90年代以来中国科幻小说“永生”想象的现实精神

在1990年代以来的中国科幻小说中,小说家不仅对人类实现技术化“永生”后产生的追逐功利欲望、沦为技术奴隶、陷入精神空虚等生命体验变化展开直观想象,同时也在科技理性与人文冲突导致的伦理困境中思索人类本质属性。与想象和思索相呼应,对现实情感的强调成为小说家确证人类生存意义和生命价值的精神内核。尽管可能存在描述片面、陷入俗套等方面的缺陷,但小说家通过“永生”模式畅想人类未来图景体现出的批判性反思意识仍有不可忽视的价值。

“有死”的人寻求宗教的“永生”——以基督教和佛教为例作一初步考察

本文以基督教与佛教为例 ,从人的生物学意义上的“亡故”与本体论意义上的“死亡”两方面分析了人的“有死”性 ,并指出正因人具有这种有死性 ,才推出了人在宗教中的求“永生”的神圣追求。

Heterogeneity in Soil Seed Banks in a Mediterranean Coastal Sand Dune

Characteristics of total soil seed banks and permanent soil seed banks in three microhabitats in a Mediterranean coastal sand dune were investigated by using natural germination method combined with physically scanning separation method. The composition and structure of soil seed banks were analyzed between the microhabitats by using functional group method. The distribution patterns of soil seed bank were also analyzed between the microhabitats. We also analyzed the relationship between seed size and seed persistence in soil. The results show greatly spatial heterogeneity existed in soil seed bank of the Mediterranean coastal sand dune, even in the same microhabitats seed distribution was uneven. Sometimes a great difference occurred between them. Microhabitats significantly affected the distribution patterns of total soil seed banks and seed banks of the functional groups. The open area generally had the greater densities of seeds, but the seed densities under shrub and in trail were lower than that in the open area. Legumes seeds accounted for 76.0% total persistent seed banks. Annual and perennial grasses produced transient seed banks as no seeds were retrieved from the sieved soils. Seed persistence of legumes, umbeliferaes, perennial forbs, compositaes, annual forbs, crucifer decreased gradually. They were 50.1%, 45.6%, 40.6%, 6.3%, 5.6% and 0.6% respectively in the soil. There was a positive relationship between seed size and seed persistence. Bigger seeds had higher persistence, and vice versa.

High level of urokinase plasminogen activator contributes to cholangiocarcinoma invasion and metastasis

AIM: To investigate the role of urokinase plasminogen activator (uPA) in cholangiocarcinoma (CCA) invasion and its correlation with clinicopathological parameters. METHODS: uPA expression in CCA tissue was determined by immunohistochemistry. The level of uPA from two CCA cell lines (HuCCA-1 and KKU-M213) and a noncancer immortalized cholangiocyte cell line (H69) was monitored by plasminogen-gelatin zymography and western blotting, whereas that of plasminogen activator inhibitor type 1 (PAI-1) protein and uPA receptor (uPAR)mRNA was monitored by western blotting and quantitative real-time reverse transcriptase polymerase chain reaction, respectively. Two independent methods were employed to suppress uPA function: a synthetic uPA inhibitor (B428) and silencing of uPA gene expression using siRNA. In vitro invasion of the uPA-disrupted cells was assessed by Matrigel-coated Transwell assay. RESULTS: The immunohistochemical study showed that 75.3% (131/174) of CCA tissues expressed uPA. High uPA expression was correlated with lymphatic invasion and metastasis of CCA patients. Plasminogen-gelatin zymography of the conditioned media and cell-surface eluates showed that both CCA cell lines, but not H69, expressed both secreted and membrane-bound forms of uPA. Although the two CCA cell lines, HuCCA-1 and KKU-M213, expressed a relatively high level of uPA and uPAR, the latter exhibited a much lower degree of in vitro invasiveness, correlating with a high expression of PAI-1 in the latter, but not in the former. Suppressing uPA function with a specific uPA inhibitor, B428, or with siRNA against uPA reduced in vitro invasiveness of KKU-M213 cells, demonstrating the requirement for uPA in the invasiveness of CCA cells. Therefore, our in vivo and in vitro studies suggest that uPA is an important requirement for the invasion process of CCA. CONCLUSION: uPA expression correlates with lymphatic invasion and metastasis in vivo and is required for CCA cell invasion in vitro , suggesting its potential as a therapeutic target.

