يعرض 1 - 10 نتائج من 13 نتيجة بحث عن '"Christopher, S."', وقت الاستعلام: 0.75s تنقيح النتائج
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    المصدر: Behaviour. 148:287-305

    الوصف: Many animal signals have been produced by selection operating upon behavioural precursors that lack signal function, a process known as 'ritualization'. When the precursor remains in the repertoire, comparisons of its structure with that of the derived signal permit inference of the forces responsible. Selection for signal efficacy and recognition produce characteristic changes (e.g., increases in intensity and duration, and repetition). The tidbitting display of male fowl, Gallus gallus , has long been considered an example of ritualization. However, the changes associated with this evolutionary process have never been characterized, nor has there been any test of whether the signal is perceived as distinct from its putative precursor (self-feeding). To address this, we first analysed video recordings of males feeding and tidbitting. We found a significant increase in the intensity, duration and repetition of specific movements during the tidbitting display compared to feeding. These results suggest that tidbitting is a ritualized form of self-feeding behaviour, but the critical test requires assessment of receiver response. If females recognized the tidbitting signal as distinct from male feeding behaviour, we predicted that females would food search significantly more in response to tidbitting. The results of high-definition video playbacks support this hypothesis. This is the first empirical demonstration of the perceptual and functional predictions made by a classic ethological hypothesis.

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    المؤلفون: Christopher S. Welser

    المصدر: Mnemosyne. 63:1-22

    الوصف: An examination of Herodotus’s use of the circumstantial participle in the future tense with and without the adverbial particle ς reveals that Herodotus reserves ς almost exclusively for those cases in which the expectations or intentions represented by the participle are ultimately disappointed. This observation should teach us to distrust the conventional assertion that the appearance of ς with the circumstantial participle has no implications for an author’s thoughts. It also suggests that, in those cases where we lack direct knowledge of historical outcomes, the presence of ς with a circumstantial participle may permit us to be reasonably certain that any expectations or intentions expressed by that participle are likely to have gone unfulfilled. Thus, Herodotus’s use of the phrase ς νασοντες at the end of the Histories to refer to the Athenians’ intentions to dedicate the equipment from Xerxes’ bridge (9.121) should probably be understood as implying that no such dedication ever took place.

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    المؤلفون: Christopher S. Evans, Terry J. Ord

    المصدر: Behaviour. 140:1495-1508

    الوصف: Summary Honest signals allow animals to assess an opponent without the injury risk of e ghting. Playback experiments have shown that call rate is an important parameter in the acoustic signals of several taxa. Here we describe an analogous study of a visual display. Male Jacky dragons, Amphibolurus muricatus , respond to intruding conspecie cs with a stereotyped series of motor patterns, including a push-up. These displays are typically given in bouts and there is substantial individual variation in inter-bout interval. In a recent video playback experiment, we found that the display rate depicted in two sequences appeared to ine uence the type of signal response evoked. The present study was designed to systematically examine the importance of this cue, while controlling opponent morphology and all other aspects of signal structure. Male lizards were presented with e ve digital video stimuli, each depicting the same male conspecie c, but with inter-bout intervals that varied over the full natural range. The duration of aggressive push-up responses changed signie cantly as a function of stimulus

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    المصدر: Behaviour. 140:353-369

    الوصف: The design of many animal signals reflects the need to maximize signal efficacy while minimizing conspicuousness to eavesdroppers. The aerial alarm calls of birds have been a useful model system for exploring such evolutionary tradeoffs at the level of general call structure, but much less is known about changes in fine-scale signal characteristics over the course of an encounter with a potential predator. We analyzed variation in the alarm calls that male fowl, Gallus gallus, produced in response to raptor silhouettes moving overhead. Spectrogram cross-correlation was used to test for changes in structure over the course of a call bout. This analysis revealed that aerial alarm calls are individually distinctive and that they vary significantly from the first call to the second. We then measured single acoustic parameters, including the duration, dominant frequency and frequency bandwidth of each component in successive calls. Males almost invariably began the first call in a bout with a high amplitude broad-band pulse, which was followed by a much longer and highly variable sustained element. They then selectively reduced or eliminated the introductory pulse, while leaving other aspects of alarm structure unchanged. Recent work has shown that the introductory pulse is potentially costly because it has attributes that are readily localized by raptors. We suggest that male fowl have adaptive plasticity in alarm call structure, allowing them to manage short-term predation risk while continuing to signal to companions.

