An optimal internet location strategy for markets with different tax rates

The traditional view that a high sales tax rate reduces trade by driving a wedge between the purchase and sale price may not apply to internet commerce for two reasons. The first reason is that the sales tax paid by buyers purchasing via the internet is determined by the tax rate in the region of the buyer. The second reason is that a high sales tax may lower the before-tax price if sellers absorb part of the tax. Taken together, this implies that internet distributors may profitably target customers in regions with low tax rates by locating their selling addresses in high tax regions. Consequently the optimal marketing strategy for a global internet distributor may include siting selling locations in regions with high tax rates in order to target customers in regions with low tax rates. An empirical analysis of the European car market suggests that this is more than a remote theoretical possibility by demonstrating that the before-tax prices recommended by manufacturers for new cars are lower in high tax countries

Endothelialization and In Vitro Characterization of a Small Diameter Tissue Engineered Vascular Graft for Patients with Diabetes

Prosthetic vascular grafting is largely successful in patients undergoing surgical intervention for vascular diseases in medium and large caliber arteries (inner diameter \u3e6 mm). In small diameter arteries, however, prosthetic grafts are insufficiently non-thrombogenic, and autologous vein grafting and endovascular stenting are considered to be standard treatments. However, up to one third of patients lack proper donor vessels due to donor site morbidities or severe vascular disease, and stenting fails to provide long-term patency. Further, patients with diabetes have not only increased risk for the development of cardiovascular diseases, but also have poorer outcomes following intervention. To meet this need, a small diameter tissue engineered vascular graft was developed to meet the needs of diabetic patients with vascular diseases. First, a biocompatible scaffold was created by decellularization of porcine renal arteries, then stabilizing the scaffolds using pentagalloyl glucose (PGG). PGG is a matrix-binding polyphenol previously shown to improve mechanical strength of decellularized tissues and to resist calcification and the accumulation of advanced glycation endproducts in STZ-induced type I diabetic rats. Decellularization was assessed by histological analysis and isolation and quantification of DNA. Next, human adipose derived stem cells (hADSC) were differentiated in vitro to endothelial cells in media supplemented with vascular endothelial growth factor (VEGF) and insulin-like growth factor (IGF-1). ADSC-derived endothelial cells and human aortic endothelial cells (hAEC) were cultured in normal or high glucose for one week. Cells were assessed by immunofluorescence to confirm differentiation toward endothelial cells. Protein and RNA isolates were assessed for the expression of metabolic and inflammatory markers for diabetes to measure the resistance of differentiated hADSCs to a high glucose environment compared to hAEC. Finally, hAEC and human aortic adventitial fibroblasts (hAAFb) were drop-seeded onto the prepared scaffolds and conditioned in a custom-designed vascular bioreactor in normal or high glucose media for 4 weeks. Constructs explanted from the bioreactors were assessed for cell retention by Live/Dead Assay, scanning electron microscopy, and histology. Protein and RNA isolates were assessed for the same metabolic and inflammatory markers for diabetes. Histological analysis and DNA concentration showed complete decellularization of porcine renal arteries. A pilot study to assess the in vitro response of endothelial-differentiated hADSCs to diabetic conditions was similar to that of hAEC. Decellularized arterial scaffolds seeded with fibroblasts and endothelial cells conditioned in a bioreactor retained some endothelial cells, but lacked fibroblasts after conditioning

A detector for muon tomography: Data acquisition and preliminary results

I describe the general design of the prototype particle detector constructed by the Maya Muon Tomography Group and how it can be used to e ectively \x-ray" building and ground structure in a location of interest using cosmic-ray muons. I give detailed descriptions of the high level data acquisition and tracking systems, which are responsible for reconstructing muon trajectories from raw data. In addition, I present the rst images obtained from the detector. These images show the basic features of several University of Texas buildings in the vicinity of the Engineering Science Building and demonstrate the feasibility of muon tomographic imaging with our detector.Physic

Applications of CT Perfusion-Based Triaging and Prognostication in Acute Ischemic Stroke

CT Perfusion (CTP) is a minimally invasive imaging technique that aids acute ischemic stroke (AIS) triage and prognostication by determining tissue viability based on hemodynamic parameters. The goals of this research are to determine: 1) CTP thresholds for estimation of infarct and penumbra volume, 2) how CTP scan duration impacts infarct and penumbra volume estimates, and 3) reliability of CTP for predicting functional outcomes following intra-arterial therapy (IAT). Chapter 2 introduced an experimental study for determining ischemia-time dependent thresholds for brain infarction using multimodal imaging in a porcine stroke model that is easier to implement than previous large animal stroke models. CTP determined an absolute cerebral blood flow (CBF) threshold of 12.6±2.8mL∙min-1∙100g-1 for brain infarction after 3h of ischemia, which was close to that derived using hydrogen clearance in a previous study by Jones et al (Journal of Neurosurgery, 1981;54(6):773-782). Chapter 3 retrospectively investigated the impact of CTP scan duration on cerebral blood volume (CBV), CBF, and time-to-maximum (Tmax) and found optimal scan durations that minimized radiation dose while not under- or over-estimating infarct volumes measured using two previously derived CBF thresholds for infarction. We found that CBV and Tmax decreased at shorter scan durations, whereas CBF was independent of scan duration, consequently, infarct volume estimated by both CBF thresholds was independent of scan duration. Chapter 4 compared reperfusion seen on follow-up CTP to reperfusion predicted by post-IAT digital subtraction angiography (DSA) and the ability of the two modalities to predict good 90-day functional outcome in a retrospective study. We found that patients with ‘complete reperfusion’ grades on DSA often had ischemic tissue on follow-up CTP and that follow-up CTP had superior specificity and accuracy for predicting functional outcome compared to DSA. In summary, this research has shown that CBF thresholds can reliably detect infarct in AIS and are independent of scan duration, allowing radiation dose to be minimized by limiting scans to 40s without compromising accuracy of infarct volume estimates. Finally, CTP is a more specific and accurate predictor of functional outcome than the commonly used post-procedural DSA, this could help select patients for neuroprotective therapy

Connecting Schools to Communities With Student-Produced Multimodal Compositions

In this paper, I use research on embodied cognition to support learning objectives for a unit that I’ve designed to increase reading comprehension, promote digital citizenship, and provide scaffolding for students to produce digital multimodal compositions. The unit is aligned to English Language Arts Common Core and International Society for Technology in Education (ISTE) standards. I conclude with an argument for schools to focus on transparency over accountability and propose using digital literary magazines that contain the students\u27 multimodal compositions to connect with communities

A Third Planet Orbiting HIP 14810

We present new precision radial velocities and a three-planet Keplerian orbit fit for the V = 8.5, G5 V star HIP 14810. We began observing this star at Keck Observatory as part of the N2K Planet Search Project. Wright et al. (2007) announced the inner two planets to this system, and subsequent observations have revealed the outer planet planet and the proper orbital solution for the middle planet. The planets have minimum masses of 3.9, 1.3, and 0.6 M_Jup and orbital periods of 6.67, 147.7, and 952 d, respectively. We have numerically integrated the family of orbital solutions consistent with the data and find that they are stable for at least 10^6 yr. Our photometric search shows that the inner planet does not transit.Comment: ApJL, accepte