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DNA is recognized as a nanomaterial, not as a biological material, in the research field of nanotechnology. This article reviews recent research on nanowires, nanoarchitectures, computing, aptamers, biocatalysts, devices, and machines using DNA. In these works, the characteristics of DNA including facile synthesis by the solid-phase method, self-assembly, electro-conductivity, information elements, amplification, switching, molecular recognition, and catalytic functions, were appropriately applied. Multiple functions of DNA could be used simultaneously, and activated independently, by molecular switching. Therefore, the combinations of functional sequences of DNA can produce unique materials. It is obvious that the DNA molecule is one of the most promising functional nanomaterials. However, the application of DNA molecules is still under study because of the big gap that exists between theory and practice. We eagerly anticipate a ‘coming out’ of DNA due to breakthroughs in nanobiotechnology.  相似文献   

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This article addresses a classic ethnographic problem in the study of Italy: how is it that people can subscribe simultaneously to seemingly contradictory ideologies, such as Catholicism and Communism? It does so by describing examples from Italy's ‘showcase city’ of the left, ‘Red Bologna’, in which to be ‘red’ is ubiquitous but each person's ‘red’ is a different thing: being ‘red’ (differently) is the idiom in which real political distinctions are expressed over issues like religion or immigration. In parallel, I discuss the relationship between the ‘field’ as a location and the ‘field’ as a conceptual topic. My account replicates internal ethnographic differences at the analytical level by highlighting the differences between being left‐wing in Bologna and its meaning as a concept in anthropology. Hence the ‘equivocal location’: a field‐site that is productively different, from what an inexperienced ethnographer expected from it, from conceptual discussions in anthropology, and from itself.  相似文献   

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For several years, aid programs in the Mekong region have taken an increasing interest in cross‐border mobility and human trafficking and its relationship with development. More recently, there has been an increasing interest in the identification of trafficked victims and the investigation, arrest and prosecution of traffickers. Whereas anti‐trafficking programs ubiquitously define themselves as being in a battle with traffickers, this article argues that although they are not homologous social actors, both engage in acts of bad faith. The article elaborates this argument by drawing attention to the recruitment process within the Lao sex industry as well as to the way in which aid programs attempt to identify trafficked victims. It concludes that imaginary aspects of development underpin a simultaneous disjuncture yet enable the social reproduction of the life worlds of ‘traffickers’ and ‘anti‐traffickers’ alike.  相似文献   

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Throughout Australia, many Aboriginal responses to the legislative and administrative pressures of the native title regime have been couched in a nation‐building idiom expressed through legally incorporated Aboriginal associations. The membership criteria of these umbrella associations are often derived from definitions of the ‘tribe’ or ‘language group’. Yet, in a kind of Balkanisation, those who see themselves as marginalised to positions of uncertainty on the peripheries of the nation often seek to establish their own independent corporations on the basis of exclusive ties to specific areas of land within it, in search of greater recognition and in competition for scarce resources. In Katherine, in the Northern Territory of Australia, the administrative and legislative gaze of the State, particularly the Aboriginal Land Rights (Northern Territory) Act 1976, brought into focus a Jawoyn ‘tribe’, soon to express itself in the idiom of nationhood, closely followed by a Wardaman ‘tribe’ and ‘nation’. More recently, a native title gaze has now brought into focus ‘new’ configurations of kindred clusters, apparently located on the ‘peripheries' of the Jawoyn and Wardaman nations, and named and valued them as Dagoman. This paper discusses the processes associated with an emerging, but seemingly already fragmenting, Dagoman nation. It argues that divergent and changing Aboriginal subjectivities disrupt what might be seen as mimetic processes as Aboriginal people employ strategies of transforming essentialist representations of their collective selves in changing conditions of possibility.  相似文献   

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Recently, two quite different approaches exemplifying ‘bottom-up’ and ‘top-down’ philosophies have shed new light on basal ganglia function. In vitro work using organotypic co-cultures has implicated the subthalamic nucleus (STN) and the external segment of the globus pallidus (GPe) as pacemakers for low-frequency bursting that is reminiscent of the activity produced in Parkinsonian tremor. A circuit essential for avian song learning has been identified as part of the basal ganglia with surprisingly well conserved cellular details; investigation of this system may help to address general issues of basal ganglia function.  相似文献   

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In the Christian tradition, representing the divine has often been considered both an impossible and yet necessary endeavour rooted in the human need in certain moments of weakness to visualize God. In this article, based on research findings from fieldwork carried out with urban indigenous groups in La Paz, Bolivia, I suggest that the articulation of local and Catholic representational traditions and practices has produced an understanding of the religious image not so much as an object of detached contemplation or a reference to a religious symbol but rather as an energized element which physically shapes the relationship and exchange between the material and the spiritual world. I suggest that through a study of Andean religious images we may be able to produce an alternative ontological perspective on the relationship between the spiritual, material, and living worlds.

