An introduction to the indirect exposure assessment approach: modeling human exposure using microenvironmental measurements and the recent National Human Activity Pattern Survey.

Indirect exposure approaches offer a feasible and accurate method for estimating population exposures to indoor pollutants, including environmental tobacco smoke (ETS). In an effort to make the indirect exposure assessment approach more accessible to people in the health and risk assessment fields, this paper provides examples using real data from (italic>a(/italic>) a week-long personal carbon monoxide monitoring survey conducted by the author; and (italic>b(/italic>) the 1992 to 1994 National Human Activity Pattern Survey (NHAPS) for the United States. The indirect approach uses measurements of exposures in specific microenvironments (e.g., homes, bars, offices), validated microenvironmental models (based on the mass balance equation), and human activity pattern data obtained from questionnaires to predict frequency distributions of exposure for entire populations. This approach requires fewer resources than the direct approach to exposure assessment, for which the distribution of monitors to a representative sample of a given population is necessary. In the indirect exposure assessment approach, average microenvironmental concentrations are multiplied by the total time spent in each microenvironment to give total integrated exposure. By assuming that the concentrations encountered in each of 10 location categories are the same for different members of the U.S. population (i.e., the NHAPS respondents), the hypothetical contribution that ETS makes to the average 24-hr respirable suspended particle exposure for Americans working their main job is calculated in this paper to be 18 microg/m3. This article is an illustrative review and does not contain an actual exposure assessment or model validation

Validity of the uniform mixing assumption: determining human exposure to environmental tobacco smoke.

When using the mass balance equation to model indoor air quality, the primary assumption is that of uniform mixing. Different points in a single compartment are assumed to have the same instantaneous pollutant concentrations as all other points. Although such an assumption may be unrealistic, under certain conditions predictions (or measurements) of exposures at single points in a room are still within acceptable limits of error (e.g., 10%). In this article, three studies of the mixing of environmental tobacco smoke (ETS) pollutants are reviewed, and data from several other ETS field studies are presented. Under typical conditions for both short sources (e.g., 10 min) and the continuous sources of ETS in smoking lounges, I find that average exposure concentrations for a single point in a room represent the average exposure across all points in the room within 10% for averaging times ranging from 12 to 80 min. I present a method for determining theoretical estimates of acceptable averaging times for a continuous point source

Phase separation in hydrogen-helium mixtures at Mbar pressures

The properties of hydrogen-helium mixtures at Mbar pressures and intermediate temperatures (4000 to 10000 K) are calculated with first-principles molecular dynamics simulations. We determine the equation of state as a function of density, temperature, and composition and, using thermodynamic integration, we estimate the Gibbs free energy of mixing, thereby determining the temperature, at a given pressure, when helium becomes insoluble in dense metallic hydrogen. These results are directly relevant to models of the interior structure and evolution of Jovian planets. We find that the temperatures for the demixing of helium and hydrogen are sufficiently high to cross the planetary adiabat of Saturn at pressures around 5 Mbar; helium is partially miscible throughout a significant portion of the interior of Saturn, and to a lesser extent in Jupiter.Comment: 6 pages, 7 figures. Published in "Proceedings of the National Academy of Sciences USA

