21 research outputs found
Utilisation of trace element contents in benthic foraminifera for reconstructing sea water composition
Ausgewählte Spurenelemente wurden im Labor unter kontrollierten Umweltbedingungen in karbonatische Gehäuse benthischer Foraminiferen eingebaut. Die Konzentrationen aller verwandten Elemente wurden in neu gewachsenen Kammern mittels µ-Sy-RFA und LA-ICP-MS ermittelt. Die hieraus errechneten Verteilungskoeffizienten wurden zunächst für eine rezente Spezies, in einem zweiten Schritt dann für eine fossile Spezies benthischer Foraminiferen zur Rekonstruktion der Ozeanbedingungen angewandt
Anti-cyclonic eddy imprint on calcite geochemistry of several planktonic foraminiferal species in the Mozambique Channel
H5N1: Containing and Preventing Avian Flu in Vietnam
In a country with a poultry population over 385 million birds, controlling the Highly Pathogenetic Avian Influenza (HPAI) strain H5N1 in Vietnam is of global importance. Vietnam’s early polices of mass bird culling with no compensation had a higher socioeconomic impact on the nation’s poorer citizens who depend on poultry sales, leaving them without product to sell or the means to replace their flock that had been destroyed. This case study aims to explore the disproportionate impact on low-income residents of Vietnam in the wake of the nation’s response to H5N1 in 2004 , and highlights the evolution in bird culling as a result of the socioeconomic issues experienced by those dependent on poultry sales for survival. We discuss the viability of vaccination against H5N1 and the importance of the continued collaboration necessary to mitigate outbreaks of H5N1 and other infectious disease events of concern
Somewhere a voice tells my heart to rejoice, for it\u27s dreamtime, [first line]
Performers: Patrice MunselPiano, Voice and Chord
Evaluating Continuing Education Needs and Program Effectiveness Using a Survey of Virginia\u27s SHARP Logger Program Participants
Virginia\u27s SHARP logger program is a Cooperative Extension program currently providing training to over 1,500 loggers, foresters, and others. We conducted a mail survey of SHARP loggers to characterize program participants, assess programming needs, and evaluate program effectiveness. Results indicate a diverse group of participants in terms of education and occupation. Responses illustrated a need for diverse continuing education class topics and formats. Sixty-two percent of participants reported making changes to their operation as a result of attending SHARP logger trainings. The most commonly reported changes included improvements in safety and implementation of BMPs for water quality
Determination of trace element incorporation into tests of in vitro grown foraminifera by micro SYXRF - a basis for the development of paleoproxies
Incorporation of hydrothermal elements in foraminiferal calcite: Results from culturing experiments
The trace race element chemistry of foraminiferal tests reflect the environment in which they grew. Thus geochemical data can be used as paleo-proxies constraining environmental conditions in ancient seas [e.g.: 1]. Seawater chemistry may be influenced by local sources such as hydrothermal activity. However, for elements considered diagnostic for hydrothermalism, reliable experimental data is rare [e.g. 2]. To provide a solid basis for a more complete understanding of trace element partitioning between foraminiferal calcite and seawater, we carried out culture experiments under controlled laboratory conditions. This is the main objective of our study.For our experiment we grew freshly collected benthic foraminifera (Ammonia tepida) in seawater, containing a cocktail of Mn, Co, Ni and Cu, at defined trace element levels.Measurements of the culture solutions were carried out regularly by HR-ICP-MS whereas the calcite of newly grown chambers of the cultured foraminifera was detected by a non-destructive technique - µSy-XRF [3]. To confirm the data LA-ICP-MS measurements have been performed. To distinguish between old and new chambers the calcein labeling technique [4] was applied.First results demonstrate that especially Ni and Cu could be determined with high precission and accuracy using µSy-XRF measurements. We determined trace element/Ca ratios and DNi as well as DCu using LA ICP-MS
Heavy metal incorporation in foraminiferal calcite: results from multi-element enrichment culture experiments with Ammonia tepida
The incorporation of heavy metals into carbonate tests of the shallow water benthic foraminifer <i>Ammonia tepida</i> was investigated under controlled laboratory conditions. Temperature, salinity, and pH of the culture solutions were kept constant throughout the duration of this experiment, while trace metal concentrations were varied. Concentrations of Ni, Cu, and Mn were set 5-, 10-, and 20 times higher than levels found in natural North Sea water; for reference, a control experiment with pure filtered natural North Sea water was also analysed. The concentrations of Cu and Ni from newly grown chambers were determined by means of both μ-synchrotron XRF and Laser Ablation Inductively Coupled Plasma Mass Spectroscopy (LA-ICP-MS). The results of both independent analytical techniques agreed within the analytical uncertainty. In general, the concentration of the analysed elements in the tests increased in line with their concentration in the culture solutions. Potential toxic and/or chemical competition effects might have resulted in the decreased incorporation of Ni and Cu into the calcite of the specimens exposed to the highest elemental concentrations. Mn incorporation exhibited large variability in the experiment with the 20-fold increased element concentrations, potentially due to antagonistic effects with Cu. The partition coefficients of Cu and Ni were calculated to be 0.14 ± 0.02 and 1.0 ± 0.5, respectively, whereas the partition coefficient of Mn was estimated to be least 2.4. These partition coefficients now open the way for reconstructing past concentrations for these elements in sea water