Identifying Stress Variables Linking Socioeconomic Status and Smoking

Smoking is the leading cause of preventable death accounting for approximately 480,000 deaths every year (Jamal et al., 2015). Across the socioeconomic status gradient smoking prevalence differs greatly, with those of lower socioeconomic status smoking at much higher rates. Within the literature relationships have been identified between socioeconomic status, stress variables, and smoking. However, little research has explored the possibility of stress variables mediating the relationship between socioeconomic status and smoking. The goal of the current study was to identify stress variables linking socioeconomic status and smoking in order to identify variables to address in cessation programs for individuals across the socioeconomic status gradient. Stress variables examined as potential mediators between socioeconomic status and smoking included financial strain, discrimination, urban life stress, perceived stress, depression, and neighborhood perceptions. Participants (N = 238) were primarily female (67.6%) and African American (51.7%) adults from the Dallas metropolitan area. A majority of the sample reported being nonsmokers (n = 164). Participants who identified as being smokers at baseline (n = 74) reported smoking 9.96 (SD = 10.79) cigarettes per a day. Analyses revealed that financial strain and perceived neighborhood disorder were the only variables found to significantly mediate the relationship between socioeconomic status and cigarettes smoked per week. Additionally, financial strain was also found to significantly mediate the relationship between socioeconomic status and smoking status. Cessation programs targeting lower socioeconomic status groups should look to include some component to reduce financial strain and address perceived neighborhood disorder as these variables may act as barriers to successful cessation for this population

Readiness to Change and Smoking Expectancies Among Adult Male Substance Users Currently in Substance Use Treatment

The primary aims of the current study were to examine if smoking expectancies and readiness to quit smoking, important components in predicting smoking behavior and cessation, changed across time for adult smokers in substance use treatment. Participants (N = 51) were predominantly white (96.1%), adult, male smokers who were admitted to residential substance use treatment. Smoking outcome expectancies and readiness to change smoking were assessed among participants at treatment entry (n = 51), and subsequently at 30 days (n = 13), 60 days (n = 9), and 90 days (n = 3) from treatment entry. Ninety-day follow-up assessments were excluded from outcome analyses due to significant participant attrition. At baseline, the majority of participants were in the contemplation (40%) or preparation (action) (40%) stage of change for smoking cessation. Repeated measures analyses of variance (ANOVAs) revealed a significant decrease in health risk and negative affect reduction smoking expectancies across time points. Readiness to change smoking did not significantly differ across time points. Existing literature on smoking expectancies has shown that elevated health risk beliefs predict cessation treatment entry, whereas elevated expectations for negative affect reduction predict relapse after a cessation attempt. Findings in the current study suggest that manipulation of health risk expectancies at treatment entry may increase engagement in a subsequent cessation attempt. In addition, negative affect reduction expectancies may change with the acquisition of alternate skills to manage negative affect learned in substance use treatment. Although readiness to change smoking did not increase over time in substance use treatment, the majority of smokers at baseline were already in the contemplation and preparation stages for quitting smoking. Based on the current findings, the optimal time for smoking cessation intervention efforts may be between 30 to 60 days after entering substance use treatment

Undercutting Studies of Protected Kapton. H Exposed to In-Space and Ground-Based Atomic Oxygen

This study is part of a Materials International Space Station Experiment (MISSE) sequence to characterize the performance of prospective spacecraft materials when subjected to the synergistic effects of the space environment. Atomic oxygen (AO) is the most prevalent species in low earth orbit (LEO). In this environment AO is mainly responsible for the erosion of hydrocarbons and halocarbon polymers. The AO erosion rates of Kapton (DuPont) H are known and well documented. Hence, it is customary to compare the AO erosion yields of candidate materials to the commonly accepted standard of this polyimide. The purpose of this study was to provide characterization of AO degradation of SiO(x) protected Kapton H film, which was subject during MISSE 2 to undercutting erosion beneath microscopic defects in the protective film, and compare the degradation resulting from hyperthermal ram (approx.4.5 eV) LEO AO to the degradation resulting from exposure to thermal ground-based (approx.0.04 eV) AO

The importance of replicating genomic analyses to verify phylogenetic signal for recently evolved lineages

