A Sixteen Thousand Year Old Organic Deposit, Northern Baffin Island, N.W.T., Canada: Palynology and Significance

A 3 m exposure of sediment containing organics was sampled near the settlement of Arctic Bay, Baffin Island, N.W.T. A total of seven radiocarbon dates have been obtained from the deposit. Three dates between 182.5 and 290 cm depth gave radiocarbon ages between 14,185 ± 760 and 16,849 ± 860. A date from 82.5 to 87.5 cm resulted in an age of 8635 ± 565. An apparent reversal in 14C dates may reflect folding of the sediments associated with the downslope creep of the deposit or rapid accumulation of organics. The three basal dates are the first terrestrial sediments from Baffin Island to date from older than ca. 10,000 BP and less than 20,000 BP. Analysis of the sediment for pollen indicated that it is generally sparse. The pollen assemblage is dominated by Salix, Cyperaceae, and Gramineae pollen and exotic pollen types {Pinus, Picea, Betula, and Alnus) occur sporadically throughout the section.Dans les Territoires du Nord-Ouest, près de la localité de Arctic Bay, dans l'île de Baffin, on a échantillonné une coupe de 3 m effectuée dans des sédiments renfermant des matériaux organiques. On en a tiré sept datations au radiocarbone. Entre 182,5 et 290 cm, trois datations font remonter les sédiments entre 14 185 ± 760 et 16 849 ± 860. Entre 82,5 et de 87,5 cm, la datation les fait remonter à 8635 ± 565. L'inversion apparente des dates au 14C pourrait indiquer qu'un plissement des sédiments s'est associé au glissement du dépôt ou à l'accumulation rapide de sédiments organiques. Les trois datations effectuées à la base de la coupe représentent les premiers sédiments terrestres de l'île de Baffin à remonter avant 10 000 BP, soit entre 10 000 et 20 000 BP. L'analyse pollinique des sédiments a révélé que le pollen y est plutôt rare. L'assemblage pollinique est dominé par les pollens de Salix, de cyperacées et de graminés ; quelques types de pollens exotiques (Pinus, Picea, Betula, et Alnus) apparaissent de façon sporadique dans toute la coupe.In der Nàhe der Siedlung Arctic Bay, Baffin-lnsel, Nord-West-Territorien, wurden Sediment-Proben, die Organisches Material enthalten, aus einem 3 m tiefen Schnitt entnommen. Insgesamt konnten sieben Radiokarbon-Daten aus dieser Ablagerung gewonnen werden. Zwischen 182.5 und 290 cm Tiefe ergaben drei Datierungen Radiokarbon-Alter zwischen 14 185 ± 760 und 16 849 ± 860. Zwischen 82,5 bis 87,5 cm fùhrte die Datierung zu einem Alter von 8635 ± 565. Eine offenbare Umkehrung in den 14C Datierungen mag wohl das Résultat einer Faltung der Sedimente sein in Verbindung mit einem Herunterrutschen der Ablagerung oder einer raschen Anhàufung organischen Materials. Die drei Datierungen von der Basis des Schnitts sind die ersten Erd-Sedimente von der Baffin-lnsel, die als alter als ca. 10 000 v.u.Z. zu datierne sind und weniger als 20 000 v.u.Z. Die Analyse des Sediments in Bezug auf Pollen zeight, da(3 dieser im allgemeinen spârlich ist. Die Pollen-Ansammlung ist beherrscht von Salix-, Cyperaceae- und Gramineae-Pollen und exotische Pollen-Typen (Pinus, Picea, Betula und Alnus) finden sich sporadisch in dem Schnitt

Groundwater and Intergovernmental Relations in the Southern San Joaquin Valley, California

25 pages (includes maps)

Comment on 'Non-equilibrium thermodynamics of light absorption'

A recent paper by Meszéna and Westerhoff (1999 J. Phys. A: Math. Gen. 32 301) has aimed to address what is referred to as a principal question of biological thermodynamics, the possibility of describing photosynthesis in terms of non-equilibrium thermodynamics. The issue is associated with a misrepresentation of the fundamental photophysics involved, and as a result the analysis is invalid

