Search

Since Ted Nelson coined the term “hypertext” in 1965, there have been frequent debates on the merits and dangers of digital texts and whether the development of digital technology would outdate the print-based medium. The prophecies were apocalyptic and the future of books seemed bleak. About fifty years later, the doomed print-based medium and the digital hypertexts, their would-be executioners,both still exist. Novels are still popular and so is hyperfiction. Neither outdated or eradicated the other. Instead, the coexistence of books and their digital counterparts has affected ourperception of text, reader, writer and the reading experience. More importantly, the exchange between the two media has resulted in exceptional experimental fiction both on screen and on paper. The conjunction between fiction and digital technology is of concern to this project which attempts to study hyperfiction, its roots in fiction and its printed descendants.; Depuis l’invention du terme hypertexte par Ted Nelson en 1965, il y a eu des débats fréquents à propos des mérites et des dangers des textes numériques, pour savoir si le développement des technologies informatiques causerait l’obsolescence des supports imprimés. Les prophéties étaient apocalyptiques et l’avenir des livres semblait sombre. Environ cinquante ans plus tard, tant les supports imprimés qui étaient condamnés que les hypertextes numériques qui semblaient être leurs exécuteurs existent encore. Les romans sont toujours populaires et les hypertextes aussi. Nul n’est dépassé ou éradiqué par l’autre. Au contraire, la coexistence des livres et leurs homologues numériques a affecté notre perception des textes, des lecteurs, des auteurs et de l’expérience de lecture. Plus important, l’échange entre les deux médias a eu comme résultat l’apparition d’une fiction expérimentale exceptionnelle à la fois sur écran et sur papier. La conjonction entre la fiction et les technologies numériques est au centre de ce projet qui vise à d’étudier l’hyperfiction, ses racines dans la fiction traditionnelle et ses descendants imprimés.

Since Ted Nelson coined the term “hypertext” in 1965, there have been frequent debates on the merits and dangers of digital texts and whether the development of digital technology would outdate the print-based medium. The prophecies were apocalyptic and the future of books seemed bleak. About fifty years later, the doomed print-based medium and the digital hypertexts, their would-be executioners,both still exist. Novels are still popular and so is hyperfiction. Neither outdated or eradicated the other. Instead, the coexistence of books and their digital counterparts has affected ourperception of text, reader, writer and the reading experience. More importantly, the exchange between the two media has resulted in exceptional experimental fiction both on screen and on paper. The conjunction between fiction and digital technology is of concern to this project which attempts to study hyperfiction, its roots in fiction and its printed descendants., Depuis l’invention du terme hypertexte par Ted Nelson en 1965, il y a eu des débats fréquents à propos des mérites et des dangers des textes numériques, pour savoir si le développement des technologies informatiques causerait l’obsolescence des supports imprimés. Les prophéties étaient apocalyptiques et l’avenir des livres semblait sombre. Environ cinquante ans plus tard, tant les supports imprimés qui étaient condamnés que les hypertextes numériques qui semblaient être leurs exécuteurs existent encore. Les romans sont toujours populaires et les hypertextes aussi. Nul n’est dépassé ou éradiqué par l’autre. Au contraire, la coexistence des livres et leurs homologues numériques a affecté notre perception des textes, des lecteurs, des auteurs et de l’expérience de lecture. Plus important, l’échange entre les deux médias a eu comme résultat l’apparition d’une fiction expérimentale exceptionnelle à la fois sur écran et sur papier. La conjonction entre la fiction et les technologies numériques est au centre de ce projet qui vise à d’étudier l’hyperfiction, ses racines dans la fiction traditionnelle et ses descendants imprimés.

Aquest article proposa una resposta a la pregunta sobre la funció i orientació pròpies del grau en Humanitats. En aquest sentit, reafirmem la confiança en la capacitat que tenen avui les Humanitats de ser un motor de desenvolupament humà i social, de forjar persones que siguin ciutadans compromesos i professionals del sector cultural. Entre les eines pedagògiques que afavoreixen les catarsis transformadores dels alumnes, cal destacar la lectura de grans obres de la tradició cultural. A tall d’exemple analitzarem una versió contemporània del mite d’Antígona, La tumba de Antígona de María Zambrano, per veure com les Humanitats poden aportar una reflexió sobre la identitat i el compromís social dels estudiants, a més de donar-los un perfil professional dins el sector cultural.

