A new Late Ordovician microdomatid gastropod genus from Seville,south west Spain,with a revision of Ordovician Microdomatoidea

A new microdomatid gastropod, Eopagodea sevillana gen. and sp. nov., is described from the Late Ordovician (pre-Hirnantian Ashgill) limestones of Seville, Ossa Morena Zone, Spain. Palaeozoic microdomatids lived in shallow-water environments and were restricted to warm-water regions. Occurrence of microdomatid gastropods in the pre-Hirnantian Ashgill limestones of the Cerrón del Hornillo syncline (Ossa Morena Zone, Spain) is interpreted as an example of an influx of warm-water faunal elements into the otherwise cool to cold climate of the Mediterranean region during a short-termed, pre-Hirnantian increase of palaeotemperatures. The Late Ordovician microdomatid genus Daidia Wilson, 1951, is revised and two new Late Ordovician (Ashgill) subspecies of Daidia cerithioides (Salter, 1859) are described: Daidia cerithioides sewardensis n. subsp. from the Don River area of the York Mountains, Seward Peninsula, western Alaska, and Daidia cerithioides wilsonae n. subsp. from the Little East Lake Formation of northwestern Maine.     

Study of interactions between polyethylene glycol and archaeological wood components by C high-resolution solid-state CP-MAS NMR

While use of polyethylene glycols, PEG, polymers for archaeological wood conservation has been well established, there is almost no study of such composite materials with carbon thirteen high-resolution solid-sate NMR. We demonstrate that NMR is an useful analytical tool to characterize rapidly samples of conserved wooden objects. By choosing an appropriate value of the contact time (from 3 to 5 ms) for which the PEG component gives only a small residual NMR signal in the CP-MAS experiment, it is possible to edit selectively the spectra of the wood components. It allows one to visualize the degradation extent of the archaeological wood even when the conservation processes have been already applied. Moreover, by studying the kinetics of CP-MAS experiments, the time constants, T_1ρH and T_CH values for PEG moiety were computed. From these data, it is shown that either in the crude commercial product or in incorporated in archaeological woods, two components are present and they are the signatures of crystalline (or ordered) and amorphous (or disordered) molecular domains. Moreover, it was shown in the archaeological woods that almost 30% of PEG was in close molecular interactions with lignins. This study is the first evidence that the PEG in conserved wood can interact at a molecular level with wood components. It also demonstrates that the PEG diffuses inside the residual cell walls of archaeological wood. This data are important for scientists in charge of process development for the conservation of wooden artifacts.     

Quebec and Canada at the Crossroads: A Nation within a Nation

Abstract. I argue first that there are many different concepts of the nation, and advocate a certain conceptual pluralism. I also argue that a population as a whole cannot constitute a nation unless it has a certain national consciousness. I then show that we must adopt a fundamental principle of tolerance. I also try to attend to the complexities of the relations between Quebec and Canada, and argue that different populations represent themselves as nations in different ways and with different concepts. 1 show that Quebec constitutes a nation within a nation. I then wonder what it would mean for Canadians to accept a Quebec nation. Finally, I try to explain why a very large proportion of the population of Quebec has increasingly been favourable to sovereignty, and favourable to making a partnership proposal to Canada.     

Modeling Air Quality in Urban Areas: A Cell‐Based Statistical Approach

Statistical regression models are presented that explain the observed variations, across urban areas, in the concentrations of two major pollutants, ozone and carbon monoxide. Model specification and estimation are based on an explicit and new spatial framework derived from the theoretical concept of well‐mixed cells, whereby the basic Fickian system of diffusion equations is integrated over the regional space partitioned into a grid of large cells. The concentration in each cell results from the balance of pollutant flows into and out of this cell and of pollutant emissions and removal within that cell, and is expressed as the sum of two concentration contributions: (1) the local effect, dependent upon pollution‐related factors around the measuring station, and (2) the regional effect, dependent upon pollutant flows originating outside the local area. A large database is developed, making extensive use of GIS technology, to spatially relate such data as pollution measurements, meteorological factors, land‐use characteristics, census socioeconomic data, and major highway network characteristics. The results confirm the appropriateness of the well‐mixed cell framework, are in line with general knowledge regarding the determinants of ozone and carbon monoxide concentrations, and clarify the role of transportation, residential fuel use, economic activities, natural environments, and meteorological factors such as temperature and solar radiation. About SO percent of the variations in concentrations are explained by these models. Several areas of further research are outlined.