DEPENDENCE OF SPRING WHEAT YIELD ON HYDROTHERMIC CONDITIONS IN THE SARATOV REGION

Using long-term stationary field studies on the phases of development of spring wheat, a prognostic equation for calculating the yield of a given crop depending on the duration of the growing season with a monthly lead time was derived. Taking into account the hydrothermic factors of the Saratov region, the prognostic equation of the multiple function of the yield of spring wheat from the amount of precipitation for April-May, the average air temperature in May, the amount of precipitation in June, the amount of precipitation in July, and the duration of the growing season was calculated.

Evaluation of a Method for Calculating the Height of the Stable Boundary Layer based on Wind Profile Lidar and Turbulent Fluxes

The height of the stable boundary layer (SBL), known as the nocturnal boundary layer height, is controlled by numerous factors of different natures. The SBL height defines the state of atmospheric turbulence and describes the diffusion capacity of the atmosphere. Therefore, it is unsurprising that many alternative (sometimes contradictory) formulations for the SBL height have been proposed to date, and no consensus has been achieved. In our study, we propose an iterative algorithm to determine the SBL height h based on the flux–profile relationship using wind profiles and turbulent fluxes. This iterative algorithm can obtain temporally continuous, accurate estimates of h and is widely applicable. The predicted h presents relatively good agreement with four observation-derived SBL heights, hJ, h1, hi, and hθ (hJ: maximum wind speed height, h1: zero wind shear height, hi: temperature inversion height, and hθ: height at which 0.8 times the inversion strength appears for the first time), especially with hθ, which shows the best fit. In addition, h exhibits a low absolute difference and relative difference with hJ, which presents the second-best result. The agreement with hi and h1 may be satisfactory, but small differences are observed, and the one standard deviation of the mean relative difference is large. In addition, the predicted h is compared with other SBL height estimation methods, including diagnostic, λ1, λ2 and λ3 (three typical dimensional scale height parameters) and prognostic equation-based methods, λ(h) (an equation for the growth of h developed). The diagnostic formulas are found to be appropriate, especially under extremely stable conditions. Additionally, the equation of λ3 presents the best result of all the dimensional scale height parameters. However, the prognostic equation λ(h) in our study is very unsatisfactory.

Validation of the REVEAL Prognostic Models in Systemic Lupus Erythematosus-Associated Pulmonary Arterial Hypertension

No previous studies have investigated the predictive performance of the Registry to Evaluate Early and Long-term Pulmonary Arterial Hypertension Disease Management (REVEAL) prognostic equation and simplified risk score calculator in patients with systemic lupus erythematosus-associated pulmonary arterial hypertension (SLE-PAH). We aimed to validate these prediction tools in an external cohort of patients with SLE-PAH. In this study, the validation cohort consisted of patients with SLE-PAH registered in a prospective, multicenter, nationwide database between November 2006 and May2016. The follow-up of patients was censored at 1 year. Discrimination, calibration, model fit, and risk stratification of the REVEAL prognostic equation and simplified risk score calculator were validated. As a result, a total of 306 patients with SLE-PAH were included. The 1-year overall survival rate was 91.5%. The C-index of the prognostic equation was 0.736, demonstrating reasonably good discrimination, and it was greater than that for the simplified risk score calculator (0.710). The overall calibration slope was 0.83, and the Brier score was 0.079. The risk of renal insufficiency and World Health Organization Functional Class III (WHO FC III) were underestimated, and the risk assigned to a heart rate >92 bpm in the REVEAL prognostic models was not observed in our validation cohort. Both model discrimination and calibration were poor in the very high-risk group. In conclusion, the REVEAL models exhibit good discriminatory ability when predicting 1-year overall survival in patients with SLE-PAH. Findings from both models should be interpreted with caution in cases of renal insufficiency, WHO FC III, and heart rate >92 bpm.

