Parallel FDTD modelling of nonlocality in plasmonics

As nanofabrication techniques become more precise, with ever smaller feature sizes, the ability to model nonlocal effects in plasmonics becomes increasingly important. While nonlocal models based on hydrodynamics have been implemented using various computational electromagnetics techniques, the finite-difference time-domain (FDTD) version has remained elusive. Here we present a comprehensive FDTD implementation of nonlocal hydrodynamics, including for parallel computing. As a sub-nanometer step size is required to resolve nonlocal effects, a parallel implementation makes the computational cost of nonlocal FDTD more affordable. We first validate our algorithms for small spherical metallic particles, and find that nonlocality smears out staircasing artifacts at metal surfaces, increasing the accuracy over local models. We find this also for a larger nanostructure with sharp extrusions. The large size of this simulation, where nonlocal effects are clearly present, highlights the importance and impact of a parallel implementation in FDTD. CCB

Strategic Surrogates or Sad Sinners: U.S. Taxation of Bartering in Digital Services

The COVID-19 pandemic caused both a surge in technology use and a deterioration in government finances. At the same time, big tech companies are under scrutiny by lawmakers for tax avoidance, antitrust issues, and other concerns. These realities call for governments to reassess tax policy toward tech companies and for tech companies to reassess legal strategy toward taxes. State and federal governments\u27 tax bases are eroding because of the noncash, barter nature of modern transactions. When a taxpayer uses “free” digital services such as e-mail, social media, or search engines, she pays via access to her personal data or attention. From a legal and policy standpoint, these barter transactions should be taxed just as if cash had changed hands, but because it is not practicable to identify, value, and tax the data and time of each user, they have escaped taxation, giving many tech companies an unintended tax advantage. To address this unfairness, this article proposes a surrogate tax, through which the tech company acts as a proxy to pay the tax that is technically the liability of its users. In contrast to Digital Services Taxes (DSTs), which have been the main focus of policy makers and the extant literature, surrogate taxes adhere closely to standards of good tax policy, providing an administrable means of capturing untaxed digital barter while advancing fairness across the industry\u27s business models. From a legal strategy standpoint, this article argues that tech companies themselves should support surrogate taxes, to avoid facing more onerous, “sin”-like taxes, such as DSTs

Light the Way: Song Cycle for Baritone Voice and Piano (Honors)

Light the Way is based on seven distinct poems written by Joshua Ziemann. I was compelled to write a song cycle based on Ziemann\u27s texts after reading through his poetry and seeing great possibilities for musical settings. The poems that I chose to set are not concretely related to one another; however they are related on an abtract level. The texts in many respects, represent a sense of searching for purpose and meaning in life and our environment. I chose the title, Light the Way, in order to reflect this sentiment

Extracting DNA From Salt: Using PicoGreen To Explore Detection Limits

Biological materials surviving in modern halite (salt) on Earth may point to a method for detection of potential or former life in salt deposits on Mars. This project attempts to find an efficient method extracting cells and DNA from modern halite crystals to gain more insight into efficient method of extracting DNA from ancient salt. Our method considers the limitations of Mars Rover techniques in terms of reagents and simplicity. Halite was collected form the north shore of Great Salt Lake, Utah. Through direct experimentation, we designed a filtration system to isolate DNA from salt samples and refined this process to provide the highest yields of clean DNA. To determine quantities of DNA, we utilized the dye, pico-green, which is detectable by fluorimetry. Methods for the best yield and detection will be presented as well as design that adapts this work to remote techniques

Introduction : Texts and Their Transformations

ハワイ州マウイ, 2000年11

Foreword

ハワイ州マウイ, 2000年11

How accurate are parental responses concerning their fourth-grade children's school-meal participation, and what is the relationship between children's body mass index and school-meal participation based on parental responses?

