Statistical Methodological Issues in Studies of Air Pollution and Respiratory Disease.

Epidemiological studies have consistently shown short term associations between levels of air pollution and respiratory disease in countries of diverse populations, geographical locations and varying levels of air pollution and climate. The aims of this paper are: (1) to assess the sensitivity of the observed pollution effects to model specification, with particular emphasis on the inclusion of seasonally adjusted covariates; and (2) to study the effect of air pollution on respiratory disease in Melbourne, Australia.Air pollution; Autocorrelation; Generalized additive models; Seasonal adjustment; Respiratory disease

On surface wave fields arising in soil-structure interaction problems

Abstract The paper aims at generalization of the specialized formulation, originally developed for the surface wave fields induced by prescribed surface stresses. We extend this formulation to soil-structure interaction problems with unknown contact stresses and internal sources. The problem for an internal source embedded in an elastic half-plane is reduced to that for prescribed surface stresses by considering the point source solution for an unbounded medium. In this case the sub-problems corresponding to normal and tangential stresses assume a separate treatment. Then, we analyze interaction of an elastic half-plane with a one degree of freedom mass-spring system. The focus is on a near-resonant regime investigated by a perturbation technique

Trans-disciplinary research in synthesis of grass pollen aerobiology and its importance for respiratory health in Australasia

© 2015 Published by Elsevier B.V. Grass pollen is a major trigger for allergic rhinitis and asthma, yet little is known about the timing and levels of human exposure to airborne grass pollen across Australasian urban environments. The relationships between environmental aeroallergen exposure and allergic respiratory disease bridge the fields of ecology, aerobiology, geospatial science and public health. The Australian Aerobiology Working Group comprised of experts in botany, palynology, biogeography, climate change science, plant genetics, biostatistics, ecology, pollen allergy, public and environmental health, and medicine, was established to systematically source, collate and analyse atmospheric pollen concentration data from 11 Australian and six New Zealand sites. Following two week-long workshops, post-workshop evaluations were conducted to reflect upon the utility of this analysis and synthesis approach to address complex multidisciplinary questions. This Working Group described i) a biogeographically dependent variation in airborne pollen diversity, ii) a latitudinal gradient in the timing, duration and number of peaks of the grass pollen season, and iii) the emergence of new methodologies based on trans-disciplinary synthesis of aerobiology and remote sensing data. Challenges included resolving methodological variations between pollen monitoring sites and temporal variations in pollen datasets. Other challenges included "marrying" ecosystem and health sciences and reconciling divergent expert opinion. The Australian Aerobiology Working Group facilitated knowledge transfer between diverse scientific disciplines, mentored students and early career scientists, and provided an uninterrupted collaborative opportunity to focus on a unifying problem globally. The Working Group provided a platform to optimise the value of large existing ecological datasets that have importance for human respiratory health and ecosystems research. Compilation of current knowledge of Australasian pollen aerobiology is a critical first step towards the management of exposure to pollen in patients with allergic disease and provides a basis from which the future impacts of climate change on pollen distribution can be assessed and monitored

Near-IR-Triggered, Remote-Controlled Release of Metal Ions: A Novel Strategy for Caged Ions

Cataloged from PDF version of article.A ligand incorporating a dithioethenyl moiety is cleaved into fragments which have a lower metal-ion affinity upon irradiation with low-energy red/near-IR light. The cleavage is a result of singlet oxygen generation which occurs on excitation of the photosensitizer modules. The method has many tunable factors that could make it a satisfactory caging strategy for metal ions

Why do my thoughts feel so bad? Getting at the reciprocal effects of rumination and negative affect using dynamic structural equation modeling

