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Effects of polychlorinated biphenyls (PCBs) on the respiration of the speckled sanddab (Citharichthys stigmaeus)Haines, Virginia Ewald 11 June 1975 (has links)
Specimens of Citharichthys stigmaeus, the speckled sanddab,
were taken from Yaquina Bay, Newport, Oregon and exposed for
eight days to dissolved measured concentrations ranging from 2.9
μg/l to 190 μg/1 of the polychlorinated biphenyl, Aroclor® 1260.
Oxygen consumption was measured to determine any change from
routine levels of respiration. This research produced the following
conclusions: 1) a relationship exists between oxygen consumption and
measured concentrations of Aroclor® 1260 in the water as demonstrated
by high negative partial correlations and subsequent significant
water concentration terms in the regression equations for two of
the four experiments: also, a relationship exists between oxygen
consumption and tissue concentration of Aroclor® 1260 as demonstrated
by high negative partial correlations and subsequent significant
tissue concentration terms in the regression equations for
three out of four experiments, (because of the inherent variability
in oxygen consumption measurements and difficulties of predicting
PCB concentrations in both water and tissue, the evidence is difficult
to interprete); 2) acetone, used as a solvent for the toxicant, may
change oxygen consumption levels and interfere with determining PCB
effects; 3) after an eight day dosing period the concentration of
Aroclor® 1260 in whole body tissue can be described by the equation:
Y = 4.48(1 - e [superscript -.0365x])
where Y is the concentration of Aroclor® 1260 in the tissue and x is
the measured Aroclor® concentration in the water; 4) after eight days
a constant level of Aroclor® 1260 is present in the tissue if the
animal is exposed to water levels of Aroclor® 1260 above
approximately 25 μg/1. / Graduation date: 1976
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The distribution and role of "available" iron in two estuariesHolden, Robert Bennett 09 May 1975 (has links)
A detailed study of iron concentrations measured by the reducible,
reactive ferrous, and extractable methods was conducted in Auke Bay,
Alaska during June 1973 and in Hood Canal, Washington during October
1973 and April 1974. The concentrations by each method were generally
highest at the bottom and decreased towards the surface with
occasional pockets of high iron concentration water at the surface.
In Hood Canal in October the maximum reactive ferrous iron concentration was observed at the bottom of the pycnocline. Large changes
in the iron concentration were observed between successive surveys.
The reducible iron method (range <0.8 to 187 μg Fe/L) measures colloidal
ferric hydroxide plus easily dissolvable and reducible organically
and inorganically bound iron. The reactive ferrous iron method
(range <0.04 to 4.2 μg Fe/L) measures loosely bound organic and
inorganic ferrous iron. The extractable iron method, as finally used,
(range <4 to 170 μg Fe/L) measures that iron measured by reducible iron method plus up to twice the tightly bound organic iron.
We have defined "available" iron (with quotes) as that iron
which appears to be taken up by phytoplankton as determined by the
correlation between the in situ iron concentration and the chlorophyll
a concentration. Chlorophyll a concentration maxima generally
occurred at the depth of the iron concentration minima, strongly
supporting the idea that each method measures "available" iron.
However, significant correlation coefficients for the regression of
iron concentration versus chlorophyll a only support the "availability"
of reactive ferrous iron and that phytoplankton prefer ferrous iron to
ferric iron.
This was one of the first extensive uses of Lewin and Chen's
(1973) ferrous iron method and values observed were generally 2 to
100 times less than they reported. Changes occurring during water
storage appear to be a function of p0₂. Major changes took place
during the first five hours of storage. Interstitial water was greatly
enriched in iron compared with the overlying water. The ferrous
iron concentration was particularly high due to the low Eh of the
sediments. Although the net flow of "available" iron is out of the
sediment, the flux is small (approximately 3 x 10⁻⁵ μg Fe/m²sec).
