Fluorescent Biological Aerosol Particles in Coastal Canada and the Link to Atmospheric Ice Nuclei

Bioaerosols are a subgroup of atmospheric aerosols and are often linked to the spread of human, animal and plant diseases. Bioaerosols also may play an indirect effect on environmental processes, including the formation of precipitation and alteration of the global climate through their role as nuclei for cloud droplet formation. Several types of biological organisms (e.g., fungi and bacteria) have been shown to be effective ice nuclei (IN) and cloud condensation nuclei (CCN). During 21 days in August 2013 we participated in a collaborative international campaign at a rural, coastal site near the village of Ucluelet on the west coast of Vancouver Island, British Columbia, Canada. The experiments were conducted as part of the NETCARE project (the NETwork on Climate and Aerosols: Addressing Key Uncertainties in Remote Canadian Environments), in part to examine cloud nuclei properties of marine aerosol. The study was conducted from a mobile trailer located approximately 100 m from the coast. A suite of aerosol instrumentation was operated for approximately one month. Key instruments utilized as a part of this thesis include the wideband integrated bioaerosol sensor (WIBS-4A) and the multiple orifice uniform deposition impactor (MOUDI) coupled with an off-line droplet freezing technique (DFT) for the measurement of ice nucleation activity of particles in immersion mode. The WIBS measures the concentration and properties of individual fluorescent particles suspended in the air, which can serve as a proxy for airborne biological particle content. Particles shown to be fluorescent by the WIBS instrument were divided into seven categories based on the pattern of fluorescence each particle exhibited in the three fluorescent channels. Results of the WIBS analysis show that the fluorescent particle concentration in the region correlated well with IN number. The fluorescent particle concentration correlated well with the number of particles shown to be ice active as a function of both particle size and freezing temperature. Correlations involving marine aerosols and marine biological activity indicate that the majority of IN measured at the coastal site likely are not from have marine sources.

La ruralidad del 15-M. Iniciativas desde el movimiento agroecológico alicantino

La principal imagen del movimiento 15-M viene simbolizada por las acampadas en las plazas de numerosas ciudades españolas, es decir, su apariencia urbana. No obstante, el derecho a la alimentación sana, el consumo responsable, el acceso a la tierra, la conservación de ecosistemas agrarios y la despoblación del medio rural han sido algunas de las temáticas debatidas en el seno del movimiento. Ello demuestra una sustancial preocupación por la cuestión tanto ambiental como agraria, para las cuales se reclaman alternativas desde una perspectiva propiamente rural. Como se pretende hacer ver en este artículo, en el seno del movimiento 15-M las cuestiones urbanas y rurales son indisociables. Entre ellas destaca la reivindicación de la soberanía alimentaria y de la agroecología como horizontes de una transformación en la organización del territorio. En este artículo se sintetizan los aspectos de ruralidad del movimiento 15-M y sus reivindicaciones de carácter social, ambiental y territorial. De manera particular, se consideran las características propias de iniciativas incipientes que se están llevando a cabo en la provincia de Alicante, en el sureste del Estado español, así como de sus interrelaciones con movimientos rurales en el ámbito regional, nacional e internacional.

(Table 2) Trace metal concentrations in ODP Hole 169-1033B

We measured the concentrations of redox-sensitive trace metals (Mn, V, Mo, U, Cd and Re) in sediments from ODP Leg 169S Hole 1033B in Saanich Inlet, British Columbia, to determine changes in redox conditions associated with the onset of laminated sediments at ~12.5 kyr. The most striking result is a large peak in authigenic Re along with detrital levels of Mo at the glacial terrigenous clay-diatomaceous sediment transition. In contrast, the underlying glacial terrigenous clay, which extends throughout the bottom section of the core, is chemically similar to detrital concentrations, either Cowichan River particulates or average shale values. These data suggest a period of oxic bottom waters but reducing pore-waters. This could be due to the dramatic transformation of Saanich Inlet during the late deglaciation from an open bay to an inlet, which restricted circulation and slowed bottom water oxygen renewal. A peak and gradual increase in authigenic Mn in younger sediments subsequent to the Re peak suggests that increasingly oxic conditions followed the authigenic enrichment in Re. These conditions could be connected to the Younger Dryas cooling period, which was coincident with an increase in well oxygenated upwelled waters on the west coast of North America that form the bottom waters of Saanich Inlet. Metal concentrations in a gray clay bed (~11 kyr) are similar to their concentrations in the glacial terrigenous clay, implying that they have a common source. Authigenic enrichments of Re with little authigenic Mo and Cd suggest that before the deposition of this bed, bottom waters were oxic and pore-water oxygen was consumed in the top centimeter or less. Laminations above the clay layer suggest anoxic conditions, which are also indicated by higher authigenic Mo and Cd and slightly lower Re/Mo ratios in these sediments. The basin remained mostly anoxic after the gray clay was emplaced, as seen by continuous authigenic enrichment of the redox-sensitive trace metals. These results are consistent with increased stratification of the water column, brought about by an influx of fresh water to the basin by a large flood.

Total organic carbon, metal concentrations and metal and aluminium ratios in bulk sediment from the ODP sample 169-1033B-4H-4,54-74

Holocene laminated sediments in Saanich Inlet, British Columbia, are interrupted by frequent, non-laminated, massive layers. These layers may be debris flows released by earthquakes or bioturbated sediments deposited during periods of relatively high bottom water oxygen concentration and/or low surface productivity, or both. We determined the organic carbon content and the concentration of a suite of redox-sensitive metals in bulk sediments at approximately 1-cm resolution across a laminated-massive-laminated interval (ODP Leg 169S Sample 1033B-4H-4,54-74), to determine the redox conditions under which the massive layer was deposited. Our results indicate that this massive interval was deposited under anoxic bottom waters. Manganese/Al ratios are consistently low throughout the massive section, while Mo/Al, Cd/Al, Re/Al, and U/Al ratios are enriched relative to their metal/Al ratios in detrital material (represented by Cowichan River suspended sediments). The concentration of organic carbon in the lower portion of the massive layer is higher than in the upper portion, which has a concentration similar to that in the overlying and underlying laminated sediments. Well-defined peaks in Mo/Al, Cd/Al, and Re/Al and a broad peak in U/Al occur in the lower portion of the massive layer. The positions of the Cd/Al, Re/Al, and Mo/Al peaks, as well as the increase in organic carbon content with depth in the massive layer, are best explained by a process of diagenetic redistribution of metals that occurred after the massive layer was emplaced.

Debate on the subject of confederation with Canada.

"Reprinted from the Government Gazette Extraordinary of March, 1870."to 1870."

Estimates of revenue and expenditure.

Report year ends Mar. 31.

Western clarion.

Description based on: No. 535 (July 10, 1909).

Geology and ore-deposits of Rossland, B.C. /

Vita.

The works of Hubert Howe Bancroft.

For discussion of authorship and authors see Quarterly of the Oregon historical society, v. 4 (1903) p. 287-364.

Annual report.

The reports cover both the proceedings of the annual meeting, held in January, and the report for the preceding calendar year.

Report.

Report year ends Dec. 31.

The story of the Canadian people /

Includes index.

A pioneer, 1851.

Mode of access: Internet.

The Scotsman in Canada.

v. 1. Eastern Canada, including Nova Scotia, Prince Edward island, New Brunswick, Quebec and Ontario, by Wilfred Campbell.--v. 2. Western Canada, including Manitoba, Saskatchewan, Alberta, British Columbia, and portions of old Rupert's land and the Indian territories, by George Bryce.

Who's who in the West.

Imprint varies: New Providence, N.J. <2000/2001->