± 0.6, 9.6 ± 0.5 and 9.0 ± 0.6 cm, respectively, without significant intergroup differences. The time of isovolumic relaxation of the LV myocardium in patients of the three groups was equal to 100 ± 5.0, 103 ± 5.6 and 108 ± 5.1 ms, respectively (p> 0.05). According to Doppler echocardiography, 242 (80.0%) of all 302 patients with STEMI showed signs of DDLV in type I on the 1st day of the disease, in 15 (5%) types II (pseudonormal type), in 45 (15%) - for type III (restrictive). The restrictive type of diastolic dysfunction was more common in patients of the 3rd group with no myocardial reperfusion, which may be due to severe myocardial dysfunction. Among patients of the 1st group who had adequate reperfusion, 97% had diastolic dysfunction of the type of relaxation disorder, and 3% had a pseudonormal type of diastolic dysfunction. In this group, the restrictive type of diastolic dysfunction was not registered. Pseudonormal type of diastolic dysfunction among patients of the 3rd group was found in 13%, the 2nd - in 6%, the 1st - in 3%. Conclusion in this way, the process of ischemia and reperfusion, along with impaired systolic function, also leads to impaired LV diastolic function in STEMI. Ontime and successful reperfusion of the myocardium in STEMI contributes to the preservation of indicators of LV diastolic function. With unsuccessful myocardial revascularization, a restrictive type of diastolic dysfunction often develops, which is one of the predictors of unfavorable post-infarction LV remodeling.