Comparison of CMAQ Simulation to Satellite Observations: NO₂ Column versus OMI NO₂

Compared to the sparse ground-based monitoring network, satellite observations have the advantage of coverage in unmonitored areas. This document describes a procedure for comparing tropospheric NO₂ columns simulated by the regional CMAQ model to those retrieved from the OMI satellite, with an example application in the Great Lakes Region. The tropospheric NO₂ profile shapes from CMAQ are used to derive new tropospheric vertical column densities (VCD) of NO₂ for comparison. The use of modeled NO₂ profile shapes ensures self-consistency and can improve retrieval accuracy through the improved spatial representation of the air mass factor that converts slant columns to vertical columns. The algorithm detailed in this document follows Goldberg et al. (2017). An implementation of the algorithm in R is appended to the document. Also included are instructions on how to download the data, how to use the algorithm to recalculate NO₂ VCD, how to regrid the data with WHIPS (the Wisconsin Horizontal Interpolation Program for Satellites), and how to perform the model-satellite data comparison

The evolving role of science in society

The world is experiencing a traumatic change brought about by the Covid-19 pandemic. It is traumatic because it is sudden and affects everyone around the globe at once. Nothing like this has ever happened so rapidly before, but as the world and the environment grow under pressure from an expanding global village it might also not be the last time that we experience such a dramatic transformation. The University of the Western Cape (UWC), over its 60 years of existence, has seen the world change profoundly and the university has in many ways steered our society through these changes in the past. I propose to take a look at how science at UWC is helping us navigate the brave new world being defined by the coronavirus

Adaptive grid modeling and direct sensitivity analysis for predicting the air quality impacts of DOD activities

Issued as final repor

Dibutyltin activates MAP kinases in human natural killer cells, in vitro

Previous studies have shown that dibutyltin (DBT) interferes with the function of human natural killer (NK) cells, diminishing their capacity to destroy tumor cells, in vitro. DBT is a widespread environmental contaminant and has been found in human blood. As NK cells are our primary immune defense against tumor cells, it is important to understand the mechanism by which DBT interferes with their function. The current study examines the effects of DBT exposures on key enzymes in the signaling pathway that regulates NK responsiveness to tumor cells. These include several protein tyrosine kinases (PTKs), mitogen-activated protein kinases (MAPKs), and mitogen-activated protein kinase kinases (MAP2Ks). The results showed that in vitro exposures of NK cells to DBT had no effect on PTKs. However, exposures to DBT for as little as 10 min were able to increase the phosphorylation (activation) of the MAPKs. The DBT-induced activations of these MAPKs appear to be due to DBT-induced activations of the immediate upstream activators of the MAPKs, MAP2Ks. The results suggest that DBT-interference with the MAPK signaling pathway is a consequence of DBT exposures, which could account for DBT-induced decreases in NK function

Cosmology and Astrophysical Constraints of Gauss-Bonnet Dark Energy

Cosmological consequences of a string-motivated dark energy scenario featuring a scalar field coupled to the Gauss-Bonnet invariant are investigated. We study the evolution of the universe in such a model, identifying its key properties. The evolution of the homogeneous background and cosmological perturbations, both at large and small scales, are calculated. The impact of the coupling on galaxy distributions and the cosmic microwave background is examined. We find the coupling provides a mechanism to viably onset the late acceleration, to alleviate the coincidence problem, and furthermore to effectively cross the phantom divide at the present while avoiding a Big Rip in the future. We show the model could explain the present cosmological observations, and discuss how various astrophysical and cosmological data, from the Solar system, supernovae Ia, cosmic microwave background radiation and large scale structure constrain it.Comment: 6 pages, 3 figures. References added. Accepted for publication in Phys. Lett.