Prognostic Equation for Radar Radial Velocity Derived by Considering Atmospheric Refraction and Earth Curvature

The prognostic equation for the radial velocity field observed with a Doppler radar is derived to include the effects of atmospheric refraction and earth curvature on radar-beam height and slope angle. The derived equation, called the radial velocity equation, contains a high-order small term that can be truncated. The truncated radial velocity equation is shown to be much more accurate than its counterpart radial velocity equation derived without considering the effects of atmospheric refraction and earth curvature. The truncated equation has the same concise form as its counterpart radial velocity equation but remains to be sufficiently accurate as a useful dynamic constraint for radar wind analysis and assimilation (in normal situations) even up to the farthest 300-km radial range of operational Weather Surveillance Radar-1988 Doppler (WSR-88D) scans where its counterpart radial velocity equation becomes erroneous.

Abstract 65: Identifying and Adapting a Prognostic Risk Equation for Relevant Subpopulations in a Pharmacoeconomic Model of Major Adverse Cardiovascular Event Prevention

Background: Pharmacoeconomic models in cardiovascular disease (CVD) are typically developed on the basis of an assumed relative risk reduction (RRR) for new treatments which is in turn applied to estimates of baseline risk in patients subject to standard of care medications for coronary heart disease. However, baseline risk of CVD varies by relevant patient characteristics (e.g., age, gender, event history) and additional risk factors (e.g., smoking, diabetes, chronic kidney disease, lipids, blood pressure, obesity) which can be applied across diverse populations and settings. This study aimed to find and adapt a prognostic equation to adjust baseline risk of major adverse cardiovascular events (MACE=CV death, non fatal MI, Stroke), in a general pharmacoeconomic model, based on population risk factor prevalence. Methods: In order to find an equation that includes all relevant risk factors, a literature search was conducted to update a review (published 2008) of 70 pre-2005 primary cardiovascular risk equations. Once an equation was selected, a relative risk was calculated from the ratio of estimated one-year CV risks of the modeled population versus the population in the selected equation. An initial assumption of independence of risk factors was made. The resulting ratio is adapted as a risk multiplier to estimate risk when modeling specific trial populations or subpopulations. Results: None of the original 70 equations included all of the six factors of interest, and only two contained kidney disease. In addition to updates and modifications of the 70 equations, four new studies were identified, including the UK-based QRISK2 which was the only prognostic equation that uses all six factors. QRISK2 was developed using over 16 million person-years’ worth of observations with 140,000 cardiovascular events, and was validated against the UK THIN population. The adapted QRISK2 equation estimates the first-year CV risk for a population adjusted for the six additional risk factors to be 7.1%. However the subset with diabetes and/or kidney disease, which makes up about 43% of the population, has an estimated risk of about 11%. If a treatment is assumed to reduce CV risk by 15% in both the entire and subset populations, then the number needed to treat to avoid one event is reduced from 93 for the entire population to 61 for the diabetes and/or renal impairment subset. Conclusions: Estimating the ratio of absolute risks for specific populations and subsets using QRISK2 can help a model to predict the value of targeting relevant subpopulations for a new treatment. When this risk adjustment is included in a lifetime model, additional benefits from secondary prevention, and increased likelihood that a treatment is cost effective in a UK context, can also be estimated. For non-UK populations, calibration of QRISK2 is needed or an alternative equation must be used.

The Gregoriev Ice Cap evolution according to the 2-D ice flowline model for various climatic scenarios in the future

Different flowline thickness distributions and flowline length changes of the Gregoriev Ice Cap were obtained for some surface mass balance histories which can be considered as possible surface mass balances in the future. The ice cap modeling was performed by solving full Stokes equations in the form of one mechanical equilibrium equation in terms of stress deviator components in couple with continuity equation for incompressible substance. The numerical solution was obtained by the finite-difference method. The problem of diagnostic equations stability was overcome by a~compound approximation of the ice surface boundary condition based on the extending of the mechanical equilibrium equation to ice surface points. The problem of stability in the prognostic equation can arise at relatively small grid size in horizontal direction in the case of steep velocity decreasing closely to the ice front and was overcome by introducing the artificial viscosity into the prognostic equation. The basal sliding can arise in the glacier tongue at certain climatic conditions and was introduced through the linear friction law. The correlations between glacier length changes and annual air temperature histories were investigated within the simplified equation in the form of linear dependence of annual air temperature versus the glacier length and time derivation of the length.