“第六代”：后现代文化的符码“仿真”——张元、管虎创作比较研究

张元出生于1963年,1985年进入北京电影学院摄影系学习。他在1990年代初期拍摄完成的《妈妈》被认为是当代国内第一部“独立电影”。张元称得上是中国新生代导演群体中少有的“高产者”。在“浮出地表”之前,电影《北京杂种》《儿子》和《东宫.西宫》为他赢得了众多的国际声誉;而在1998年取得国际广播电影电视总局的“解禁令”之后,他又相继执导了影片《过年回家》《疯狂英语》《我爱你》《绿茶》《江姐》和《看上去很美》,也因此成为较早涉足国内电影商业化运作的一位新生代导演。作为新生代导演群体中的一类代表,张元的典型意义不仅在于他往返游走于“先锋”与“主旋律”之间的那份从容,而且“张元现象”也成为考量中国新生代导演十余年间辗转于电影美学与市场运作之间独特体验的生动样本。别有深意的是,这些细节都在某种特定的“全球化语境”中得到了更进一步的放大和渲染。本期邀约的四篇论文中,孙绍谊博士与李迅研究员提供的导演访谈尽可能地保留了许多现场交流的细节,使我们得以直接了解张元本人对于国内电影市场不无真诚又略显偏激的态度。这不仅是对读者反应式批评的有益补充,而且也正是本栏目所期冀的多元文体与多元研究路向的一次探索实践。刘福泉教授的《张元:在寻找中站立》秉承了传统美学批评的理路,以反叛、寻找、皈依为关键词,梳理张元从“小众”到“大众”乃至“主旋律”创作的心路历程。Adam Lam博士的《“第六代”:后现代文化的符码“仿真”》则通过对张元与另一位新生代导演管虎作品的比较研究,试图说明在“国际化”的巨型“能指”背后隐藏的权力运作机制。关于此问题,钱春莲、邱宝林二位博士合作完成的论文《论新生代电影导演的跨文化传播策略》提供出另外一种思路。论文从传播学的角度入手,探讨在经济全球化和文化全球化的双重维度上,新生代导演如何在直面市场的经济策略与以民族认同为基点的文化策略之间寻求微妙的平衡,并且将两岸三地青年导演的区域性合作纳入新生代电影的产业实践。这无疑开辟出一个新的研究路向,同时也呈现出一种新的合作发展的现实可能性。     

Period multupling-evidence for nonlinear behaviour of the canine heart

Although there has recently been considerable interest in applying the theory of nonlinear dynamics to the analysis of complex systems, as yet applications of the theory to biological systems in vivo have been very limited. We report here evidence of nonlinear behaviour in the electrocardiogram and arterial blood pressure traces of the noradrenaline-treated dog. Noradrenaline produces variations in these traces that repeat themselves with regular periods of integral numbers of heart-beats (period multupling), an effect that resembles the 'period-doubling' and other 'bifurcative' behaviour observed when the driving frequency of a nonlinear oscillator is increased above a critical value. The simplest type of periodic variation that we report is the so-called 'electrical alternans', which has long been known as one response of cardiac electrical activity to certain stresses and disease states.     

Stereoselectivity in mammalian chemical communication: Male mouse pheromones

Two male mouse pheromones, 3,4-dehydro-exo-brevicomin (DHB) and 2-sec-butyldihydrothiazole (SBT), are chiral molecules which were previously tested in their respective bioasays as racemic mixtures. The focus of this study has been to determine the absolute configuration of their natural forms and its relation to stereospecific biological action. DHB was established as the R,R-enantiomer possessing biological activity. Due to an extremely easy racemization of SBT under very mild conditions, enantioselectivity of its transmission and its action at the receptor site appear to be of secondary importance.     

A naturally occurring MTA1 variant sequesters oestrogen receptor-alpha in the cytoplasm

Oestrogen receptor (ER) is a good prognostic marker for the treatment of breast cancers. Upregulation of metastatic tumour antigen 1 (MTA1) is associated with the invasiveness and metastatic potential of several human cancers and acts as a co-repressor of nuclear ER-alpha. Here we identify a naturally occurring short form of MTA1 (MTA1s) that contains a previously unknown sequence of 33 amino acids with an ER-binding motif, Leu-Arg-Ile-Leu-Leu (LRILL). MTA1s localizes in the cytoplasm, sequesters ER in the cytoplasm, and enhances non-genomic responses of ER. Deleting the LRILL motif in MTA1s abolishes its co-repressor function and its interaction with ER, and restores nuclear localization of ER. Dysregulation of human epidermal growth factor receptor-2 in breast cancer cells enhances the expression of MTA1s and the cytoplasmic sequestration of ER. Expression of MTA1s in breast cancer cells prevents ligand-induced nuclear translocation of ER and stimulates malignant phenotypes. MTA1s expression is increased in human breast tumours with no or low nuclear ER. The regulation of the cellular localization of ER by MTA1s represents a mechanism for redirecting nuclear receptor signalling by nuclear exclusion.     

Systematic screen for human disease genes in yeast

High similarity between yeast and human mitochondria allows functional genomic study of Saccharomyces cerevisiae to be used to identify human genes involved in disease. So far, 102 heritable disorders have been attributed to defects in a quarter of the known nuclear-encoded mitochondrial proteins in humans. Many mitochondrial diseases remain unexplained, however, in part because only 40-60% of the presumed 700-1,000 proteins involved in mitochondrial function and biogenesis have been identified. Here we apply a systematic functional screen using the pre-existing whole-genome pool of yeast deletion mutants to identify mitochondrial proteins. Three million measurements of strain fitness identified 466 genes whose deletions impaired mitochondrial respiration, of which 265 were new. Our approach gave higher selection than other systematic approaches, including fivefold greater selection than gene expression analysis. To apply these advantages to human disorders involving mitochondria, human orthologs were identified and linked to heritable diseases using genomic map positions.     

Insertional mutagenesis in zebrafish rapidly identifies genes essential for early vertebrate development

To rapidly identify genes required for early vertebrate development, we are carrying out a large-scale, insertional mutagenesis screen in zebrafish, using mouse retroviral vectors as the mutagen. We will obtain mutations in 450 to 500 different genes--roughly 20% of the genes that can be mutated to produce a visible embryonic phenotype in this species--and will clone the majority of the mutated alleles. So far, we have isolated more than 500 insertional mutants. Here we describe the first 75 insertional mutants for which the disrupted genes have been identified. In agreement with chemical mutagenesis screens, approximately one-third of the mutants have developmental defects that affect primarily one or a small number of organs, body shape or swimming behavior; the rest of the mutants show more widespread or pleiotropic abnormalities. Many of the genes we identified have not been previously assigned a biological role in vivo. Roughly 20% of the mutants result from lesions in genes for which the biochemical and cellular function of the proteins they encode cannot be deduced with confidence, if at all, from their predicted amino-acid sequences. All of the genes have either orthologs or clearly related genes in human. These results provide an unbiased view of the genetic construction kit for a vertebrate embryo, reveal the diversity of genes required for vertebrate development and suggest that hundreds of genes of unknown biochemical function essential for vertebrate development have yet to be identified.