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991.
The gradual upward changes of standards in normal everyday life have significant environmental implications, and it is therefore important to study how these changes come about. The intention of the article is to analyze the social construction of normal expectations through a case study. The case concerns the present boom in bathroom renovations in Denmark, which offers an excellent opportunity to study the interplay between a wide variety of consumption drivers and social changes pointing toward long-term changes of normal expectations regarding bathroom standards. The study is problem-oriented and transdisciplinary and draws on a wide range of sociological, anthropological, and economic theories. The empirical basis comprises a combination of statistics, a review of magazine and media coverage, visits to exhibitions, and qualitative interviews. A variety of consumption drivers are identified. Among the drivers are the increasing importance of the home as a core identity project and a symbol of the unity of the family, the opportunities for creative work, the convenience of more grooming capacity during the busy family's rush hours, the perceived need for retreat and indulgence in a hectic everyday life, and the increased focus on body care and fitness. The contours of the emerging normal expectations are outlined and discussed in an environmental perspective.  相似文献   
992.
Virulence is generally considered to benefit parasites by enhancing resource-transfer from host to pathogen. Here, we offer an alternative framework where virulent immune-provoking behaviours and enhanced immune resistance are joint tactics of invading pathogens to eliminate resident competitors (transferring resources from resident to invading pathogen). The pathogen wins by creating a novel immunological challenge to which it is already adapted. We analyse a general ecological model of 'proactive invasion' where invaders not adapted to a local environment can succeed by changing it to one where they are better adapted than residents. However, the two-trait nature of the 'proactive' strategy (provocation of, and adaptation to environmental change) presents an evolutionary conundrum, as neither trait alone is favoured in a homogenous host population. We show that this conundrum can be resolved by allowing for host heterogeneity. We relate our model to emerging empirical findings on immunological mediation of parasite competition.  相似文献   
993.
Much recent work stresses the role of embodiment and action in thought and reason, and celebrates the power of transmitted cultural and environmental structures to transform the problem-solving activity required of individual brains. By apparent contrast, much work in evolutionary psychology has stressed the selective fit of the biological brain to an ancestral environment of evolutionary adaptedness, with an attendant stress upon the limitations and cognitive biases that result. On the face of it, this suggests either a tension or, at least, a mismatch, with the symbiotic dyad of cultural evolution and embodied cognition. In what follows, we explore this mismatch by focusing on three key ideas: cognitive niche construction; cognitive modularity; and the existence (or otherwise) of an evolved universal human nature. An appreciation of the power and scope of the first, combined with consequently more nuanced visions of the latter two, allow us to begin to glimpse a much richer vision of the combined interactive potency of biological and cultural evolution for active, embodied agents.  相似文献   
994.
Arctic charr, a highly plastic salmonid that inhabits the circumpolar region, colonized its current environment after the last glaciation. Recent colonization limits the capacity of many techniques to define and characterize constituent populations. As a novel approach, we used the major histocompatibility (MH) class IIalpha gene polymorphism as a marker that would characterize the genetic divergence of global Arctic charr populations caused by drift and by local adaptation to pathogens. We were able to detect significant isolation of all the lineages previously defined by mitochondrial DNA sequencing and also isolation of some populations within those groups. We found that most of the polymorphism of the class IIalpha gene was distributed globally, which indicates ancestral selection; however, in most cases, distinctive allele frequencies and specific haplotypes distinguished each population suggesting that recent selection has also occurred. Although all studied populations showed similar MH class IIalpha polymorphisms, we also found variation in which particular amino acid positions were polymorphic and which were constant in the different populations studied. This variation provides a greater adaptive capacity for the MH class IIalpha receptors in Arctic charr and is yet another illustration of the extraordinary plasticity of the species.  相似文献   
995.
