A. Arnlds, Geografía económica argentina, Buenos Aires, Ed. Kapeluz, 1963

Fil: Lasalle, R.. Universidad Nacional de Cuyo. Facultad de Filosofía y Letra

Early signaling defects in human T cells anergized by T cell presentation of autoantigen.

Major histocompatibility complex class II-positive human T cell clones are nontraditional antigen-presenting cells (APCs) that are able to simultaneously present and respond to peptide or degraded antigen, but are unable to process intact protein. Although T cell presentation of peptide antigen resulted in a primary proliferative response, T cells that had been previously stimulated by T cells presenting antigen were completely unresponsive to antigen but not to interleukin 2 (IL-2). In contrast, peptide antigen presented by B cells or DR2+ L cell transfectants resulted in T cell activation and responsiveness to restimulation. The anergy induced by T cell presentation of peptide could not be prevented by the addition of either autologous or allogeneic B cells or B7+ DR2+ L cell transfectants, suggesting that the induction of anergy could occur in the presence of costimulation. T cell anergy was induced within 24 h of T cell presentation of antigen and was long lasting. Anergized T cells expressed normal levels of T cell receptor/CD3 but were defective in their ability to release [Ca2+]i to both alpha CD3 and APCs. Moreover, anergized T cells did not proliferate to alpha CD2 monoclonal antibodies or alpha CD3 plus phorbol myristate acetate (PMA), nor did they synthesize IL-2, IL-4, or interferon gamma mRNA in response to either peptide or peptide plus PMA. In contrast, ionomycin plus PMA induced both normal proliferative responses and synthesis of cytokine mRNA, suggesting that the signaling defect in anergized cells occurs before protein kinase C activation and [Ca2+]i release

Starlight Meditation

https://digitalcommons.library.umaine.edu/mmb-ps/1899/thumbnail.jp

Quantifying Litter Decomposition Rates on a Semi-Intensive Green Roof

The overall goal of this study was to provide a measure of the decomposition rate constant on a semi- intensive green roof located in Fayetteville, Arkansas. The specific approach chosen was the use of the Tea Bag Index (TBI), a standardized plant litter decomposition test. There was some heterogeneity observed on site and the locations of samples tested were chosen based on this. Additional laboratory tests were conducted in order to determine whether there would be a large impact of temperature on decomposition or if it would be outweighed by other factors. The temperatures compared were 5°C, 20°C, and 30°C. Decomposition data collected in the laboratory test fit to some extent with the exponential decay model suggested (0.9 \u3e P \u3e 0.85). This data suggests a comparable rate of decomposition to other biomes which had been previously studied, which was further supported by samples tested on site. The decomposition rate constants calculated from data collected on site were slightly less than those seen in grasslands or healthy forests but higher than those seen in more arid environments. The stabilization factor was more similar to those seen in sandy soils, which fits with the composition of the engineered soil used. The main recommendation for future research is replication during the summer months, which could confirm the influence of season or temperature on decomposition while further assessing soil health at the site

City of Chicago v. Environmental Defense Fund, Inc. Making the Case for Broader Application of Chevron, U.S.A. v. Natural Resource Defense Council

The purpose of this Note is to examine the Supreme Court\u27s reasoning in City of Chicago v. Environmental Defense Fund, and to explore the implications of the Court\u27s decision. First, Section II of this Note delineates the relevant statutory and regulatory background concerning the regulation of municipal solid waste. Next, Section III presents the statement of the case. Finally, Section IV analyzes the Supreme Court\u27s decision. Section IV(A) criticizes the Court\u27s limited focus in interpreting the Resource Conservation and Recovery Act of 1976 (RCRA). Section IV(B) contends that the Court\u27s interpretation of RCRA is incorrect because it violates one of the express purposes of the Act. Section IV(C) argues that deference should have been given to the Environmental Protection Agency\u27s interpretation of RCRA, in accordance with the standard set out in Chevron U.S.A. v. Natural Resources Defense Council