100 resultados para McCorkle, Tegan
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Anthropogenic ocean acidification is likely to have negative effects on marine calcifying organisms, such as shelled pteropods, by promoting dissolution of aragonite shells. Study of shell dissolution requires an accurate and sensitive method for assessing shell damage. Shell dissolution was induced through incubations in CO2 enriched seawater for between 4 and 14 days. We describe a procedure that allows the level of dissolution to be assessed and classified into three main types: Type I with partial dissolution of the prismatic layer; Type II with exposure of underlying crossed-lamellar layer, and Type III, where crossed-lamellar layer shows signs of dissolution. Levels of dissolution showed a good correspondence to the incubation conditions, with the most severe damage found in specimens held for 14 d in undersaturated condition (Ohm ~ 0.8). This methodology enables the response of small pelagic calcifiers to acidified conditions to be detected at an early stage, thus making pteropods a valuable bioindicator of future ocean acidification.
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We have developed sampling methods and an analytical system to determine the concentration of dissolved organic C (DOC) in marine pore waters. Our analytical approach is a modification of recently developed high-temperature, Pt-catalyzed oxidation methods; it uses Chromatographic trapping of the DOC-derived CO2 followed by reduction to CH4 and flame ionization detection. Sampling experiments with nearshore sediments indicate that pore-water separation by whole-core squeezing causes artificially elevated DOC concentrations, while pore-water recovery by sectioning and centrifugation does not appear to introduce DOC artifacts. Results from a set of northwestern Atlantic continental slope cores suggest that net DOC production accounts for >50% of the organic C that is recycled at the sediment-water interface.
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Maura Hawkins, Kate Hanson, Wendy Bigler, Tegan McCorkel, Patricia Good, Coach Sue LeClair, Erica Zonder, Tiffany McCorkel, Jenny Boring, Kirsten Woodson, Jenny Zimmerman, Carrie Nosanchuk,
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head coach Sue LeClair, Maura Hawkins, Kate Hanson, Tegan McCorkel, Shannon McDonald, Tiffany McCorkel, Wendy Bigler, Carrie Nosanchuk, Jenny Zimmerman,
Not pictured: Patricia Good.
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Front Row: Tegan McCorkel, Tiffany McCorkel,
Middle Row: Molly Vandenbark, Jenny Zimmerman, Wendy Westfall
Back Row: Coach Kathy Teichert, Kate Hanson, Shannon McDonald, Ashley Williams, Jodi Smith
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Mode of access: Internet.
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Mode of access: Internet.
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A collection of miscellaneous pamphlets on religion.
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Mode of access: Internet.
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Hookworms feed on blood, but the mechanism by which they lyse ingested erythrocytes is unknown. Here we show that Ancylostoma caninum, the common dog hookworm, expresses a detergent soluble, haemolytic factor. Activity was identified in both adult and larval stages, was heat-stable and unaffected by the addition of protease inhibitors, metal ions, chelators and reducing agents. Trypsin ablated lysis indicating that the haemolysin is a protein. A closely migrating doublet of hookworm proteins with apparent molecular weights of 60-65 kDa bound to the erythrocyte membrane after lysis of cells using both unlabeled and biotinylated detergent-solubilised hookworm extracts. In addition, separation of detergent-soluble parasite extracts using strong cation-exchange chromatography, resulted in purification of 60-65 kDa proteins with trypsin-sensitive haemolytic activity. Erythrocytes lysed with particulate, buffer-insoluble worm extracts were observed using scanning electron microscopy and appeared as red cell ghosts with approximately 100 nm diameter pores formed in the cell membranes. Red blood cell ghosts remained visible indicating that lysis was likely caused by pore formation and followed by osmotic disruption of the cell. (C) 2004 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.
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This study presents tympanometric normative data for Australian children at school entry in view of the lack of age-specific population-based data for this group. Participants were 327 children (164 boys, 163 girls) aged between 5 and 6 years, who had no history of middle ear infection, and passed pure-tone screening at 20 dB HL. Normative values for static admittance (SA), ear canal volume (ECV), tympanometric peak pressure, tympanometric width (TW) and tympanometric gradient were established. Based on these normative data, the use of the ASHA (1997) guidelines for medical referral, in which ECV > 1.0 ml in the presence of a flat tympanogram, SA < 0.3 ml, or TW > 200 daPa may not provide the best criteria for Australian children aged between 5 and 6 years. If SA < 0.3 ml were used instead of SA < 0.16 ml, a greater proportion of Australian children would have failed tympanometry, thus increasing the false alarm rate.
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The present study compared the ability of school-aged children with and without a history of otitis media (OM) to understand everyday speech in noise using the University of Queensland Understanding of Everyday Speech Test (UQUEST). Participants were 484 children (246 boys, 238 girls) attending Grade 3 (272, mean age = 8.25 yr., SD = 0.43) and Grade 4 (212, mean age = 9.28 yr., SD = 0.41) at 19 primary schools in Brisbane metropolitan and Sunshine Coast schools. Children selected for inclusion were native speakers of English with normal hearing on the day of testing and had no reported physical or behavioral impairments. The children were divided into three groups according to the number of episodes of OM since birth. The results showed no significant differences in speech scores across the participant groups. However, a significant difference in mean speech scores was found across the grades and the noise conditions. Although children with a history of OM performed equally well at a group level when compared to the controls, they exhibited a large range of abilities in speech comprehension within the same group.