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Phase function of light scattering on large atmospheric particles has very strong peak in forward direction constituting a challenge for accurate numerical calculations of radiance required in remote sensing problems. Scaling transformation replaces original phase function with a sum of the delta function and a new regular smooth phase function. Geometric truncation is one of the ways to construct such a smooth function. The replacement phase function coincides with the original one outside the forward cone and preserves the asymmetry parameter. It has discontinuity at the cone. Another simple functional form of the replacement phase function within the cone is suggested. It enables continuity and allows for a number of modifications. Three of them are considered in this study: preserving asymmetry parameter, providing continuity of the 1st derivative of the phase function, and preserving mean scattering angle. Yet another problem addressed in this study is objective selection of the width of the forward cone. That angle affects truncation fraction and values of the phase function within the cone. A heuristic approach providing unambiguous criterion of selection of the truncation angle is proposed. The approach has easy numerical implementation. Suggested modifications were tested on cloud phase function using discrete ordinates and Monte Carlo methods. It was shown that the modifications provide better accuracy of the radiance computation compare to the original geometric truncation with discrete ordinates while continuous derivative approach provides significant gain in computer time with Monte Carlo simulations. [ABSTRACT FROM AUTHOR]

This paper presents a new method of numerical solution of the integral equation for the radiance reflected from an anisotropic surface. The equation relates the radiance at the surface level with BRDF and solutions of the standard radiative transfer problems for a slab with no reflection on its surfaces. It is also shown that the kernel of the equation satisfies the condition of the existence of a unique solution and the convergence of the successive approximations to that solution. The developed method features two basic steps: discretization on a 2D quadrature, and solving the resulting system of algebraic equations with successive over-relaxation method based on the Gauss-Seidel iterative process. Presented numerical examples show good coincidence between the surface-reflected radiance obtained with DISORT and the proposed method. Analysis of contributions of the direct and diffuse (but not yet reflected) parts of the downward radiance to the total solution is performed. Together, they represent a very good initial guess for the iterative process. This fact ensures fast convergence. The numerical evidence is given that the fastest convergence occurs with the relaxation parameter of 1 (no relaxation). An integral equation for BRDF is derived as inversion of the original equation. The potential of this new equation for BRDF retrievals is analyzed. The approach is found not viable as the BRDF equation appears to be an ill-posed problem, and it requires knowledge the surface-reflected radiance on the entire domain of both Sun and viewing zenith angles. [ABSTRACT FROM AUTHOR]

Hydroxyapatite Ca 10 (OH) 2 (PO 4) 6 is a well-known efficient adsorbent of dyes, heavy metal ions, and radionuclides. Its adsorption efficacy strongly depends on crystalline/amorphous structure, defectiveness, texture characteristics, and morphology. Herein, we synthesized Mg2+-, Sr2+-, and Fe3+-substituted (5 mol%) amorphous calcium phosphates as an effective 85Sr and 60Co radionuclides adsorbents. The introduction of Mg2+-, Sr2+-, and Fe3+ ions led to the formation of amorphous calcium phosphates with particles size in the nanoscale range of approximately 10–50 nm. The features of the adsorption behavior of amorphous calcium phosphates were determined depending on the variation of the pH of aqueous, NaCl and CaCl 2 solutions. Fe3+-substituted samples demonstrated the superior adsorption efficiency to 85Sr (K d 7.77 ×103 cm3/g) and 60Co (K d 6.84 ×104 cm3/g) radionuclides at pH of 10.0 and 4.0, respectively. The adsorption performance of obtained adsorbents slowly decreased at 0.1 M NaCl backgrounds and K d 85Sr and 60Co reached 1.67 × 103 and 2.78 × 104 cm3/g for non-substituted calcium phosphate. The dramatic decrease of calcium phosphates adsorbents efficiency to 85Sr (K d <150 cm3/g) and 60Co (K d <1.34 ×103 cm3/g) for 0.05 M CaCl 2 model solution was established. The adsorption mechanism of dissolution-precipitation (for 85Sr) and chemisorption (for 60Co) was proposed. Fe3+-substituted calcium phosphate showed the competitive affinity and selectivity to 85Sr and 60Co comparing with described inorganic adsorbents and to be considered as prospective adsorbent for wastewater treatment in nuclear industry. [Display omitted] • Mg2+-, Sr2+-, and Fe3+-substituted amorphous calcium phosphates were prepared. • The obtained adsorbents were characterized by XRD, FTIR, SEM, EDX techniques. • Effect of pH, NaCl, CaCl 2 salt backgrounds on K d (85Sr, 60Co) were studied. • Fe3+-substituted adsorbent showed the highest affinity and selectivity to 85Sr and 60Co. • The dissolution-precipitation and chemisorption mechanism for 85Sr and 60Co was defined. [ABSTRACT FROM AUTHOR]

