Nanomembrane-driven co-elution and integration of active chemotherapeutic and anti-inflammatory agents

The release of therapeutic drugs from the surface of implantable devices is instrumental for the reduction of medical costs and toxicity associated with systemic administration. In this study we demonstrate the triblock copolymer-mediated deposition and release of multiple therapeutics from a single thin film at the air-water interface via Langmuir–Blodgett deposition. The dual drug elution of dexamethasone (Dex) and doxorubicin hydrochloride (Dox) from the thin film is measured by response in the RAW 264.7 murine macrophage cell line. The integrated hydrophilic and hydrophobic components of the polymer structure allows for the creation of hybrids of the copolymer and the hydrophobic Dex and the hydrophilic Dox. Confirmation of drug release and functionality was demonstrated via suppression of the interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF α) inflammatory cytokines (Dex), as well as TUNEL staining and DNA fragmentation analysis (Dox). The inherent biocompatibility of the copolymeric material is further demonstrated by the lack of inflammation and apoptosis induction in cells grown on the copolymer films. Thus a layer-by-layer anchored deposition of an anti-inflammatory and chemotherapeutic functionalized copolymer film is able to localize drug dosage to the surface of a medical device, all with an innate material thickness of 4 nm per layer

Toward a heterodox theory of the business enterprise: the Going Concern Model and the US computer industry

Title from PDF of title page, viewed on November 27, 2013Dissertation advisor: James I. SturgeonVitaIncludes bibliographic references (pages 205-221)Thesis (Ph.D.)--Dept. of Economics. University of Missouri--Kansas City, 2013This dissertation applies heterodox concepts of the social construction and allocation of resources in the provisioning process; the organization of going concerns in societies that are themselves going concerns; and the governance of markets, and production more generally, toward a heterodox theory of the firm. It is argued that, in contrast to extant theories of the firm, the boundaries of modern firms are not the result of processes of individual contracting in the face of transactions costs, or coterminous with knowledge-based resources. Rather, they are principally the product of the coevolution of business and technological practices, chiefly in the interest of the former over the latter. It is furthermore argued that this process, in a socioeconomic system defined by the firm as a hierarchy of going concerns, is more akin to the gerrymandering of congressional districts than to an efficient allocation of material transactions between the firm and market spheres. The history of the US software industry from the 1950s through the 1990s is provided as a case both illustrating and informing the theory. In particular, it is shown that this industry owes its structure, and indeed its existence, to the evolution of business strategies concerning the technological relationships surrounding the provision and use of computer systems. The industry's history corroborates the general hypotheses that (1) markets and firms themselves tend to be governed by the concerns operating therein; and (2) the resulting governance structures necessarily involve state sanctioning, including the administration of appropriate property rights over the relevant technological relationships.Introduction -- Meta-theoretical foundation of the Going Concern Model -- The Going Concern Model of the business enterprise, I -- The Going Concern Model of the business enterprise, II -- The going enterprise in the computer industry -- Open systems and intellectual property: the evolution of market governance mechanisms -- Conclusio

Arthritis Is Developed in Borrelia-Primed And -Infected Mice Deficient of Interleukin-17

Interleukin-17 (IL-17) has been shown to participate in the development of Lyme arthritis in experimental mice. For example, neutralization of IL-17 with antibodies inhibits induction of arthritis in Borrelia-primed and -infected C57BL/6 wild-type mice. We hypothesized that mice lacking IL-17 would fail to develop Borrelia-induced arthritis. IL-17-deficient and wild-type C57BL/6 mice were primed with heat-inactivated Borrelia and then infected with viable spirochetes 3 weeks later. No swelling or major histopathological changes of the hind paws were detected in IL-17-deficient or wild-type mice that were primed with Borrelia or infected with viable spirochetes. By contrast, IL-17-deficient and wild-type mice that were primed and subsequently infected with heterologous Borrelia developed severe swelling and histopathological changes of the hind paws. In addition, Borrelia-primed and -infected IL-17-deficient mice exhibited elevated gamma-interferon (IFN-γ) levels in sera and increased frequencies of IFN-γ-expressing lymphocytes in popliteal lymph nodes compared to Borrelia-primed and -infected wild-type mice. These results demonstrate that IL-17 is not required for development of severe pathology in response to infection with Borrelia burgdorferi, but may contribute to disease through an interaction with IFN-γ

