Polar Version Research Articles

Abstract 4481: Enhancing AOH1996 through structure activity relationship exploration for caPCNA inhibition

Abstract Recently, we have developed AOH1996, a small molecule PCNA ligand currently in phase I clinical trial, designed to selectively inhibit the functions of cancer-associated PCNA (caPCNA). Seeking to enhance the potency and selectivity of AOH1996, we conducted an exhaustive Structure-Activity-Relationship (SAR) investigation. Over 100 analogues of AOH1996 were synthesized, systematically modifying its three main components: the naphthyl group, glycine linker, and diphenyl ether. The glycine linker underwent substitution with various natural and unnatural amino acids, while the 1-naphthyl group saw replacements with diverse monocyclic and bicyclic aromatic groups, including quinoline and isoquinoline derivatives. The diphenyl ether moiety was extensively explored by substituting the bridging oxygen with different functional groups (sulfonyl, imido, sulfur, amide), substituting both phenyl rings with various functional groups (fluorine, chlorine, hydroxy, methoxy, methyl, trifluoromethyl), and adopting a nitrogen-walk approach on the terminal phenyl ring to evaluate critical ligand/caPCNA-binding positions. This meticulous effort resulted in the identification of several analogues, such as AOH1160S (featuring a diphenyl thioether group), AOH1996S-4CH3 (with a methyl group at the para-position of the terminal thiophenyl ring), and AOH1996-3CH3 (incorporating an m-methoxy function in the terminal phenyl ring and bridging oxygen), exhibiting similar or superior potency compared to AOH1996. The target binding of these analogues was verified by capturing the binary complex of the more polar version of these analogues in the crystal structure. The synthesis, characterization, and detailed biological activities of these promising AOH analogues will be thoroughly described. Citation Format: Pouya Haratipour, Maryam Zangi, Mahshid Yaghoubi, Long Gu, Jennifer Jossart, John J. Perry, Linda H. Malkas, Robert J. Hickey. Enhancing AOH1996 through structure activity relationship exploration for caPCNA inhibition [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4481.

Spatial and temporal coherence via polarization mutual coherence function

We address polarization coherence in terms of correlations of Stokes variables. We develop an scalar polarization mutual coherence function that allows us to define a polarization coherence time. We find a suitable spectral polarization density allowing a polarization version of the Wiener-Khintchine theorem. With these tools we also address the polarization version of the van Cittert-Zernike theorem.

Generalized Turan-type Inequalities for Polar Derivative of a Polynomial

Let $P(z)=a_0+\sum\limits_{\nu=\mu}^na_{\nu}z^{\nu}$, $1\leq\mu\leq n$, be a polynomial of degree $n$ having all its zeros in $|z|\leq k$, $k\geq 1$. We obtain an improvement and a generalization of an inequality in polar derivative proved by Somsuwan and Nakprasit [1]. Further, we also extend a result proved by Chanam and Dewan [2] to its polar version. Besides, our results are also found to generalize and improve some known inequalities.

Improved regional forecasting of an extreme Arctic cyclone in August 2016 with WRF MRI‐4DVAR

AbstractCycling data assimilation and forecast experiments in August 2016 together with a case study of an intense Arctic cyclone (AC16) are performed. Initial conditions from newly developed Multi‐Resolution Incremental Four‐Dimensional Variational (MRI‐4DVAR) and Three‐Dimensional Variational (3DVAR) data assimilation along with forecasts from the polar version of the Weather Research and Forecasting (Polar WRF) model, mimicking operational configurations, are applied. The tasks are to evaluate MRI‐4DVAR performance during a 20‐day cycling run, to investigate the impacts of initial conditions on the forecast skill of AC16, and to identify the factors impacting AC16's predictability. The results from the 20‐day cycling period demonstrate the robustness and reliability of MRI‐4DVAR for data assimilation and subsequent forecast skill. Multiple processes, including mergers of Arctic cyclones, mergers of vortices, vertical coupling between low‐level and upper‐level circulations, baroclinic processes and jet stream forcing, contributed to the generation and development of AC16. Compared to the initial conditions from 4DVAR, 3DVAR produced amplified polar vortices, stronger baroclinic instability, intensified upper‐level jet streams and a stronger low‐level frontal zone, causing the overdevelopment of AC16 in 3DVAR‐based forecasts. For MRI‐4DVAR, the accurate prediction of AC16 5–7 days ahead is likely due primarily to the more accurate representation of upper‐level atmospheric fields, that was facilitated by better satellite radiance assimilation with MRI‐4DVAR that also produced a balanced initial model state. It is concluded that the high‐resolution Polar WRF which is optimized for Arctic conditions combined with 4DVAR facilitated the improved prediction of AC16 compared to the Global Forecast System (GFS) operational deterministic global forecast.