Publisher Summary This chapter focuses on ammonia assimilation and discusses the mechanisms by which the ammonia produced is incorporated into organic compounds. Nitrate and dinitrogen gas, two of the major sources of inorganic nitrogen available to plants, are reduced to ammonia before the nitrogen is incorporated into organic matter. Ammonia is released and reassimilated in large amounts at different stages of the plant's metabolism. Nitrate is the major source of inorganic N available to the leaves of most land plants; ammonia is not present in the xylem stream leaving the roots. Thus, the ammonia assimilated is normally generated in situ from the reduction of nitrate through nitrite. Ammonia is not normally transported into a leaf but is rather a product of nitrate reduction; however, it can also be generated within the leaf by two other ways: (1) by the breakdown of asparagine through transaminase or asparaginase and (2) in photorespiration.

Publisher Summary This chapter discusses transport and metabolism of asparagine and other nitrogen compounds within the plant. Only a limited number of compounds are utilized for N transport in higher plants. The most common compounds are the amides asparagine and glutamine and to a lesser extent the ureides. Canavanine and the various substituted amides are only found in a very small number of species. Glutamine is the only transport compound that does not require any additional energy, as the amide is itself directly involved in ammonia assimilation. However, for asparagine, the three adenosine triphosphate (ATP) units required to synthesize the amide group are lost when ammonia is released either by the action of asparaginase or by the deamidation of 2-hydroxysuccinamate. The ubiquitous distribution of high levels of glutamine synthetase in plant tissues is necessary to prevent the buildup of toxic ammonia levels. The energy cost of utilization of allantoin as an N transport compound is particularly high. ATP is required in the synthesis of purines along with two activated methyl groups.

Publisher Summary This chapter discusses the synthesis and interconversion of glycine and serine. Glycolate pathway is initiated by the production of glycolate in the chloroplasts. The glycolate is oxidized to glyoxylate from which glycine is formed by transamination. Glyoxylate is not necessarily produced only from glycolate. It is also formed as an intermediate of the glyoxylate cycle from threo-Ds-isocitrate by the action of isocitrate lyase. Serine is made in the mitochondria by reactions involving two molecules of glycine. One molecule is oxidatively decarboxylated and deaminated to produce an active hydroxymethyl group that becomes attached to the β-carbon of the second molecule. Most of the serine produced is converted, by way of hydroxypyruvic acid and glyceric acid, to sucrose and polysaccharides. In unicellular algae, more of the carbon in the glycolate pathway is destined for immediate synthesis of proteins, other nitrogen compounds, and organic acids. Serine is not necessarily made from glycine. In organisms other than plants, serine is made from phosphoglyceric acid.

Publisher Summary This chapter focuses on histidine biosynthesis. Histidine derives its carbon and nitrogen from ATP, ribose, and glutamine. The first product of the pathway of histidine biosynthesis, 5-phosphoribyosyl-1-pyrophosphate (PRPP), is also the starting point for the synthesis of purine nucleotides and a substrate for the synthesis of orotidylic acid in the formation of pyrimidine nucleotides. The condensation of PRPP with adenosine triphosphate (ATP) involves the loss of pyrophosphate from the PRPP and the formation of a N-glycosyl linkage between the C-1 of the phosphoribosyl group and the N-1 of the purine ring of ATP. The carboxyl group of histidine is not derived in the normal manner from a corresponding α-keto acid but instead arises from the oxidation of the —CH2OH group, originating from ribose in a two-step reaction involving a single enzyme. This occurs after the addition of the α -amino group by transamination to form the α -amino alcohol histidinol. The breakdown of the purine ring to release 5-phosphoribosyl 4-carboxamide-5-amino imidazole during the formation of imidazole glycerophosphate is also a unique reaction.