Bias in U.S. Import Prices and Demand

The purpose of the paper is to measure the potential bias in the U.S. import price index due to the appearance of new product varieties, or new foreign suppliers, and determine the effect of this bias on the estimated income elasticity of import demand. Existing import price indexes are based on a sample of products from importing firms. We argue that if the share of import expenditure on the sampled products is falling over time, this will lead to an upward bias in the measured index. Using a correction based on the falling expenditure share on sampled countries, we find that the income elasticity of aggregate U.S. import demand is reduced from 2.5 to 1.7, or about halfway to unity. Our estimates suggest that the aggregate import price index is upward biased by about one and one-half percentage points annually.

Molecular characterization of novel transcription of antisense toxin-antitoxin RNA in regulating Mycobacterium tuberculosis

2020 Spring.Includes bibliographical references.Despite more than seventy years of available anti-tuberculosis (TB) treatments, Mycobacterium tuberculosis (Mtb) remains the deadliest human pathogen. Novel short-course therapies are needed that effectively treat latent TB infection (LTBI), which is like a major source for new infections. However, the molecular determinants of LTBI, including a large repertoire of regulators encoded by Mtb that mediate survival, are largely uncharacterized. Gene expression studies have implicated numerous regulators and particularly toxin-antitoxin (TA) systems in Mtb pathogenesis. Whole genome sequencing (i.e. WGS) studies have linked the massive genomic expansion of TA systems along with other pathogen-specific gene families to the emergence of TB-causing mycobacteria. In addition, a multitude of TA systems show genotypic differences that distinguish between ancient and modern lineages of Mtb. These predominantly include lineage-specific changes in amino acids, altering antitoxin DNA-binding, and nucleotides, generating new promoters. These mutations have led to an overrepresentation of differentially expressed Mtb TA genes responsible for mediating epigenetic changes that are associated with gains in virulence of modern lineages. Thus, the work presented in this dissertation begins to define the novel co-regulation of TA systems that underlie Mtb pathogenesis. Unraveling of more complex regulation of Mtb TA systems will provide keen insights into the phenotypic changes responsible for Mtb survival and persistence in vivo. This will ultimately help to streamline research and development of novel antibiotics as well as host directed immunotherapies against hard-to-treat tubercle bacilli, effectively shortening the duration of TB treatment. TA systems are ubiquitous among bacteria, especially pathogens, and increasingly found to be essential for adaptation to host immune defenses and in vivo drug pressures, resulting in the development of persistent or chronic infections. Phylogenomics comparisons have revealed that Mtb encodes a significantly expanded repertoire of TA systems that are solely conserved by tubercle bacilli, including homologous ParDE/RelBE systems like RelBE2 (i.e. Rv2865-Rv2866). Herein, we report a novel antisense (as)RNA, we call asRelE2, which is uniquely encoded by Mtb and involved in differentially post-transcriptionally regulating relE2 mRNA levels as part of the response to host-associated stress such as low pH in a cAMP-dependent manner. This dynamic regulation of the tripartite relBE2/asrelE2 TA locus appear to be essential for long-term survival under acidic stress in vitro. In addition, the overexpression of relE2 is found to mediate phenotypic development of a persistent state in Mtb associated with increasing tolerance towards frontline anti-TB drugs isoniazid (Inh) and rifampicin (Rif). In mice, asRelE2 acts in differentially regulating bi-cistronic relB2 and relE2 mRNA levels in a host tissue-specific manner dependent upon the downstream effector functions of interferon gamma (i.e. IFN-γ) in murine TB. Specifically, relE2 and relB2 mRNA levels are found to steadily increase in lungs and in spleens, respectively, in the development of the chronic phase of Mtb infection. To our knowledge, this is the first time a Mtb TA system has been shown to be co-regulated by an asRNA antitoxin. Furthermore, this is linked with the development of the adaptive host immune response to Mtb, demonstrating that the post-transcriptional regulation of TA systems is an important mechanism, coordinating the epigenetic changes that are a hallmark of Mtb persistence and pathogenesis

Joseph Haydn\u27s Te Deum for the Empress Marie Therese : A Historical Reference and Musical Analysis

Franz Joseph Haydn is regarded as one of the pillars of the Classical era. Often regarded as the father of the symphony and string quartet, Haydn was equally involved in vocal music. Haydn’s Te Deum for the Empress Marie Therese is a multifaceted work composed near the end of his life in 1799. This short work was conceived on a large scale, and exhibits elements found in his symphonies. Composed in three clearly delineated sections, the work is through-composed and transitions from one section to the next without large breaks. Given the simple key of this work, one may be quick to believe that this piece will be easy to learn. In preparing to perform this work I discovered that this seemingly straight-forward piece presents many challenges. These challenges include such items as the changes of tempi, the execution of the musical expressiveness, and the text. A general understanding of Classical era performance practices and the structure of this work needs to be attained in order to give an accurate performance of this piece. To provide some guidance in preparing this piece, one will find a short biography of Haydn’s life, the history of the Te Deum, a formal analysis of this work, some rehearsal considerations, and a review of recordings within this document

PROMOTIONAL EFFORTS VS. ECONOMIC FACTORS AS DRIVERS OF PRODUCERS' DECISIONS TO EXPAND OR START A DAIRY

Replaced with revised version of paper 07/13/04.Farm Management,

Unsteady pressure and structural response measurements of an elastic supercritical wing

Results are presented which define unsteady flow conditions associated with high dynamic response experienced on a high aspect ratio elastic supercritical wing at transonic test conditions while being tested in the NASA Langley Transonic Dynamics Tunnel. The supercritical wing, designed for a cruise Mach number of 0.80, experienced the high dynamic response in the Mach number range from 0.90 to 0.94 with the maximum response occurring at a Mach number of approximately 0.92. At the maximum wing response condition the forcing function appears to be the oscillatory chordwise movement of strong shocks located on both the wing upper and lower surfaces in conjunction with the flow separating and reattaching in the trailing edge region