Les particules fines (PM₂.₅) présentes dans l'air extérieur peuvent être inhalées puis retenues au niveau pulmonaire, conduisant à l'apparition ou à l'aggravation de différentes pathologies cardio-respiratoires. La composition complexe des PM₂.₅ rend d'autant plus difficile l'étude de leurs mécanismes d'action. Cette thèse s'inscrit donc dans une démarche d'identification des processus impliqués dans un éventuel potentiel cancérigène des PM₂.₅, en lien avec leur composition chimique. Nous avons étudié la toxicité de six échantillons de PM₂.₅, collectés sous influence industrielle, urbaine ou rurale au cours des saisons printemps-été 2008 et automne-hiver 2008-2009. L'étude de la fraction biologique a révélé la diversité et la richesse des particules en contaminants fongiques et bactériens. Le test d'Ames nous a permis de mettre en évidence une forte mutagénicité des PM₂.₅, vraisemblablement liée aux composés nitro-aromatiques. Sur la base de tests de cytotoxicité préalables, nous avons étudié l'effet de 3,75 et 15 µg/cm² de particules sur la lignée de cellules épithéliales bronchiques humaines BEAS-2B. Nous avons mis en évidence une induction génique de différents enzymes impliquées dans l'activation métabolique des hydrocarbures aromatiques polycycliques, associée à une augmentation d'activité catalytique. Cette induction semble conduire à la formation d'adduits encombrants à l'ADN. De plus, les PM₂.₅ induisent des cassures simple- et double-brin de l'ADN, la formation de micronoyaux, ainsi que des perturbations de l'activité télomérase. Ces effets génotoxiques sont associés à des altérations épigénétiques que sont une hyperméthylation du promoteur de P16ᴵᴺᴷ⁴ᴬ, des modifications post-traductionnelles de l'histone 3 et des changements dans l'expression des miRNA étudiés. Considérant l'influence de la composition des PM₂.₅, les composés organiques semblent être responsables des effets génotoxiques les plus importants, alors que les métaux paraissent avoir des effets épigénétiques supérieurs. En conclusion, il apparaît que les échantillons de PM₂.₅ étudiés, de par l'action conjointe de leurs fractions organique et inorganique, sont susceptibles d'induire in vitro de multiples lésions décrites dans les étapesd'initiation et de promotion de la cancérogénèse broncho-pulmonaire. / Fine airborne particulate matter (PM₂.₅) can be inhaled and retained in deep lung for long periods, leading to onset or exacerbation of cardio-respiratory diseases. However, the complex composition of PM₂.₅ makes difficult the study of their mechanisms of action. This work fits into a global approach aiming to identify the toxicity mechanisms involved in a putative PM₂.₅ carcinogenicity, in association with PM composition. We study six PM samples collected either under industrial, urban or rural area, in spring-summer 2008 or autumn-winter 2008-2009 seasons. Biological fraction analysis revealed numerous and diverse bacterial and fungal components. We carried out Ames tests revealing a high mutagenic potency for PM samples, presumably linked to their nitro-aromatic content. Based on previous cytotoxicity assays, we studied PM effect on bronchial epithelial cell line BEAS-2B, at two concentrations (3.75 and 15µg/cm²). We demonstrated gene induction of several xenobiotic metabolizing enzymes involved in polycyclic aromatic hydrocarbons metabolic activation. This was associated with an increase in their catalytic activity, leading to bulky DNA-adducts formation in exposed cells. Furthermore, PM₂.₅ lead to DNA single- and double-strand breaks, micronuclei formation, and disturbed telomerase activity. In addition to these genotoxic effects, our study revealed epigenetic alterations such as P16ᴵᴺᴷ⁴ᴬ promoter hypermehylation, histone 3 post-translational modifications, and miRNAs expression changes. Considering the impact of chemical composition on PM toxicity, organic compounds lead to the highest genotoxicity, whereas metals seem to induce more pronounced epigenetic modifications. Altogether, our results indicate that the studied PM₂.₅ samples, through cooperative action of organic and inorganic fractions, may lead in vitro to multiple alterations involved in initiation and promotion steps toward pulmonary carcinogenesis.

