Electronic Cigarette User Plasma Nicotine Concentration and Puff Topography: Influence of Liquid Nicotine Concentration and User Experience

Electronic cigarettes (ECIGs) aerosolize an often nicotine-containing solution for user inhalation. ECIG nicotine delivery may depend on liquid nicotine concentration and user puffing behavior (topography). This study examined the relationship among liquid nicotine concentration, puff topography, and plasma nicotine concentration. Thirty-three ECIG-experienced and 31 ECIG-naïve individuals completed four laboratory sessions that differed by ECIG liquid nicotine concentration (0, 8, 18, or 36 mg/ml). A 3.3 volt “eGo” ECIG battery attached to a 1.5 Ohm dual coil “cartomizer” filled with 1 ml of 70% propylene glycol/30% vegetable glycerin nicotine liquid was used in two ECIG-bouts (10 puffs; 30 s IPI). Plasma nicotine concentration, puff topography, and HR were evaluated. Some ECIG/liquid combinations can deliver physiologically active doses of nicotine to users, and nicotine delivery depends on liquid nicotine concentration and user puffing behavior. Liquid contents, device characteristics, and user behavior should be considered when regulating ECIGs

THE INFLUENCE OF ELECTRONIC CIGARETTE HEATING COIL RESISTANCE ON NICOTINE DELIVERY, HEART RATE, SUBJECTIVE EFFECTS, AND PUFF TOPOGRAPHY

Electronic cigarette (ECIG) users can manipulate several device features including liquid nicotine concentration (mg/ml) and heating coil resistance (Ohms). One class of ECIG models, called “sub-Ohm” devices, use coils with a resistance of \u3c 1 Ohms, lower than those observed in conventional ECIGs (e.g., ≥ 1.5 Ohms). Increasing voltage or decreasing coil resistance increases device power. Given that ECIG coil resistance and liquid nicotine concentration have not been manipulated systematically and simultaneously in clinical laboratory studies, the influence of these factors on ECIG acute effects remain unclear. The primary purpose of this study was to examine the influence of coil resistance and liquid nicotine concentration on nicotine delivery, heart rate (HR), subjective effects, puff topography, and liquid consumption. Thirty-two experienced ECIG users completed four independent laboratory sessions that differed by coil resistance (0.5Ohm or 1.5Ohm ) and liquid nicotine concentration (3 or 8 mg/ml). In each session, participants used a 4.5 V “Kanger SUBOX” loaded with 3.5 ml ECIG liquid in a 10-puff directed and 60-minute ad libitum bout. Nicotine delivery was greatest when using 8 mg+0.5Ohm combination and lowest when using the 3 mg/ml+1.5Ohm combination and HR followed a similar pattern. Abstinence symptom suppression was most pronounced for the 8 mg+0.5Ohm combination and least pronounced for the 3 mg/ml+1.5Ohm combination. Participants provided the highest ratings for pleasantness, satisfaction, and liking of harshness/irritancy and throat hit sensations for the 3 mg+0.5Ohm combination. Overall, use of ECIGs filled with 3 mg/ml nicotine concentration resulted in longer/larger puffs, increased puff frequency, and greater consumption of ECIG liquid. ECIG coil resistance, liquid nicotine concentration, and user puff topography, all of which influence ECIG nicotine delivery, should be considered together when making regulatory decisions aimed at protecting public health

The Communication of Design to Non-Experts: An Investigation Into Effective Methods of Communicating Design Through Drawing Styles

Communication between designers and their client has always been an essential element in the design of buildings and interior spaces. This communication occurs in various different ways, but the key method of a designer communicating their space is through their drawings. Clients come from many different backgrounds and many may not have the training or experience that allows them to fully understand what they are seeing in the drawings being presented and as such can be considered non-experts. A majority of drawings are typically presented and developed in two-dimensions which can be confusing for non-experts to understand since they rarely experience a space in two-dimensions. In establishing this research two main questions were developed to focus the study. Firstly, how do designers use drawings to communicate design intent and spatial elements? Secondly, how do non-experts interpret these drawings into perceiving a space that they can occupy? This research will assist designers with insight into how non-experts translate drawings in their minds to create a mental perception of a space. The research will also provide information on elements in drawings that communicate effectively in helping people perceive a space. Finally, the research will delve into if a particular style of drawing, two-dimensional, three-dimensional or a combination of both, communicates with higher accuracy the elements of design that assist people in perceiving a space. Understanding how drawings can effectively communicate design to assist non-experts in perceiving space is a critical part of a designer\u27s role. Advisor: Timothy Hemsat

