Virtual Frame Technique: Ultrafast Imaging with Any Camera

Many phenomena of interest in nature and industry occur rapidly and are difficult and cost-prohibitive to visualize properly without specialized cameras. Here we describe in detail the Virtual Frame Technique (VFT), a simple, useful, and accessible form of compressed sensing that increases the frame acquisition rate of any camera by several orders of magnitude by leveraging its dynamic range. VFT is a powerful tool for capturing rapid phenomenon where the dynamics facilitate a transition between two states, and are thus binary. The advantages of VFT are demonstrated by examining such dynamics in five physical processes at unprecedented rates and spatial resolution: fracture of an elastic solid, wetting of a solid surface, rapid fingerprint reading, peeling of adhesive tape, and impact of an elastic hemisphere on a hard surface. We show that the performance of the VFT exceeds that of any commercial high speed camera not only in rate of imaging but also in field of view, achieving a 65MHz frame rate at 4MPx resolution. Finally, we discuss the performance of the VFT with several commercially available conventional and high-speed cameras. In principle, modern cell phones can achieve imaging rates of over a million frames per second using the VFT.Comment: 7 Pages, 4 Figures, 1 Supplementary Vide

The Regulatory Trajectory of Synthetic Securitization: A Breakdown of International Regulatory Environments

The harmful effects on global financial stability that accompanied the 2007-2008 financial crisis (the “crisis”) were largely intensified by loose regulatory practices in the United States’ (U.S.) secondary mortgage market. Accordingly, the harm suffered on a global level warrants a comparative perspective on international securities regulation. This Article will examine several securitization methods in Europe and the U.S. and derive prospective solutions from these existing approaches that have the potential to address undue risks associated with asset-backed securities today. This Article will initially discuss the history and causes of the subprime mortgage crisis and then discuss the particular difficulties with the secondary housing market and mortgage-backed securities. This Article will then compare the different methods of securitization in several countries and illustrate how these methods may improve the functioning of the U.S.’s secondary mortgage market today. Next, this Article will review several countries’ regulatory structures with respect to securities and bank regulations, and analyze the issues that have been addressed by U.S. and European legislators since the crisis. More specifically, this section will analyze the obstacles to financial stability that exist in global markets today. Finally, this Article will propose potential solutions to identified regulatory shortcomings in order to enhance and thereby preserve a vital part of the global economy and housing market. A key conclusion of this Article is that a global perspective is essential when developing a response to a future financial crisis due to the interconnectedness of the global economy. Regulatory effects, domestic or global, will impact the world economy. Future regulatory reforms must have the clear objective of reducing the risks and consequences of future systemic financial crises, such that overall economic growth is not adversely impacted. This Article urges policy makers to focus on the financial system as a whole when developing legislation intended to mitigate undue risk exposure. While policy makers have recognized the need for this broad approach to securities regulation, the United States’ legislation post-crisis has failed to account for the interconnectedness of international economies. While economic systems necessarily differ according to specific needs and political imparities, the growth of technology and globalization in the twentieth century has created a worldwide interconnected and interdependent “system of systems.” Coupled with this Article’s proposed broad approach, the latest financial crisis is a very useful exemplar, which policy makers can use to address issues that remain pertinent to global financial markets in order to avoid future crises

Cognitive responses, attitudes, and product involvement of female consumers to traditional and non-traditional models in beauty advertising

This study investigates how female consumers cognitively respond to traditional and non-traditional models in beauty product advertisements, and why they have the attitudes they do toward those ads. Using identification theory and schema theory as a framework, results showed that regardless of demographic variables, women felt traditional models in beauty product advertisements were unrealistic. Many said advertisements were hard to ignore, and continued to serve as a reminder that their own bodies, skin, and hair were nowhere near the standard depicted in modern day advertising

Predictors of morbidity and mortality with endovascular and open thoracic aneurysm repair