This paper presents a new approach for separating atmospheric radiative transport from the lower boundary condition in the case of one-dimensional problem. The approach allows for an exact analytical expression of the solution for an arbitrary surface reflectance. The solution has the form of linear combination of the standard problem solutions with illumination from both top and bottom of the atmosphere. The problem with illumination from below can be solved with existing radiative transfer codes by reversing the order of the atmospheric layers. The solutions for illumination from below are weighted with a surface resolving kernel that is specific for every lower boundary condition. The surface resolving kernel is defined by an integral equation of the Fredholm type. The solution for the Lambertian surface is also obtained in the framework of this approach. Different methods of solution for the surface resolving kernel are considered. The successive iterations of the integral equation for the surface resolving kernel are equivalent to the decomposition of the surface reflected radiance by the orders of reflection. Recipes for the cases when standard problems are solved with the methods of discrete ordinates and spherical harmonics are also considered. [ABSTRACT FROM AUTHOR]

Abstract: State-of-the-art airborne lidar data of passive scalars have shown that the spatial stratification of the atmosphere is scaling: the vertical extent (Δz) of structures is typically where Δx is the horizontal extent and Hz is a stratification exponent. Assuming horizontal isotropy, the volumes of the structures therefore vary as where the “elliptical dimension”Ds characterizes the rate at which the volumes of typical non-intermittent structures vary with scale. Work on vertical cross-sections has shown that 2+Hz =2.55±0.02 (close to the theoretical prediction 23/9). In this paper we extend these (x, z) analyses to (z, t). In the absence of overall advection, the lifetime Δt of a structure of size Δx varies as with Ht =2/3 so that the overall space-time dimension is Dst =29/9=3.22…. However, horizontal and vertical advection lead to new exponents: we argue that the temporal stratification exponent Ht ≈1 or ≈0.7 depending on the relative importance of horizontal versus vertical advection velocities. We empirically test these space-time predictions using vertical-time (z, t) cross-sections using passive scalar surrogates (aerosol backscatter ratios from lidar) at ∼3m resolution in the vertical, 0.5–30s in time and spanning 3–4 orders of magnitude in scale as well as new analyses of vertical (x, z) cross-sections (spanning over 3 orders of magnitude in both x, z directions). In order to test the theory for density fluctuations at arbitrary displacements in (Δz, Δt) and (Δx, Δz) spaces, we developed and applied a new Anisotropic Scaling Analysis Technique (ASAT) based on nonlinear coordinate transformations. Applying this and other analyses to data spanning more than 3 orders of magnitude of space-time scales we determined the anisotropic scaling of space-time finding the empirical value Dst =3.13±0.16. The analyses also show that both cirrus clouds and aerosols had very similar space-time scaling properties. We point out that this model is compatible with (nonlinear) “turbulence” waves, hence potentially explaining the observed atmospheric structures. [Copyright &y& Elsevier]

