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1.
The structure and evolution of the spider monkey delta-globin gene   总被引:1,自引:0,他引:1  
We have isolated the delta-globin gene of the New-World spider monkey, Ateles geoffroyi, and compared its nucleotide sequence with those of other primate delta- and beta-globin genes. Among primate delta-globin genes, the rate of nonsynonymous substitutions is much less than the rate of synonymous substitutions. This suggests that primate delta- globin genes may remain under evolutionary conservation, perhaps because hemoglobin A2 has an as yet unknown physiological importance.   相似文献   
2.
For the first time, a credible prokaryotic phylogenetic tree is being assembled by Woese and others using quantitative sequence analysis of oligonucleotides in the highly conservative rRNA. This provides an evolutionary scale against which the evolutionary steps that led to the arrangement and regulation of contemporary biochemical pathways can be measured. This paper presents an emerging evolutionary picture of aromatic amino acid biosynthesis within a large superfamily assemblage of prokaryotes that is sufficiently developed to illustrate a new perspective that will be applicable to many other biochemical pathways.   相似文献   
3.
In Drosophila pseudoobscura, the amylase (Amy) multigene family is contained within a series of inversions, or gene arrangements, on the third chromosome. The Standard (ST), Santa Cruz (SC), and Tree Line (TL) inversions are central to the phylogeny of arrangements, and have clusters of other arrangements derived from them. The gene arrangements belonging to each of these three clusters have a characteristic number of Amy genes, ranging from three in ST to two in SC to one in TL. This distribution pattern can reflect a history of either duplications or deletions, although the data available in the past did not permit a decision between these alternatives. We provide unambiguous evidence that three Amy genes were present before the divergence of the ST, SC, and TL arrangements. Thus, the current status of the Amy multigene family is the result of deletions in the TL and SC arrangements, which created three new pseudogenes: TL Amy2-psi, TL Amy3-psi, and SC Amy3- psi. Analysis of pseudogene sequences revealed that, in the SC and ST arrangements, pseudogene evolution has been retarded, most likely due to the homogenization effect of gene conversion. Finally, by determining the original copy number, we have reconstructed the evolutionary history of the Amy multigene family and linked it with the evolution of the central gene arrangements.   相似文献   
4.
The application of sensory methodology for measuring deodorizing effect of an air conditioner equipped with electric plasma was introduced. Deodorizing effect was measured using chemical and sensory methods at different time (0, 30 and 60 min) and mode (control, blowing and cooling) of an air conditioner. Smoke from a roll of cigarette in a closed room was used as a source of odor and the concentrations of acetic acid and ammonia were measured as odorous chemical components. As one of the sensory methods triangle test was used and as a first step to obtain deodorizing effects by triangle test, the threshold of each panelist was obtained as the log dilution ratio of odor concentration at which the difference from odorless air was detected. The odor concentration at each time and mode was calculated using the threshold of the panel and the deodorizing effect was obtained on the basis of the odor concentration. In addition to a triangle test, scaling methods such as category scaling or magnitude estimation were used to measure deodorizing effect of an air conditioner. Deodorizing effects by scaling methods were calculated based on odor intensity with time at each mode. The regression analysis was done between the efficacy of deodorizing effect by sensory test and those by acetic acid and ammonia, the R2 values of the regression equations for triangle test, category scale, and magnitude estimation were 0.84, 0.72 and 0.69, respectively. Deodorizing effect by triangle test explained the decrease of acetic acid and ammonia better than those by category scaling or magnitude estimation while high cost and time consuming labor involved in triangle tests reduced the merit. The results of this study demonstrated that various sensory methods could be used to measure deodorizing effect of air conditioners and further researches on fast and reliable methods are needed to establish the official procedures.  相似文献   
5.
6.
Considerable evidence indicates that the renal Na+,K+-ATPase is regulated through phosphorylation/dephosphorylation reactions by kinases and phosphatases stimulated by hormones and second messengers. Recently, it has been reported that amino acids close to the NH2-terminal end of the Na+,K+-ATPase α-subunit are phosphorylated by protein kinase C (PKC) without apparent effect of this phosphorylation on Na+,K+-ATPase activity. To determine whether the α-subunit NH2-terminus is involved in the regulation of Na+,K+-ATPase activity by PKC, we have expressed the wild-type rodent Na+,K+-ATPase α-subunit and a mutant of this protein that lacks the first thirty-one amino acids at the NH2-terminal end in opossum kidney (OK) cells. Transfected cells expressed the ouabain-resistant phenotype characteristic of rodent kidney cells. The presence of the α-subunit NH2-terminal segment was not necessary to express the maximal Na+,K+-ATPase activity in cell membranes, and the sensitivity to ouabain and level of ouabain-sensitive Rb+-transport in intact cells were the same in cells transfected with the wild-type rodent α1 and the NH2-deletion mutant cDNAs. Activation of PKC by phorbol 12-myristate 13-acetate increased the Na+,K+-ATPase mediated Rb+-uptake and reduced the intracellular Na+ concentration of cells transfected with wild-type α1 cDNA. In contrast, these effects were not observed in cells expressing the NH2-deletion mutant of the α-subunit. Treatment with phorbol ester appears to affect specifically the Na+,K+-ATPase activity and no evidence was observed that other proteins involved in Na+-transport were affected. These results indicate that amino acid(s) located at the α-subunit NH2-terminus participate in the regulation of the Na+,K+-ATPase activity by PKC. Received: 10 July 1996/Revised: 19 September 1996  相似文献   
7.
The International Journal of Life Cycle Assessment - Weighting in life cycle assessment (LCA) incorporates stakeholder preferences in the decision-making process of comparative LCAs. Research...  相似文献   
8.
Abstract

