University of Texas at Dallas

About: University of Texas at Dallas is a education organization based out in Richardson, Texas, United States. It is known for research contribution in the topics: Population & Computer science. The organization has 14986 authors who have published 35589 publications receiving 1293714 citations. The organization is also known as: UT-Dallas & UT Dallas.

Economic Transition and Growth

Abstract: Some extensions of neoclassical growth models are discussed that allow for cross section heterogeneity among economies and evolution in rates of technological progress over time. The models oer a spectrum of transitional behavior among economies that includes con- vergence to a common steady state path as well as various forms of transitional divergence and convergence. Mechanisms for modeling such transitions and measuring them econo- metrically are developed in the paper. A new regression test of convergence is proposed, its asymptotic properties are derived and some simulations of its …nite sample properties are reported. Transition curves for individual economies and subgroups of economies are estimated in a series of empirical applications of the methods to regional US data, OECD data and Penn World Table data.

Insider Trading, Earnings Quality, and Accrual Mispricing

Abstract: The paper provides evidence that the signal contained in insiders' trading behavior is useful in making refined assessments of earnings quality, and informative about the valuation implications of accruals. We find that income-increasing accruals and unexpected accruals have lower (higher) persistence when managers engage in abnormal selling (buying) suggesting that insider trading information is useful in assessing the quality of the non-cash components of earnings. We show that the accrual mispricing phenomenon observed in previous work is largely due to the mispricing of positive accruals. We find that investors price all positive accruals as if they were informative and that a subset of positive accruals is correctly priced. That is, (1) investors correctly price positive accruals that are likely to be informative because concurrently insiders engage in abnormal buying, and (2) investors price all positive accruals the same independently of insider trading. We find that the extent of the mispricing is greater when positive accruals occur concurrently with abnormal selling relative to cases where there is no trading. The extent of the mispricing and the magnitude of the one-year ahead returns (14.7 to 22 percent) to a trading strategy based on positive accruals and abnormal selling suggests that these accruals arise from opportunistic earnings management that is successful in misleading investors. By contrast, the smaller positive accrual mispricing when there is no insider trading is more likely related to either the complexity of the firms' accrual generating process (Thomas and Zhang (2001) or to earnings fixation (Sloan 1996). Our evidence thus suggests that opportunistic earnings management is a partial explanation for the accrual mispricing phenomenon.

Origin of Back‐Arc Basin Magmas: Trace Element and Isotope Perspectives

Abstract: The compositions of back-arc basin basalts (BABB) can usefully be viewed as products of four factors: (1) the composition of inflowing mantle and its preconditioning during flow to the site of melting; (2) the influx of a subduction component into the arc-basin system; (3) the nature of the interaction between the mantle and subduction components; (4) the melting of water-rich mantle and the assimilation/ crystallization history of the resulting hydrous magma. Geochemical mapping using Nb/Yb as a mantle flow tracer indicates that mantle flow in arc-basin systems varies according to contributions from subduction-driven corner flow, flow around subduction edges, and deflection by barriers to flow. Geochemical mapping using Ba/Nb as a subduction tracer indicates that the magnitude of the subduction input is a function primarily of basin evolution, mantle flow patterns, and arc proximity. The subduction component may reach the back-arc by mixing with ambient mantle, by direct addition of a subduction component, by addition of a hydrous mantle melt, or by incorporation of a component stored in mantle lithosphere. Trace element and water contents of back-arc glasses indicate that decompression melting beneath back-arc basins is augmented by flux melting but suppressed by mixing with depleted mantle. Cl-K systematics indicate that water in back-arc basin magmas may be augmented by assimilation of hydrated ocean crust. The increased water content of primary BABB magmas leads to enhanced olivine and oxide crystallization, and to fluid exsolution at depth, both of which will influence the composition and architecture of the resulting back-arc oceanic crust.

Nitrogen assimilation and global regulation in Escherichia coli.

Abstract: Nitrogen limitation in Escherichia coli controls the expression of about 100 genes of the nitrogen regulated (Ntr) response, including the ammonia-assimilating glutamine synthetase. Low intracellular glutamine controls the Ntr response through several regulators, whose activities are modulated by a variety of metabolites. Ntr proteins assimilate ammonia, scavenge nitrogen-containing compounds, and appear to integrate ammonia assimilation with other aspects of metabolism, such as polyamine metabolism and glutamate synthesis. The leucine-responsive regulatory protein (Lrp) controls the synthesis of glutamate synthase, which controls the Ntr response, presumably through its effect on intracellular glutamine. Some Ntr proteins inhibit the expression of some Lrp-activated genes. Guanosine tetraphosphate appears to control Lrp synthesis. In summary, a network of interacting global regulators that senses different aspects of metabolism integrates nitrogen assimilation with other metabolic processes.

Linezolid versus Vancomycin for the Treatment of Methicillin-Resistant Staphylococcus aureus Infections

Abstract: Linezolid, the first available member of a new antibiotic class, the oxazolidinones, is broadly active against gram-positive bacteria, including drug-resistant strains. In this randomized, open-label trial, hospitalized adults with known or suspected methicillin-resistant Staphylococcus aureus (MRSA) infections were treated with linezolid (600 mg twice daily; n = 240) or vancomycin (1 g twice daily; n = 220) for 7-28 days. S. aureus was isolated from 53% of patients; 93% of these isolates were MRSA. Skin and soft-tissue infection was the most common diagnosis, followed by pneumonia and urinary tract infection. At the test-of-cure visit (15-21 days after the end of therapy), among evaluable patients with MRSA, there was no statistical difference between the 2 treatment groups with respect to clinical cure rates (73.2% of patients in the linezolid group and 73.1% in the vancomycin group) or microbiological success rates (58.9% in the linezolid group and 63.2% in the vancomycin group). Both regimens were well tolerated, with similar rates of adverse events.