<p>Abstract</p> <p>Background</p> <p>This article investigated (1) parental response accuracy of fourth-grade children's school-meal participation and whether accuracy differed by children's body mass index (BMI), sex, and race, and (2) the relationship between BMI and school-meal participation (based on parental responses).</p> <p>Methods</p> <p>Data were from four cross-sectional studies conducted from fall 1999 to spring 2003 with fourth-grade children from 13 schools total. Consent forms asked parents to report children's usual school-meal participation. As two studies' consent forms did not ask about lunch participation, complete data were available for breakfast on 1,496 children (51% Black; 49% boys) and for lunch on 785 children (46% Black; 48% boys). Researchers compiled nametag records (during meal observations) of meal participation on randomly selected days during children's fourth-grade school year for breakfast (average nametag days across studies: 7-35) and for lunch (average nametag days across studies: 4-10) and categorized participation as "usually" (≥ 50% of days) or "not usually" (< 50% of days). Weight and height were measured. Concerning parental response accuracy, marginal regression was used with agreement between parental responses and nametag records as the dependent variable; independent variables were BMI, age, sex, race, and study. Concerning a relationship between BMI and school-meal participation, marginal regression was used with BMI as the dependent variable; independent variables were breakfast participation, lunch participation, age, sex, race, and study.</p> <p>Results</p> <p>Concerning breakfast participation and lunch participation, 74% and 92% of parents provided accurate responses, respectively. Parental response accuracy was better for older children for breakfast and lunch participation, and for Black than White children for lunch participation. Usual school-meal participation was significantly related to children's BMI but in opposite directions -- positively for breakfast and inversely for lunch.</p> <p>Conclusions</p> <p>Parental response accuracy of children's school-meal participation was moderately high; however, disparate effects for children's age and race warrant caution when relying on parental responses. The BMI results, which showed a relationship between school-meal participation (based on parental responses) and childhood obesity, conflict with results from a recent article that used data from the same four studies and found no significant relationship when participation was based on nametag records compiled for meal observations.</p

Plantar fasciitis and calcaneal spur formation are associated with abductor digiti minimi atrophy on MRI of the foot

Objective To determine the association of atrophy of the abductor digiti minimi muscle (ADMA), an MRI manifestation of chronic compression of the inferior calcaneal nerve suggesting the clinical diagnosis of Baxter’s neuropathy, with MRI markers of potential etiologies, including calcaneal spur formation, plantar fasciitis, calcaneal edema, Achilles tendinosis and posterior tibial tendon dysfunction (PTTD). Materials and methods Prevalence of calcaneal spur formation, plantar fasciitis, calcaneal edema, Achilles tendinosis and PTTD was assessed retrospectively on 100 MRI studies with ADMA and 100 MRI studies without ADMA. Patients ranged in age from 10–92 years. Pearson chi-square analyses and Fisher’s exact test were used to compare prevalence of the above findings in patients with and without ADMA. Logistic regression was used to determine which variables were significantly associated with ADMA. Results Among patients with ADMA, there was significantly greater age (57.2 years vs 40.8 years, p \u3c 0.001), presence of Achilles tendinosis (22.0% vs 3.0%, P \u3c 0.001), calcaneal edema (15.0% vs 3.0%, P = 0.005), calcaneal spur (48.0% vs 7.0%, P \u3c 0.001), plantar fasciitis (52.5% vs 11.0%, P \u3c 0.001), and PTTD (32.0% vs 11.0%, P \u3c 0.001). After multivariate logistic regression analysis, only age [odds ratio (OR) 1.06, 95% confidence interval (CI) 1.03, 1.09], calcaneal spur (OR 3.60, 95% CI 1.28, 10.17), and plantar fasciitis (OR 3.35, 95% CI 1.31, 8.56) remained significant. Conclusion Advancing age, calcaneal spur, and plantar fasciitis are significantly associated with ADMA. Their high odds ratios support the notion of a possible etiologic role for calcaneal spur and plantar fasciitis in the progression to Baxter’s neuropathy