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41.
Neuza Domingues André R. A. Marques Rita Diogo Almeida Calado Inês S. Ferreira Cristiano Ramos José Ramalho Maria I. L. Soares Telmo Pereira Luís Oliveira José R. Vicente Louise H. Wong Inês C. M. Simões Teresa M. V. D. Pinho e Melo Andrew Peden Cláudia Guimas Almeida Clare E. Futter Rosa Puertollano Winchil L. C. Vaz Otília V. Vieira 《Traffic (Copenhagen, Denmark)》2023,24(7):284-307
42.
Bruce C. Chessman Martin L. Dillon Darren P. Fielder Philip H. Spark Louise M. Streeting 《Austral ecology》2023,48(8):1588-1602
The extreme longevity of turtles and tortoises can make it difficult to determine the conservation status of their populations because high annual adult survival may mask gradual attrition due to low levels of recruitment. When long-term demographic trends are unknown and available data are insufficient for population modelling, it may be assumed that a scarcity of juveniles indicates low recruitment that will result in population ageing and numerical decline. However, the reliability with which the proportion of juveniles foreshadows demographic change is uncertain. We tested the hypothesis that a low proportion of juveniles in a turtle population presages its ageing by analysing over 20 years of survey data for five discrete populations of the Australian western saw-shelled turtle (Myuchelys bellii: Chelidae), a listed threatened species. The analysis tested whether the initial proportion of juvenile turtles in each population was related to its temporal trend in average body size. The five populations had varied structure and trends, with the initial proportion of juvenile turtles ranging from 10% to 39% and average body size increasing over time in some populations and decreasing in others. Contrary to expectation, the initial proportion of juveniles was unrelated to the trend in average body size and, by inference, average age, indicating that effective trend forecasting requires more detailed demographic information than merely population structure. 相似文献
43.
Transgenic mice carrying the 3-hydroxy-3-methylglutarylCoA reductase (HMG) promoter driving theEscherichia coli -galactosidase (lacZ) gene did not display the expected ubiquitous and constitutive expression inHMG-lacZ transgenic mice. The same promoter is however able to drive ubiquitous expression of the chloramphenicol acetyltransferase (cat) gene. Two lines of doubleHMG-lacZ andHMG-cat transgenic mice were obtained in which the two constructs were integrated at the same genomic sites. These mice expressed both reporter genes, but exclusively in the testes. These results suggest that thelacZ sequence might interfere negatively with the expression of the adjacentHMG-cat transgene. 相似文献
44.
Yu-Sen Wang Anne F. Frederick Mary M. Senior Barbara A. Lyons Stuart Black Paul Kirschmeier Louise M. Perkins Oswald Wilson 《Journal of biomolecular NMR》1996,7(2):89-98
Summary The growth factor receptor-bound protein-2 (Grb2) is an adaptor protein that mediates signal transduction pathways. Chemical shift assignments were obtained for the SH2 domain of Grb2 by heteronuclear NMR spectroscopy, employing the uniformly 13C-/15N-enriched protein as well as the protein containing selectively 15N-enriched amino acids. Using the Chemical Shift Index (CSI) method, the chemical shift indices of four nuclei, 1H, 13C, 13C and 13CO, were used to derive the secondary structure of the protein. Nuclear Overhauser enhancements (NOEs) were then employed to confirm the secondary structure. The CSI results were compared to the secondary structural elements predicted for the Grb2 SH2 domain from a sequence alignment [Lee et al. (1994) Structure, 2, 423–438]. The core structure of the SH2 domain contains an antiparallel -sheet and two -helices. In general, the secondary structural elements determined from the CSI method agree well with those predicted from the sequence alignment.Abbreviations crk
viral p47gag-crk
- EGF
epidermal growth factor
- GAP
GTPase-activating protein
- PI3K
phosphatidylinositol-3-kinase
- PLC-
phospholipase-C-, shc, src homologous and collagen
- src
sarcoma family of nonreceptor tyrosine kinase 相似文献
45.