Most of the iron that appears to be coming from the sediment is
probably being produced by bacterial decomposition as in the case
of subsurface sources of iron associated with ammonia or urea maxima. Fresh water is a significant source of extractable and
reactive ferrous iron into the well-mixed surface layer. Fresh
water is also a source of organically bound iron. Zooplankton appear
to produce "available" iron by eating or excretion. Light appears
to cause the production of ferrous iron through an undetermined
mechanism. / Graduation date: 1976
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Purification and characterization of recombinant calpain-5Wang, Mei-Chuan 29 October 2003 (has links)
Recombinant human calpain-5 was expressed in insect cells using a baculovirus
system. The expressed calpain-5 was purified by both traditional chromatography and
by affinity-column chromatography. Both methods yielded active protease. Calpain-5
displayed very limited hydrophobicity. This indicated that calpain-5 is not a membrane
binding protein. Calpain-5 had pI of 8.3. The recombinant calpain-5 also exhibited
calcium-dependent proteolytic activity. The calculated calcium requirement for half-maximal
activity was 9.6 mM when incubated at 37��C and 26.5 mM when incubated at
30��C. Compared to traditional calpains, which require less than 1 mM calcium for half-maximal
activity, calpain-5 exhibited weaker proteolytic activity. This is an unusual
observation because calpain-5 lacks the typical calcium-binding domain of the calpains
and implied that other calcium-binding region of the protein account for calcium-binding
and sensitivity. Our results also showed that calpain-5 was different from
traditional calpains because its activity was higher at 37��C compared to 30��C and
remained active at 37��C for more than 2 hours. This differs from traditional calpains
which display better proteolytic activity at lower temperatures and become inactive
within 30 minutes of incubation in 37��C. Calpain-specific inhibitors, calpastatin and
E64, did not inhibit calpain-5. Only one calcium-binding inhibitor, PD150606, inhibited
calpain-5 proteolytic activity. These results confirmed that calpain's calcium-binding
domain is important in calpastatin binding and calpain-5 possesses other calcium-binding
regions. Calpain-5 was able to degrade spectrin, a ubiquitous cytoskeletal
protein. This indicates that calpain-5 might have a role in cell remodeling. Finally,
calpain-5 has the ability to degrade itself. It is not clear if this is the result of inter- or
intra-molecular proteolysis and whether this leads to activation of the protein or is,
instead, the first step in its degradation. Calpain-5 is expressed at highest concentrations
in testis, brain, liver and gastrointestinal tract. It is not clear why these tissues require a
unique calpain. Calpain-5 may provide these tissues with an additional calcium-dependent
proteolytic activity which is not regulated by calpastatin and which could
participate in cytoskeletal protein turnover. / Graduation date: 2004
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Purine nucleotide-induced seizures in rat prepiriform cortexZhao, Xiaoqin S. 20 December 1994 (has links)
Graduation date: 1995
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Intravenous closed-loop glucose control in type I diabetic patients28 August 2008 (has links)
Not available
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Comparing the effects of different whole-body vibration intensities on vertical jump performanceBazett-Jones, David M. 03 June 2011 (has links)
Whole-body vibration (WBV) has been shown to enhance vertical jump performance. The purpose of this study was to determine which WBV intensity has the greatest effect on counter movement jump (CMJ) height and the duration of that affect. Forty-four participants, of varying training statuses, were tested. They participated in > 4 familiarization sessions, to eliminate learning effects. Participants performed a pre-test, followed randomly by one of 5 WBV intensities. Participants performed 3 maximal CMJs immediately, 5, and 10 min following treatment. The best performance was used and calculated as a percentage of the pre-treatment values. A multivariate model (treatment X time X gender) was used to analyze the data. The three-way interaction approached significance (p=0.053) and significance was found for all two way interactions. Females performed the best immediately following the 2.71g treatment (116.9 + 38.4%). Male participants did not increase their performance; however, they may require longer durations of vibration exposure to elicit effects. The differences between males and females may also indicate that the effects of WBV are dependent on strength, stiffness, and/or training levels. Future research should continue to systematically investigate the effects of vibration and participant characteristics on WBV and performance.Keywords: power, frequency, amplitude, training, potentiation, stiffness. / School of Physical Education, Sport, and Exercise Science
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The effect of silver diammine fluoride on tooth tissueLou, Yali., 娄雅俐. January 2009 (has links)
published_or_final_version / Dentistry / Doctoral / Doctor of Philosophy
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Effects of silver diammine fluoride on microtensile bond strength of GIC to dentinWang, Shuhua, Angelina, 汪淑华 January 2013 (has links)
published_or_final_version / Dental Materials Science / Master / Master of Science in Dental Materials Science
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Heroin use and neuropsychological functionsPau, Wai-ho, Charles. January 1998 (has links)
published_or_final_version / abstract / toc / Clinical Psychology / Master / Master of Social Sciences
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BIOLOGICAL EFFECTS OF IONIZED AIRSmith, Richard Furnald, 1922- January 1962 (has links)
No description available.
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