Prodicus on the Rise of Civilization

Prodicus gained a reputation for formulating a novel theory concerning the origins of religious belief, sometimes labelled as atheistic in antiquity, notably by the Epicureans. He suggests that humans initially regarded as gods whatever was useful for their survival such as fruits and rivers, and in a more advanced stage they deified culture heroes such as Demeter and Dionysus. I first suggest that Prodicus’ theory can be connected with other doctrines attributed to him, especially the speech concerning “Heracles’ choice” and the keen interest in the etymology of words. Moreover, I argue that the different representations of his theory reflect the debate between the Epicureans and the Stoics concerning the involvement of gods in human and cosmic affairs. An examination of the fragmentary evidence shows Prodicus to be a thinker who was interested in the rise of civilization in general, and so his theory was part and parcel of a large-scale project to explain several interconnected aspects of social life in rational terms.Prodicus est réputé pour avoir formulé une théorie nouvelle sur les origines de la croyance religieuse, qui a parfois été taxée d’athéisme dans l’Antiquité, notamment par les épicuriens. Il suggère que les hommes ont d’abord considéré comme des dieux des choses qui étaient utiles à leur survie, comme les fruits et les rivières, et qu’à un stade plus avancé, ils ont déifié des héros culturels, comme Déméter et Dionysos. Je suggère d’abord que la théorie de Prodicus peut être reliée à d’autres doctrines qui lui sont attribuées, en particulier au discours concernant « le choix d’Héraclès » et à un fort intérêt pour l’étymologie des mots. En outre, je soutiens que les différentes représentations de sa théorie reflètent le débat entre les épicuriens et les stoïciens concernant l’implication des dieux dans les affaires humaines et cosmiques. Un examen des preuves fragmentaires montre que Prodicus était un penseur qui était intéressé par les origines de la civilisation en général, et ainsi que sa théorie était partie intégrante d’un projet de grande envergure cherchant à expliquer plusieurs aspects interconnectés de la vie sociale en termes rationnels.

Studies on the readability and on the detection rate in a Mach-Zehnder interferometer-based implementation for high-rate, long-distance QKD protocols

We study the way that chromatic dispersion affects the visibility and the synchronization on Quantum Key Distribution (QKD) protocols in a widely-used setup based on the use of two fiber-based Mach-Zehnder (MZ) interferometers at transmitter/receiver stations. We identify the necessary conditions for the path length difference between the two arms of the interferometers for achieving the desired visibility given the transmission distance -- where the form of the detector's window can be considered. We also associate the above limitations with the maximum detection rate that can be recorded in our setup, including the quantum non-linearity phenomenon, and to the maximum time window of the detector's gate. Exploiting our results we provide two methods, depending on the clock rate of the setup, to perform chromatic dispersion compensation techniques to the signal for keeping the correct order of the transmitted symbols. At the end, we apply our theoretical outcomes in a more realistic QKD deployment, considering the case of phase-encoding BB84 QKD protocol, which is widely used. Our proposed methods, depending on the transmission distance and on the photon emission rate at transmitter station, can be easily generalized to every fiber-optic QKD protocol, for which the discrimination of each symbol is crucial.Comment: 14 pages, 12 figure

Enhancing dynamic student learning by teamwork in innovative projects at an Erasmus Mundus master subject adapted to the EHEA (EEES)

The EHEA (EEES in Spain) is creating common academic degree standards comparable and compatible between the European countries. The definition of the new Credit unit, the ECTS, focused on the hours of study devoted by the students, is also promoting the renovation of the educational process at the higher studies of Graduate Degree and Master. We describe the experience of innovation of the teaching practice of the “Fibres & Telecommunications” subject of the Master PhotonicsBCN (part of the Erasmus Mundus Master EUROPHOTONICS), by introducing team9 working techniques for promoting: the development of cooperative learning, interpersonal skills, and positive interdependence among the students, not forgetting the individual initiative and responsibility. The teamwork is oriented to small innovation projects (inspired in state9of9the9art research challenges faced by the European FP7 EURO9FOS Network9 of 9Excellence) promoting interactive and dynamic student learning process. Each team member is spontaneously encouraged to learn as much as possible on both: the area of his task inside the common project, and also the influence of his task in the over all results of the project. This is implemented by the use of commercial software for professional systems deployment (VPIphotonics TM ), which allows each team to check the real viability of their innovative solutionPostprint (published version