Michael E. Pacold Fred J. Stevens Dong Li Louise E. Anderson 《Photosynthesis research》1995,43(2):125-130
Light activation of NADP-linked glyceraldehyde-3-P dehydrogenase involves reductive cleavage of a disulfide bond. We have proposed that the inactivating disulfide locks the two domains of the enzyme, preventing catalysis, and we have tentatively identified the two critical cysteine residues in the chloroplast enzyme (D. Li, F.J. Stevens, M. Schiffer and L.E. Anderson (1994) Biophys J. 67: 29–35). We reasoned that if activation of this enzyme involves these cysteines that enzymes lacking one or both should be active in the dark and insensitive to reductants. One of these cysteines is present in the enzymes from Anabaena variabilis and Synechocystis PCC 6803 but the other is not. Consistent with the proposed mechanism, glyceraldehyde-3-P dehydrogenase is not affected by DTT-treatment in extracts of either of these cyanobacteria. Fructosebisphosphatase is DTT-activated in extracts of both of these cyanobacteria and glucose-6-P dehydrogenase is inactivated in Synechocystis, as in higher plant chloroplasts. Apparently reductive modulation is possible in these cyanobacteria but glyceraldehyde-3-P dehydrogenase is not light activated. 相似文献
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49.
Louise A. Lewis 《Journal of phycology》1997,33(2):279-285
Sequence data from the nuclear small-subunit ribosomal RNA gene was obtained for nine strains of Bracteacoccus Tereg, representing at least five morphological species and four distinct geographic locations. These, along with sequence data from two additional chlorophycean taxa, Spongiochloris spongiosa Starr and Ascochloris multinucleata Bold et MacEntee, and 48 published sequences from green algal taxa, were used to determine the phylogenetic placement of Bracteacoccus with respect to other chlorophycean green algae. Results support the monophyly of Bracteacoccus strains, contrasting with patterns observed so far for many other coccoid green algae. The range of variation among Bracteacoccus strains is similar to that of other congeners. Basal body orientation in Bracteacoccus has been interpreted as clockwise; however, the 18S data point to a relationship between Bracteacoccus and taxa with the directly opposed configuration of the flagellar apparatus. No close relationship was found to the multinucleated green coccoids with clockwise orientation of basal bodies, such as Spongiochloris, or to those with parallel basal bodies, such as Spermatozopsis. However, 18S data confirm that the motile and vegetative cells of Bracteacoccus are structurally distinct from the representatives of sphaeroplealean families currently studied. It is premature to reclassify Bracteacoccus until 18S comparisons can be made with additional sphaeroplealean taxa and with algae with similar flagellar structure such as Dictyochloris and Heterochlamydomonas. 相似文献
50.
Sorichter Stephan; Mair Johannes; Koller Arnold; Gebert Walter; Rama Daniel; Calzolari Charles; Artner-Dworzak Erika; Puschendorf Bernd 《Journal of applied physiology》1997,83(4):1076-1082
Sorichter, Stephan, Johannes Mair, Arnold Koller, WalterGebert, Daniel Rama, Charles Calzolari, Erika Artner-Dworzak, and BerndPuschendorf. Skeletal troponin I as a marker of exercise-inducedmuscle damage. J. Appl. Physiol.83(4): 1076-1082, 1997.The utility of skeletal troponin I (sTnI)as a plasma marker of skeletal muscle damage after exercise wascompared against creatine kinase (CK), myoglobin (Mb), and myosin heavychain (MHC) fragments. These markers were serially measured in normalphysical education teacher trainees after four different exerciseregimens: 20 min of level or downhill (16% decline) running(intensity: 70% maximal O2uptake), high-force eccentric contractions (70 repetitions), orhigh-force isokinetic concentric contractions of the quadriceps group(40 repetitions). Eccentrically biased exercise (downhill running andeccentric contractions) promoted greater increases in all parameters.The highest plasma concentration were found after downhill running{median peaks: 309 U/l CK concentration ([CK])}, 466 µg/l Mb concentration([Mb]), 1,021 µU/l MHC concentration ([MHC]),and 27.3 µg/l sTnI concentration ([sTnI]). Level running produced a moderate response (median peaks: 178 U/l [CK],98 µg/l [Mb], 501 µU/l [MHC], and 6.6 µg/l [sTnI]), whereas the concentric contraction protocoldid not elicit significant changes in any of the markers assayed. sTnIincreased and peaked in parallel to CK and stayed elevated (>2.2µg/l) for at least 1-2 days after exercise. In contrast to MHC,sTnI is an initial, specific marker of exercise-induced muscle injury,which may be partly explained by their different intracellularcompartmentation with essentially no (MHC <0.1%) or a small solublepool (sTnI: median 3.4%). 相似文献