Lifestyle migrants

Die zunehmend flexible Mobilität unserer Zeit führt dazu, dass immer mehr Menschen aus dem Westen beschließen, auszuwandern. In Aussicht auf eine Verbesserung der eigenen Lebensumstände und Möglichkeiten der Selbstverwirklichung verschwimmen die Grenzen zwischen Migration und Tourismus. Dies beeinflusst natürlich auch das vorherrschende Verständnis und Selbstverständnis von expatriate als Personen, welche von westlichen Unternehmen oder Regierungen in weniger wohlhabende Länder entsandt werden und in luxuriösen Anwesen, abgeschottet von der Mehrheitsgesellschaft, leben. Ausgehend von einer ethnographischen Untersuchung westlicher Ausländer in Kunming (Yunnan, Volksrepublik China), betrachtet die vorliegende Arbeit diese neue Art des expats in Einbezug von Theorien zum Thema Lifestyle Migration. Das zentrale Erkenntnisinteresse der Studie stellt die Frage dar, warum diese expats sich entschlossen haben, sowohl (zeitweise) nach Kunming zu ziehen als auch etwaige Ursachen, von dort wieder weg zu ziehen. Um diese Frage zu beantworten, wird ein genauer Blick auf die Gründe und Motivationen gerichtet, welche sie anfangs dazu bewegt haben, ihre Heimatländer zu verlassen. Des Weiteren werden die Herausforderungen und Hürden, denen sich die expats in ihrem neuen Zuhause gegenüber sehen, erörtert. Daraus ergibt sich die Frage nach der Erfüllung der anfänglichen Erwartungen und weshalb die meisten trotz Enttäuschungen bleiben. Für ein umfassenderes Verständnis setzt sich die vorliegende Studie zudem mit den Dynamiken innerhalb der expat community der Auswanderer auseinander. Dabei beleuchtet die Arbeit den höchst flüchtigen Charakter dieser community und erkundet die Art und Weise, in der Kunmings Einwanderer mit der chinesischen Umwelt interagieren und sich kulturell und sozial integrieren. Die Beziehung zwischen expats und der lokalen Bevölkerung werden unter Einbezug theoretischer Überlegungen zu "kulturellem Kapital" und "whiteness" genauer erläutet. Diese weisen den Migranten einerseits eine privilegierte Stellung innerhalb der Mehrheitsgesellschaft zu, während sie andererseits in bestimmte Jobnischen gedrängt werden, deren Zugang fast ausschließlich auf Hautfarbe und Nationalität basiert.Due to an increasing flexibility in movement, a growing number of Western people make a decision to migrate based on the prospect of an improvement in lifestyle and the opportunity for self-fulfillment, blurring the distinction between migration and tourism. This expands on the dominant understanding of expats as being people sent to less affluent countries by Western companies or governments and living in luxurious mansions isolated from the host society. Based on ethnographic research amongst Western foreigners in Kunming (Yunnan, P.R. China), the present thesis looks at this new type of expat through the lens of lifestyle migration. The focus of the study lies on question of why these expats decided to (temporarily) move to Kunming as well as why they might wish to leave. In order to answer this question a close look will be taken at the reasons and motivations that have led them to leave their home countries in the first place, as well as the challenges and restrictions they face in their new place of home. For a better comprehension, this study also deals with the dynamics within the expat community, highlighting its transient nature and further exploring the ways in which Kunming’s expats interact with the Chinese environment, as well as how they integrate both culturally and socially. This is explained by drawing on theories regarding ‘cultural capital’ and ‘whiteness’, that on one hand identify their privileged position with their host society, whilst on the other reveal that the jobs they are able to obtain are limited and highly racialized

Comparative Evolution of Jupiter and Saturn

We present evolutionary sequences for Jupiter and Saturn, based on new nongray model atmospheres, which take into account the evolution of the solar luminosity and partitioning of dense components to deeper layers. The results are used to set limits on the extent to which possible interior phase separation of hydrogen and helium may have progressed in the two planets. When combined with static models constrained by the gravity field, our evolutionary calculations constrain the helium mass fraction in Jupiter to be between 0.20 and 0.27, relative to total hydrogen and helium. This is in agreement with the Galileo determination. The helium mass fraction in Saturn's atmosphere lies between 0.11 and 0.25, higher than the Voyager determination. Based on the discrepancy between the Galileo and Voyager results for Jupiter, and our models, we predict that Cassini measurements will yield a higher atmospheric helium mass fraction for Saturn relative to the Voyager value.Comment: 18 pages, LaTeX, 4 figures. submitted to ``Planetary and Space Science.'