Microbiota of Fossil Animals Preserved in Yakut Permafrost

Microbiological investigation of the fossil animals preserved in permafrost represents obvious interest for science. Lack of data in this sphere gives even greater importance to any findings giving us opportunity to learn more about remote past of microorganisms. In this respect, preserved remains of fossil are considered as unique biological materials for scientific investigations. Bacillus bacteria strains isolated from the paleomicrobiota of mammoth fauna are not only have high durability （20-30 thousand of years） in permafrost, but are still able to produce biologically active substances. Strains of bacteria of the genus Bacillus, isolated from the tissues of the representatives of the mammoth fauna have strong antagonistic properties to hemolytic streptococci--Streptococcus equi, pathogenic for animals--Salmonella abortus equi, also toxigenic micromycetes genera Aspergillus, Alternuria, Penicillum and fungal pathogens of plant diseases--Botrytis cimeria and Fuzarium oxysporium. The strains of bacteria of the genus Bacillus are not pathogenic to plants and animals, but initially resistant to wide range of antibiotics. Dominance strains of Bacillus bacteria, producing strong bacteriocins in the soft tissues of fossil animals, contributing to their long cryo bio conservation. In addition, bacterial strains of Bacillus subtilis, isolated from paleo microbiota have strong oxidizing properties. Microbiota of fossils preserved in permafrost of Yakutia is of particular interest for microbiology and modem biotechnology.

Perpetual Professor： Changing Patterns of Faculty-Student Interaction in the Twenty-First Century

Current communication technologies have provided new modalities for students to contact professors outside of the normal office settings and regulated office hours traditionally found in higher education. This study concentrates on the faculty perceptions of how the usage of e-mail and cell phones has changed interactions with students over the past decade. General levels of usage are analyzed as well as correlation to curricular disciplines, An online survey of faculty members at Indiana University of Pennsylvania found maior changes in the type and frequency of contact between professors and students as well as a shift from personal contact to e-mail and telephone usage. The expanded level of communication opportunities has placed faculty in the position of having to extend direct student-oriented time outside of the classroom, while continuing to maintain academic scholarship and other professional responsibilities.

Epstein-Barr virus induces human nasopharyngeal epithelial cells to escape from the replicative senescence

OBJECTIVE: To observe the biological changes of primary human nasopharyngeal epithelial cells in the early stage of immortalization. METHODS: The morphological changes of nasopharyngeal epithelial cells were observed by phase contrast microscopy, and the activity profile of senescence-associated beta-galactosidase (SA-beta-Gal) was detected by SA-beta-Gal staining. The expression of p16(INK4a) protein was tested by immunochemical assay, and the life span in vitro of nasopharyngeal epithelial cells was calculated as population doublings. In addition, the expression of Epstein-Barr (EB) virus latent membrane protein 1 (LMP1) was also detected by immunofluorescence staining. RESULTS: Morphologically, cells treated with EB virus and 12-o-tetradecanoyl-phorbol-13-acetate (TPA) formed multi-layer foci, and their cellular life span in vitro was extended (about 155 days of culture). A low percentage of cells (about 4.8%) expressed SA-beta-Gal activity at late primary culture, and did not always express p16(INK4a) protein in the progression of culture. CONCLUSIONS: Nasopharyngeal epithelial cells treated with EB virus in cooperation with TPA can pass through the stage of senescence and enter the early stage of immortalization. Some changes of phenotype occur in these cells.Our results provide data for further studying the mechanism of immortalization and the establishment of a human nasopharyngeal epithelial cell line.

