Preparation and characterization of micro-bore wall-coated open-tubular capillaries with low phase ratios for fast-gas chromatography–mass spectrometry: Application to ignitable liquids and fire debris

Fast Gas Chromatography (GC) allows for analysis times that are a fraction of those seen in traditional capillary GC. Key modifications in fast GC include using narrow, highly efficient columns that can resolve mixtures using a shorter column length. Hence, a typical fast GC column has an inner diameter of 100–180 μm. However, to maintain phase ratios that are consistent with typical GC columns, the film thickness of fast GC stationary phases are also low (e.g., 0.1–0.18 μm). Unfortunately, decreased film thickness leads to columns with very low sample capacity and asymmetric peaks for analytes that are not sufficiently dilute. This paper describes micro-bore (50 μm i.d.) capillary columns with thick films (1.25 μm), and low phase ratios (10). These columns have greater sample capacity yet also achieve minimum plate heights as low as 110 μm. Hence, separation efficiency is much higher than would be obtained using standard GC columns. The capillary columns were prepared in-house using a simple static-coating procedure and their plate counts were determined under isothermal conditions. The columns were then evaluated using temperature programming for fast GC–MS analysis of ignitable liquids and their residues on fire debris exemplars. Temperature ramps of up to 75 °C min−1 could be used and separations of ignitable liquids such as gasoline, E85 fuel, and lighter fluid (a medium petroleum distillate) were complete within 3 min. Lastly, simulated fire debris consisting of ignitable liquids burned on carpeting were extracted using passive headspace absorption-elution and the residues successfully classified

Effect of Tire Size on Skidder Productivity Under Wet Conditions

Evaluation of skidder productivity and costs among 30.5L-32 (78-cm), 67x34.00-25 (86-cm), and 66x43.00-25 (109-cm) size tires under wet conditions was conducted in a clearcut harvest during the Spring of 1998 on an Upper Coastal Plain site in southeast Alabama. There was not a significant difference in adjusted mean whole-tree skidder production among the three tire sizes at the 0.05 level. Adjusted mean whole-tree skidder production for the 78-cm, 86-cm, and 109-cm tires was 32.7, 35.8, and 32.9 green tonnes per Productive Machine Hour (PMH), respectively. Total whole-tree skidding costs were $1.96,$1.80, and $1.97 per green tonne for the 78-cm, 86-cm, and 109-cm tires, respectively

News-Related Social Media Use, Political Knowledge, and Participation in the 2016 Election

Social media’s role in the 2016 election was one of many aspects of that election which make it unique. Record numbers of Americans were active social media users in 2015-2016, and many used the platforms not only for entertainment, but to learn about the news. Social media were also used by candidates in novel ways and to unprecedented extents, and the quality of information distributed through social media came into question for multiple reasons. Previous studies have shown that news-related social media use leads to increases in political knowledge and likelihood of voting, but the unique circumstances surrounding the 2016 election make generalization of those findings to that election perilous. Therefore, this thesis used national survey data from the 2016 Cooperative Congressional Election Survey to investigate the relationships between news-related social media use, political knowledge, and participation specifically in the 2016 election. Exploratory factor analyses, logit regressions, and marginal effects were used. Analysis found that consuming social media news content did predict higher likelihood of voting in 2016, and it found that that effect was partially mediated by an increase in political knowledge. Additionally, evidence suggested that whether someone shared, commented on, or forwarded news-related content – in addition to consuming it – was found to moderate each of the aforementioned relationships, though that finding was not statistically significant. The relationships between social media use, knowledge, and voting also varied by state and by party. Further research should consider personality in analysis and use experimental, rather than observational, methods to the extent possible.Bachelor of Art

Justice as a Dynamic Construct: Effects of Individual Trajectories on Distal Work Outcomes

Despite an amassing organizational justice literature, few studies have directly addressed the temporal patterning of justice judgments and the effects that changes in these perceptions have on important work outcomes. Drawing from Gestalt characteristics theory (Ariely & Cannon, 2000, 2003), we examine the concept of justice trajectories (i.e., levels and trends of individual fairness perceptions over time) and offer empirical evidence to highlight the value of considering fairness within a dynamic context. Participants included 523 working adults who completed surveys about their work experiences on 4 occasions over the course of 1 year. Results indicate that justice trends explained additional variance in distal work outcomes (job satisfaction, organizational commitment, and turnover intentions) after controlling for end-state levels of justice, demonstrating the cumulative effects of justice over time. Findings also reveal that change in procedural justice perceptions affected distal work outcomes more strongly than any other justice dimension. Implications for theory and future investigations of justice as a dynamic construct are discussed

Cognitive level and attitudes of global understanding in undergraduate students : effects of instruction in international studies

It was the purpose of this study to examine the effects of four independent variables upon undergraduate college student performance on a measure of global understanding. The four variables used in this study were: 1) academic performance in International Studies Seminar 233; 2) overseas experience; 3) frequency of discussion of world problems in the college classroom; and 4) source of current event information. An additional purpose of this study was to determine if students who participated in International Studies Seminar 233 scored significantly higher than a nationwide random sample of students in undergraduate higher education on the affective and cognitive portions of Measures of Global Understanding. The subjects were fifty-one undergraduate students enrolled at the University of North Carolina at Greensboro during the academic year 1981- 1982. They had participated in a section of International Studies Seminar 233 during the period from Fall 1978 through Fall 1981

