Linking Audiences to News: A Network Analysis of Chicago Websites

The mass media model, which sustained news and information in communities like Chicago for decades, is being replaced by a "new news ecosystem" consisting of hundreds of websites, podcasts, video streams and mobile applications. In 2009, The Chicago Community Trust set out to understand this ecosystem, assess its health and make investments in improving the flow of news and information in Chicagoland. The report you are reading is one of the products of the Trust's local information initiative, Community News Matters. "Linking Audiences to News: A Network Analysis of Chicago Websites" is one of the first -- perhaps the first -- research projects seeking to understand a local

Adapting Biotoxin Monitoring For The Future: An Opportunity For A Harmful Algae Bloom (HAB) Network In Casco Bay, Maine

Harmful Algae Blooms (HABs) related to marine biotoxins have considerable impacts on coastal communities and have been increasing in size and frequency globally. Maine is recognized as a leader in biotoxin management as it relates to bivalve shellfish, but it has been unclear how current management practices effect the growth of shellfish aquaculture and how they will adapt to future conditions. This research uses a collaborative approach to analyze the current state of biotoxin management in Maine. First, the current management practices in Maine were compared and contrasted with five other states dealing with similar issues. Then, the perspectives of primary stakeholders in the oyster aquaculture industry were investigated through surveys and interviews. Lastly, the interactions specifically between the oyster aquaculture industry and biotoxin management were examined in Casco Bay. Comparative case study results demonstrate that Maine effectively manages biotoxins but is lacking in data transparency and stakeholder engagement. Survey results suggest, oyster aquaculturists in Casco Bay are acutely aware of issues in biotoxin monitoring and are eager to find innovative solutions, as their livelihoods are directly impacted by the closures. An independent HAB network in Casco Bay would be an effective approach to increase stakeholder engagement and transparency around closure decisions. This will require initiative from both the grower community as well as the regulators. A new HAB Network has the potential to build trust between the regulators and oyster aquaculturists, as well as contribute to future HAB research

Finding the balance: Mindfulness meditations to foster interdisciplinary artistic exploration

While mindfulness has existed as a tenant of prominent Asian spiritualities since the sixth century B.C., the last fifty years have seen an appropriation of mindfulness practices into diverse sectors of American life, including into clinical research. Within the same fifty years, contemporary artists have increasingly pushed their crafts towards interdisciplinary collaborating between and across artistic disciplines. The body of academic research into creativity suggests a correlation between mindfulness practices and elevated collaborative artistry. Thus, this project seeks to answer the question, how can mindfulness practices encourage interdisciplinary artistic collaboration? My contribution to this inquiry consisted of two main studies. First, a case study on myself where, for twelve months, I systematically practiced different mindfulness meditations from religious and secular sources, including breath awareness, walking, eating, listening to Tibetan Bowl music, and Satsang gazing. For the second stage of my project, I facilitated two cohorts of collegiate artists in hour-long meditation sessions over the course of twelve weeks. While my own meditative practice appears to be linked with my elevated success as an individual and collaborative artist, the findings from my two cohorts suggest that mindfulness meditations do not contribute to artistic collaboration within just six weeks of initial practice. Towards my discussion of these findings, it may be necessary for collegiate artists to invest more time in their own personal mindfulness routines to reap benefits similar to those which my case study indicate. Surprisingly, my own consistent meditation practice aligned with an increased level of detachment from academia and general responsibility that I have noticed within myself. While this relationship between my meditations and my decreased collegiate involvement indicates only anecdotal relatedness, the literature supports an additional hypothesis that mindfulness may bring about amplified dedication to artistic craft, while simultaneously fostering detachment from urgent responsibilities in other sectors in the lives of meditation practitioners

System Optimization and Patient Translational Motion Correction for Reduction of Artifacts in a Fan-Beam CT Scanner