Genomewide SNP data generated by nontargeted methods such as RAD and GBS are increasingly being used in phylogenetic and phylogeographic analyses. When these methods are used in the absence of a reference genome, however, little is known about the locations and evolution of the SNPs. In using such data to address phylogenetic questions, researchers risk drawing false conclusions, particularly if a representative number of SNPs is not obtained. Here, we empirically test the robustness of phylogenetic inference based on SNP data for closely related lineages. We conducted a genomewide analysis of 75 712 SNPs, generated via GBS, of southern bull-kelp (Durvillaea). Durvillaea chathamensis co-occurs with D. antarctica on Chatham Island, but the two species have previously been found to be so genetically similar that the status of the former has been questioned. Our results show that D. chathamensis, which differs from D. antarctica ecologically as well as morphologically, is indeed a reproductively isolated species. Furthermore, our replicated analyses show that D. chathamensis cannot be reliably distinguished phylogenetically from closely related D. antarctica using subsets (ranging in size from 400 to 10 000 sites) of the 40 912 parsimony-informative SNPs in our data set and that bootstrap values alone can give misleading impressions of the strength of phylogenetic inferences. These results highlight the importance of independently replicating SNP analyses to verify that phylogenetic inferences based on nontargeted SNP data are robust. Our study also demonstrates that modern genomic approaches can be used to identify cases of recent or incipient speciation that traditional approaches (e.g. Sanger sequencing of a few loci) may be unable to detect or resolve.This research was supported by an Australian Research Council Discovery Early Career Research Award (DE140101715 to CIF) and University of Otago Performance Based Research Funding (to JMW)

Comparison of Atomic Oxygen Erosion Yields of Materials at Various Energy and Impact Angles

The atomic oxygen erosion yields of various materials, measured in volume of material oxidized per incident atomic oxygen atom, are compared to the commonly accepted standard of Kapton H (DuPont) polyimide. The ratios of the erosion yield of Kapton H to the erosion yield of various materials are not consistent at different atomic oxygen energies. Although it is most convenient to use isotropic thermal energy RF plasma ashers to assess atomic oxygen durability, the results can be misleading because the relative erosion rates at thermal energies are not necessarily the same as low Earth orbital (LEO) energies of approx.4.5 eV. An experimental investigation of the relative atomic oxygen erosion yields of a wide variety of polymers and carbon was conducted using isotropic thermal energy (approx.0.1 eV) and hyperthermal energy (approx.70 eV) atomic oxygen using an RF plasma asher and an end Hall ion source. For hyperthermal energies, the atomic oxygen erosion yields relative to normal incident Kapton H were compared for sweeping atomic oxygen arrival with that of normal incidence arrival. The results of isotropic thermal energy, normal incident, and sweeping incident atomic oxygen are also compared with measured or projected LEO values

Illumina MiSeq Phylogenetic Amplicon Sequencing Shows a Large Reduction of an Uncharacterised Succinivibrionaceae and an Increase of the Methanobrevibacter gottschalkii Clade in Feed Restricted Cattle

peer-reviewedPeriodic feed restriction is used in cattle production to reduce feed costs. When normal feed levels are resumed, cattle catch up to a normal weight by an acceleration of normal growth rate, known as compensatory growth, which is not yet fully understood. Illumina Miseq Phylogenetic marker amplicon sequencing of DNA extracted from rumen contents of 55 bulls showed that restriction of feed (70% concentrate, 30% grass silage) for 125 days, to levels that caused a 60% reduction of growth rate, resulted in a large increase of relative abundance of Methanobrevibacter gottschalkii clade (designated as OTU-M7), and a large reduction of an uncharacterised Succinivibrionaceae species (designated as OTU-S3004). There was a strong negative Spearman correlation (ρ = -0.72, P = <1x10-20) between relative abundances of OTU-3004 and OTU-M7 in the liquid rumen fraction. There was also a significant increase in acetate:propionate ratio (A:P) in feed restricted animals that showed a negative Spearman correlation (ρ = -0.69, P = <1x10-20) with the relative abundance of OTU-S3004 in the rumen liquid fraction but not the solid fraction, and a strong positive Spearman correlation with OTU-M7 in the rumen liquid (ρ = 0.74, P = <1x10-20) and solid (ρ = 0.69, P = <1x10-20) fractions. Reduced A:P ratios in the rumen are associated with increased feed efficiency and reduced production of methane which has a global warming potential (GWP 100 years) of 28. Succinivibrionaceae growth in the rumen was previously suggested to reduce methane emissions as some members of this family utilise hydrogen, which is also utilised by methanogens for methanogenesis, to generate succinate which is converted to propionate. Relative abundance of OTU-S3004 showed a positive Spearman correlation with propionate (ρ = 0.41, P = <0.01) but not acetate in the liquid rumen fraction.This study was supported by the Science Foundation Ireland (http://www.sfi.ie) (Contract number SFI 09/RFP/GEN2447-awarded to SMW) and Teagasc Walsh Fellowship Funding (www.teagasc.ie) (Teagasc project RMIS 6341-awarded to SMW)