Processing and thermal properties of molecularly oriented polymers

Thesis (S.M. in Mechanical Engineering and Naval Architecture and Marine Engineering)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.Includes bibliographical references (p. 61-63).High molecular weight polymers that are linear in molecular construction can be oriented such that some of their physical properties in the oriented direction are enhanced. For over 50 years polymer orientation and processing has been extensively studied to improve the mechanical properties of polymers. In more recent history the anisotropic thermal properties of oriented polymers have been studied. This thesis investigates the thermal properties of Ultra High Molecular Weight Polyethylene (UHMW-PE) and explores applications for the same. This thesis details an effective means of aligning the molecules in bulk polyethylene sheets through stretching in the gel state. Tests have shown that bulk UHMW-PE can be stretched 50-80 times in xylene. The thermal conductivity of bulk UHMW-PE is 0.3 W/mK, while that of a sample stretched 20-25 times is over 4.5 W/mK.by Erik Skow.S.M.in Mechanical Engineering and Naval Architecture and Marine Engineerin

Viewing the unseen: Using Google Docs to track prewriting strategies of ESL students

Language teachers often encourage the use of prewriting strategies such as outlining, brain storming, and mind-mapping as a means of helping students improve their writing. However, it is difficult to determine which strategies were used based only on the finished assignment. Google Docs has a version history feature which could allow teachers to see their students’ writing processes in addition to the final product. This researcher examined the written assignments of a class of university ESL students completed using Google Docs to see what strategies ESL students used, how strategy use related to their writing performance, and what version history could reveal about ESL students’ writing processes. The study found that ESL students used a variety of strategies with some of them specific to the given assignment. The use of prewriting strategies increased after explicit instruction, and some students had a recursive writing process while others appeared to write in stages

Willingness to Pay and Willingness to Accept are Probably Less Correlated than You Think

An enormous literature documents that willingness to pay (WTP) is less than willingness to accept (WTA) a monetary amount for an object, a phenomenon called the endowment effect. Using data from an incentivized survey of a representative sample of 3,000 U.S. adults, we add one (probably) surprising additional finding: WTA and WTP for a lottery are, at best, slightly correlated. Across all respondents, the correlation is slightly negative. A meta-study of published experiments with university students shows a correlation of around 0.15--0.2, consistent with the correlation in our data for high-IQ respondents. While poorly related to each other, WTA and WTP are closely related to different measures of risk aversion, and relatively stable across time. We show that the endowment effect is not related to individual-level measures of loss aversion, counter to Prospect Theory or Stochastic Reference Dependence

Econographics

We study the pattern of correlations across a large number of behavioral regularities, with the goal of creating an empirical basis for more comprehensive theories of decision-making. We elicit 21 behaviors using an incentivized survey on a representative sample (n = 1;000) of the U.S. population. Our data show a clear and relatively simple structure underlying the correlations between these measures. Using principal components analysis, we reduce the 21 variables to six components corresponding to clear clusters of high correlations. We examine the relationship between these components, cognitive ability, and demographics, and discuss the theoretical implications of the structure we uncover

Morphological convergence of shell shape in distantly related scallop species (Mollusca: Pectinidae)

Morphological convergence is a central concept in evolutionary biology, but convergent patterns remain under-studied in nonvertebrate organisms. Some scallop species exhibit long-distance swimming, a behaviour whose biomechanical requirements probably generate similar selective regimes. We tested the hypothesis that shell shape similarity in long-distance swimming species is a result of convergent evolution. Using landmark-based geometric morphometrics, we quantified shell shape in seven species representing major behavioural habits. All species displayed distinct shell shapes, with the exception of the two long-distance swimmers, whose shells were indistinguishable. These species also displayed reduced morphological variance relative to other taxa. Finally, a phylogenetic simulation revealed that these species were more similar in their shell shape than was expected under Brownian motion, the model of character evolution that best described changes in shell shape. Together, these findings reveal that convergent evolution of shell shape occurs in scallops, and suggest that selection for shell shape and behaviour may be important in the diversification of the group