In computed tomography (CT) systems, many different artifacts may be present in the reconstructed image. These artifacts can greatly reduce image quality. For our laboratory prototype CT system, a fan-beam/cone-beam focal high-resolution computed tomography (fHRCT) scanner, the major artifacts that affect image quality are distortions due to errors in the reconstruction algorithm\u27s geometric parameters, ring artifacts caused by uncalibrated detectors, cupping and streaking created by beam hardening, and patient-based motion artifacts. Optimization of the system was required to reduce the effects of the first three artifact types, and an algorithm for correction of translational motion was developed for the last. System optimization of the system occurred in three parts. First, a multi-step process was developed to determine the geometric parameters of the scanner. The ability of the source-detector gantry to translate allowed a precise method to be created for calculating these parameters. Second, a general flat-field correction was used to linearize the detectors and reduce the ring artifacts. Lastly, beam hardening artifacts were decreased by a preprocessing technique. This technique assumes linear proportionality between the thickness of the calibration material, aluminum, and the experimental measurement of ln(No/N), where No is the total number of photons entering the material and N is the number of photons exiting the material. In addition to system optimization to minimize artifacts, an algorithm for correction of translational motion was developed and implemented. In this method, the integral mass and center of mass at each projection angle was seen to follow a sinusoidal or sinusoidal-like curve. Fits were used on the motion-encoded sinograms to determine both of these curves and, consequently, the amount and direction of motion that occurred. Each projection was individually adjusted to compensate for this motion by widening or narrowing the projection based on the ratio of the actual and calculated ideal projection integrals and shifting the projection to match the actual centroid to the calculated ideal location. A custom imaging phantom with an outer diameter of approximately 16 mm was used to test the motion-correction algorithm in both simulated and experimental cases. A baseline of the error measured, taken as a fraction, was established as 0.16 for motion-free images measured on the scanner. Various motion patterns were tested. These included the distance of motion, the angle at which the motion occurred, and the ratio of the sinograms that was corrupted by motion. Experimental testing showed a maximum error increase of 2.7% from the baseline error for the motion-corrected images at 4 mm motion. The overall optimization provided acceptable results for the reconstructed image and good-quality projections for use in the motion-correction algorithm. Distortion and ring artifacts were almost completely removed, and the beam hardening artifacts were greatly reduced. The motion-correction algorithm implemented in this thesis helps minimize the amount of error due to translational motion and provides a foundation for future corrections of more complex motions

Biomarkers of oligomeric 1,6-hexamethylene diisocyanate exposure in the automotive refinishing industry

Spray-painters in automotive refinishing industries are exposed to the oligomeric trimer of 1,6-hexamethylene diisocyanate (HDI) monomer, HDI isocyanurate, a sensitizing agent that poses a significant risk for acute and chronic health effects. Biomonitoring of HDI exposures has been mostly limited to quantification of 1,6-diaminohexane (HDA), the hydrolysis product of HDI monomer, in urine or plasma. Because biomarkers of HDI monomer exposure are not appropriate biomarkers of oligomeric HDI exposures, the magnitude and distinct characteristics of HDI monomer and oligomer exposures and their relationships to their biomarkers need to be determined in exposed workers. We hypothesized that trisaminohexyl isocyanurate (TAHI), a hydrolysis product of HDI isocyanurate, is quantifiable in urine or plasma and is associated with HDI isocyanurate exposures. Towards this goal, sample extraction and analytical methods were developed and optimized to measure TAHI levels in urine and plasma of 47 spray-painters whose HDI monomer and HDI isocyanurate inhalation and skin exposures and urine and plasma HDA levels were previously characterized. Urine and plasma samples were acid hydrolyzed, extracted with dichloromethane, and derivatized with acetic anhydride for analysis of TAHI by nano-UPLC-ESI-MS/MS. TAHI biomarker levels were significantly associated with HDI isocyanurate inhalation exposure levels and the duration of spray-painting task in both linear regression and linear mixed model analyses. Painting in downdraft booths significantly reduced exposure to HDI isocyanurate and urine TAHI levels. TAHI biomarker levels were also significantly correlated with HDI monomer exposures. As expected, HDA levels in urine or plasma were observed to be unsuitable biomarkers of HDI isocyanurate exposure. Based on the observations in this study, painting in downdraft booths, wearing nitrile or neoprene gloves, and wearing full-face air purifying, PAPR, or supplied-air respirators offers the greatest combination of respiratory and skin protection to reduce hazardous HDI exposures and biomarkers of exposure in automotive spray-painters. In summary, the developed method for quantification of HDI isocyanurate biomarker, TAHI, in urine and plasma is a significant advancement for HDI exposure assessment and will advance future investigations to oligomeric isocyanate exposures and biomarkers as well as associated health effects.Doctor of Philosoph

Compensation effects in GaN:Mg probed by Raman spectroscopy and photoluminescence measurements