Electrophoretic Clarification of Water

There is an ever growing need for new and superior water treatment methods which will remove the alarming growth and variety of pollutants present in our waters. Suspended particulate matter such as clay, algae, and bacteria are troublesome pollutants in almost all waters and particularly in surface water. This research project was primarily an investigation into the direct use of electric currents and electric fields to bring about water clarification and purification. Electrophoretic and electrochemical systems appear well adapted for removal of these electrically charged pollutants and in addition have the potential of being entirely automated. Numerous design concepts are advanced and tested through the use of laboratory models. These include a parallel plate model which was designed entirely for electrophoretic removal, and porous filter and electrode grid models which incorporated both electrophoretic and electrochemical capabilities. Successful water clarification was attained with the parallel plate model only when the influent water was of very low electrical conductivity. Electrolysis products at high conductivities caused sufficient turbulence to completely disrupt electrophoretic transport. In addition, primary and secondary chemical reactions took place due to electrolysis, which altered the characteristics of the suspension. It was also concluded that the ease of automation with an electrophoretic system does not justify the high cost of water treatment by this method. Water purification by electrochemical means overcame this problem and was successful both operationally and economically. As a result of the experimental testing, an example design of a small semiautomated electrochemical water system is offered which incorporates electrochemical flocculation, settling and electrochemical disinfection operations

The unrecognized importance of carbon stocks and fluxes from Swamps in Canada and the USA

Abstract Swamps are a highly significant wetland type in North America both in terms of areal extent and their role in terrestrial carbon cycling. These wetlands, characterized by woody vegetation cover, encompass a diverse suite of ecosystems, including broad-leaved, needle-leaved, mixedwood or shrub/thicket swamps. Uncertainties in the role of swamps in carbon uptake and release continue to be substantial due to insufficient data on variabilities in carbon densities across diverse swamp types and relatively few flux measurements from swamp sites. Robust measurements of rates of vertical accretion of swamp soils and the associated long-term rates of carbon accumulation, alongside measurements of carbon losses from swamps, are needed for emerging frameworks for carbon accounting, and for assessments of the impacts of climate warming and land use change on this important wetland type. Based on data compilation, we present here a comparative analysis from a series of North American swamp sites on carbon dioxide, methane and dissolved organic carbon fluxes, aboveground biomass, net primary productivity, and soil carbon properties including bulk densities, organic carbon contents, peat depths, rates of vertical accretion, and rates of long-term carbon accumulation. We compare these properties for four major swamp types: needle-leaved, broad-leaved, mixedwood and shrub/thicket swamps. We show differences in carbon fluxes, biomass and NPP across the four types, with broad-leaved swamps having the largest CH4 flux, highest soil bulk densities, thinnest peat depths and lowest soil organic matter contents, whereas needle-leaved swamps have the smallest CH4 flux, highest aboveground biomass and highest NPP. We show high soil carbon stocks (kgC m-2) in all types of swamps, even those where organic deposits were too shallow to meet the definition of peat. However, we note there is a significant lack of studies focused on swamp carbon dynamics despite their abundance across Canada and the United States.</jats:p

Evaluation of Microorganisms Cultured from Injured and Repressed Tissue Regeneration Sites in Endangered Giant Aquatic Ozark Hellbender Salamanders