Récemment reconnus comme cancérogènes certains pour l'homme par l’IARC, la pollution atmosphérique et les particules fines (PM₂.₅) peuvent être inhalées et pourraient être retenues au niveau pulmonaire ou passer dans la circulation systémique. Ceci peut causer ou renforcer de nombreuses pathologies auxquelles les personnes âgées sont souvent plus sensibles. Cette thèse s’inscrit dans une démarche d’identification des processus impliqués dans la modulation du potentiel cancérogène des PM₂.₅, en lien avec l’âge ou le statut tabagique. Les particules ont été collectées à Dunkerque, agglomération présentant des influences maritimes mais également caractérisée par des activités industrielles et un trafic automobile importants. Pour évaluer l'influence de l'âge, des lymphocytes sanguins prélevés chez 90 patients issus de trois classes d'âge (25-30, 50-55 et 75-80 ans) ont été exposés ex vivo à des PM₂.₅ d’origine urbaine. Les lymphocytes isolés ont été exposés aux PM₂.₅ pendant 72 heures, avant de mesurer l'activité télomérase et la modulation d'expression de gènes tels que P16INK4A et MGMT. Les PM₂.₅ entraînent des variations de l'activité télomérase et de la longueur des télomères dans toutes les tranches d'âge indifféremment. L’expression du gène P16INK4A est significativement augmentée avec l'âge après exposition aux PM₂.₅. L'âge augmenterait l'expression du gène MGMT après exposition aux particules, en diminuant le niveau de méthylation de son promoteur uniquement dans le groupe des patients les plus âgés. Concernant le rôle du statut tabagique, 26 lavages broncho-alvéolaires ont été réalisés chez des patients fumeurs et non-fumeurs. Les macrophages issus de ces prélèvements ont été mis en culture avec des cellules épithéliales bronchiques BEAS-2B, avant exposition aux PM₂.₅ (3 et 15 µg/cm², 72 h). L’activité télomérase et la longueur des télomères varient après exposition aux PM2.5 et le statut tabagique modifie ces paramètres dans les cellules BEAS-2B et les macrophages alvéolaires. La méthylation des promoteurs et l’expression des gènes P16INK4A et MGMT ne sont pas modifiées dans les cellules BEAS-2B, alors que dans les macrophages alvéolaires les particules induisent l’expression de ces gènes par une diminution de la méthylation de leurs promoteurs. Le statut tabagique fumeur semble au contraire accroître la méthylation et limite l’expression de ces deux gènes. En conclusion, il apparaît que l’échantillon de PM₂.₅ étudié peut induire ex vivo plusieurs lésions décrites dans les étapes d’initiation et de promotion de la cancérogenèse broncho-pulmonaire. L’âge et le tabagisme sont susceptibles de moduler les effets toxiques des particules. Alors que les symptômes du cancer du poumon apparaissent seulement à une étape avancée de la maladie, nos résultats pourraient aider à la découverte de nouveaux marqueurs de diagnostic précoce permettant ainsi d’améliorer la survie. / Recently recognized as carcinogenic to human by IARC, air pollution and fine particulate matter (PM₂.₅) can be inhaled and could be retained into the lung or reach the systemic circulation. This can cause or worsen many diseases for which the elderly are often more sensitive. The PhD objective corresponds to the identification of the mechanisms of action involved in the modulation of carcinogenic potential of PM₂.₅, in connection with age or smoking status. PM₂.₅ were collected in Dunkerque, a French seaside city characterized by important industrial activities and heavy motor vehicle traffic. In order to estimate the influence of age, blood lymphocytes sampled from 90 patients from age classes (25-30, 50-55 and 75-80 years old) were ex vivo exposed to PM₂.₅ during 72 hours, before evaluation of telomerase activity and gene expression modulation of P16INK4A and MGMT. PM₂.₅ modulated telomerase activity and telomeres length in all age groups without any influence of age. P16INK4A gene expression increased significantly with age after exposure to PM₂.₅. Age could enhance MGMT gene expression after exposure to particles by decreasing the level of promoter methylation in the oldest group. Regarding the role of smoking status, 26 broncho-alveolar lavage were performed in smoker and non-smoker people. Macrophages were cultured with bronchial epithelial BEAS-2B cells before PM₂.₅ exposure (3 or 15µg/cm²; 72h). The telomerase activity and telomere length vary after exposure and the tobacco modify these parameters in BEAS-2B cells and alveolar macrophages. Methylation of P16INK4A and MGMT genes promoters and their expression are not modified in BEAS-2B cells. In alveolar macrophages, particles lead to a decrease of methylation of P16INK4A gene promoter. The smoking status seems also to increase methylation and to down-regulate expression of these two genes. In conclusion, it seems that the studied PM₂.₅ sample can induce ex vivo modifications described in the initiation and promotion of lung carcinogenesis. The age and smoking status may modulate the toxic effects of particles. Since lung cancer symptoms appear only at an advanced stage, our results could help in proposing new biomarkers of carcinogenesis allowing an early diagnosis to improve survival.