Previous studies initiated defining the role of host genetics in influencing the outcome of exposure to ovine progressive pneumonia virus. However, specific genes influencing host control of virus replication and disease progression have not been identified. This study, using 383 ewes of the Columbia, Polypay, and Rambouillet breeds, tested the hypothesis that host control of OPPV as measured by provirus levels in the peripheral blood associates with certain breeds and MHC class II Ovis aries (Ovar)-DRB1 expressed alleles. Rambouillet ewes were less likely to have measurable provirus levels as compared to Columbia ewes at ages 5 and 6 (P value < 0.02), and they exhibited lower provirus levels when compared to both Columbia and Polypay ewes of the same ages (P value < 0.05). The presence of DRB1*0403- or DRB1*07012-expressed alleles were significantly associated (P value = 0.019 and 0.0002, respectively) with lower OPP provirus levels but only were only found in 11% of the ewe flock. Analysis of each segregating amino acid in the β1 domain of DR β-chain revealed that amino acids Y31, T32, N37, T51, Q60, or N74 significantly associated (P value range = 0.0003–0.018) with lower OPP provirus levels, whereas amino acids H32, A38, or I67 associated (P value range = 0.013–0.043) with higher OPP provirus levels. These results suggest that Ovar-DRB1 contributes as one host genetic factor that controls OPP provirus levels, but does not fully account for the breed-specific OPP proviral differences.  相似文献   
996.
Critics of Darwinian cultural evolution frequently assert that whereas biological evolution is blind and undirected, cultural change is directed or guided by people who possess foresight, thereby invalidating any Darwinian analysis of culture. Here I show this argument to be erroneous and unsupported in several respects. First, critics commonly conflate human foresight with supernatural clairvoyance, resulting in the premature rejection of Darwinian cultural evolution on false logical grounds. Second, the presence of foresight is perfectly consistent with Darwinian evolution, and is found in biology, in the form of open, teleonomic processes such as genetically-biased behavioural learning. Finally, empirical evidence from the social sciences suggests that cultural change appears far less guided and directed, and human foresight far less accurate, than is commonly assumed.
Alex MesoudiEmail:
  相似文献   
997.
Screening interesting biocatalysts directly from soil samples is a more convenient and applicable approach than conventional cultivation-dependent ones. In our present work, a soil-derived metagenomic library containing 24,000 transformants was constructed with an efficient strategy for cloning xylanase genes. A gene encoding the enzyme (XynH) able to hydrolyze xylan was obtained. Similarity analysis revealed that this enzyme is a new member in the family 10 of xylanases. The molecular mass of XynH purified from Escherichia coli was estimated to be 39 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis. It was found to display the maximal activity at lower temperature, under weakly alkaline conditions, different from most of xylanases. The K m and Vmax values of XynH with birchwood xylan as substrate are 7.5 mg/ml and 190 μmol min−1 mg−1, respectively. It is greatly interesting to note that the activity of XynH was not reduced significantly by Mn2+, Zn2+, Co2+, Ag+, and Cu2+, even at the concentration of 5 mM, which strongly inhibits most of the other xylanases studied previously. Yong Hu and Guimin Zhang contributed equally to this work.  相似文献   
998.
999.
【目的】蛋白质Y3具有抗烟草花叶病毒(TMV)活性并由y3基因编码。本文的目的是从真菌毛头鬼伞(Coprinus comatus)中克隆y3基因全长并在植物体中展现其对TMV的抑制活性。【方法】我们利用试剂盒5′-Full RACE Core Set(TaKaRa)扩增了y3基因cDNA5′-端未知序列,通过RT-PCR获得了全长序列,并把该全长序列与CaMV 35 S启动子和NOS终止子一起插入多克隆位点(MCS)构建了植物表达载体pCAMBIA1301-y3,用于农杆菌介导的烟草转化。【结果】y3基因全长534碱基对,包含1个开放阅读框(ORF),编码一条含130个氨基酸残基的肽链(GenBank检索号:GQ859168;EMBL:FN546262)。其cDNA序列和由它推到的氨基酸序列均与已发表的y3基因部分片段有高度相似性(94%)。Northern杂交分析证实了y3基因在转基因烟草中得到表达。接种TMV的转基因植株表现出抗TMV的活性。【结论】我们克隆了y3基因全长并得到了转基因植株。在转基因植株中,由于y3基因的表达改善了植株的抗病毒活性。y3基因的克隆和表达无疑为该基因的进一步研究奠定了基础。  相似文献   
1000.
构树聚花果及其果实原汁营养成分的研究   总被引:18,自引:1,他引:17  
对构树聚花果的营养成分进行分析,结果表明,其果实含有丰富的营养物质,氨基酸,糖类,矿质元素等成分,其果实原汁含有丰富的可溶性糖类,蛋白质,氨基酸,维生素等营养成分,此外,种子含有丰富的脂肪油(40.28%),其脂肪油中人体必需的脂肪酸亚油酸的含量达(85.42),其聚花果,果实原汁,种子油具有开发利用的价值。  相似文献   
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