Nucleon Energy Correlators.

We introduce the concept of the nucleon energy correlators, a set of novel objects that encode the microscopic details of a nucleon, such as the parton angular distribution in a nucleon, the collinear splitting to all orders, as well as the internal transverse dynamics of the nucleon. The nucleon energy correlators complement the conventional nucleon or nucleus tomography, but without introducing the nonperturbative fragmentation functions or the jet clustering algorithms. We demonstrate how the nucleon energy correlators can be measured in the lepton-nucleon deep inelastic scattering. The predicted distributions display a fascinating phase transition between the perturbative and nonperturbative regime. In the perturbative phase, a polar angle version of the Bjorken scaling behavior is predicted. We discuss its possible applications and expect it to aggrandize the physics content at the electron ion colliders with a far-forward detector.

Effect of polarity on prediction of second order derivative thermodynamic properties of refrigerants

In this research, the SAFT-VR Morse has been extended to polar system by considering the dipolar interactions between non-spherical molecules. The second order derivative thermodynamic properties of refrigerants such as speed of sound, specific heat capacity and Joule-Thomson coefficient have been predicted and compared to PPC-SAFT EoS. The model parameters have been obtained using vapor pressure and saturated liquid density data of pure refrigerants. Using obtained model parameters the aforementioned properties have been predicted in the vapor, liquid, saturation and supercritical phases. The effect of polar contribution on model prediction performance has been studied. The results show that, the polar contribution can be neglected without losing model accuracy. The obtained average error of the polar PC-SAFT and polar SAFT-VR Morse is very close to their original versions. As well, the PPC-SAFT EoS gives accurate results compared to SAFT-VR Morse and its polar version, especially in the case of Joule-Thomson coefficient prediction.

Dogs as a constant of culture of Russian arctic old timers

The article examines the zoomorphic code of a dog in the culture of the Russian Ustians - descendants of the Russian old-timers of the lower Indigirka. Russian settlers, having adapted to the harsh climate of the Arctic, created a polar version of Russian culture, in which dogs became an obligatory element. Their role in commercial and economic activities is extremely great. Having become the center of everyday life, the dog is a cultural code of the sub-ethnic group. The linguoculturological approach was adopted to analyze the involvement of dogs in the script of various folklore genres. The article describes materials of dialectal dictionaries and archival funds, demonstrating the linguistic representation of the image of a dog.

Estimating the astronomical seeing above Dome A using Polar WRF based on the Tatarskii equation

A seeing model based on the Tatarskii equation, which uses wind shear and temperature gradient as inputs, has been proposed for Dome A in our previous study. It has been shown that the seeing was correctly reproduced statistically. In this paper, in order to investigate the ability of the Polar version of the Weather Research and Forecasting (PWRF) model to forecast the seeing, we have tried three different PWRF-simulated wind shear and temperature gradient combinations of two levels for the near-ground. The three combinations all give good performance with the correlation coefficients being higher than 0.75, when compared with the seeing measured by the Kunlun Differential Image Motion Monitor at Dome A during the summer of 2019. Besides this, the gradient Richardson number (Ri), which was also simulated by the PWRF model, basically behaved as expected as the Ri is generally large when the measured seeing is small. These results suggest that the PWRF model can be used to forecast the astronomical seeing above Dome A.

Thermodynamic Assessment of the Partitioning of Acetone between Supercritical CO2 and Polystyrene Using the Polar PC-SAFT Equation of State

Supercritical carbon dioxide (scCO2) has gained considerable attention in the process industry due to its favorable economic, environmental, and technical characteristics. Polymer processing is one of the key industrial applications where scCO2 plays an important role. In order to be able to efficiently design the polymer processing equipment, understanding the phase behavior and partition of solutes between scCO2 and polymers is necessary. This paper investigates the partitioning of acetone – a conventional polar cosolvent – between scCO2 and polystyrene – a glassy polymer. We highlight the importance of taking into account the polar interactions between acetone molecules and their role in the polymer phase behavior. The system is modeled under a wide range of temperatures and pressures (278.15–518.2 K and 1.0–20.0 MPa) using the polar version of the perturbed chain statistical associating fluid theory (polar PC-SAFT) equation of state. The results show that at relatively low pressure, the system exhibits a vapor–liquid–liquid (VLL) three-phase region bounded by two two-phase regions (VL and LL). At high pressure, VLL and VL regions disappear and only the LL region remains. The temperature effect is more interesting, showing a transition of upper critical solution temperature behavior to lower critical solution temperature behavior at 10 MPa and 398.15 K. It is found that neglecting the polar term can lead to significant changes in the description of the polymeric-system phase behavior especially at lower temperatures. No such differences are observed at higher temperatures (above 500 K) where the effect of polar interaction is considerably weaker.