Master of Science / Department of Biological & Agricultural Engineering / Ronaldo G. Maghirang / Large cattle feedlots emit considerable amounts of particulate matter (PM), including TSP (total suspended particulates), PM[subscript]10 (PM with equivalent aerodynamic diameter of 10 μm or less), and PM[subscript]2.5 (PM with equivalent aerodynamic diameter of 2.5 μm or less). Particulate emissions result from pen surface disturbance by cattle hoof action, vehicle traffic on unpaved roads and alleyways, and wind erosion. Research is needed to determine concentrations of various size fractions, size distribution, and emission rates from various sources in feedlots. This research was conducted to measure particle size distribution using laser diffraction method and estimate emissions from unpaved roads and wind erosion. Particle size distribution and concentrations of PM[subscript]10 and PM[subscript]2.5 at a commercial cattle feedlot in Kansas (Feedlot 1) were measured over a 2-yr period. The feedlot had a capacity of 30,000 head and total pen area of 50 ha and was equipped with a sprinkler system for dust control. Collocated low-volume samplers for TSP, PM[subscript]10, and PM[subscript]2.5 were used to measure concentrations of TSP, PM[subscript]10, and PM[subscript]2.5 at the upwind and downwind edges of the feedlot. Dust samples that were collected by TSP samplers were analyzed with a laser diffraction analyzer to determine particle size distribution. Particle size distribution at the downwind edge of the feedlot was also measured with micro-orifice uniform deposit impactor (MOUDI). The laser diffraction method and MOUDI did not differ significantly in mean geometric mean diameter (13.7 vs. 13.0 μm) but differed in mean geometric standard deviation (2.9 vs. 2.3). From laser diffraction and TSP data, PM[subscript]10 and PM[subscript]2.5 concentrations were also calculated and were not significantly different from those measured by low-volume PM[subscript]10 and PM[subscript]2.5 samplers (122 vs. 131 μg/m[superscript]3 for PM[subscript]10; 26 vs. 35 μg/m[superscript]3 for PM[subscript]2.5). Both PM[subscript]10 and PM[subscript]2.5 fractions decreased as pen surface moisture contents increased, while the PM[subscript]2.5/PM[subscript]10 ratio did not change much with pen surface moisture content. Published emission models were used to estimate PM[subscript]10 emissions from unpaved roads and wind erosion at Feedlot 1 and another nearby feedlot (Feedlot 2). Feedlot 2 had a capacity of 30,000 head, total pen surface area of 59 ha, and used water trucks for dust control. Estimated PM[subscript]10 emissions from unpaved roads and wind erosion were less than 20% of total PM[subscript]10 emissions obtained from inverse dispersion modeling. Further research is needed to establish the applicability of published emission estimation models for cattle feedlots.

