Angle diversity to increase coverage and position accuracy in 3D visible light positioning

The most common approach to light-based indoor positioning relies on multilateration of received signals to the mobile device. Any deficiencies in the fidelity of these light signals can significantly distort position estimates. In this paper, we propose a method to dynamically control the light distribution from the overhead luminaires to mitigate fading effects that would otherwise occur under static lighting. By manipulating the direction of the luminaire, effectively the dispersion pattern, we introduce signal diversity in the form of multiple pointing angles and light distributions. In addition to providing angle diversity, steering and then tracking sustains the maximal line-of-sight path between a source and receiver, which reduces angle-dependent attenuation and optimizes the signal-to-noise ratio for any coordinate without needing to change the physical properties of the source or receiver. This gain in signal strength combats the limited field-of-view of luminaires and photodiodes to provide better overall coverage, which translates directly to increase positioning accuracy, particularly in a 3D space. In the results, we show field-of-view gains of 43% and improvements in MSE of 20cm.Accepted manuscrip

Predictors of Conspiracy Believers

Why do many Americans believe in conspiracy theories? One answer could be the lack of trust and transparency between many American citizens and the United States government. Conspiracy theories have been used throughout history as an explanation for events and situations that were carried out by the government without any credible evidence. That said, what factors influence one to believe in them? Using Chapman University Survey of American Fears, this paper assesses the two most believed conspiracy theories in America, John F. Kennedy’s assassination and the 9/11 attacks and whether the factors of partisanship, fear of financial uncertainty, education, age and the media are impact one’s belief in conspiracy theories. Linear regression results found partisanship has no influence on either of the two conspiracy theories tested whereas the other factors do impact one’s belief for conspiracy theories. The most salient result emerges when comparing the influential factors of the two conspiracy theories used. Belief in both conspiracy theories was influenced by fear of uncertainty, education, age, and social media. Although, education and age are both influential for the belief in conspiracy theories, the magnitude of the factors were significantly different. This implies the factors’ magnitude of influence varies among theories

I’m a Big Kid Now: Enhancing Transition RN Residents’ Confidence During Pediatric Patient Care

The title of the clinical nurse leader project is “I’m a Big Kid Now: Enhancing Transition RN Residents’ Confidence During Pediatric Patient Care”. The project aims to improve the support components for Transition RN residents during their Transition RN Residency at Children’s Hospital Los Angeles. The clinical leadership theme that correlates to this project is communication. The clinical nurse leader’s role is to act as an educator and a facilitator throughout this project. In examining the clinical nurse leader competencies, competencies “use performance measures to assess and improve the delivery of evidence-based practices and promote outcomes that demonstrate delivery of higher-value care” and “promote a culture of continuous quality improvement within a system” closely mirror the foundation of this clinical nurse leader project (American Association of Colleges of Nursing, 2013). The process begins with (1) diligent assessment of the past Transition RN residents’ feedback regarding support components, and (2) a review of past mentors and debriefers’ meeting agendas with the aim of transforming these into two consolidated professional development coaching meetings. The process ends with enhanced support components for integration with the Transition RN Residency curriculum to facilitate Transition RN residents’ confidence/ competency in delivering pediatric patients’ care, and thus, enhance overall patients’ outcomes. By working on the process, leadership team expects (1) better learning experience, (2) increased Transition RN residents’ satisfaction with the program, and (3) enhanced Transition RN residents’ confidence/ competency in treating pediatric patients. It is important to work on this in a timely manner because the leadership team has identified the need to improve (1) Transition RN residents’ satisfaction with the support components, and (2) Transition RN residents’ self report confidence/ competency in treating pediatric patients. Ultimately, this project will contribute a significant impact on enhancing pediatric patients’ outcomes. This project is undertaken as an evidence-based change of practice project at Children’s Hospital Los Angeles and as such was not formally supervised by the Institutional Review Board

Indoor 3D localization with low-cost LiFi components

Indoor positioning or localization is an enabling technology expected to have a profound impact on mobile applications. Various modalities of radio frequency, ultrasound, and light can be used for localization; in this paper we consider how visible light positioning can be realized for 3D positioning as a service comprised of optical sources as part of an overarching lighting infrastructure. Our approach, called Ray-Surface Positioning, uses one or more overhead luminaires, modulated as LiFi, and is used in conjunction with a steerable laser to realize position estimates in three dimensions. In this paper, we build and demonstrate Ray-Surface Positioning using low-cost commodity components in a test apparatus representing one quadrant of a 4m × 4m × 1m volume. Data are collected at regular intervals in the test volume representing 3D position estimates and is validated using a motion capture system. For the low-cost components used, results show position estimate errors of less than 30cm for 95% of the test volume. These results, generated with commodity components, show the potential for 3D positioning in the general case. When the plane of the receiver is known a priori, the position estimate error diminishes to the resolution of the steering mechanism.Accepted manuscrip

