2,385 research outputs found

    Uncles ex Machina: Familial Epiphany in Euripides' Electra

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    At the close of Euripides’ Electra, the Dioscuri suddenly appear ‘on high’ to their distraught niece and nephew, who have just killed their mother, the divine twins’ mortal sister. This is in fact the second longest extant deus ex machina (after the final scene in Hippolytus), and the only scene in which a tragedian attempts to resolve directly the aftermath of the matricide. In this article, I argue that Castor's and Polydeuces’ sudden apparition to Orestes and Electra constitutes a specialised point of intersection between the mortal and immortal realms in Greek tragedy: familial epiphany, an appearance by a god who has an especially intimate relationship with those on stage. Euripides’ focus on the familial divine as a category accentuates various contradictions inherent to both ancient Greek theology and dramaturgy. The Dioscuri are a living paradox, ambiguously traversing the space between dead heroes and gods, managing at the same time to occupy both. They oscillate uniquely between the mortal and immortal worlds, as different sources assign different fathers to each brother, and others speak of each one possessing divinity on alternate days. As I propose, the epiphany of these ambiguous brothers crystallises the problem of the gods’ physical presence in drama. Tragedy is the arena in which gods burst suddenly into the mortal realm, decisively and irrevocably altering human action. The physical divine thus tends to be both marginal and directorial, tasked with reining in the plot or directing its future course. The appearance of the familial divine, on the other hand, can in fact obscure the resolution and future direction of a play, undermining the authority of the tragic gods. In the specific case of Electra, I contend that the involvement of the Dioscuri, who are Electra's and Orestes’ maternal uncles, produces a sense of claustrophobia at the close of the play, which simultaneously denies the resolution that is expected from a deus ex machina while also revealing the pessimistic nature of what is typically considered a reassuringly ‘domestic’ and character driven drama

    Pollinator attractiveness of five weeds

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    The number of pollinators in agro-ecosystems world wide has declined alarminglyin recent decades due to poora gricultural practices such as the intensive use of pesticides and monocultures.Postprint (published version

    Concentrated Ground Plane Booster Antenna Technology for Multiband Operation in Handset Devices

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    The current demand in the handset antenna field requires multiband antennas due to the existence of multiple communication standards and the emergence of new ones. At the same time, antennas with reduced dimensions are strongly required in order to be easily integrated. In this sense, the paper proposes a compact radiating system that uses two non-resonant elements to properly excite the ground plane to solve the abovementioned shortcomings by minimizing the required Printed Circuit Board (PCB) area while ensuring a multiband performance. These non-resonant elements are called here ground plane boosters since they excite an efficient mode of the ground plane. The proposed radiating system comprises two ground plane boosters of small dimensions of 5 mm x 5 mm x 5 mm. One is in charge of the low frequency region (0.824-0.960 GHz) and the other is in charge of the high frequency region (1.710-2.170 GHz). With the aim of achieving a compact configuration, the two boosters are placed close to each other in a corner of the ground plane of a handset device (concentrated architecture). Several experiments related to the coupling between boosters have been carried out in two different platforms (barphone and smartphone), and the best position and the required matching network are presented. The novel proposal achieves multiband performance at GSM850/900/1800/1900 and UMTS

    Commissioning and Evaluation of an Electronic Portal Imaging Device-Based In-Vivo Dosimetry Software.

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    This study reports on our experience with the in-vivo dose verification software, EPIgray® (DOSIsoft, Cachan, France). After the initial commissioning process, clinical experiments on phantom treatments were evaluated to assess the level of accuracy of the electronic portal imaging device (EPID) based in-vivo dose verification. EPIgray was commissioned based on the company's instructions. This involved ion chamber measurements and portal imaging of solid water blocks of various thicknesses between 5 and 35 cm. Field sizes varied between 2 x 2 cm2 and 20 x 20 cm2. The determined conversion factors were adjusted through an additional iterative process using treatment planning system calculations. Subsequently, evaluation was performed using treatment plans of single and opposed beams, as well as intensity modulated radiotherapy (IMRT) plans, based on recommendations from the task group report TG-119 to test for dose reconstruction accuracy. All tests were performed using blocks of solid water slabs as a phantom. For single square fields, the dose at isocenter was reconstructed within 3% accuracy in EPIgray compared to the treatment planning system dose. Similarly, the relative deviation of the total dose was accurately reconstructed within 3% for all IMRT plans with points placed inside a high-dose region near the isocenter. Predictions became less accurate than < 5% when the evaluation point was outside the treatment target. Dose at points 5 cm or more away from the isocenter or within an avoidance structure was reconstructed less reliably. EPIgray formalism accuracy is adequate for an efficient error detection system with verifications performed in high-dose volumes. It provides immediate intra-fractional feedback on the delivery of treatment plans without affecting the treatment beam. Besides the EPID, no additional hardware is required. The software evaluates local point dose measurements to verify treatment plan delivery and patient positioning within 5% accuracy, depending on the placement of evaluation points