Ammonium salicylate: a synchrotron study

The structure of the title salt, NH4 +·C7H5O3 −, is stabilized by substantial hydrogen bonding between ammonium cations and salicylate anions that links the components into a two-dimensional array

Analytic binary alloy volume-concentration relations and the deviation from Zen`s law

Alloys expand or contract as concentrations change, and the resulting relationship between atomic volume and alloy content is an important property of the solid. While a well-known approximation posits that the atomic volume varies linearly with concentration (Zen`s law), the actual variation is more complicated. Here we use an apparent size of the solute (solvent) atom and the elasticity to derive explicit analytical expressions for the atomic volume of binary solid alloys. Two approximations, continuum and terminal, are proposed. Deviations from Zen`s law are studied for 22 binary alloy systems

Evaluation of an Automated Tissue Sectioning Machine for Digital Pathology

Background: Automation and digital pathology are the trends for future anatomic pathology with the increasing workload in histology laboratories. While tissue process, embedding, staining and coverslipping, and digitizing have been available for automated use, tissue sectioning appears to be the biggest roadblock to a fully automated histology process. In this study we were aimed to investigate a tissue automated sectioning machine for both clinical and research use. Methods: Totally 77 surgical resection blocks of various organs embedded with clinical standard paraffin were sectioned automatically using AS-410 (Dainippon Seiki Co. LTD., Japan) at 5 μm thickness with the default setting (Setting A). 10 slides per block were sectioned and the last 5 slides were stained with H&E. All stained slides were digitized with whole-slide imaging scanner, and then evaluated by the image scientist and the pathologist. The image scientist scored the images base on the extent of imperfection (Evaluation I), while the pathologist scored the images based on the clinical diagnosis purpose (Evaluation II). Both scoring systems were scored from 1 to 5, with 1 the worst quality and 5 the highest quality. Tissues with unsatisfied score were sectioned with modified setting (Setting B), and evaluated again by the same image scientist and pathologist using the same scoring systems. And the scores from the two different settings were compared. Auto-trimming and barcode reading and printing of AS-410 were also evaluated. Results: The AS-410 provided auto-trimming function to detect exposed tissue for cutting, accomplished by the installed camera and calculation software. It read sample information and printed barcode as well as input text and automatically generated slide order information. It produced good quality of sections for most cases with median score more than 4 in both Evaluation I and Evaluation II using setting A. The scores of the unsatisfied blocks sectioned with setting A improved significantly when those blocks were sectioned with setting B. Conclusion: The AS-410 tissue sectioning machine produces high-quality sections with clinical standard paraffin tissue blocks of a variety of organs with proper settings. It promises high automation with sound sectioning quality in the era of digital pathology for both clinical and research use.    Lung Breast Prostat

Computational Model for Behavior Shaping as an Adaptive Health Intervention Strategy

Adaptive behavioral interventions that automatically adjust in real-time to participants’ changing behavior, environmental contexts, and individual history are becoming more feasible as the use of real-time sensing technology expands. This development is expected to improve shortcomings associated with traditional behavioral interventions, such as the reliance on imprecise intervention procedures and limited/short-lived effects. JITAI adaptation strategies often lack a theoretical foundation. Increasing the theoretical fidelity of a trial has been shown to increase effectiveness. This research explores the use of shaping, a well-known process from behavioral theory for engendering or maintaining a target behavior, as a JITAI adaptation strategy. A computational model of behavior dynamics and operant conditioning was modified to incorporate the construct of behavior shaping by adding the ability to vary, over time, the range of behaviors that were reinforced when emitted. Digital experiments were performed with this updated model for a range of parameters in order to identify the behavior shaping features that optimally generated target behavior. Narrowing the range of reinforced behaviors continuously in time led to better outcomes compared with a discrete narrowing of the reinforcement window. Rapid narrowing followed by more moderate decreases in window size was more effective in generating target behavior than the inverse scenario. The computational shaping model represents an effective tool for investigating JITAI adaptation strategies. Model parameters must now be translated from the digital domain to real-world experiments so that model findings can be validated