Zr–Ca–Mg composite phosphates of various chemical compositions were prepared by facile heterogeneous synthesis and their adsorption properties towards 137Cs, 85,90Sr, 60Co radionuclides were studied. The obtained composites showed a high efficiency for 137Cs, 85,90Sr, and 60Co adsorption (K d > 104 mL/g) from model 0.1M NaNO 3 aqueous solution. A sharp decrease in adsorption properties was found against 0.01M CaCl 2 and seawater background, due to a decrease in the adsorbents selectivity. Zr–Ca–Mg phosphates exhibited high efficiency of radionuclides immobilization during metal ions leaching in water (desorption efficiency ∼10%). At the same time, the desorption rate of radionuclides in seawater solutions increased by 4–8 times. Calcination of saturated adsorbents at 1000 °C led significantly to increase in the efficiency of radionuclides immobilization. Thus, the activity of 60Со and 85Sr radionuclides in seawater solutions after exposure for 28 days did not exceed the lower detection limit, and the desorption efficiency of 137Cs was less than 4%. This was due to the formation of mixed Cо 0.5 Zr 0.5 (PO 4), SrZr 4 (PO 4) 6 phosphates, characterized by high efficiency of radionuclides immobilization. The obtained Zr–Ca–Mg composite phosphates are promising materials for the adsorption and immobilization of 137Cs, 85,90Sr, and 60Co radionuclides. • The adsorption of 137Cs, 85,90Sr, 60Co from model solutions was studied. • The high efficiency of Zr–Ca–Mg composite phosphates as adsorbents was shown. • The peculiarities of radionuclides leaching from saline solutions was established. • Enhanced radionuclides immobilization during adsorbents calcination was shown. • The mechanism of radionuclides adsorption and immobilization were carried out. [ABSTRACT FROM AUTHOR]

Epidermal growth factor receptor (EGFR) over-signaling leads to more aggressive tumor growth. The antitumor effect of Cetuximab, an anti-EGFR antibody, depends on oncogenic-signal blockade leading to tumor cell apoptosis and antibody dependent cell-mediated cytotoxicity (ADCC). However, whether adaptive immunity plays a role in Cetuximab-mediated tumor inhibition is unclear, as current xenograft models lack adaptive immunity and human-EGFR-dependent mouse tumor cell lines are unavailable. Using a newly developed xenograft model with reconstituted immune cells, we demonstrate that the Cetuximab effect becomes more pronounced and reduces the EGFR+ human tumor burden when adaptive immunity is present. To further study this in a mouse tumor model, we created a novel EGFR+ mouse tumor cell line and demonstrated that Cetuximab-induced tumor regression depends on both innate and adaptive immunity components, including CD8+ T cells, MyD88, and FcγR. To test whether strong innate signals inside tumor tissues amplifies the Cetuximab-mediated therapeutic effect, Cetuximab was conjugated to CpG. This conjugate is more potent than Cetuximab alone for complete tumor regression and resistance to tumor rechallenge. Furthermore, Cetuximab-CpG conjugates can activate tumor-reactive T cells for tumor regression by increasing dendritic cell (DC) cross-presentation. Therefore, this study establishes new models to evaluate immune responses induced by antibody-based treatment, defines molecular mechanisms, and provides new tumor-regression strategies. [ABSTRACT FROM AUTHOR]

Summary: Anti-HER2/neu antibody therapy is reported to mediate tumor regression by interrupting oncogenic signals and/or inducing FcR-mediated cytotoxicity. Here, we demonstrate that the mechanisms of tumor regression by this therapy also require the adaptive immune response. Activation of innate immunity and T cells, initiated by antibody treatment, was necessary. Intriguingly, the addition of chemotherapeutic drugs, although capable of enhancing the reduction of tumor burden, could abrogate antibody-initiated immunity leading to decreased resistance to rechallenge or earlier relapse. Increased influx of both innate and adaptive immune cells into the tumor microenvironment by a selected immunotherapy further enhanced subsequent antibody-induced immunity, leading to increased tumor eradication and resistance to rechallenge. This study proposes a model and strategy for anti-HER2/neu antibody-mediated tumor clearance. [ABSTRACT FROM AUTHOR]

The inclusive pion double charge exchange (DCX) on oxygen nuclei has been measured in the region where additional pion production is kinematically forbidden. The experiment was performed at the ITEP PS at incident π− kinetic energies T0=0.59, 0.75 and 1.1 GeV. The integrated forward differential cross section was found to decrease with energy slowly. At 1.1 GeV it exceeds the theoretical prediction within the conventional sequential single charge exchange mechanism with a neutral pion in the intermediate state (Glauber elastic rescattering) by about a factor of five. The sequential mechanism with two pions in the intermediate state (Glauber inelastic rescatterings), which was proposed recently, seems to be able to explain the observed energy dependence and allows to predict the DCX cross section at higher energies. [Copyright &y& Elsevier]