Cosmological parameter estimation with large scale structure and supernovae data

Most cosmological parameter estimations are based on the same set of observations and are therefore not independent. Here, we test the consistency of parameter estimations using a combination of large-scale structure and supernovae data, without cosmic microwave background (CMB) data. We combine observations from the IRAS 1.2 Jy and Las Campanas redshift surveys, galaxy peculiar velocities and measurements of type Ia supernovae to obtain h=0.57_{-0.14}^{+0.15}, Omega_m=0.28+/-0.05 and sigma_8=0.87_{-0.05}^{+0.04} in agreement with the constraints from observations of the CMB anisotropies by the WMAP satellite. We also compare results from different subsets of data in order to investigate the effect of priors and residual errors in the data. We find that some parameters are consistently well constrained whereas others are consistently ill-determined, or even yield poorly consistent results, thereby illustrating the importance of priors and data contributions.Comment: (1) Astrophysics Group, Cavendish Laboratory, Cambridge Unviersity, UK (2) Dipartimento di Fisica, Universita di Roma "La Sapienza", Ital

Myxoid fibroblastic tumor of the maxillary sinus in a 21-month-old child: An unusual diagnosis.

Myxoid tumors of the soft tissue are a heterogeneous group of lesions with significant differences in behavior, from being totally harmless to malignant tumors with metastasizing potential. We describe the unusual case of a 21-month-old boy who developed a paranasal low-grade myxoid neoplasm with recurrent potential. The histological findings showed a proliferation of spindle cells within a vascular and myxoid background. The immunohistochemistry had the features of myofibroblasts and fibroblasts with strong Vimentin and light Smooth Muscle Actin reactivity. Close collaboration between clinician and pathologist is necessary to deal with these unusual lesions to predict their local aggressiveness and long-term behavior. Most of these cellular myxomas have been described in adults, involving primarily the limbs, but this case shows that any localization is possible

Distinguishing among Scalar Field Models of Dark Energy

We show that various scalar field models of dark energy predict degenerate luminosity distance history of the Universe and thus cannot be distinguished by supernovae measurements alone. In particular, models with a vanishing cosmological constant (the value of the potential at its minimum) are degenerate with models with a positive or negative cosmological constant whose magnitude can be as large as the critical density. Adding information from CMB anisotropy measurements does reduce the degeneracy somewhat but not significantly. Our results indicate that a theoretical prior on the preferred form of the potential and the field's initial conditions may allow to quantitatively estimate model parameters from data. Without such a theoretical prior only limited qualitative information on the form and parameters of the potential can be extracted even from very accurate data.Comment: 15 pages, 5 figure

First results from the Very Small Array -- IV. Cosmological parameter estimation

We investigate the constraints on basic cosmological parameters set by the first compact-configuration observations of the Very Small Array (VSA), and other cosmological data sets, in the standard inflationary LambdaCDM model. Using a weak prior 40 < H_0 < 90 km/s/Mpc and 0 < tau < 0.5 we find that the VSA and COBE_DMR data alone produce the constraints Omega_tot = 1.03^{+0.12}_{-0.12}, Omega_bh^2 = 0.029^{+0.009}_{-0.009}, Omega_cdm h^2 = 0.13^{+0.08}_{-0.05} and n_s = 1.04^{+0.11}_{-0.08} at the 68 per cent confidence level. Adding in the type Ia supernovae constraints, we additionally find Omega_m = 0.32^{+0.09}_{-0.06} and Omega_Lambda = 0.71^{+0.07}_{-0.07}. These constraints are consistent with those found by the BOOMERanG, DASI and MAXIMA experiments. We also find that, by combining all the recent CMB experiments and assuming the HST key project limits for H_0 (for which the X-ray plus Sunyaev--Zel'dovich route gives a similar result), we obtain the tight constraints Omega_m=0.28^{+0.14}_{-0.07} and Omega_Lambda= 0.72^{+0.07}_{-0.13}, which are consistent with, but independent of, those obtained using the supernovae data.Comment: 10 pages, 6 figures, MNRAS in pres