BackgroundOpen and endovascular thoracic aneurysm repairs are associated with significant complications including paraplegia, stroke, vascular insufficiency, and death. Predictors of adverse outcomes are not well-defined in this patient population.MethodsThe database of the GORE TAG (W.L. Gore, Flagstaff, Ariz) Pivotal Trial comparing the TAG endograft to open repair was interrogated. Univariate (UVA) and multivariate analyses (MVA) of demographic, clinical, anatomic, and procedural variables were conducted to discover possible predictors of serious adverse events for the whole group and for the TAG and open cohort groups separately. Early adverse outcomes occurred within 30 days or the initial hospitalization. P value of ≤ .05 was significant.ResultsA total of 140 TAG and 94 open descending thoracic aneurysm (DTA) patients were analyzed, consisting of 128 men and 106 women. Perioperative deaths were 9/94 for open surgery and 3/140 for TAG patients, with 10/12 (7 open, 3 TAG) deaths occurring in men. Two female deaths were both after open surgery. Multivariate analysis showed predictors of death for all patients were symptomatic aneurysms and male gender. Analysis of a combined morbidity/mortality endpoint (stroke/paralysis/MI/death) showed elevated creatinine predicted these events for the whole group. Open surgery (P < .001) and increasing aneurysm diameter (P < .001) predicted an increased likelihood of any major adverse event. Open surgery was significantly associated with an increased risk of paraplegia (P = .002). Vascular complications were more frequent in the TAG (19%) than in open DTA patients (9%) (P = .038). Female gender (P = .01) predicted vascular complications within the endovascular group. For all analyses, long procedure times were correlated with adverse events. Women were noted to have longer procedure times for both TAG and open repairs.ConclusionElevated creatinine levels and symptomatic aneurysms predict morbidity and mortality, respectively, regardless of repair type. Male gender predicted death after open surgery, and since most deaths (9 of 12) were in this group, male gender predicted death overall, despite women's more difficult endovascular TAA repairs as evidenced by longer procedure times and higher vascular complication rates. All major adverse events and paraplegia were more common for open surgery patients

Improving aneurysm-related outcomes: Nationwide benefits of endovascular repair

ObjectivesEndovascular aneurysm repair (EVAR) has changed the practice of abdominal aortic aneurysm (AAA) surgery. We examined a national Medicare database to establish the effect of EVAR introduction into the United States.MethodsA 5% random sample of inpatient Medicare claims from 2000 to 2003 was queried using International Classification of Diseases, 9th Revision (ICD-9) diagnosis and procedure codes. An EVAR procedure code was available after October 2000. Occurrences were multiplied by 20 to estimate yearly national volumes and then divided into the yearly Centers for Medicare and Medicaid Services (CMS) population of elderly Medicare recipients for rates per capita, reported as cases per 100,000 elderly Medicare recipients. Statistical analysis was performed by using χ2, Student’s t test, nonparametric tests, and multiple regression analysis, with significance defined as P ≤ .05.ResultsElective AAA repairs averaged 87.7 per 100,000 Medicare patients between 2000 and 2003, with EVAR has steadily increasing to 41% of elective repairs in 2003. From 2000 to 2003, overall elective AAA mortality declined from 5.0% to 3.7% (P < .001), while open repair mortality remained unchanged. EVAR patients are significantly older than patients treated with open repair. From 2000 to 2003 patients >84 years receiving EVAR increased to 62.7% (P < .001). Overall hospital length of stay (LOS) decreased from 8.6 days in 2000 to 7.3 days in 2003, P < .001, but increased for open AAA patients. EVAR patients were more likely to be discharged home rather than to skilled facilities. Average elective repair hospital charges were not different between groups, but Medicare reimbursement was lower for EVAR, with a higher proportion cases classified as DRG 111 (major cardiovascular procedure without complications). EVAR was used in 10.6% of ruptured AAA repairs in 2003, with a significant reduction in mortality compared with open repairs for rupture (31.8% vs 50.8%; P < .001).ConclusionsEVAR is replacing open surgery without an increase in overall case volume. EVAR is responsible for overall decrease in operative mortality even in ruptured aneurysms while decreasing utilization variables. Reimbursement to hospitals is shrinking, however