Harmattan and Dust (sand) storms together with anthropogenic activities including the use of firewood and kerosene as fuel for cooking, and diesel/petrol generators for electricity generation are potential sources of particulate and gaseous pollutants in homes in Damaturu town, Nigeria. Other activities like the burning of locally produced incense and mosquito coils as well as the use of aerosol sprays are further possible sources of indoor pollution, which may result in exposure of people to a range of pollutants through inhalation, by ingestion of settled dusts as well as dermal contact. Local people associate occurrence of dust events with adverse health effects and hence there is a need for an understanding of the composition of the settled and airborne dusts in order to assess the possible associated health risks. The first phase of the study involved selection and development of methods of dust sampling and analysis. For validation of the methods employed and to establish a broad understanding of the characteristics of the settled dusts, an initial survey study was conducted involving the application of thermal desorption/gas chromatography/mass spectrometry (TD/GC/MS) analysis for organic compound analysis, scanning electron microscopy (SEM), inductively coupled plasma-mass spectrometry (ICP-MS) for analysis of metals, and microbiological analysis. Airborne samples were also collected using sorbent tubes to determine organic compounds in air during activities such as cooking with kerosene, gas, and firewood as well as during electricity generation with fossil fuels. Carbon monoxide (CO) and ultrafine particles (UFPs) monitored simultaneously during some of the household activities. The study involved a novel method of extracting organic chemical emissions from dust by heating of the dusts directly in a micro chamber (μ-CTETM) and collection of emissions on sampling tubes. The method provided a relatively quick way of collecting chemical emissions from dusts that are readily available for release. The sampled tubes were analysed by TD/GC/MS. The conventional solvent extraction of the dusts was also carried out and the extracts were analysed by liquid injection-GC/MS and results of the two methods compared. The study determined a number of constituents (metals, SVOCs, phthalates and physical properties) of dusts collected from households in Damaturu during different weather events and from different indoor/outdoor locations; and compared with some UK samples. The samples investigated include dusts deposited; during two notable dusty-weather events (Harmattan and Storm) as well as when there was no notable dust event; during human activities; and dusts from different types of buildings (modern and traditional homes) as well as inside and outside homes. A standard reference material for organic chemicals (SRM 2585) was also analysed. The physical characterization of the settled house dust samples analysed revealed the various shapes and sizes, and elemental composition of the constituents, which included respirable particles. The microbial analysis also indicated the presence of the spores of a host of fungi and bacterial species; and the possible contributions of household activities to the increased production of pollutants (UFP and CO) ascertained. The μ-CTE extraction of the house dusts by heating with TD/GC/MS analysis of the emissions as well as the solvent extraction-GC/MS revealed the presence of many organic chemical compounds with different analytical retention times and varying concentrations in the dust samples. Chemicals of interest quantified: benzene, hexanal, nonanal, diethyl phthalate (DEP), diisobutylphthalate (DIBP), dibutylphthalate (DBP), and diethylhexylphthalate (DEHP). A host of other chemicals commonly present in the analysed samples identified using the NIST library associated with the MS system software. These chemicals included naphthalene and C10-C16 aliphatic and aromatic hydrocarbons, which would need confirmation by running the pure compound samples. There was an observed higher concentration of the chemicals in the solvent extracts than the μ-CTE extracted dust. The higher concentration of the chemicals in the solvent extracts expected due to the aggressive removal of the chemicals by the organic solvent whereas in the case of thermal extraction only the readily available chemicals (loosely bound to the matrix) released by increases in temperature were removed. Generally, the concentrations of the chemicals found were higher in the indoor than in the outdoor dust samples. In the analysis of the dusts collected during weather events; higher chemical concentrations observed in the samples collected during Harmattan period than the other periods. The Harmattan dust period may pose increased exposures to dust and possible health risks. More exposure is expected to occur in the traditional homes compared with the modern homes due to the higher concentrations of the chemicals in both the indoors and the outdoors and this may be especially important to women and children who spend most of their times at home. Metal analysis involved microwave-assisted digestion of the dust samples followed by ICP-MS analysis. The total quant method of metal analysis for a general profiling indicated the presence of more than 50 elemental contaminants in house dust. The results of the quantitative analysis for six target metals: Cd, Cr, Cu, Ni, Pb, and Zn showed their presence in all indoor and the outdoor dust samples. The mean concentrations showed that the metals were in higher concentrations in the indoor dusts than in the outdoor dusts. The quantitative analysis carried out indicated higher metal contents in the storm dusts than the dusts during the other periods. Results of the dusts collected from modern and traditional homes indicated the presence of the metals in higher concentrations in the dusts from traditional homes than the dusts from the modern homes. The estimated mean concentrations of the metals and phthalates inadvertently ingested as a constituent of dust indicated that some of the pollutants could exceed the tolerable daily intake (TDI) due to high exposures to dust expected to be the case in Damaturu. The results of the investigation of the dust composition, combined with information on exposure to dust and pollutants, show that dusts are a risk to the health of people in the Damataru community. Recommendations are made for more studies to provide a better understanding of dust ingestion and exposure to some phthalates and heavy metals in particular and the possible health risks. To the best of my knowledge, this is the first ever research study of airborne and settled dusts undertaken in North-Eastern Nigeria.