Rumination means to perseveratively think about one\u27s negative feelings and problems. It is a response to affective distress that is often referred to as maladaptive emotion regulation. According to the response styles theory and control theory, rumination may further prolong and exacerbate affective distress. This means that rumination can be viewed as both an antecedent and an outcome of negative affect (NA), and vice versa. However, at the level of short-term dynamics, state rumination and NA have previously mainly been examined as two separate outcomes. To model the reciprocal within-person effects and hence, to match theoretical assumptions, we combined the two interrelated time series in one model using dynamic structural equation modeling (DSEM). Both effects (NA on subsequent rumination and rumination on subsequent NA) were modeled simultaneously while acknowledging the autoregressive nature of both states (inert properties). We used data from two experience sampling studies (NStudy 1 = 200 Belgian university students; NStudy 2 = 70 German university students). Participants were paged on smartphones several times a day (Study 1: 10; Study 2: 6) for several days (Study 1: 7; Study 2: 9-12). In both studies, we found evidence for reciprocal effects of NA and rumination, and both processes showed autoregressive relationships. Aside from central findings, higher levels of rumination were also associated with higher rumination inertia, pointing toward more habitual rumination also being associated with prolonged rumination. Together, using DSEM, we found reciprocal associations between rumination and NA, while providing new insights into the dynamics between the two processes. (DIPF/Orig.

Dispersion of elastic waves in a layer interacting with a Winkler foundation

ABSTRACT Dispersion of plane harmonic waves in an elastic layer interacting with a one- or two-sided Winkler foundation is analyzed. The long-wave low-frequency polynomial approximations of the full transcendental dispersion relations are derived for a relatively soft foundation. The validity of the conventional engineering formulation of a Kirchhoff plate resting on an elastic foundation is investigated. It is shown that this formulation has to be refined near the cutoff frequency of bending waves. The associated near cutoff expansion is obtained for both cases. A simple explicit formula demonstrating veering of bending and extensional waves is presented for a one-sided foundation

Asymptotic analysis of an anti-plane dynamic problem for a three-layered strongly inhomogeneous laminate

Anti-plane dynamic shear of a strongly inhomogeneous dynamic laminate with traction-free faces is analysed. Two types of contrast are considered, including those for composite structures with stiff thick or thin outer layers. In both cases, the value of the cut-off frequency corresponding to the lowest anti-symmetric vibration mode tends to zero. For this mode the shortened dispersion relations and the associated formulae for displacement and stresses are obtained. The latter motivate the choice of appropriate settings supporting the limiting forms of the original anti-plane problem. The asymptotic equation derived for a three-layered plate with thick faces is valid over the whole low-frequency range, whereas the range of validity of its counterpart for another type of contrast is restricted to a narrow vicinity of the cut-off frequency

A Varying Coefficient Model to Measure the Effectiveness of Mass Media Anti-Smoking Campaigns in Generating Calls to a Quitline

Background: Anti-smoking advertisements are an effective population-based smoking reduction strategy. The Quitline telephone service provides a first point of contact for adults considering quitting. Because of data complexity, the relationship between anti-smoking advertising placement, intensity, and time trends in total call volume is poorly understood. In this study we use a recently developed semi-varying coefficient model to elucidate this relationship. Methods: Semi-varying coefficient models comprise parametric and nonparametric components. The model is fitted to the daily number of calls to Quitline in Victoria, Australia to estimate a nonparametric long-term trend and parametric terms for day-of-the-week effects and to clarify the relationship with target audience rating points (TARPs) for the Quit and nicotine replacement advertising campaigns. Results: The number of calls to Quitline increased with the TARP value of both the Quit and other smoking cessation advertisement; the TARP values associated with the Quit program were almost twice as effective. The varying coefficient term was statistically significant for peak periods with little or no advertising. Conclusions: Semi-varying coefficient models are useful for modeling public health data when there is little or no information on other factors related to the at-risk population. These models are well suited to modeling call volume to Quitline, because the varying coefficient allowed the underlying time trend to depend on fixed covariates that also vary with time, thereby explaining more of the variation in the call model

Challenges for Allergy Diagnosis in Regions with Complex Pollen Exposures

Over the past few decades, significant scientific progress has influenced clinical allergy practice. The biological standardization of extracts was followed by the massive identification and characterization of new allergens and their progressive use as diagnostic tools including allergen micro arrays that facilitate the simultaneous testing of more than 100 allergen components. Specific diagnosis is the basis of allergy practice and is always aiming to select the best therapeutic or avoidance intervention. As a consequence, redundant or irrelevant information might be adding unnecessary cost and complexity to daily clinical practice. A rational use of the different diagnostic alternatives would allow a significant improvement in the diagnosis and treatment of allergic patients, especially for those residing in complex pollen exposure areas