Differentiation of Structurally Similar Phenethylamines via Gas Chromatography - Vacuum Ultraviolet Spectroscopy (GC – VUV)

The vacuum ultraviolet region includes wavelengths shorter than 200 nm. Electronic transitions of sigma and pi bonds lie in this region, which have the potential to yield structural information. Thus, a VUV detector should be able to detect nearly any molecule analyzable by gas chromatography. This study sought to determine the extent to which structurally similar phenethylamines are differentiated using their VUV spectra. Phenethylamines are a common drug class including pseudoephedrine and illicit drugs such as methamphetamine. Several phenethylamines are difficult to analyze by electron impact mass spectrometry due to their fragmentation giving the same mass to charge ratio fragments at similar ratios. While phenethylamines are generally differentiable by retention time, an extra layer of specificity is preferred in forensic analyses. A vacuum ultraviolet (VUV) spectrophotometer coupled to a gas chromatograph was used to collect VUV spectra at high frequency between 125 and 430 nm. Eight phenethylamines were analyzed for this work using GC/VUV. A calibration curve and limit of detection study was performed that indicates a limit of detection around 10 μg mL−1 and an upper limit of linearity around 1000 μg mL−1. The spectra, analyzed by Principal Component Analysis and Discriminant Analysis, indicate the ability to reliably differentiate each of the drugs from one another including structural isomers and diastereomers. Lastly, five “street” samples containing amphetamines were analyzed to demonstrate “real world” performance

Longitudinal Stability of Genetic and Environmental Influences on Irritability: From Childhood to Young Adulthood.

OBJECTIVE: Little is known about genetic influences on juvenile irritability and whether such influences are developmentally stable and/or dynamic. This study examined the temporal pattern of genetic and environmental effects on irritability using data from a prospective, four-wave longitudinal twin study. METHOD: Parents and their twin children (N=2,620 children) from the Swedish Twin Study of Child and Adolescent Development reported on the children's irritability, defined using a previously identified scale from the Child Behavior Checklist. RESULTS: Genetic effects differed across the sexes, with males exhibiting increasing heritability from early childhood through young adulthood and females exhibiting decreasing heritability. Genetic innovation was also more prominent in males than in females, with new genetic risk factors affecting irritability in early and late adolescence for males. Shared environment was not a primary influence on irritability for males or females. Unique, nonshared environmental factors suggested strong effects early for males followed by an attenuating influence, whereas unique environmental factors were relatively stable for females. CONCLUSIONS: Genetic effects on irritability are developmentally dynamic from middle childhood through young adulthood, with males and females displaying differing patterns. As males age, genetic influences on irritability increase while nonshared environmental influences weaken. Genetic contributions are quite strong in females early in life but decline in importance with age. In girls, nonshared environmental influences are fairly stable throughout development.The National Institutes of Health/National Institute of Mental HealthPublishe

Topical Rapamycin Therapy to Alleviate the Cutaneous Manifestations of Tuberous Sclerosis Complex

Background and Objectives: Facial angiofibromas are disfiguring facial lesions, present in up to 80% of patients with tuberous sclerosis complex. Recent elucidation of the complex cell signaling pathways that are disrupted in tuberous sclerosis indicates that rapamycin may be successful in alleviating the appearance of these lesions. The objectives of the current study were to evaluate the safety of topically applied rapamycin in patients with tuberous sclerosis complex and to determine its potential effectiveness in treatment of facial angiofibromas. Patients and Methods: The study was a prospective, randomized, double-blind, placebo-controlled study performed at the University of Texas Health Science Center at Houston. Study subjects were recruited from the patient populations at the University of Texas Tuberous Sclerosis Center of Excellence. All subjects were over the age of 13 years and had a diagnosis of tuberous sclerosis complex. Subjects were excluded if they were using any form of rapamycin or if they were pregnant. Study subjects applied the study product to their facial angiofibromas nightly for a duration of 6 months. The investigational product contained one of three doses of rapamycin compounded with Skincerity®: (i) no rapamycin; (ii) 1 mg of rapamycin per 30 cc (0.003%); or (iii) 5 mg of rapamycin per 30 cc (0.015%). Plasma rapamycin concentrations were measured monthly to test for systemic absorption. Complete blood counts were performed monthly to test for anemia, neutropenia, or thrombocytopenia. Upon completion of the trial, subjects were asked if the formulation had improved the appearance of their facial angiofibromas. Results: Twenty-three subjects completed the study. There was no detectable systemic absorption of rapamycin (all blood concentrations were <1.0 ng/mL). There were no significant changes in white blood cell, red blood cell, or platelet counts. Seventy-three percent of subjects in the treatment arms versus 38% of subjects in the placebo arm reported a subjective improvement in the appearance of their facial angiofibromas. Conclusion: The application of low-dose topical rapamycin (0.003–0.015%) to the face can safely decrease the appearance of facial angiofibromas in patients with tuberous sclerosis complex