Particulate Matter (PM) Research Centers (1999–2005) and the Role of Interdisciplinary Center-Based Research

Objective: The U.S. Environmental Protection Agency funded five academic centers in 1999 to address the uncertainties in exposure, toxicity, and health effects of airborne particulate matter (PM) identified in the “Research Priorities for Airborne Particulate Matter” of the National Research Council (NRC). The centers were structured to promote interdisciplinary approaches to address research priorities of the NRC. In this report, we present selected accomplishments from the first 6 years of the PM Centers, with a focus on the advantages afforded by the interdisciplinary, center-based research approach. The review highlights advances in the area of ultrafine particles and traffic-related health effects as well as cardiovascular and respiratory effects, mechanisms, susceptibility, and PM exposure and characterization issues. Data sources and synthesis: The collective publications of the centers served as the data source. To provide a concise synthesis of overall findings, authors representing each of the five centers identified a limited number of topic areas that serve to illustrate the key accomplishments of the PM Centers program, and a consensus statement was developed. Conclusions: The PM Centers program has effectively applied interdisciplinary research approaches to advance PM science

Photoinduced energy- and electron-transfer from a photoactive coordination cage to bound guests.

In a coordination cage which contains an array of twelve naphthyl chromophores surrounding a central cavity, photoinduced energy or electron-transfer can occur from the chromophore array to the bound guest in supramolecular host/guest complexes

Model systems for photosynthesis - III. Primary photoprocesses of chloroplast pigments in monomolecular arrays on solid surfaces

By means of the Langmuir-Blodgett technique, monomolecular layers containing chloroplast pigments and lipids have been prepared and transferred from a water surface to solid substrates for spectroscopic study. The absorption spectra of such monolayers of pure chlorophyll a and b have been characterized on several different surfaces. Phytol and M2+ -1:1 stearate–oleate have been used as inert, transparent layer diluents for the chlorophylls to enable the effect of pigment concentration on the absorption and fluorescence spectra to be studied. Self-quenching of the fluorescence of both chlorophylls has been observed and the chromophore separation at the half-quenching concentration is compared with similar data for monolayers on the surface of water, as well as solid and solution systems. Energy transfer between chlorophyll b and a within a monolayer has also been investigated, and found to involve essentially irreversible transfer of excitation energy from b to a. Experiments involving the quenching of chlorophyll fluorescence by quinones in the monolayer leads to the conclusion that the efficiency of quinone quenching is not enhanced at high chlorophyll concentrations. The monolayer properties of the photosynthetically important quinone, plastoquinone A, were investigated, and it was found to form very unstable layers, unsuitable in the present work

Les politiques anti-tabac en milieu de travail : les attitudes des travailleurs et les rôles de la direction et des syndicats

Afin de mieux comprendre la réticence chez beaucoup de travailleurs et de syndicats à appuyer les politiques antitabac et les programmes d'éducation sur les lieux de travail, les auteurs ont fait enquête auprès des membres d'un syndicat national de travailleurs dans des industries à haut risque. L'article présente les résultats de deux enquêtes. Quatre répondants sur dix se sont déclarés fumeurs, mais neuf sur dix fumeurs ont déclaré qu'ils aimeraient arrêter de fumer. Quoique les non-fumeurs ont montré une tendance plus forte à appuyer des restrictions antitabac sur les lieux de travail, trois sur quatre fumeurs ont aussi appuyé des restrictions. Le pourcentage des répondants qui appuyait la préoccupation de l'entreprise et du syndicat pour l'usage du tabac en dehors du milieu du travail et le pourcentage qui s'y opposait était à peu près égal. En général, les répondants qui croyaient que l'employeur et le syndicat travaillaient pour améliorer la santé et la sécurité au travail ont montré une tendance plus forte à appuyer des politiques antitabac. Les auteurs discutent des implications de ces résultats pour leurs hypothèses et pour les programmes d'éducation antitabac sur les lieux de travail.To better understand the reluctance of many workers and unions to support workplace smoking policies and education programs, the authors surveyed members of a national union of workers in high-risk industries. The article presents findings from two surveys. Four out of every ten respondents reported being current smokers, but nine out of ten smokers said they would like to quit. Although nonsmokers were more likely to support restrictions against smoking at work, three out of four smokers also supported restrictions. About equal percentages of respondents supported and opposed the company and the union being concerned with whether workers smoke off the job. In general, respondents who believed that management and unions were trying to improve workplace health and safety were more likely to support workplace smoking policies. The authors discuss the implications of the findings for their hypotheses and for workplace smoking education programs.Para comprender mejor el desgano de muchos trabajadores y sindicatos para apoyar políticas y programas de educación antitabaco en los lugares de trabajo, el autor observó a los miembros de sindicatos nacionales de trabajadores en industrias de alto riesgo. El artículo presenta los resultados de dos observaciones. Cuatro de cada diez encuestados son fumadores habituales, pero nueve de cada diez fumadores dicen que les gustaría dejarlo. Aunque los no fumadores fueron probablemente más mayoritarios en apoyar las restricciones de fumar en el trabajo, tres de cada cuatro fumadores apoyaron también las restricciones. Un porcentaje más o menos igual de encuestados a favor y en contra, tanto de la compañía como del sindicato estaban interesados en si los trabajadores fuman fuera del trabajo. En general, los encuestados que creían que los dirigentes y los sindicatos tratan de mejorar la salud y la seguridad de los lugares de trabajo fueron más proclives a apoyar las políticas anti-tabaco en los lugares de trabajo. Los autores discuten las implicaciones de los resultados en relación a sus propias hipótesis y a los programas de educación anti-tabaco para los lugares de trabajo