Population Genetic Structuring in Opisthorchis viverrini over Various Spatial Scales in Thailand and Lao PDR

Khon Kaen Province in northeast Thailand is known as a hot spot for opisthorchiasis in Southeast Asia. Preliminary allozyme and mitochondrial DNA haplotype data from within one endemic district in this Province (Ban Phai), indicated substantial genetic variability within Opisthorchis viverrini. Here, we used microsatellite DNA analyses to examine the genetic diversity and population structure of O. viverrini from four geographically close localities in Khon Kaen Province. Genotyping based on 12 microsatellite loci yielded a mean number of alleles per locus that ranged from 2.83 to 3.7 with an expected heterozygosity in Hardy-Weinberg equilibrium of 0.44-0.56. Assessment of population structure by pairwise F(ST) analysis showed inter-population differentiation (P<0.05) which indicates population substructuring between these localities. Unique alleles were found in three of four localities with the highest number observed per locality being three. Our results highlight the existence of genetic diversity and population substructuring in O. viverrini over a small spatial scale which is similar to that found at a larger scale. This provides the basis for the investigation of the role of parasite genetic diversity and differentiation in transmission dynamics and control of O. viverrini

Structural and elastic characterization of Cu-implanted SiO₂ films on Si(100) substrates

Cu-implanted SiO₂ films on Si(100) have been studied and compared to unimplanted SiO₂ on Si(100) using x-ray methods, transmission electron microscopy, Rutherford backscattering, and Brillouin spectroscopy. The x-ray results indicate the preferred orientation of Cu {111} planes parallel to the Si substrate surface without any directional orientation for Cu-implanted SiO₂∕Si(100) and for Cu-implanted and annealedSiO₂∕Si(100). In the latter case, transmission electron microscopy reveals the presence of spherical nanocrystallites with an average size of ∼2.5 nm. Rutherford backscattering shows that these crystallites (and the Cu in the as-implanted film) are largely confined to depths of 0.4−1.2 μm below the film surface. Brillouin spectra contain peaks due to surface, film-guided and bulk acoustic modes. Surface (longitudinal) acoustic wave velocities for the implanted films were ∼7% lower (∼2% higher) than for unimplanted SiO₂∕Si(100). Elastic constants were estimated from the acoustic wave velocities and film densities. C₁₁ (C₄₄) for the implanted films was ∼10% higher (lower) than that for the unimplanted film. The differences in acoustic velocities and elastic moduli are ascribed to implantation-induced compaction and/or the presence of Cu in the SiO₂ film.B.J. and M.C.R. are grateful for financial support from the Australian Synchrotron Research Program, funded by the Commonwealth of Australia. M.C.R. would also like to thank the Australian Research Council for their financial support. The financial support of the Natural Sciences and Engineering Research Council of Canada NSERC is gratefully acknowledged by G.T.A. and J.S

Identifying the development in phase and amplitude of dipole and multipole radiation

The spatial variation in phase and the propagating wave-front of plane wave electromagnetic radiation are widely familiar text-book territory. In contrast, the developing amplitude and phase of radiation emitted by a dipole or multipole source generally receive less attention, despite the prevalence of these systems. There is additional complexity in such cases where, in consequence of retardation, the character and features significantly and progressively change as radiation propagates onwards, from the near-field and out towards the wave-zone. Readily developed analytical representations of the electric field, cast as a function of distance from the source, provide illuminating insights into the most prominent and distinctive properties of radiant electromagnetic emission. Graphical implementations and animations of the results prove particularly instructive in revealing the spatial form and temporal evolution of the emergent electromagnetic fields

First order phase transition in the quark matter

We investigate chiral phase transition of the first order in the quark matter. Using the Nambu-Jona-Lasinio model, an equation of state of the quark matter which is similar to the van der Waals' one is obtained. Moreover the specific heat and the compressibility are calculated. It is shown that they are enhanced in the symmetry broken phase, in particular diverge near the tricritical point.Comment: 6 pages, 7 figure