Electrical stimulation enhances the acetylcholine receptors available for neuromuscular junction formation

Neuromuscular junctions (NMJ) are specialized synapses that link motor neurons with muscle fibers. These sites are fundamental to human muscle activity, controlling swallowing and breathing amongst many other vital functions. Study of this synapse formation is an essential area in neuroscience; the understanding of how neurons interact and control their targets during development and regeneration are fundamental questions. Existing data reveals that during initial stages of development neurons target and form synapses driven by biophysical and biochemical cues, and during later stages they require electrical activity to develop their functional interactions. The aim of this study was to investigate the effect of exogenous electrical stimulation (ES) electrodes directly in contact with cells, on the number and size of acetylcholine receptor (AChR) clusters available for NMJ formation. We used a novel in vitro model that utilizes a flexible electrical stimulation system and allows the systematic testing of several stimulation parameters simultaneously as well as the use of alternative electrode materials such as conductive polymers to deliver the stimulation. Functionality of NMJs under our co-culture conditions was demonstrated by monitoring changes in the responses of primary myoblasts to chemical stimulants that specifically target neuronal signaling. Our results suggest that biphasic electrical stimulation at 250 Hz, 100 ¿s pulse width and current density of 1 mA/cm2 for 8 h, applied via either gold-coated mylar or the conductive polymer PPy, significantly increased the number and size of AChRs clusters available for NMJ formation. This study supports the beneficial use of direct electrical stimulation as a strategic therapy for neuromuscular disorders

1001–24 Local Delivery of Urokinase to Porcine Coronary Arteries Using the Localmed Infusion Sleeve

Local Delivery of thrombolytic agents may reduce thrombus formation after balloon angioplasty. The Localmed Infusion Sleeve enables localized infusion of urokinase to be performed at the time of balloon angioplasty without the need for catheter exchange.MethodsBalloon angioplasty was performed on 13 coronary arteries of 5 pigs at 4 atmospheres with a balloon to artery ratio of approximately 1.1 to 1. After angioplasty the Infusion Sleeve was advanced over the dilatation balloon and the balloon was reinflated to 2 atmospheres to appose the sleeve to the vessel wall. 50,000 Units (8 cc) of 123l-urokinase was infused through the microperforations in the sleeve for 10 seconds by a computer controlled pump. The coronaries were then excised and counted in a gamma counter.ResultsConclusions(1) The Localmed Infusion Sleeve enables drug infusion to be uncoupled from balloon dilatation. (2) Successful delivery of Urokinase to the vessel wall may be achieved using this device without the need for catheter exchange. (3) Persistence of urokinase within the vessel wall occurs after local delivery

Transport of Sputtered Carbon During Ground-Based Life Testing of Ion Thrusters

High voltage, high power electron bombardment ion thrusters needed for deep space missions will be required to be operated for long durations in space as well as during ground laboratory life testing. Carbon based ion optics are being considered for such thrusters. The sputter deposition of carbon and arc vaporized carbon flakes from long duration operation of ion thrusters can result in deposition on insulating surfaces, causing them to become conducting. Because the sticking coefficient is less than one, secondary deposition needs to be considered to assure that shorting of critical components does not occur. The sticking coefficient for sputtered carbon and arc vaporized carbon is measured as well as directional ejection distribution data for carbon that does not stick upon first impact