Diesel engine emissions of oxides of nitrogen and particulate matter can be reduced simultaneously through the use of high levels of exhaust gas recirculation (EGR) to achieve low temperature combustion (LTC). Although the potential benefits of diesel LTC are clear, the main challenges to its practical implementation are the requirement of EGR levels that can exceed 60%, high fuel consumption, and high unburned hydrocarbon and carbon monoxide emissions. These limit the application of LTC to medium loads. In order to implement the LTC strategy in a passenger vehicle engine, a transition to conventional diesel operation is required to satisfy the expected high load demands on the engine. The investigation presented in this thesis was therefore aimed at improving the viability of the high-EGR LTC strategy for steady-state and transient operation. An experimental investigation was carried out on a single cylinder high-speed direct injection diesel engine. This thesis presents research on engine in-cylinder performance and engine-out gaseous and particulate emissions at operating conditions (i.e. EGR rate, intake pressure, fuel quantity, injection pressure) likely to be encountered by an engine during transient and steady-state operation. At selected operating points, further investigation in terms of in-cylinder spray and combustion visualization, flame temperature and soot concentration measurements provided deeper insight into the combustion and emissions phenomena. Increased intake pressure at single injection high-EGR LTC operation was investigated as a strategy to reduce the emissions of partial combustion by-products and to improve fuel economy. The higher intake pressure, although effective in reducing partial combustion by-products emissions and improving fuel economy, increased the EGR requirement to achieve LTC. A split fuel injection strategy with advanced injection timing on the other hand was effective in reducing the EGR requirement for LTC from 62% with single injection to 52% with split injections at 120 kPa (absolute) intake pressure. Unburned hydrocarbon emissions and fuel economy were particularly sensitive to intake oxygen mass fraction, and injection and dwell timings with the split injection strategy. In-cylinder soot formation and oxidation mechanisms with the split injection strategy were found to be significantly different from the single injection high-EGR LTC case. Transient simulation of an engine during combustion mode transition identified engine operating parameters on a cycle-by-cycle basis. Steady-state investigation of these test conditions provided significant insight into the combustion conditions and their effect on emissions and performance. The results from this thesis demonstrated the importance of optimizing both the air handling system performance and the fuel injection system during engine transients. The increased emissions and impaired performance due to slow response of the EGR and turbocharger systems during transitions to and from LTC modes can in part be mitigated through split injections optimized for the specific transient point. This provides a clear direction for engine developers to pursue in optimizing engine calibration when running with LTC-conventional diesel dual-mode strategies.

Doctor of Philosophy / Department of History / Donald J. Mrozek / This study argues that after World War I, corporate executives continued a strategy of perception management (PM) to control Americans’ choices in the commercial sphere and to shape the economic and cultural landscape of the 1920s. The state used PM on an unprecedented scale in 1917 and 1918 to promote a model of loyal American behavior (as part its effort to manage the mobilized U.S. society), but the use of PM did not end after the Armistice. While many historians have seen wartime propaganda measures as the result of special fears and circumstances tied to a sense of pervasive national emergency, they fail to explain the continuation of comparable methods into the period of peace supposedly characterized by a return to "normalcy." Whereas most historical studies sharply delineate between political propaganda and commercial advertising, this study stresses leaders' continuous use of PM to promote their notions of what constituted typical, normal, even loyal American behavior in times of both war and peace. While not a contemporary term in the early twentieth century, PM offers an appropriate conceptual framework to analyze a deliberate strategy at that time. This study defines it as actions used to convey or deny selected information to audiences to influence their emotions, motives, and objective reasoning, resulting in behaviors and actions favorable to the originators’ objectives. During WWI, policymakers and bureaucrats concealed the state's effort to control people's behavior with claims of defending liberty and democracy. After the war, corporate executives used PM to manufacture consumer demand and encourage Americans to think of themselves foremost as consumers. A cross section of political, economic, and cultural history, Perception Management in the United States from the Great War to the Great Crash offers an original perspective that emphasizes the consistency between the wartime and postwar eras by highlighting leaders' ongoing use of perception management to control Americans' behavior.