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in J. Appl. Phys. 113, 103504 (2013) and may be found at https://doi.org/10.1063/1.4794094.Compensation effects in metal organic chemical vapour deposition grown GaN doped with magnesium are investigated with Raman spectroscopy and photoluminescence measurements. Examining the strain sensitive E2(high) mode, an increasing compressive strain is revealed for samples with Mg-concentrations lower than 7 × 1018 cm−3. For higher Mg-concentrations, this strain is monotonically reduced. This relaxation is accompanied by a sudden decrease in crystal quality. Luminescence measurements reveal a well defined near band edge luminescence with free, donor bound, and acceptor bound excitons as well as a characteristic donor acceptor pair (DAP) luminescence. Following recent results, three acceptor bound excitons and donor acceptor pairs are identified. Along with the change of the strain, a strong modification in the luminescence of the dominating acceptor bound exciton and DAP luminescence is observed. The results from Raman spectroscopy and luminescence measurements are interpreted as fingerprints of compensation effects in GaN:Mg leading to the conclusion that compensation due to defect incorporation triggered by Mg-doping already affects the crystal properties at doping levels of around 7 × 1018 cm−3. Thereby, the generation of nitrogen vacancies is introduced as the driving force for the change of the strain state and the near band edge luminescence.DFG, 43659573, SFB 787: Halbleiter - Nanophotonik: Materialien, Modelle, Bauelement

Identification of Binding Regions of Bilirubin in the Ligand-Binding Pocket of the Peroxisome Proliferator-Activated Receptor-A (PPARalpha)

Recent work has shown that bilirubin has a hormonal function by binding to the peroxisome proliferator-activated receptor-α (PPARα), a nuclear receptor that drives the transcription of genes to control adiposity. Our previous in silico work predicted three potential amino acids that bilirubin may interact with by hydrogen bonding in the PPARα ligand-binding domain (LBD), which could be responsible for the ligand-induced function. To further reveal the amino acids that bilirubin interacts with in the PPARα LBD, we harnessed bilirubin’s known fluorescent properties when bound to proteins such as albumin. Our work here revealed that bilirubin interacts with threonine 283 (T283) and alanine 333 (A333) for ligand binding. Mutational analysis of T283 and A333 showed significantly reduced bilirubin binding, reductions of 11.4% and 17.0%, respectively. Fenofibrate competitive binding studies for the PPARα LBD showed that bilirubin and fenofibrate possibly interact with different amino acid residues. Furthermore, bilirubin showed no interaction with PPARγ. This is the first study to reveal the amino acids responsible for bilirubin binding in the ligand-binding pocket of PPARα. Our work offers new insight into the mechanistic actions of a well-known molecule, bilirubin, and new fronts into its mechanisms

Mode and Carrier Choice in the Quebec City - Windsor Corridor: A Random Parameters Approach

The Quebec City-Windsor corridor is the busiest and most important trade and transportation corridor in Canada. The transportation sector is the second largest contributor to greenhouse gas (GHG) emissions in the country. Governments around the world, including Canada, are considering increased mode share by rail as a way to reduce transportation emissions. Evaluating the potential of freight mode shift as a means to reduce transportation emissions requires rigorous analytical models that can predict the effect of government policy on mode split. This paper presents the findings of a random parameters mixed-logit model of shipper carrier choice in the Quebec City-Windsor Corridor. The model itself was developed using the results of a stated preference Survey undertaken in the fall of 2005. The survey was designed explicitly to evaluate shipper preferences for the carriage of intercity consignments, and particularly for their preferences for carriers that contract the services of rail companies to carry these shipments via rail. A fixed parameters approach suggests that shippers are very mistrustful of using rail to move their consignments and suggests that increasing rails share of freight faces tremendous challenges. This result is not entirely consistent with shipper interviews conducted during survey development that suggested some shippers might prefer rail for environmental-public relations reasons. A random-parameters approach was adopted to test whether preference variation across respondents would be able to explain this inconsistency. This random-parameter analysis suggests that there is some variation in shippers preferences for the use of intermodal transportation. In particular, the model suggests that for 20% of shippers, knowledge of a carriers use of rail has a positive effect. This appears to be the first attempt at a random parameter approach in the freight choice literature

Is Carrier Choice Different for 3PLs and other End-shippers? Some Preliminary Findings

As companies have increasingly sought to outsource their non-essential activities, there has been a dramatic rise in the use of the services of external companies (often referred to as Third Party Logistics Companies or 3PLs) to organize transportation logistics. Little is known about the degree to which their choice of carriers differs from that of traditional end-shippers. Because this sector is expected to grow in the future and thereby to exert more influence on the way freight is shipped, understanding any differences that they might manifest in carrier choice is useful in itself, but also potentially critical in evaluating the potential for rail to increase its share of freight. This paper presents some findings of a unique shipper carrier-choice stated preference survey of shippers in the Quebec City-Windsor Corridor. The survey was conducted during the fall of 2005. The survey was designed explicitly to evaluate shipper preferences for the carriage of intercity consignments, and particularly their preferences for carriers that contract the services of rail companies to carry these shipments via trailer on flat car (TOFC). Preliminary analysis suggests that 3PLs behave differently from other end-shippers, and in particular, are even more mistrustful of the use of rail to move their consignments than other end shippers. Among other things, this suggests that increasing rails share of freight faces tremendous challenges