Quantum shape effects on Zeeman splittings in semiconductor nanostructures

We develop a general method to calculate Zeeman splittings of electrons and holes in semiconductor nanostructures within the tight-binding framework. The calculation is carried out in the electron-hole picture and is extensible to the excitonic calculation by including the electron-hole Coulomb interaction. The method is suitable for the investigation of quantum shape effects and the anisotropy of the g-factors. Numerical results for CdSe and CdTe nanostructures are presented

Scaling Relations for Galaxies Prior to Reionization

The first galaxies in the Universe are the building blocks of all observed galaxies. We present scaling relations for galaxies forming at redshifts $z \ge 15$ when reionization is just beginning. We utilize the ``Rarepeak' cosmological radiation hydrodynamics simulation that captures the complete star formation history in over 3,300 galaxies, starting with massive Population III stars that form in dark matter halos as small as ~$10^6 M_\odot$. We make various correlations between the bulk halo quantities, such as virial, gas, and stellar masses and metallicities and their respective accretion rates, quantifying a variety of properties of the first galaxies up to halo masses of $10^9 M_\odot$. Galaxy formation is not solely relegated to atomic cooling halos with virial temperatures greater than $10^4$ K, where we find a dichotomy in galaxy properties between halos above and below this critical mass scale. Halos below the atomic cooling limit have a stellar mass -- halo mass relationship $\log M_\star \simeq 3.5 + 1.3\log(M_{\rm vir} / 10^7 M_\odot)$. We find a non-monotonic relationship between metallicity and halo mass for the smallest galaxies. Their initial star formation events enrich the interstellar medium and subsequent star formation to a median of $10^{-2} Z_\odot$ and $10^{-1.5} Z_\odot$, respectively, in halos of total mass $10^7 M_\odot$ that is then diluted by metal-poor inflows, well beyond Population III pre-enrichment levels of $10^{-3.5} Z_\odot$. The scaling relations presented here can be employed in models of reionization, galaxy formation and chemical evolution in order to consider these galaxies forming prior to reionization.Comment: 10 pages, 10 figures. Accepted to Ap

Profitability of Product Bundling

Using copulas to model the stochastic dependence of values, this paper establishes new general conditions on the profitability of product bundling. A multiproduct monopolist generally achieves higher profit from mixed bundling than from separate selling if consumer values for two products are negatively dependent, independent, or have limited positive dependence. With more than two goods, the same conditions are sufficient for an optimal monopoly selling scheme to include a bundle of at least two products. The profitability of monopoly bundling also extends to situations where a multiproduct firm competes with a single-product rival

TGF-β-responsive CAR-T cells promote anti-tumor immune function.

A chimeric antigen receptor (CAR) that responds to transforming growth factor beta (TGF-β) enables the engineering of T cells that convert this immunosuppressive cytokine into a potent T-cell stimulant. However, clinical translation of TGF-β CAR-T cells for cancer therapy requires the ability to productively combine TGF-β responsiveness with tumor-targeting specificity. Furthermore, the potential concern that contaminating, TGF-β?producing regulatory T (Treg) cells may preferentially expand during TGF-β CAR-T cell manufacturing and suppress effector T (Teff) cells demands careful evaluation. Here, we demonstrate that TGF-β CAR-T cells significantly improve the anti-tumor efficacy of neighboring cytotoxic T cells. Furthermore, the introduction of TGF-β CARs into mixed T-cell populations does not result in the preferential expansion of Treg cells, nor do TGF-β CAR-Treg cells cause CAR-mediated suppression of Teff cells. These results support the utility of incorporating TGF-β CARs in the development of adoptive T-cell therapy for cancer

The Impact of Pork Advertising on US Meat Demand in the Presence of Competing Beef Advertising and Food Safety Events

We examine the effects of domestic advertising and promotion expenditures on meat demand, extending previous efforts in several areas, including the use of more recent data, employing a complete demand system and simultaneously measuring the impacts of generic pork and beef advertising and food safety information on the demand for beef, pork, and poultry. Using the Generalized Almost Ideal Demand System (GAIDS), own- and cross- beef and pork advertising and own- and cross- beef, pork, and poultry food safety effects are measured jointly and consistently. To allow for a more complex dynamic response of advertising and food safety effects, the flexible distributed lag technique of Mitchell and Speaker (1986) is employed. The coefficients on pork advertising in the pork and poultry equations are highly significant. The coefficients on beef advertising are only statistically significantly different from zero in the poultry equation indicating the primary impact from these efforts is a cross-commodity effect. To investigate the economic significance of these effects, elasticities for price, expenditure, food safety and advertising are calculated and compared. Consistent with previous work we find the impacts of advertising and food safety effects to be economically small compared with price and expenditure effects.food safety, Generalized Almost Ideal Demand System, generic advertising, meat demand, polynomial inverse lag, Demand and Price Analysis, Food Consumption/Nutrition/Food Safety,

Price-increasing competition

In a discrete choice model of product differentiation, the symmetric duopoly price may be lower than, equal to, or higher than the single-product monopoly price. While the market share effect of competition encourages a firm to charge less than the monopoly price because a duopolist serves fewer consumers, the price sensitivity effect of competition motivates a higher price when more consumer choice steepens the firm's demand curve. The joint distribution of consumer values for the two conceivable products determines the relative strength of these effects, and whether presence of a symmetric competitor results in a higher or lower price compared to single-product monopoly. The analysis reveals that rice-increasing competition is unexceptional from a theoretical perspective

Detections of massive stars in the cluster MCM2005b77, in the star-forming regions GRS G331.34−-00.36 (S62) and GRS G337.92−-00.48 (S36)

Large infrared and millimeter wavelength surveys of the Galactic plane have unveiled more than 600 new bubble HII regions and more than 3000 candidate star clusters. We present a study of the candidate clusters MCM2005b72, DBS2003-157, DBS2003-172, and MCM2005b77, based on near-infrared spectroscopy taken with SofI on the NTT and infrared photometry from the 2MASS, VVV, and GLIMPSE surveys. We find that (1) MCM2005b72 and DBS2003-157 are subregions of the same star-forming region, HII GRS G331.34-00.36 (bubble S62). MCM2005b72 coincides with the central part of this HII region, while DBS2003-157 is a bright mid-infrared knot of the S62 shell. We detected two O-type stars at extinction \Aks=1.0-1.3 mag. Their spectrophotometric properties are consistent with the near-kinematic distance to GRS G331.34-00.36 of 3.9pm0.3 kpc. (2) DBS2003-172 coincides with a bright mid-infrared knot in the S36 shell (GRS G337.92-00.48), where we detected a pair of candidate He I stars embedded in a small cometary nebula. (3) The stellar cluster MCM2005b77 is rich in B-type stars, has an average Aks of 0.91 mag, and is adjacent to the HII region IRAS 16137-5025. The average spectrophotometric distance of $\sim 5.0$ kpc matches the near-kinematic distance to IRAS 16137-5025 of 5.2pm0.1 kpc.Comment: 22 pages, 11 Figures, ApJ accepte