Nonconvex lifted unbalanced branch flow model: Derivation, implementation and experiments

This paper develops a novel nonconvex formulation of the unbalanced power flow equations. This formulation extends the lifted nonconvex ‘DistFlow’ a.k.a. balanced branch flow model formulation to the unbalanced case. The feasible set is characterized by linear and nonconvex quadratic equations in matrix variables. It is shown that this formulation is equivalent to previously published rank-constrained semidefinite programming formulations. The formulation is implemented and compared numerically with rectangular and polar versions of the nonlinear AC unbalanced optimal power flow problem.

A weak values approach for testing simultaneous Einstein\u2013Podolsky\u2013Rosen elements of reality for non-commuting observables

In questioning the completeness of quantum mechanics, Einstein–Podolsky–Rosen (EPR) claimed that from the outcomes of local experiments performed on an entangled system, it was possible to ascribe simultaneous reality to the values of certain incompatible observables. As EPR acknowledged, the inevitable disturbance of quantum measurements prevents the precise verification of these assertions on a single system. However, the EPR elements of reality can still be tested at the ensemble level through weak measurements—which minimally disturb the measured system—by interpreting the EPR assertions as assertions about weak values that follow from the outcomes of projective measurements. Here, we report an implementation of such a test through joint weak measurements followed by post-selection on polarization-entangled photon pairs. Our results show that there is a correspondence between the obtained joint weak values and the inferred elements of reality in the polarization version of the EPR assertions.

The added value of high resolution in estimating the surface mass balance in southern Greenland

Abstract. The polar version of the regional climate model RACMO2, version 2.3p1, is used to study the effect of model resolution on the simulated climate and surface mass balance (SMB) of south Greenland for the current climate (2007–2014). The model data at resolutions of 60, 20, 6.6, and 2.2 km are intercompared and compared to SMB observations using three different data refinement methods: nearest neighbour, bilinear interpolation, and a statistical downscaling method utilising the local dependency of fields on elevation. Furthermore, it is estimated how the errors induced by model resolution compare to errors induced by the model physics and initialisation. The results affirm earlier studies that SMB components which are tightly linked to elevation, like runoff, can be refined successfully, as soon as the ablation zone is reasonably well resolved in the source dataset. Precipitation fields are also highly elevation dependent, but precipitation has no systematic correlation with elevation, which inhibits statistical downscaling to work well. If refined component-wise, 20 km resolution model simulations can reproduce the SMB ablation observations almost as well as the finer-resolution model simulations. Nonetheless, statistical downscaling and regional climate modelling are complementary; the best results are obtained when high-resolution RACMO2 data are statistically refined. Model estimates in the accumulation zone do not benefit from statistical downscaling; hence, a resolution of about 20 km is sufficient to resolve the majority of the accumulation zone of the Greenland Ice Sheet with respect to the limited measurements we have. Furthermore, we demonstrate that using RACMO2, a hydrostatic model, at 2.2 km resolution led to invalid results as topographic and synoptic vertical winds exceed 10 m s−1, which violates the hydrostatic model assumptions. Finally, additional tests show that model resolution is as important as properly resolving spatial albedo patterns, correctly initialising the firn column, and uncertainties in the modelled precipitation and turbulent exchange.

Using a polar version of PC-SAFT to understand the impact of added CO2 on the phase behavior of biodiesel systems

Two obstacles to efficient transesterification of triglycerides to form biodiesel are the initial immiscibility of the reactants and the potential depletion of the short chain alcohol into the glycerol-rich phase formed as a result of the reaction. Consequently, co-solvents have been used to promote mixing and lower the energetic requirements of the process. Amongst the multiple proposed co-solvents in the literature carbon dioxide exhibits the highest vapor pressure, which provides multiple benefits in the downstream separation process of the biodiesel products and excess reactants. In previous work the presence of an optimal content of CO2 for each set of P-T conditions was demonstrated for a system containing CO2, methanol and triglycerides. In this work, that approach has been extended to the quaternary system of CO2, methanol, glycerol and biodiesel, with an aim towards understanding how added CO2 can reduce the loss of the reactant methanol to the glycerol-rich phase that forms during the transesterification reaction. Variation of the phase separation over a range of pressures (10–40 MPa) temperatures (40–200 °C) and different methanol to glycerol ratios (2–30:1) and the influence on the optimal conditions are reported using a polar version of PC-SAFT that can easily be extended to multiple substances and process conditions. In general, it has been found that adding CO2 promotes retention of methanol in the oil-rich phase until a very light third phase is formed; the appearance of this third phase is predicted by the PC-SAFT model.