Résumé

Dans la tradition chrétienne, la représentation du divin est souvent considérée comme une gageure impossible et pourtant nécessaire, motivée par la nécessité humaine de visualiser Dieu dans les moments de faiblesse. À partir des matériaux de terrain obtenus auprès de groupes autochtones urbains à La Paz, en Bolivie, l'auteur suggère ici que l'articulation des traditions et pratiques de représentation locales et catholiques a conduit à concevoir l'image religieuse moins comme un objet de contemplation détachée ou une référence à un symbole religieux que comme un élément chargé d'énergie, qui donne physiquement forme à la relation et aux échanges entre le monde matériel et le monde spirituel. L'article suggère qu'à travers l'étude des images religieuses andines, on pourrait élaborer un autre point de vue ontologique sur la relation entre les mondes spirituel, matériel et vivant.  相似文献   

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A survey was made to determine the incidence of phytoplasmas in 39 sweet and sour cherry, peach, nectarine, apricot and plum commercial and experimental orchards in seven growing regions of Poland. Nested polymerase chain reaction (PCR) using the phytoplasma‐universal primer pairs P1/P7 followed by R16F2n/R16R2 showed the presence of phytoplasmas in 29 of 435 tested stone fruit trees. The random fragment length polymorphism (RFLP) patterns obtained after digestion of the nested PCR products separately with RsaI, AluI and SspI endonucleases indicated that selected Prunus spp. trees were infected by phytoplasmas belonging to three different subgroups of the apple proliferation group (16SrX‐A, ‐B, ‐C). Nucleotide sequence analysis of 16S rDNA fragment amplified with primers R16F2n/R16R2 confirmed the PCR/Restriction Fragment Length Polymorphism (RFLP) results and revealed that phytoplasma infecting sweet cherry cv. Regina (Reg), sour cherry cv. Sokowka (Sok), apricots cv. Early Orange (EO) and AI/5, Japanese plum cv. Ozark Premier (OzPr) and peach cv. Redhaven (RedH) was closely related to isolate European stone fruit yellows‐G1 of the ‘Candidatus Phytoplasma prunorum’ (16SrX‐B). Sequence and phylogenetic analyses resulted in the highest similarity of the 16S rDNA fragment of phytoplasma from nectarine cv. Super Queen (SQ) with the parallel sequence of the strain AP15 of the ‘Candidatus Phytoplasma mali’ (16SrX‐A). The phytoplasma infecting sweet cherry cv. Kordia (Kord) was most similar to the PD1 strain of the ‘Candidatus Phytoplasma pyri’ (16SrX‐C). This is the first report of the occurrence of ‘Ca. P. prunorum’, ‘Ca. P. mali’ and ‘Ca. P. pyri’ in naturally infected stone fruit trees in Poland.  相似文献   

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To date, six candidate genera of anaerobic ammonium‐oxidizing (anammox) bacteria have been identified, and numerous studies have been conducted to understand their ecophysiology. In this study, we examined the physiological characteristics of an anammox bacterium in the genus ‘Candidatus Jettenia’. Planctomycete KSU‐1 was found to be a mesophilic (20–42.5°C) and neutrophilic (pH 6.5–8.5) bacterium with a maximum growth rate of 0.0020 h?1. Planctomycete KSU‐1 cells showed typical physiological and structural features of anammox bacteria; i.e. 29N2 gas production by coupling of 15NH4+ and 14NO2?, accumulation of hydrazine with the consumption of hydroxylamine and the presence of anammoxosome. In addition, the cells were capable of respiratory ammonification with oxidation of acetate. Notably, the cells contained menaquinone‐7 as a dominant respiratory quinone. Proteomic analysis was performed to examine underlying core metabolisms, and high expressions of hydrazine synthase, hydrazine dehydrogenase, hydroxylamine dehydrogenase, nitrite/nitrate oxidoreductase and carbon monoxide dehydrogenase/acetyl‐CoA synthase were detected. These proteins require iron or copper as a metal cofactor, and both were dominant in planctomycete KSU‐1 cells. On the basis of these experimental results, we proposed the name ‘Ca. Jettenia caeni’ sp. nov. for the bacterial clade of the planctomycete KSU‐1.  相似文献   

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In recent years evidence has accumulated that at least some animals can remember the ‘what’, ‘where’ and ‘when’ of personal experiences. Currently, evidence for such ability is taxonomically restricted to birds and mammals. Here, we demonstrate for the first time that cleaner wrasses Labroides dimidiatus are able to remember when they interacted with what after a single event. In nature, cleaners remove ectoparasites from other reef fishes, so‐called clients. Clients are depleted, non‐stationary food patches at the end of an interaction and replenished only after a delay. In our experiments, we presented twelve cleaners every 2.5 min, a choice between two of a total of four plates with different colours and patterns. One plate was always accessible but contained a non‐preferred food item while the other three contained a preferred food item, but allowed a next feeding event only after 5, 10 or 15 min. Thus, to maximise food intake, cleaners had to remember for each choice when they had last interacted with which plate. When confronted with two plates offering preferred food, cleaners showed an overall significant preference for the plate that allowed access during the trial. For six cleaners, the preference was significant. Also, on trials involving the always accessible plate, cleaners discriminated between trials in which they had to eat the non‐preferred food and trials on which they could eat the preferred food. In conclusion, cleaners are able to track the ‘when’ and ‘what’ (or possibly ‘who’) within a biologically meaningful time period.  相似文献   

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Leaf temperatures were lower when light entry at the leaf tip window was prevented through covering the window with reflective tape, relative to leaf temperatures of plants with leaf tip windows covered with transparent tape. This was true when leaf temperatures were measured with an infrared thermometer, but not with a fine‐wire thermocouple. Leaf tip windows of Lithops growing in high‐rainfall regions of southern Africa were larger than the windows of plants (numerous individuals of 17 species) growing in areas with less rainfall and, thus, more annual insolation. The results of this study indicate that leaf tip windows of desert plants with an underground growth habit can allow entry of supra‐optimal levels of radiant energy, thus most likely inhibiting photosynthetic activity. Consequently, the size of the leaf tip windows correlates inversely with habitat solar irradiance, minimising the probability of photoinhibition, while maximising the absorption of irradiance in cloudy, high‐rainfall regions.  相似文献   

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