Packet clock recovery using a bismuth oxide fiber-based optical power limiter

Abstract: We demonstrate an optical clock recovery circuit that extracts the line rate component on a per packet basis from short data packets at 40 Gb/s. The circuit comprises a Fabry-Perot filter followed by a novel power limiting configuration, which in turn consists of a 5m highly nonlinear bismuth oxide fiber in cascade with an optical bandpass filter. Both experimental and simulation-based results are in close agreement and reveal that the proposed circuit acquires the timing information within only a small number of bits, yielding a packet clock for every respective data packet. Moreover, we investigate theoretically the scaling laws for the parameters of the circuit for operation beyond 40 Gb/s and present simulation results showing successful packet clock extraction for 160 Gb/s data packets. Finally, the circuit's potential for operation at 320 Gb/s is discussed, indicating that ultrafast packet clock recovery should be in principle feasible by exploiting the passive structure of the device and the fsec-scale nonlinear response of the optical fiber

Optical terabit transmitter and receiver based on passive polymer and InP technology for high-speed optical connectivity between datacenters

We demonstrate the hybrid integration of a multi-format tunable transmitter and a coherent optical receiver based on optical polymers and InP electronics and photonics for next generation metro and core optical networks. The transmitter comprises an array of two InP Mach-Zehnder modulators (MZMs) with 42 GHz bandwidth and two passive PolyBoards at the back- and front-end of the device. The back-end PolyBoard integrates an InP gain chip, a Bragg grating and a phase section on the polymer substrate capable of 22 nm wavelength tunability inside the C-band and optical waveguides that guide the light to the inputs of the two InP MZMs. The front-end PolyBoard provides the optical waveguides for combing the In-phase and Quadrature-phase modulated signals via an integrated thermo-optic phase shifter for applying the pi/2 phase-shift at the lower arm and a 3-dB optical coupler at the output. Two InP-double heterojunction bipolar transistor (InP-DHBT) 3-bit power digital-to-analog converters (DACs) are hybridly integrated at either side of the MZM array chip in order to drive the IQ transmitter with QPSK, 16-QAM and 64-QAM encoded signals. The coherent receiver is based on the other side on a PolyBoard, which integrates an InP gain chip and a monolithic Bragg grating for the formation of the local oscillator laser, and a monolithic 90° optical hybrid. This PolyBoard is further integrated with a 4-fold InP photodiode array chip with more than 80 GHz bandwidth and two high-speed InP-DHBT transimpedance amplifiers (TIAs) with automatic gain control. The transmitter and the receiver have been experimentally evaluated at 25Gbaud over 100 km for mQAM modulation showing bit-error-rate (BER) performance performance below FEC limit

Four-channel all-fibre dispersion-managed 2R regenerator

We experimentally investigate a dispersion managed four-channel 2R regenerator that relies on self-phase modulation-induced spectral broadening and offset filtering at four shifted wavelengths. The device consists of several alternating sections of dispersion compensating fibres (DCF) and single mode fibres (SMF). Due to this arrangement and the use of low duty-cycle return-to-zero (RZ) pulses nonlinear interchannel effects are sufficiently mitigated resulting in almost no additional degradation compared to the single-channel case

