Prehistoric Hopewell Meteorite Collecting : Further Evidence

Author Institution: Department of Humanities and Social Studies, Case Institute of Technology, Cleveland, Ohi

Prehistoric Hopewell Meteorite Collecting : Context and Implications

Author Institution: Department of Humanities and Social Studies, Case Institute of Technology, Cleveland, Ohi

The Abri Schmidt, an Important Upper Palaeolithic Site in Bavaria

Author Institution: Cleveland Museum of Natural History and Case Institute of Technology, Cleveland, Ohi

Firms, Nonprofits, and Cooperatives: A Theory of Organizational Choice

We formalize the difference between profit-maximizing firms, nonprofits, and cooperatives and identify optimal organizational choice in a model of quality provision. Firms provide lowest and nonprofits highest levels of quality. Efficiency, however, depends on the competitive environment, the decision making process among owners and technology. Firms are optimal when decision making costs are high. Else, firms are increasingly dominated by either nonprofits or cooperatives. Increased competition improves relative efficiency of firms and decreases relative efficiency of nonprofits

Firms, Nonprofits, and Cooperatives: A Theory of Organizational Choice

We formalize the difference between firms, nonprofits, and cooperatives and identify optimal organizational choice in a model of quality provision. Firms provide lowest and nonprofits highest levels of quality. Efficiency, however, depends on the competitive environment, the decision making process among owners and technology. Firms are optimal when decision making costs are high. Else, firms are increasingly dominated by either nonprofits or cooperatives (depending on the incremental costs of quality production). Increased competition improves relative efficiency of firms and decreases relative efficiency of nonprofits

Étude comparative des accidents impliquant des véhicules lourds avec ou sans matière dangereuse au Québec.

RÉSUMÉ Les accidents routiers impliquant des matières dangereuses présentent, du fait de la présence de ces matières, de sérieux risques d’aggravations. Aussi il est essentiel d’étudier leur transport afin de permettre aux autorités de réguler de façon efficace et sécuritaire ce secteur du transport. Cette présente étude vise à déterminer l’influence de la présence de matières dangereuses sur l’accidentologie des véhicules lourds au Québec, à l’aide d’une analyse statistique des données puis d’une analyse spatiale. On trouve dans la littérature de nombreuses études descriptives et spatiales du transport des matières dangereuses (TMD) mais peu traitent spécifiquement du Québec. Les études descriptives du TMD étudient de nombreux aspects du domaine comme l’évolution du TMD, la répartition entre les types de transport, les matières dangereuses impliquées, les conséquences humaines et financières des accidents ou encore les circonstances des accidents. Les études spatiales s’intéressent plus à la détermination des zones à risque (« points chauds ») ainsi qu’à l’estimation de l’impact des accidents sur la population et à la minimisation des risques par l’optimisation des itinéraires des camions de TMD. Cette étude s’appuie sur deux bases de données québécoises recensant d’une part les accidents impliquant les véhicules lourds (« base globale ») et d’autre part les accidents impliquant des véhicules de transport de matière dangereuse (« base TMD »). Dans un premier temps un travail de mise en forme et de préparation des données a été réalisé. Les accidents de la base TMD ont été identifiés dans la base globale grâce à un programme Visual Basic, et la base TMD a été consolidée. De plus les accidents ont été localisés, et un outil de visualisation des rapports d’accidents intégrant le positionnement de l’accident sur une carte a été mis en place dans les deux bases de données.----------ABSTRACT Road accidents involving hazardous materials present, due to such materials, serious risk of exacerbations. Thus it is essential to study their transport, to enable the authorities to regulate effectively and safely this transport sector. The present study aims to determine the influence of hazardous materials presence on the heavy vehicle accident in Quebec, using a statistical analysis of data and spatial analysis. Many descriptive and spatial studies of hazardous materials transport (hazmat) exist in the literature but few deal specifically with the Quebec. Descriptive studies of hazmat study many aspects of the field as the evolution of hazmat, the distribution between types of transport, hazardous materials involved, the human and financial consequences of accidents or the circumstances of accidents. Space studies are more interested in identifying risk areas (hot spots) and the estimation of the accidents impact on the population, and minimizing risks by optimizing hazmat truck routes. This study uses two databases of the Quebec identifying, on one hand accidents involving heavy vehicles (global basis) and on the other hand other accidents involving vehicles transporting dangerous materials (hazmat basis). Initially a work of editing and data preparation has been done. Hazmat accidents have been identified in the global base with a VB program, and the hazmat base has been completed and corrected. Moreover, accidents have been located, and a visualization tool of accident reports, integrating the accident’s position on a map, has been realized in both databases. A comparative analysis of common fields was then conducted using statistical tools such as descriptive statistics, charts and hypothesis testing. First the field "date" was studied. The analysis of the number of accidents per year did not reveal any clear trend. It seems that years with high proportion of heavy vehicle accidents are also years of high hazmat vehicle accident rates, but the link is not very marked. However, in equal proportions, hazmat accidents annual variations are more than 2 times superior to the annual variations of global base. Moreover, the winter is especially conducive to hazmat accidents with particularly high accident rate. The hourly distribution obtained is similar between the two databases, with a majority of accidents during the day, with two peaks around 20h and 14h and a pause at noon

Molecular signatures of dissolved organic matter in a tropical karst system

Karst areas are widespread landforms present on all continents, formed by the dissolution of carbonate or evaporite host rock. Little is known about the composition and nature of dissolved organic matter (DOM) as it moves through karst systems, although karst DOM has been recognized as important for a range of natural processes. Microbial communities living in karst systems are some of the most diverse and intriguing on the planet, and their metabolism and life cycle can give clues related to the development of a host of different life forms. Karst areas are also of interest due to their mostly subterranean hydrology, and the repercussions of these processes on local carbon cycles. We illustrate some of the processes acting on DOM in karst waters through the analysis of soil, drip and cave pool waters at the tropical site of Yok Balum Cave, in southern Belize. Water samples were analyzed using ultra-high resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR-MS), a technique that enables the resolution of single molecular formulae within a DOM spectrum. We perform multivariate statistics to detect trends in the data and identify provenance of detected molecular components. In addition to karst waters, four aliquots of a powdered stalagmite sample from the same cave system are analyzed. Our results show a clear gradient between the soil and the cave system. We hypothesize that both sorption on mineral surfaces and microbial reworking are responsible for the observed trend in DOM composition. The stalagmite extracts show an anomalous DOM pattern, which may be due to a variety of factors, including microbial activity on the stalagmite surface and different affinities of compounds to incorporation in the carbonate. The goal of this study was to follow the molecular transformations of DOM on its journey from the surface to the cave, and to provide a molecular basis for the establishment of stalagmite DOM proxies in karst systems