Stories about Property

A Review of Carol M. Rose, Property and Persuasion: Essays on the History, Theory, and Rhetoric of Ownershi

The Development of a Dual-ligand PEGylated Liposome Nanotechnology for Cell-selective Targeted Vascular Gene Therapy

Percutaneous transluminal angioplasty (PTA) is a common endovascular procedure that restores blood flow in peripheral vascular disease. Unfortunately, endovascular procedures inherently cause injury to intimal layer. This exposing the medial layer and vascular smooth muscle cells (VSMCs) to hemodynamic flow. The injury response induces dysfunctional VSMC phenotypes, leading to thickening of the vessel wall known as intimal hyperplasia (IH). Eventually, IH leads to restenosis, a common complication of PTA.Most therapeutic strategies for IH are aimed at reducing VSMC migration and proliferation. However, recent studies have shown healing of the VEC layer is crucial mitigating factor in IH. We postulate that an optimal intervention could be achieved by employing both therapeutic strategies simultaneously in a cell-type specific manner at the site of PTA-induced injury. Gene therapy techniques provide an opportunity to accomplish this goal. Many IH-associated genetic targets have been successfully modulated to improve reendothelialization of VECs and inhibit the proliferation of VSMCs. However, clinical success of vascular gene therapy is limited due to the lack of a translational delivery vehicle.Liposomes have been shown to be effective gene vectors with translational efficacy. The addition of polyethylene glycol (PEG) to liposomes (PLP) can improve in vivo pharmacokinetics, but reduces cellular uptake of liposomal cargo. Ligand-modified liposomes provide an opportunity to enhance transfection of neutral PLPs and target specific cell types for gene delivery. Cell-penetrating peptides (CPPs) containing arginine-rich motifs have the ability to enhance membrane translocation of their conjugated cargo. Cell-targeting peptides (CTP) can also be used to decorate the liposome surface, providing cell-type specificity. In this in vitro proof-of-concept study, we aim to develop a modified PLP comprised of neutral lipids and capable of enhanced transfection and cell-type specific delivery to VSMCs and VECs, respectively.Using a Ca2+-mediated ethanol injection technique, a novel method for the self-assembly of CPP-modified PLPs with enhanced transfection, optimized siRNA loading efficiency, minimal cytotoxicity, and cell-targeting capabilities was developed. These nanocarriers convey chemical stability to siRNA in the presence of nuclease activity. This liposomal delivery system could provide the foundation necessary to increase the bench-to-bedside success of systemically administered vascular gene therapy

Streaming, Distributed Variational Inference for Bayesian Nonparametrics

This paper presents a methodology for creating streaming, distributed inference algorithms for Bayesian nonparametric (BNP) models. In the proposed framework, processing nodes receive a sequence of data minibatches, compute a variational posterior for each, and make asynchronous streaming updates to a central model. In contrast to previous algorithms, the proposed framework is truly streaming, distributed, asynchronous, learning-rate-free, and truncation-free. The key challenge in developing the framework, arising from the fact that BNP models do not impose an inherent ordering on their components, is finding the correspondence between minibatch and central BNP posterior components before performing each update. To address this, the paper develops a combinatorial optimization problem over component correspondences, and provides an efficient solution technique. The paper concludes with an application of the methodology to the DP mixture model, with experimental results demonstrating its practical scalability and performance.Comment: This paper was presented at NIPS 2015. Please use the following BibTeX citation: @inproceedings{Campbell15_NIPS, Author = {Trevor Campbell and Julian Straub and John W. {Fisher III} and Jonathan P. How}, Title = {Streaming, Distributed Variational Inference for Bayesian Nonparametrics}, Booktitle = {Advances in Neural Information Processing Systems (NIPS)}, Year = {2015}

A flight evaluation of a trailing anemometer for low-speed calibrations of airspeed systems on research aircraft

Research airspeed systems on three low-speed general aviation airplanes were calibrated by the trailing anemometer method. Each airplane was fitted with an NASA pitot-static pressure tube mounted on either a nose or wing boom. The uncalibrated airspeed systems contained residual static-pressure position errors which were too large for high-accuracy flight research applications. The trailing anemometer calibration was in agreement with the tower flyby calibration for the one aircraft for which the comparison was made. The continuous deceleration technique for the trailing anemometer method offers reduced test time with no appreciable loss of accuracy for airspeed systems with pitot-static system lag characteristics similar to those described