Heraclitus and the Medical Theorists on the Circle

The coincidence of opposites in a circle is a topic that attracted the interest of several thinkers who were active between the fifth and the third century BC. A key text is a Heraclitean fragment, transmitted by Porphyry, which refers to the coincidence of beginning and end in a circle’ s circumference. After analysing the context in which the fragment is embedded, three interpretations are examined : the circle represents the regularity of the large-scale processes ; the circle offers a geometrical example of the unity or coincidence of opposites ; and the circle alludes to the unity of the microcosmic processes pertaining to the soul. I then turn to medical theorists who deal with the coincidence of beginning and end in circles and circuits : (a) the author of On Regimen, who tries to show the interconnection between macrocosm, microcosm, and crafts ; (b) the authors of Places in Man and On the Nature of Bones, who stress the organic unity of bodily parts ; and (c) Alcmaeon, who describes the death of humans as a failure to complete a circuit. An examination of the fragment in connection with the medical literature displays the diversity of ancient tradition, as well as the novelty of Heraclitus’ thought.Héraclite et les théoriciens médicaux sur la question du cercle. La coïncidence des contraires dans un cercle est un sujet qui a attiré l’ intérêt de plusieurs penseurs actifs entre le cinquième et le troisième siècle avant J.-C. Un texte-clé est un fragment d’ Héraclite, transmis par Prophyre, qui fait allusion à la coïncidence entre le commencement et la fin dans la circonférence d’ un cercle. Après analyse du contexte dans lequel ce fragment se place, trois interprétations sont examinées : le cercle représente la régularité des processus de grande ampleur ; le cercle offre un exemple géométrique de l’ unité ou de la coïncidence des contraires ; et le cercle renvoie à l’ unité des processus microcosmiques qui ont trait à l’ âme. Je me tourne ensuite vers les théoriciens médicaux qui traitent de la coïncidence du commencement et de la fin dans les cercles et les circuits : (a) l’ auteur de Du régime, qui tente de montrer l’ interconnexion entre macrocosme, microcosme et techniques ; (b) les auteurs de Des lieux dans l’ homme et Nature des os, qui mettent l’ accent sur l’ unité organique des parties du corps ; et (c) Alcméon de Crotone, qui décrit la mort des êtres humains comme un échec à terminer un circuit. Un examen du fragment en liaison avec la littérature médicale met en relief la diversité de la tradition antique de même que la nouveauté de la pensée d’ Héraclite.Kouloumentas Stavros. Heraclitus and the Medical Theorists on the Circle. In: Dialogues d'histoire ancienne, vol. 44, n°2, 2018. pp. 43-63

Heraclitus and the Medical Theorists on the Circle

The coincidence of opposites in a circle is a topic that attracted the interest of several thinkers who were active between the fifth and the third century BC. A key text is a Heraclitean fragment, transmitted by Porphyry, which refers to the coincidence of beginning and end in a circle’ s circumference. After analysing the context in which the fragment is embedded, three interpretations are examined : the circle represents the regularity of the large-scale processes ; the circle offers a geometrical example of the unity or coincidence of opposites ; and the circle alludes to the unity of the microcosmic processes pertaining to the soul. I then turn to medical theorists who deal with the coincidence of beginning and end in circles and circuits : (a) the author of On Regimen, who tries to show the interconnection between macrocosm, microcosm, and crafts ; (b) the authors of Places in Man and On the Nature of Bones, who stress the organic unity of bodily parts ; and (c) Alcmaeon, who describes the death of humans as a failure to complete a circuit. An examination of the fragment in connection with the medical literature displays the diversity of ancient tradition, as well as the novelty of Heraclitus’ thought.Héraclite et les théoriciens médicaux sur la question du cercle. La coïncidence des contraires dans un cercle est un sujet qui a attiré l’ intérêt de plusieurs penseurs actifs entre le cinquième et le troisième siècle avant J.-C. Un texte-clé est un fragment d’ Héraclite, transmis par Prophyre, qui fait allusion à la coïncidence entre le commencement et la fin dans la circonférence d’ un cercle. Après analyse du contexte dans lequel ce fragment se place, trois interprétations sont examinées : le cercle représente la régularité des processus de grande ampleur ; le cercle offre un exemple géométrique de l’ unité ou de la coïncidence des contraires ; et le cercle renvoie à l’ unité des processus microcosmiques qui ont trait à l’ âme. Je me tourne ensuite vers les théoriciens médicaux qui traitent de la coïncidence du commencement et de la fin dans les cercles et les circuits : (a) l’ auteur de Du régime, qui tente de montrer l’ interconnexion entre macrocosme, microcosme et techniques ; (b) les auteurs de Des lieux dans l’ homme et Nature des os, qui mettent l’ accent sur l’ unité organique des parties du corps ; et (c) Alcméon de Crotone, qui décrit la mort des êtres humains comme un échec à terminer un circuit. Un examen du fragment en liaison avec la littérature médicale met en relief la diversité de la tradition antique de même que la nouveauté de la pensée d’ Héraclite.Kouloumentas Stavros. Heraclitus and the Medical Theorists on the Circle. In: Dialogues d'histoire ancienne, vol. 44, n°2, 2018. pp. 43-63