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    المؤلفون: Christopher S. Celenza

    المصدر: Angelo Poliziano's Lamia ISBN: 9789004185906

    الوصف: The year 1492 saw the composition of Angelo Poliziano's Lamia , a praelectio , or preliminary oration, which he delivered in the fall of that year to open the course he was teaching on Aristotle's Prior Analytics at the Florentine university. To understand the Lamia , it is necessary to set it in the context of Poliziano's teaching career, before moving on to an analysis of the text. For Poliziano, the philologist was the true philosopher, since only the philologist could examine all evidence, be unimprisoned by disciplinary shackles, and go on to pass dispassionate judgment on the problems life presents. Poliziano made this case in a social context of give and take among humanists, from his interactions with his friend Giovanni Pico della Mirandola and their epistolary exchanges with Ermolao Barbaro to the more immediate circumstances of conflict at the Florentine university. Keywords: Angelo Poliziano; Aristotle; Giovanni Pico della Mirandola; Lamia

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    المؤلفون: Christopher S. Celenza

    المصدر: Angelo Poliziano's Lamia ISBN: 9789004185906

    الوصف: This chapter in Latin with translation in English, commences with a discussion on Angelo Poliziano, preliminary lecture on Aristotle's prior analytics: Lamia. This text follows Ari Wesseling's excellent edition, based on the 1492 printed edition of the Florentine Antonio Miscomini; Wesseling has given it the siglum "A," also used here. "A" was the only edition produced during Poliziano's lifetime. Wesseling has presented a fairly full critical apparatus, having collated his text with six later editions; that apparatus is not reproduced here. The present text differs from Wesseling in some minor matters of punctuation and orthography. Part of Poliziano's brilliance lies in the manner in which he seamlessly combines, recombines, and rings changes both major and minor on the form and the content of his ancient sources. In this edition, quotations are indicated as such (within quotation marks) only when Poliziano draws attention to his quotation, whether explicitly or implicitly. Keywords: Angelo Poliziano; Aristotle; English translation; Lamia; Latin text

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    المؤلفون: Christopher S. Celenza

    المصدر: Latinitas Perennis. Volume II: Appropriation and Latin Literature ISBN: 9789047430278

    الوصف: Sometime between 1485 and 1491, the humanists Angelo Poliziano (1454-94) and Paolo Cortesi (1465-1510) engaged in an exchange of letters that, among scholars of Neo-Latin, has become well known. Cortesi expressed this need to communicate clearly and in a classicizing fashion most famously in his response to Poliziano. Poliziano, needless to say, had no such Valla-sized ambitions. He did, however, have an audience: scholars, who would appreciate his recherche yet classically based Latin. The audience for which Cortesi, by contrast, aimed his loosely Ciceronian Latin was a society in which sovereign states of all stripes were growing. These states possessed bureaucratic institutions that needed standardized languages, languages that were translatable across the newly emerging order of elite European Latinate education. Scholars were included in that realm, but they were not the only audience. Keywords: Angelo Poliziano; Ciceronian Latin; elite European Latinate education; fifteenth century; humanist debate; Paolo Cortesi

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    المصدر: Humanism and Creativity in the Renaissance ISBN: 9789047408741

    الوصف: Alcionio published a volume comprising several translations of Aristotle. This chapter assesses Alcionio's strategy of self-presentation in the letters that accompanied the translations, and in particular the missive dedicating the books on animals to Ottaviano Fregoso. It provides a brief description of Sepulveda background and training, and an analysis of the dedicatory letter to Alberto Pio. The chapter treats the text of the Errata, in which Sepulveda explicitly compares passages from his own translations and from Alcionio's with the Greek text, to assess both the grounds and the cogency of the critique. Finally, it considers the professional and political contexts of the feud, which may further our understanding of a key transitional period in the history both of humanism and of Renaissance Italy. Alcionio's underestimated the importance of tempering his quest for scholarly renown with an appearance of moderation, restraint, and judiciousness. Keywords: Alcionio; Aristotle; Humanism; Sepulveda; translations