118,168 research outputs found
Interleukin-12 p40 secretion by cutaneous CD11c(+) and F4/80(+) cells is a major feature of the innate immune response in mice that develop Th1-mediated protective immunity to Schistosoma mansoni
Radiation-attenuated (RA) schistosome larvae are potent stimulators of innate immune responses at the skin site of exposure (pinna) that are likely to be important factors in the development of Th1-mediated protective immunity. In addition to causing an influx of neutrophils, macrophages, and dendritic cells (DCs) into the dermis, RA larvae induced a cascade of chemokine and cytokine secretion following in vitro culture of pinna biopsy samples. While macrophage inflammatory protein 1alpha and interleukin-1beta (IL-1beta) were produced transiently within the first few days, the Th1-promoting cytokines IL-12 and IL-18 were secreted at high levels until at least day 14. Assay of C3H/HeJ mice confirmed that IL-12 secretion was not due to lipopolysaccharide contaminants binding Toll-like receptor 4. Significantly, IL-12 p40 secretion was sustained in pinnae from vaccinated mice but not in those from nonprotected infected mice. In contrast, IL-10 was produced from both vaccinated and infected mice. This cytokine regulates IL-12-associated dermal inflammation, since in vaccinated IL-10(-/-) mice, pinna thickness was greatly increased concurrent with elevated levels of IL-12 p40. A significant number of IL-12 p40(+) cells were detected as emigrants from in vitro-cultured pinnae, and most were within a population of rare large granular cells that were Ia(+), consistent with their being antigen-presenting cells. Labeling of IL-12(+) cells for CD11c, CD205, CD8alpha, CD11b, and F4/80 indicated that the majority were myeloid DCs, although a proportion were CD11c(-) F4/80(+), suggesting that macrophages were an additional source of IL-12 in the skin
Estimating U.S. output growth with vintage data in a state-space framework
This study uses a state-space model to estimate the "true" unobserved measure of total output in the U.S. economy. The analysis uses the entire history (i.e., all vintages) of selected real-time data series to compute revisions and corresponding statistics for those series. The revision statistics, along with the most recent data vintage, are used in a state-space model to extract filtered estimates of the "true" series. Under certain assumptions, Monte Carlo simulations suggest this framework can improve published estimates by as much as 30 percent, lasting an average of 11 periods. Real-time experiments using a measure of real gross domestic product show improvement closer to 10 percent, lasting for 1 to 2 quarters.Economic development ; Economic conditions - United States
The perils of globalization: offshoring and economic insecurity of the American worker
According to polls from the 2006 congressional elections, globalization and economic insecurity were the primary concerns of many voters. These Americans apparently believe that they have fallen victim to liberal trade polices and that inexorable trends in globalization are destroying the American Dream. In this analysis, we use time series cross-section data from the General Social Survey (GSS) to examine the links among offshoring, labor market volatility, and the demand for social insurance. Unique among the GSS literature, our analysis includes a pseudo-panel model which permits including auxiliary state and regional macroeconomic information.Globalization ; International economic integration
The commercial paper market, the Fed, and the 2007-2009 financial crisis
Since its inception in the early nineteenth century, the U.S. commercial paper market has grown to become a key source of short-term funding for major businesses, with issuance averaging over $100 billion per day. In the fall of 2008, the commercial paper market achieved national prominence when increasing market stress caused some to fear that, given its size and importance, the market's failure would sharply worsen the recession. The Department of the Treasury and Federal Reserve enacted programs targeted at providing credit and liquidity to restore investor confidence. The authors review the history of the commercial paper market, describe its structure and key relationships to money market mutual funds, and present a detailed discussion of the crisis in the market, including the resulting Federal Reserve programs.Commercial paper issues ; Financial crises
A closer look: assistance programs in the wake of the crisis
An unprecedented amount of aid was extended by the Treasury, Fed and FDIC to companies, agencies and individuals. This aid was necessary and, in many cases, will return a profit to taxpayers.Financial crises ; Intermediation (Finance) ; Business failures
Offshoring, economic insecurity, and the demand for social insurance
The fear of offshoring, particularly in services since 2000, has raised workers economic insecurity and heightened concerns over future economic globalization. Many have argued that globalization has exacerbated labor market turbulence increasing the demand for social insurance programs. The authors present a simple theoretical model establishing a connection between the threat of offshoring, economic insecurity, and the demand for social insurance. Data from the 1972-2006 General Social Survey to provides supporting empirical evidence.Globalization ; International economic integration
New Symbolic Tools for Differential Geometry, Gravitation, and Field Theory
DifferentialGeometry is a Maple software package which symbolically performs
fundamental operations of calculus on manifolds, differential geometry, tensor
calculus, Lie algebras, Lie groups, transformation groups, jet spaces, and the
variational calculus. These capabilities, combined with dramatic recent
improvements in symbolic approaches to solving algebraic and differential
equations, have allowed for development of powerful new tools for solving
research problems in gravitation and field theory. The purpose of this paper is
to describe some of these new tools and present some advanced applications
involving: Killing vector fields and isometry groups, Killing tensors and other
tensorial invariants, algebraic classification of curvature, and symmetry
reduction of field equations.Comment: 42 page
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