Investigation into the causes underlying the rapid, global amphibian decline provides critical insight into the effects of changing ecosystems. Hypothesized and confirmed links between amphibian declines, disease, and environmental changes are increasingly represented in published literature. However, there are few long-term amphibian studies that include data on population size, abnormality/injury rates, disease, and habitat variables to adequately assess changes through time. We cultured and identified microorganisms isolated from abnormal/injured and repressed tissue regeneration sites of the endangered Ozark Hellbender, Cryptobranchus alleganiensis bishopi, to discover potential causative agents responsible for their significant decline in health and population. This organism and our study site were chosen because the population and habitat of C. a. bishopi have been intensively studied from 1969–2009, and the abnormality/injury rate and apparent lack of regeneration were established. Although many bacterial and fungal isolates recovered were common environmental organisms, several opportunistic pathogens were identified in association with only the injured tissues of C.a. bishopi. Bacterial isolates included Aeromonas hydrophila, a known amphibian pathogen, Granulicetella adiacens, Gordonai terrae, Stenotrophomonas maltophilia, Aerococcus viridans, Streptococcus pneumoniae and a variety of Pseudomonads, including Pseudomonas aeruginosa, P. stutzeri, and P. alcaligenes. Fungal isolates included species in the genera Penicillium, Acremonium, Cladosporium, Curvularia, Fusarium, Streptomycetes, and the Class Hyphomycetes. Many of the opportunistic pathogens identified are known to form biofilms. Lack of isolation of the same organism from all wounds suggests that the etiological agent responsible for the damage to C. a. bishopi may not be a single organism. To our knowledge, this is the first study to profile the external microbial consortia cultured from a Cryptobranchid salamander. The incidence of abnormalities/injury and retarded regeneration in C. a. bishopi may have many contributing factors including disease and habitat degradation. Results from this study may provide insight into other amphibian population declines

Comparison of the Release of Adipokines by Adipose Tissue, Adipose Tissue Matrix, and Adipocytes From Visceral and Subcutaneous Abdominal Adipose Tissues of Obese Humans

The purpose of this study was to examine the source of adipokines released by the visceral and sc adipose tissues of obese humans. Human adipose tissue incubated in primary culture for 48 h released more prostaglandin E2, IL-8, and IL-6 than adiponectin, whereas the release of plasminogen activator inhibitor 1 and hepatocyte growth factor was less than that of adiponectin but greater than that of leptin. IL-10 and TNFα were released in amounts less than those of leptin, whereas vascular endothelial growth factor and IL1-β were released in much lower amounts. The accumulation of adipokines was also examined in the three fractions (adipose tissue matrix, isolated stromovascular cells, and adipocytes) obtained by collagenase digestion of adipose tissue. Over 90% of the adipokine release by adipose tissue, except for adiponectin and leptin, could be attributed to nonfat cells. Visceral adipose tissue released greater amounts of vascular endothelial growth factor, IL-6, and plasminogen activator inhibitor 1 compared with abdominal sc tissue. The greatly enhanced total release of TNFα, IL-8, and IL-10 by adipose tissue from individuals with a body mass index of 45 compared with 32 was due to nonfat cells. Furthermore, most of the adipokine release by the nonfat cells of adipose tissue was due to cells retained in the tissue matrix after collagenase digestion

Genetic factors control nicotine self-administration in isogenic adolescent rat strains.

Adult cigarette smokers usually become dependent on cigarettes during adolescence. Despite recent advances in addiction genetics, little data delineates the genetic factors that account for the vulnerability of humans to smoke tobacco. We studied the operant nicotine self-administration (SA) behavior of six inbred strains of adolescent male rats (Fisher 344, Brown Norway, Dark Agouti, Spontaneous Hypertensive Rat, Wistar Kyoto and Lewis) and six selected F1 hybrids. All rats were trained to press a lever to obtain food starting on postnatal day (PN) 32, and then nicotine (0.03 mg/kg/infusion, i.v.) reinforcement was made available on PN41-42 (10 consecutive daily 2 h sessions). Of the 12 isogenic strains, Fisher rats self-administered the fewest nicotine infusions (1.45 ± 0.36/d) during the last 3 d, while Lewis rats took the most nicotine (13.0 ± 1.4/d). These strains sorted into high, intermediate and low self-administration groups in 2, 2, and 8 strains, respectively. The influence of heredity on nicotine SA (0.64) is similar to that reported for humans. Therefore, this panel of isogenic rat strains effectively models the overall impact of genetics on the vulnerability to acquire nicotine-reinforced behavior during adolescence. Separate groups of rats responded for food starting on PN41. The correlation between nicotine and food reward was not significant. Hence, the genetic control of the motivation to obtain nicotine is distinctly different from food reward, indicating the specificity of the underlying genetic mechanisms. Lastly, the behavior of F1 hybrids was not predicted from the additive behavior of the parental strains, indicating the impact of significant gene-gene interactions on the susceptibility to nicotine reward. Taken together, the behavioral characteristics of this model indicate its strong potential to identify specific genes mediating the human vulnerability to smoke cigarettes