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91.
92.
Carl M. Way Albert J. Burky Juliana M. Harding Skippy Hau William K.L.C. Puleloa 《Environmental Biology of Fishes》1998,51(1):53-65
Constant pressure in Hawai'i to use limited freshwater resources has resulted in increasing concern for the future of the
native stream fauna. Hawaiian freshwater gobies have an amphidromous life cycle with a marine larva period and require streams
which flow continuously to the ocean for the critical reproductive periods and during recruitment. As such, the stream fauna
is particularly sensitive to any anthropogenic perturbations which disrupt the continuity of stream flows. The objective of
this 2-year study was to compare the life cycles of the goby, Lentipes concolor, from a heavily diverted stream on Moloka'i
and a relatively undisturbed stream on Maui. In Makamaka'ole Stream, Maui, the population of L. concolor was reproductively
active all year with females potentially spawning 2–3 times annually. The timing of spawning did not occur consistently during
the wet or dry season but coincided with high stream flow conditions regardless of time-of-year. In Waikolu Stream, Moloka'i,
the reproductive pattern was more variable with the number of reproductively active females ranging from 0% to 100%. In general
the number of eggs was greater and egg size smaller for female L. concolor in Waikolu Stream than in Makamaka'ole Stream.
However, female reproductive condition of L. concolor from Maui was consistently higher than from fish on Moloka'i. Reproduction
of L. concolor in Makamaka'ole Stream was correlated with the seasonal pattern of flow rates with peaks in female reproductive
condition associated with periods of elevated discharge. No correlation between reproduction and discharge occurred in Waikolu
Stream. There were considerable differences between the magnitude of discharge in the two streams. Waikolu Stream experienced
prolonged periods of extremely low flows which have become common since the Moloka'i Irrigation System began diverting water
from the stream in 1960. In Makamaka'ole Stream, L. concolor was capable of reproducing throughout the year and adjusting
fecundity in response to stream flow conditions. In contrast, the population in Waikolu Stream appeared to have a ‘boom or
bust’ reproductive pattern; the population had reduced or no reproduction when stream flow conditions reached extreme low
levels, but the population succesfully reproduced during higher flow months. The diversion structure in Waikolu Stream has
dampened the natural seasonal discharge cycle, exacerbated natural low flow conditions, and increased the likelihood of prolonged
periods of extremely low flow. Stream management practices in the Hawaiian Islands must take into account the complex life
cycles and sensitivity to variable stream flow conditions of the native fauna.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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94.
Karsten Schnatbaum Victor Solis‐Mezarino Daniil Pokrovsky Frederike Schfer Dennis Nagl Lars Hornberger Johannes Zerweck Tobias Knaute Julia Avramova‐Nehmer Mike Schutkowski Veit Hornung Holger Wenschuh Moritz Carl Vlker‐Albert Axel Imhof Ulf Reimer 《Proteomics》2020,20(10)
Targeted proteomics depends on the availability of stable isotope labeled (SIL) peptide standards, which for absolute protein quantification need to be absolutely quantified. In the present study, three new approaches for absolute quantification of SIL peptides are developed. All approaches rely on a quantification tag (Qtag) with a specific UV absorption. The Qtag is attached to the peptide during synthesis and is removed by tryptic digestion under standard proteomics workflow conditions. While one quantification method (method A) is designed to allow the fast and economic production of absolutely quantified SIL peptides, two other methods (methods B and C) are developed to enable the straightforward re‐quantification of SIL peptides after reconstitution to control and monitor known problems related to peptide solubility, precipitation, and adhesion to vials. All methods yield consistent results when compared to each other and when compared to quantification by amino acid analysis. The precise quantitation methods are used to characterize the in vivo specificity of the H3 specific histone methyltransferase EZH2. 相似文献
95.
96.
Tzaban S Friedlander G Schonberger O Horonchik L Yedidia Y Shaked G Gabizon R Taraboulos A 《Biochemistry》2002,41(42):12868-12875
The pathological prion protein PrP(Sc) is the only known component of the infectious prion. In cells infected with prions, PrP(Sc) is formed posttranslationally by the refolding of the benign cell surface glycoprotein PrP(C) into an aberrant conformation. The two PrP isoforms possess very different properties, as PrP(Sc) has a protease-resistant core, forms very large amyloidic aggregates in detergents, and is only weakly immunoreactive in its native form. We now show that prion-infected rodent brains and cultured cells contain previously unrecognized protease-sensitive PrP(Sc) varieties. In both ionic (Sarkosyl) and nonionic (n-octyl beta-D-glucopyranoside) detergents, the novel protease-sensitive PrP(Sc) species formed aggregates as small as 600 kDa, as measured by gel filtration. The denaturation dependence of PrP(Sc) immunoreactivity correlated with the size of the aggregate. The small PrP(Sc) aggregates described here are consistent with the previous demonstration of scrapie infectivity in brain fractions with a sedimentation coefficient as small as 40 S [Prusiner et al. (1980) J. Neurochem. 35, 574-582]. Our results demonstrate for the first time that prion-infected tissues contain protease-sensitive PrP(Sc) molecules that form low MW aggregates. Whether these new PrP(Sc) species play a role in the biogenesis or the pathogenesis of prions remains to be established. 相似文献
97.
The apex of a 3-leaf pea plant was chilled in cold chambers maintained at 5–7°C. The lateral shoots 1 through 5 grew, and shoot 5 eventually dominated other lateral shoots. The apex when returned to the ambient temperature did not reimpose apical dominance. The growing lateral shoots competed with the stem apex. The apices of 2- and 3-leaf plants were chilled and P-32 distribution in these plants was studied in the entire plant, at various intervals of time. Phosphorus-32 accumulation followed the growth pattern of the plant. The lateral shoots accumulated P-32 activity and very little activity was accumulated by the apex. The dominating shoots 2 and 5 accumulated the maximum amount of activity in 2- and 3-leaf plants, respectively. Labeled-IAA moved basipetally through the stem when applied to the cut stump simulating the apex. By cold treatment the translocation of IAA was influenced more than its absorption. The plant seems to metabolize this compound in the later periods of application. The plant now becomes “insensitive” to auxin and the lateral shoots grow. 相似文献
98.
99.
100.
Torres-Guardado Rafael Esteve-Zarzoso Braulio Reguant Cristina Bordons Albert 《International microbiology》2022,25(1):1-15
International Microbiology - This review examines the different types of interactions between the microorganisms involved in the fermentation processes of alcoholic beverages produced all over the... 相似文献