Benthic marine flora of Tuscan Archipelago has been studied. Several samples were collected along five islands and some rocks. This paper is a compendium of new and already published data, in which 267 species, varieties, forms and stadia of algae and seagrasses are listed: 5 Bangiophyceae, 182 Florideophyceae, 45 Phaeophyceae, 6 Chlorophyceae, 28 Bryopsidophyceae, 1 Angiospermae.  相似文献   
9.
Abstract

Floristic notes and geographical distribution of some rare Rhodophyta (Kallymeniaceae and Sebdeniaceae) of the western Mediterranean. Callophyllis laciniata, Kallymenia requienii and Kallymenia lacerata (Kallymeniaceae) and Sebdenia rodrigueziana (Sebdeniaceae) are recorded for the first time in the bay of Naples. For each species systematic and distribution data are also given.  相似文献   
10.
Abstract

Preliminary studies on the marine phythobenthic communities in the Straits of Sicily and adjacent islands. — The results of algological researches carried out by the Gruppo di Algologia of the S.B.I. in the Straits of Sicily and adjacent islands are reported. 288 species have been collected, 275 of which have been identified: 160 were Rhodophyta, 62 Phaeophyta, 32 Chlorophyta, 16 Cyanophyta and 2 Angiospermae. The vegetational research leads to the following conclusions: 1 - the harbour areas (Pantelleria, Malta: loc. 1 and 11) show a nitrophile vegetation, particulary near La Valletta where an almost pure population of Pterocladia pinnata is found; 2 - there are important biogeographical differences between Pelagie islands (Lampedusa, Linosa) and Pantelleria. In fact the former ones have an algal flora composed mostly of eastern mediterranean species, whilst the latter shows strong affinities with the north-african basin, as is demonstrated by the rich well developed belt of Cystoseira sedoides; 3 - several species of atlantic origin, such as Callophyllis laciniata, Peyssonnelia coriacea, P. inamoena and Castagnea chordariaeformis, have been found on the banks (loc. 3, 6, 7).  相似文献   
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