The Instream Ecological Water Flow Research at the Lower Reach of Guanting Reservoir on Yongdinghe River,Beijing

作为北京市母亲河的永定河自上个世纪80年代以来三家店以下一直处于断流,河床裸露、河道两岸土地沙化严重,是北京春季沙尘天气的主要沙源之一,由于地下水超采严重,加之无水补给地下水,使得北京西部地区第四纪地下水已经基本枯竭,永定河的生态系统已经受到严重破坏。要想恢复或治理受损的河道生态环境,作为生态系统中最活跃最重要的水分多少要先算清楚。本文采用湿周法计算了永定河官厅水库下游三个控制断面（官厅水库（坝下）、雁翅、卢沟桥）的河道内生态需水流量,计算结果为:官厅水库（坝下）站的河道内流量为3.7m3 s-1。（平水年P=50%,1978年）,占年平均流量的20.7%,雁翅站的河道内流量为4.1m3 s-1（平水年P=50%,1981年）,占年平均流量的20.1%,卢沟桥站的河道内流量为1.3m3 s-1（平水年P=50%,1978年）,占年平均流量的22.1%。若能按照计算的流量来补充河道水量,即可使永定河恢复其基本的生态功能,按照Tennant法的标准,基本能使当地的河道生态系统处于较为良好的状态。

A LEGACY OF THE SPICE TRADE

Pu Lianggong,63,is the inheritor of the local incense-making tradition in Yongchun County,Quanzhou City of southeast China’s Fujian Province.With a long history,Yongchun incense is made of hundreds of Chinese herbs using ancient techniques.The production needs to go through over 10 procedures and requires finesse.

Black band disease as a possible factor of the coral decline at the northern reef-flat of Yongxing Island,South China Sea

Black band disease （BBD）, characterized by the Cyanobacterial dominated pathogenic consortium, is thought to play a key role in the global decline of the coral reef ecosystems. The present paper originally documents a case of BBD from Yongxing Island （Xisha Islands, South China Sea）, and further probes the reasons of this abnormal phenomenon. Prior to 2007, corals at northern reef-flat of Yongxing Isand were in healthy growth. Catastrophic coral mortality occurred between 2007 and 2008. The 16S rRNA gene sequencing and PCR amplification, with universally conserved primers, were applied to detect the conta- gious bacterial community of the microbial mat. The results demonstrated that six bacterial divisions constituted the clone libraries derived from the BBD mat, and that Cyanobacteria are the most diversely represented group that inhabit BBD bacteri- al mats, despite the fact that species in five others divisions （a-Proteobacteria, y-Proteobacteria, Bacteroidetes, Verrucomi- crobia and Actinobacteria） are also consistently diverse within the BBD mats of diseased coral. Other factors such as coral bleaching, typhoons, ocean acidification and crown-of-thorns starfish outbreaks, are not primarily responsible for the coral mortality within such a short time interval. The disaster expansion of BBD associated with Cyanobacterial blooms is a more likely mechanism impacting these coral reefs. Excessive human activity enhances the eutrophication of the marine water of the reefal region and may result in occurrence of the BBD.

Inter- and intraspecific variability of plant individual growth and its role on species ranking in grasslands

Aims Individual growth constitutes a major component of individual fitness.However,measuring growth rates of herbaceous plants non-destructively at the individual level is notoriously difficult.This study,based on an accurate non-destructive method of aboveground biomass estimation,aims to assess individual relative growth rates(RGRs)of some species,identify its environmental drivers and test its consequences on community patterning.We specifically address three questions:(i)to what extent environmental conditions explain differences in individual plant growth between sites,(ii)what is the magnitude of intraspecific variability of plant individual growth within and between sites and(iii)do species-averaged(dis-)advantage of individual growth compared with the whole vegetation within a site correlate with species ranking at the community level?Methods We monitored the growth of individuals of four common perennial species in 18 permanent grasslands chosen along a large pedoclimatic gradient located in the Massif Central,France.We measured soil properties,levels of resources and meteorological parameters to characterize environmental conditions at the site level.This design enables us to assess the influence of environmental conditions on individual growth and the relative extent of inter-individual variability of growth explained within and between sites.We determined the ranking of each of the four species in each site with botanical surveys to assess the relationship between species-averaged growth(dis-)advantage relative to the whole community and species rank in the community.Important Findings We found that environmental conditions explain a significant proportion of individual growth variability,and that this proportion is strongly variable between species.Light availability was the main driver of plant growth,followed by rainfall amount and potential evapotranspiration,while soil properties had only a slight effect.We further highlighted a moderate to high within-site inter-individual variability of growth.We finally showed that there was no correlation between species ranking and species-averaged individual growth.