    Mujeres piqueteras en Salta : experiencias y rebeldías

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    Fil: Andujar, Andrea. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Instituto Interdisciplinario de Estudios de Género; ArgentinaEntre los años 1997 y 2001, la provincia de Salta fue escenario de intensos conflictos\nsociales, originados en las consecuencias de la implementación del modelo neoliberal.\nParticularmente, Tartagal y General Mosconi, dos ciudades lindantes ubicadas en el\nnorte salteño, fueron los territorios en los que estas confrontaciones alcanzaron su\npunto más álgido dando lugar, asimismo, a la emergencia del movimiento piquetero\nlocal. Tanto en la construcción de este último como en los cortes de ruta, devenidos en\nherramientas preponderantes de estas protestas, la presencia activa de las mujeres fue\nmasiva. Ellas, con experiencias de participación política previa dispar y con disímil\npertenencia de clase, no sólo jaquearon su posicionamiento en la esfera de la\ndomesticidad. También retaron las normativas demarcatorias de la ocupación de los\nespacios públicos, impugnando con su práctica tanto las fronteras de lo político como la\ncirculación del poder. Este trabajo se propone explorar la trayectoria de las mujeres que\nprotagonizaron estas experiencias de lucha, acudiendo fundamentalmente al análisis\nde las memorias que han construido sobre sus propias acciones

    The response of taxonomic and functional diversity of the seed bank to agricultural intensification and soil properties in two Mediterranean cereal areas

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    Weed seed bank diversity has been severely impacted by agriculture intensifi cation. However, the functional consequences have been poorly studied in highly intensifi ed agro-ecosystems.Postprint (published version

    Towards MRI microarrays

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    Superparamagnetic iron oxide nanometre scale particles have been utilised as contrast agents to image staked target binding oligonucleotide arrays using MRI to correlate the signal intensity and relaxation times in different NMR fluids

    Hydrogen vs. Battery in the long-term operation. A comparative between energy management strategies for hybrid renewable microgrids

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    The growth of the world’s energy demand over recent decades in relation to energy intensity and demography is clear. At the same time, the use of renewable energy sources is pursued to address decarbonization targets, but the stochasticity of renewable energy systems produces an increasing need for management systems to supply such energy volume while guaranteeing, at the same time, the security and reliability of the microgrids. Locally distributed energy storage systems (ESS) may provide the capacity to temporarily decouple production and demand. In this sense, the most implemented ESS in local energy districts are small–medium-scale electrochemical batteries. However, hydrogen systems are viable for storing larger energy quantities thanks to its intrinsic high mass-energy density. To match generation, demand and storage, energy management systems (EMSs) become crucial. This paper compares two strategies for an energy management system based on hydrogen-priority vs. battery-priority for the operation of a hybrid renewable microgrid. The overall performance of the two mentioned strategies is compared in the long-term operation via a set of evaluation parameters defined by the unmet load, storage efficiency, operating hours and cumulative energy. The results show that the hydrogen-priority strategy allows the microgrid to be led towards island operation because it saves a higher amount of energy, while the battery-priority strategy reduces the energy efficiency in the storage round trip. The main contribution of this work lies in the demonstration that conventional EMS for microgrids’ operation based on battery-priority strategy should turn into hydrogen-priority to keep the reliability and independence of the microgrid in the long-term operation

    Assessment of image quality and dose calculation accuracy on kV CBCT, MV CBCT, and MV CT images for urgent palliative radiotherapy treatments.

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    A clinical workflow was developed for urgent palliative radiotherapy treatments that integrates patient simulation, planning, quality assurance, and treatment in one 30-minute session. This has been successfully tested and implemented clinically on a linac with MV CBCT capabilities. To make this approach available to all clinics equipped with common imaging systems, dose calculation accuracy based on treatment sites was assessed for other imaging units. We evaluated the feasibility of palliative treatment planning using on-board imaging with respect to image quality and technical challenges. The purpose was to test multiple systems using their commercial setup, disregarding any additional in-house development. kV CT, kV CBCT, MV CBCT, and MV CT images of water and anthropomorphic phantoms were acquired on five different imaging units (Philips MX8000 CT Scanner, and Varian TrueBeam, Elekta VersaHD, Siemens Artiste, and Accuray Tomotherapy linacs). Image quality (noise, contrast, uniformity, spatial resolution) was evaluated and compared across all machines. Using individual image value to density calibrations, dose calculation accuracies for simple treatment plans were assessed for the same phantom images. Finally, image artifacts on clinical patient images were evaluated and compared among the machines. Image contrast to visualize bony anatomy was sufficient on all machines. Despite a high noise level and low contrast, MV CT images provided the most accurate treatment plans relative to kV CT-based planning. Spatial resolution was poorest for MV CBCT, but did not limit the visualization of small anatomical structures. A comparison of treatment plans showed that monitor units calculated based on a prescription point were within 5% difference relative to kV CT-based plans for all machines and all studied treatment sites (brain, neck, and pelvis). Local dose differences >5% were found near the phantom edges. The gamma index for 3%/3 mm criteria was ≥95% in most cases. Best dose calculation results were obtained when the treatment isocenter was near the image isocenter for all machines. A large field of view and immediate image export to the treatment planning system were essential for a smooth workflow and were not provided on all devices. Based on this phantom study, image quality of the studied kV CBCT, MV CBCT, and MV CT on-board imaging devices was sufficient for treatment planning in all tested cases. Treatment plans provided dose calculation accuracies within an acceptable range for simple, urgently planned palliative treatments. However, dose calculation accuracy was compromised towards the edges of an image. Feasibility for clinical implementation should be assessed separately and may be complicated by machine specific features. Image artifacts in patient images and the effect on dose calculation accuracy should be assessed in a separate, machine-specific study. PACS number(s): 87.55.D-, 87.57.C-, 87.57.Q
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