Dynamic fluid shifts induced by fetal bypass

ObjectiveFluid shifts have been suggested to occur with fetal bypass. The degree or mechanisms behind these volume changes (or location) have not been defined. We characterized the preceding and correlated the findings to plasma vasopressin concentrations, the critical peptide of osmoregulation.MethodsSeventeen ovine fetuses (105–111 days' gestation) were started on bypass and followed 2 hours after bypass. Hemodynamics and volume replacements needed to maintain minimum reservoir volume during bypass and normal physiologic parameters after bypass were recorded. Serial blood samples were collected to assess gas exchange and vasopressin levels. Changes in total tissue water content were measured for several organs and the placenta. Plasma volume, fluid shifts, and osmolarity were calculated.ResultsHematocrit values decreased by 15 minutes of bypass to 28% from 33% and then increased to 34% by 120 minutes after bypass, corresponding to a decreased fetal plasma volume of 79 to 72 mL/kg by 120 minutes after bypass. The majority of volume shifts (approximately 100 mL/kg) occurred during bypass, but additional volume replacements were required after bypass to maintain normal hemodynamics, resulting in overall losses of 0.8 mL · kg−1 · min−1. Losses were not accounted for by placental or organ edema. Vasopressin levels increased dramatically with bypass (39–51.5 pg/mL) and were strongly predicted by increased fetal plasma volumes (R2 = 0.90), whereas osmolarity was not significantly associated with plasma volumes.ConclusionFetal bypass leads to significant fluid shifts that correlate strongly with increasing vasopressin levels (but not changes in osmolarity). The placenta is not the primary site of volume loss. Rehydration of the fetus is necessary after bypass

Thermal Models of Asteroids with Two-band Combinations of Wide-field Infrared Survey Explorer Cryogenic Data

We used the reparameterized Near-Earth Asteroid Thermal Model to model observations of a curated set of over 4000 asteroids from the Wide-field Infrared Survey Explorer in two wavelength bands (W2-3 or W3-4) and compared the results to previous results from all four wavelength bands (W1-4). This comparison was done with the goal of elucidating unique aspects of modeling two-band observations so that any potential biases or shortcomings for planned two-band surveys (e.g., the NASA Near-Earth Object Surveyor Mission) can be anticipated and quantified. The W2-3 two-band fits usually yielded slightly smaller diameters than the four-band fits, with a median diameter difference of -10%, with the 5% and 95% quantiles of the distribution at -32% and -1.5%, respectively. We conducted similar comparisons for W3-4, in part because the longest wavelength bands are expected to provide the best two-band results. We found that the W3-4 two-band diameters are slightly larger than the four-band results, with a median diameter difference of 11% and the 5% and 95% quantiles of the distribution at -2.1% and 26%, respectively. The diameter uncertainty, obtained with bootstrap analysis, is larger by 30% and 35% (median values) for the W2-3 and W3-4 fits, respectively, than for the corresponding four-band fits. Using 23 high-quality stellar occultation diameters as a benchmark, we found that the median errors of W2-3 and W3-4 diameter estimates are -15% and +12%, respectively, whereas the median error of the four-band fits is 9.3%. Although the W2-3 and W3-4 diameters appear to have greater systematic errors and uncertainties than their four-band counterparts, two-band estimates remain useful because they improve upon diameter estimates obtained from visible photometry alone.Comment: 18 pages, 21 figure

Arsenic Biotransformation as a Cancer Promoting Factor by Inducing DNA Damage and Disruption of Repair Mechanisms

Chronic exposure to arsenic in drinking water poses a major global health concern. Populations exposed to high concentrations of arsenic-contaminated drinking water suffer serious health consequences, including alarming cancer incidence and death rates. Arsenic is biotransformed through sequential addition of methyl groups, acquired from s-adenosylmethionine (SAM). Metabolism of arsenic generates a variety of genotoxic and cytotoxic species, damaging DNA directly and indirectly, through the generation of reactive oxidative species and induction of DNA adducts, strand breaks and cross links, and inhibition of the DNA repair process itself. Since SAM is the methyl group donor used by DNA methyltransferases to maintain normal epigenetic patterns in all human cells, arsenic is also postulated to affect maintenance of normal DNA methylation patterns, chromatin structure, and genomic stability. The biological processes underlying the cancer promoting factors of arsenic metabolism, related to DNA damage and repair, will be discussed here

Real-time RFI Mitigation in Radio Astronomy

As the use of wireless technology has increased around the world, Radio Frequency Interference (RFI) has become more and more of a problem for radio astronomers. Preventative measures exist to limit the presence of RFI, and programs exist to remove it from saved data, but the use of algorithms to detect and remove RFI as an observation is occurring is much less common. Such a method would be incredibly useful for observations in which the data must undergo several rounds of processing before being saved, as in pulsar timing studies. Strategies for real-time mitigation have been discussed and tested with simulated data, but ideally the results of any approach would be validated by a detailed comparison of the final data products with and without mitigation applied. The goal of this project is to develop an RFI mitigation approach based on strategies suggested by Buch et al.(2016) and to test this program on real data from the observation of pulsar J1713+0747 at the Green Bank Observatory in West Virginia. We use a Median Absolute Deviation (MAD) filter to identify interference in the observation and replace the compromised data with random Gaussian noise to match a characteristic radio signal from space. In order to verify our results, we analyze the pulsar’s timing residuals obtained both from the mitigated data and from data processed through offline RFI removal software. Comparing the two, our preliminary findings indicate that our program is able to significantly improve the quality of timing results from the observation

Arsenic Exposure and the Induction of Human Cancers

Arsenic is a metalloid, that is, considered to be a human carcinogen. Millions of individuals worldwide are chronically exposed through drinking water, with consequences ranging from acute toxicities to development of malignancies, such as skin and lung cancer. Despite well-known arsenic-related health effects, the molecular mechanisms involved are not fully understood; however, the arsenic biotransformation process, which includes methylation changes, is thought to play a key role. This paper explores the relationship of arsenic exposure with cancer development and summarizes current knowledge of the potential mechanisms that may contribute to the neoplastic processes observed in arsenic exposed human populations