Contact Distribution Encodes Frictional Strength

The static friction coefficient, $\mu$, is a central quantity in modeling mechanical phenomena. However, experiments show that it is highly variable, even for a single interface under carefully controlled experimental conditions. Traditionally, this inconsistency is attributed to fluctuations in the real area of contact between samples, $A_R$. In this work, we perform a variety of experimental protocols on three pairs of solid blocks while imaging the contact interface and measuring $\mu$. Using linear regression and images of the interface taken prior to tangential loading, we predict the static friction coefficient. Our model strongly outperforms two benchmarks, the Bowden and Tabor picture ($\mu \propto A_R$) and prediction using experimental variables, indicating that a large portion of the observed variance in the initialization of slip is encoded in the contact plane. We perform the same analysis using only sub-sections of the interface, and find that regions as small as $1\%$ of the interface can still can beat both benchmarks. However, bigger sub-sections of the interface, even when comprised of many small regions with bad individual predictive power, outperform the best small regions alone, suggesting that the interfacial state is not dependent on any single point, but is rather distributed across the contact ensemble.Comment: 5 pages 4 figure

Bellybutton: Accessible and Customizable Deep-Learning Image Segmentation

The conversion of raw images into quantifiable data can be a major hurdle in experimental research, and typically involves identifying region(s) of interest, a process known as segmentation. Machine learning tools for image segmentation are often specific to a set of tasks, such as tracking cells, or require substantial compute or coding knowledge to train and use. Here we introduce an easy-to-use (no coding required), image segmentation method, using a 15-layer convolutional neural network that can be trained on a laptop: Bellybutton. The algorithm trains on user-provided segmentation of example images, but, as we show, just one or even a portion of one training image can be sufficient in some cases. We detail the machine learning method and give three use cases where Bellybutton correctly segments images despite substantial lighting, shape, size, focus, and/or structure variation across the regions(s) of interest. Instructions for easy download and use, with further details and the datasets used in this paper are available at pypi.org/project/Bellybuttonseg.Comment: 6 Pages 3 Figure

Factors that influence perforator thrombosis and predict healing with perforator sclerotherapy for venous ulceration without axial reflux

ObjectiveRefluxing perforators contribute to venous ulceration. We sought to describe patient characteristics and procedural factors that (1) impact rates of incompetent perforator vein (IPV) thrombosis with ultrasound-guided sclerotherapy (UGS) and (2) impact the healing of venous ulcers (CEAP 6) without axial reflux.MethodsA retrospective review of UGS of IPV injections from January 2010 to November 2012 identified 73 treated venous ulcers in 62 patients. Patients had no other superficial or axial reflux and were treated with standard wound care and compression. Ultrasound imaging was used to screen for refluxing perforators near ulcer(s). These were injected with sodium tetradecyl sulfate or polidocanol foam and assessed for thrombosis at 2 weeks. Demographic data, comorbidities, treatment details, and outcomes were analyzed. Univariate and multivariable modeling was performed to determine covariates predicting IPV thrombosis and ulcer healing.ResultsThere were 62 patients (55% male; average age, 57.1 years) with active ulcers for an average of 28 months with compression therapy before perforator treatment, and 36% had a history of deep venous thrombosis and 30% had deep venous reflux. At a mean follow-up of 30.2 months, ulcers healed in 32 patients (52%) and did not heal in 30 patients (48%). Ulcers were treated with 189 injections, with an average thrombosis rate of 54%. Of 73 ulcers, 43 ulcers (59%) healed, and 30 (41%) did not heal. The IPV thrombosis rate was 69% in patients whose ulcers healed vs 38% in patients whose ulcers did not heal (P < .001). Multivariate models demonstrated male gender (P = .03) and warfarin use (P = .01) negatively predicted thrombosis of IPVs. A multivariate model for ulcer healing found complete IPV thrombosis was a positive predictor (P = .02), whereas a large initial ulcer area was a negative predictor (P = .08). Increased age was associated with fewer ulcer recurrences (P = .05). Predictors of increased ulcer recurrences were hypertension (P = .04) and increased follow-up time (P = .02). Calf vein thrombosis occurred after 3% (six of 189) of injections.ConclusionsThrombosis of IPVs with UGS increases venous ulcer healing in a difficult patient population. Complete closure of all IPVs in an ulcerated limb was the only predictor of ulcer healing. Men and patients taking warfarin have decreased rates of IPV thrombosis with UGS