Impact of Assimilation of Radiosonde and UAV Observations from the Southern Ocean in the Polar WRF Model

Weather forecasting in the Southern Ocean and Antarctica is a challenge above all due to the rarity of observations to be assimilated in numerical weather prediction (NWP) models. As observations are expensive and logistically challenging, it is important to evaluate the benefit that additional observations could bring to NWP. Atmospheric soundings applying unmanned aerial vehicles (UAVs) have a large potential to supplement conventional radiosonde sounding observations. Here, we applied UAV and radiosonde sounding observations from an RV Polarstern cruise in the ice-covered Weddell Sea in austral winter 2013 to evaluate the impact of their assimilation in the Polar version of the Weather Research and Forecasting (Polar WRF) model. Our experiments revealed small to moderate impacts of radiosonde and UAV data assimilation. In any case, the assimilation of sounding data from both radiosondes and UAVs improved the analyses of air temperature, wind speed, and humidity at the observation site for most of the time. Further, the impact on the results of 5-day-long Polar WRF experiments was often felt over distances of at least 300 km from the observation site. All experiments succeeded in capturing the main features of the evolution of near-surface variables, but the effects of data assimilation varied between different cases. Due to the limited vertical extent of the UAV observations, the impact of their assimilation was limited to the lowermost 1–2-km layer, and assimilation of radiosonde data was more beneficial for modeled sea level pressure and near-surface wind speed.

Simulations of Winter Arctic Clouds and Associated Radiation Fluxes Using Different Cloud Microphysics Schemes in the Polar WRF: Comparisons With CloudSat, CALIPSO, and CERES

Key Points Winter Arctic clouds simulated by the polar version of the Weather Research and Forecasting model are compared with satellite retrievals The cloud amount and cloud top height of model simulations agree well with those of satellite retrievals The downward longwave radiation at the surface shows realistic temporal variations, but is sensitive to the cloud microphysics scheme choice

POLITICAL WORK IN THE SOUTHERN FRONT MILITARY FORCES THROUGHOUT THE RUSSIAN CIVIL WAR (1918-1920)

Purpose of the study: Recreation of a historically truthful picture, reflecting the role of educational work in the army during the Civil War (1918-1920), which currently continues to be the subject of sharp ideological and scientific discussions. Introduction of previously unknown to the scientific community documents concerning political work in the troops. Generalization of the experience of this work with the aim of shaping the scientific historical consciousness among young people in the context of the modern information struggle.
 Methodology: The conceptual basis for the study relies on the integral paradigm of historical analysis (introduced by the representatives of the RSSU historical school). It allows not only to compare polar versions of the description of the key problems of the Civil War history to create a multidimensional historical panorama but also to find a consensus between the methodological concepts that guided the development of the national historical science in the Soviet period and the modern paradigms of historical knowledge.
 Main Findings: 1. The experience of the activities of the political bodies of the Southern Front related educational work in troops during the Civil War has been considered in order to preserve historical heritage. 2. New archival documents, including leaflets that determine the scientific argumentation of the problem, as well as new concepts (“integral paradigm of historical analysis” and “cultural-historiographic space”) have been introduced into the scientific circulation. 3. The main approaches to assessing the events of the Civil War have been defined.
 Applications of this study: The study can be used in the implementation of various educational programs and projects, scientific and methodological research of problems of national history, as well as training and professional retraining of specialists in the field of history teaching.
 Novelty/Originality of this study: A holistic picture of the activities of the Red Army political agencies in carrying out party political work in the troops of the Southern Front during the Civil War has been presented. The main forms of cultural, educational and propaganda work carried out among the frontline troops and the enemy forces have been analyzed. An assessment of the effectiveness of the mass political work in the creation and strengthening of the Red Army during the period under study has been given.