As project management (PM) and information technology (IT) evolved over the last decades, an increasing number of project management software products have emerged. Project managers in IT consulting can improve the success of projects through the utilization of such software. However, the diversity of software available cannot sensibly be grasped by a single individual. Based on this context, the study aims to examine the key considerations in the selectionof project management software in IT consulting from the project managers' perspective. A literature review identifies key aspects of IT consulting projects that may be relevant to the software selection. No evidence was found that provided a view on the process of the selection of PM software in IT consulting itself. The review also unveils the lack of common terminology in regard to PM software. The study addresses these gaps by utilizing interpretative phenomenological analysis (IPA) to understand the experiences made by project managers. To gather data, 17 semistructured interviews were conducted with experienced project managers. Thematic analysis was used to develop an understanding of the process employed by project managers in the software selection and the considerations they make along the way. The findings were synthesized to create a process guide, supported by a checklist and the working definition of key terminology. This study adds a broader perspective to the field of PM software through the application of qualitative methodology in an otherwise quantitatively dominated field of research. It addresses the lack of existing knowledge on the perspective of the project manager in the selection process through the generation of a 6-staged process guide. The detailed considerations of project managers were compiled into a checklist of selection criteria. These two also contribute to practice by providing a structured approach to PM selection for practitioners. The third output is a working definition of project management software as used in practice, which simplifies an exchange of knowledge between theory and practice.

Various solutions have been proposed to “fix” performance management (PM) over the last several decades. Pulakos, Mueller Hanson, Arad, and Moye (2015) have presented a holistic approach to improving PM in organizations. Although this approach addresses several key elements related to the social context of PM, namely the buy-in of organizational stakeholders, timely and regular feedback, and future-directed feedback, we believe that several robust findings from the PM research literature could further improve this process. Are Pulakos et al. looking at the forest but missing the trees? In the following commentary, we offer several reasons that performance judgments and perhaps even informal ratings are still operating and occurring in the proposed holistic system. Therefore, advancements in other areas of PM research may offer additional ways to fix PM.

Performance management (PM) research has traditionally been criticized because of its supposed lack of impact on PM practice. A survey of PM practices in the United States was conducted to determine the current state of PM in organizations and to evaluate the gaps between science and practice. Implications are discussed.

Research on health effects of particulate matter (PM) has been a very active area in the last two decades. One plausible mechanism by which exposure to PM affects human health includes modification of autonomic endothelium function. Decreased endothelium activity causes heightened risks of cardiovascular disease. A human exposure chamber designed to conduct experiments to quantify diminished function of endothelium from short term exposure to PM is described. The chamber consists of two stages for containment and pre-treatment of PM and exposure of human subjects. Concentrations of CO, CO2, NO, NO2, O3, and PM2.5, are monitored and controlled in the exposure room. The PM used in the human exposure experiments was characterized chemically and morphologically. During January and February of 2009, chemical analysis of PM2.5 was done during inversion periods in Salt Lake City, UT. An Ambient Ion Monitor (AIM) was deployed to measure the concentrations of anions in both particulate and gas phases. The chemical data provided by AIM was complemented by measurements by the Department of Air Quality that included PM10, PM2.5, O3, NO, NO2, NH3 and CO. The goal of the study was to determine whether ammonia or nitric acid is the limiting reagent in formation of PM during inversions. Nitric acid is the limiting reagent. Concentrations of ammonia are an order of magnitude higher than nitric acid.