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121.
The International Journal of Life Cycle Assessment - Corruption is one of the key social aspects, heavily impacting all three Planet-, People- and Prosperity sustainability pillars and is therefore...  相似文献   
122.
123.
Duplication of DNA during meiosis in baker's yeast   总被引:5,自引:0,他引:5  
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124.
Synchronous gametogenesis in the water mold Allomyces arbuscula is blocked by actinomycin D added at the onset of the process. Formation of the male gametangium can be selectively inhibited by administering actinomycin one hr after the induction of gametogenesis. The polyribosome pattern obtained after density gradient centrifugation remains virtually unchanged throughout gametogenesis until a stage immediately preceding maturation of the gametes. When ribosome from gametes and swarming zygotes are analyzed on gradients, some RNase-sensitive materials is found to band in the heavier portion of the gradient. Its presence suggests that some messenger RNA associated with ribosomes is conserved in the swarming cells. During gametogenesis RNA is de novo synthesized and becomes associated with the polyribosomes.  相似文献   
125.
The International Journal of Life Cycle Assessment - The objective of this paper is to open a discussion on the implications and challenges of including positive impacts in LCAs of products and to...  相似文献   
126.
Killer-sensitive relationships in yeasts from natural habitats   总被引:3,自引:0,他引:3  
Yeast strains (157) belonging to at least 9 genera were isolated from natural habitats and screened for killer-sensitive relationships. Killer and sensitive characteristics were exhibited by 17 and 11 percent of the isolates, respectively. The strains belong to either one of two mutually exclusive killer-sensitive groups.  相似文献   
127.
Properdin (FP) is an essential positive regulator of the complement alternative pathway (AP) providing stabilization of the C3 and C5 convertases, but its oligomeric nature challenges structural analysis. We describe here a novel FP deficiency (E244K) caused by a single point mutation which results in a very low level of AP activity. Recombinant FP E244K is monomeric, fails to support bacteriolysis, and binds weakly to C3 products. We compare this to a monomeric unit excised from oligomeric FP, which is also dysfunctional in bacteriolysis but binds the AP proconvertase, C3 convertase, C3 products and partially stabilizes the convertase. The crystal structure of such a FP-convertase complex suggests that the major contact between FP and the AP convertase is mediated by a single FP thrombospondin repeat and a small region in C3b. Small angle X-ray scattering indicates that FP E244K is trapped in a compact conformation preventing its oligomerization. Our studies demonstrate an essential role of FP oligomerization in vivo while our monomers enable detailed structural insight paving the way for novel modulators of complement.  相似文献   
128.
A. F. Croes  H. J. Dodemont  C. Stumm 《Planta》1976,130(2):131-136
Summary Saccharomyces cells induced to undergo meiosis when in late G 1 or early S-phase, proceed mitotically until a point between completion of the S-phase and nuclear division. From that point, the cells start meiotic development without intervention of a round of premeiotic DNA replication. Cells induced at any other point in the cell cycle, enter meiosis from G 1.  相似文献   
129.
Binding of auramine O to poly-(methacrylic acid) (PMA) has been established over a large range of C0p/C0d values using spectroscopic methods (UV absorption and visible fluorescence emission spectra), equilibrium and sedimentation dialysis, potentiometric and viscosimetric titrations. All the results show qualitative agreement with those obtained previously with the system crystal violet-PMA although the binding seems to be less strong for auramine O than for crystal violet. From dialysis experiments binding isotherms were obtained at three different degrees of neutralization α'; at α' = 0.10 the results could be fitted to a Langmuir isotherm but at α' equal to 0.40 and 0.65 deviations with respect to such an isotherm occur. The results of potentiometric and viscosimetric titrations confirm that the conformational transition which the dye-free PMA exhibits upon ionization is affected by the dye binding. The region in which the conformational transion occurs is broadened and is less sharply defined in the presence of auramine O.  相似文献   
130.
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