Microphysics of Snowfall Over Coastal East Antarctica Simulated by Polar WRF and Observed by Radar

AbstractThe current assessment of the Antarctic surface mass balance mostly relies on reanalysis products or climate model simulations. However, little is known about the ability of models to reliably represent the microphysical processes governing the precipitation. This study makes use of recent ground‐based precipitation measurements at Dumont d'Urville station in Adélie Land to evaluate the representation of the precipitation microphysics in the Polar version of the Weather Research Forecast (Polar WRF) atmospheric model. During two summertime snowfall events, high‐resolution simulations are compared to measurements from an X‐band polarimetric radar and from a Multi‐Angle Snowflake Camera (MASC). A radar simulator and a “MASC” simulator in Polar WRF make it possible to compare similar observed and simulated variables. Radiosoundings and surface‐meteorological observations were used to assess the representation of the regional dynamics in the model. Five different microphysical parameterizations are tested. The simulated temperature, wind, and humidity fields are in good agreement with the observations. However, the amount of simulated surface precipitation shows large discrepancies with respect to observations, and it strongly differs between the simulations themselves, evidencing the critical role of the microphysics. The inspection of vertical profiles of reflectivity and mixing ratios revealed that the representation of the sublimation process by the low‐level dry katabatic winds strongly influences the actual amount of precipitation at the ground surface. By comparing the simulated radar signal as well as MASC and model particle size distributions, it is also possible to identify the microphysical processes involved and to pinpoint shortcomings within the tested parameterizations.

Predicting Initial Reactant Miscibility for CO2-Enhanced Transesterification of Triglycerides with Methanol Using a Polar Version of PC-SAFT

The production of biodiesel via the transesterification of triglycerides by low molecular weight alcohols is generally inhibited by the poor mutual miscibility of the polar alcohol and the nonpolar...

Modelling phase behavior of triglycerides, diglycerides and monoglycerides related to biodiesel transesterification in mixtures of alcohols and CO2 using a polar version of PC-SAFT

Soh et al. [1] showed that one can achieve high conversion (98%) of triglycerides to fatty acid methyl esters at 95 °C when carbon dioxide (CO2) is used as a co-solvent to enhance mixing of the immiscible alcohol and triglyceride. Soh's results demonstrated the benefits of using CO2 as a co-solvent yet did not provide information on the evolution of the phase behavior during the reaction. The PC-SAFT equation of state has been employed to understand and predict the phase behavior of the various biodiesel components versus temperature and pressure in the presence of CO2. In previous work [2] the interaction between alkyl-esters and low molecular weight alcohols, glycerol, and CO2 were investigated. Polar PC-SAFT and the Group Contribution PPC-SAFT EoS were used to model phase equilibria amongst the various multicomponent systems. The same approach is extended here, specifically applied to mixtures containing tri-, di- and monoglycerides plus low molecular weight alcohols and CO2.Data for different types of glycerides are scarce and in general the phase boundary curves in CO2-based mixtures are only weakly dependent on CO2 concentration, creating curves with very high slopes in P-T space that accumulate larger prediction errors compared to the previously investigated alkyl-ester systems. Nonetheless, it was found that one could generate a general correlation for binary interaction coefficient that depends only on carbon chain length and degree of unsaturation for description of triglyceride-CO2 mixtures. Binary interaction parameters as low as 12% were obtained for all glyceride-methanol systems and binary interaction coefficient below 3.5% are sufficient to correctly capture CO2 – glyceride vapor-liquid and liquid-liquid phase equilibria.

A New 200‐Year Spatial Reconstruction of West Antarctic Surface Mass Balance

AbstractHigh‐spatial resolution surface mass balance (SMB) over the West Antarctic Ice Sheet (WAIS) spanning 1800–2010 is reconstructed by means of ice core records combined with the outputs of the European Centre for Medium‐Range Weather Forecasts “Interim” reanalysis (ERA‐Interim) and the latest polar version of the Regional Atmospheric Climate Model (RACMO2.3p2). The reconstruction reveals a significant negative trend (−1.9 ± 2.2 Gt/year·per decade) in the SMB over the entire WAIS during the nineteenth century, but a statistically significant positive trend of 5.4 ± 2.9 Gt/year·per decade between 1900 and 2010, in contrast to insignificant WAIS SMB changes during the twentieth century reported earlier. At regional scales, the Antarctic Peninsula and western WAIS show opposite SMB trends, with different signs in the nineteenth and twentieth centuries. The annual resolution reconstruction allows us to examine the relationships between SMB and large‐scale atmospheric oscillations. Although SMB over the Antarctic Peninsula and western WAIS correlates significantly with the Southern Annular Mode due to the influence of the Amundsen Sea Low, and El Niño/Southern Oscillation during 1800–2010, the significant correlations are temporally unstable, associated with the phase of Southern Annular Mode, El Niño/Southern Oscillation and the Pacific decadal oscillation. In addition, the two climate modes seem to contribute little to variability in SMB over the whole WAIS on decadal‐centennial time scales. This new reconstruction also serves to identify unreliable precipitation trends in ERA‐Interim and thus has potential for assessing the skill of other reanalyses or climate models to capture precipitation trends and variability.