544 research outputs found

    Remote Photonic THz Generation using an Optical Frequency Comb and Multicore Fiber

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    This paper proposes and demonstrates a photonic THz generation technique based on an optical frequency comb and multicore fiber (MCF) transmission, with the advantage of remote generation with great reconfigurability and reduced digital signal processing (DSP). The feasibility of the proposed technique is evaluated experimentally comparing the performance when transmitting a data wavelength and a local oscillator for optical heterodyning over a single core or over different cores in a 1-km MCF link. The proposed remote photonic THz generation technique is demonstrated employing a 16QAM 12.5 GBd signal. A short wireless transmission at 183 GHz center frequency with 0.25 m antenna-separation is achieved after 1 km MCF, meeting the soft-decision decision forward error correction (SD-FEC) bit error rate (BER) recommendation of 210-2. The analysis includes the received photocurrent range for which the BER meets the standard hard-decision forward error correction (HD-FEC) recommendation of 3.810-3 BER. The BER performance is analyzed considering different DSP configurations, with and without frequency offset estimation (FOE) and decision-driven least mean squares (DD LMS) equalization. The performance of the remote photonic THz generation technique is evaluated comparatively against traditional free-running laser transmission over MCF, confirming the advantage of using comb generation to reduce the frequency offset fluctuation and simplify the DSP

    Multicore fiber-assisted photonic sub-THz generation for full-duplex wireless transmission

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    This paper evaluates experimentally a centralized radio access network (C-RAN) based on multi-core fiber (MCF) for the transmission of high-bandwidth signals in the sub-THz band. We compare the system performance when the data and carrier wavelengths to be mixed at the receiver for optical heterodyning are transmitted over the same or over different cores of a MCF link. Full-duplex transmission on MCF is evaluated using the same received wireless signal downconverted and transmitted back as uplink over the same carrier wavelength. The performance with different digital signal processing (DSP) configurations and with higher-power interference in the other cores are also analyzed in this work. Successful provision of 12.5 GBd 16QAM signals is achieved after 1-km of 7-core MCF transmission including a short wireless link at 182 GHz, obtained with optical heterodyning. C-RAN implementation with MCF simplifies the remote nodes as all the lasers can be located in the central office, while minimizing the number of lasers needed at the central office thanks to wavelength re-use. It also provides more flexibility to the system, as it enables using the same LO for different purposes (i.e. THz generation of other data or optical modulation for uplink transmission)

    Denominación, alternancia onomástica y redenominación de animales domésticos

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    Este artículo tiene como objetivo analizar las razones que llevan a bautizar a perros y gatos con un nombre y demostrar que no reciben una sino múltiples denominaciones a lo largo de su vida. Para nuestra investigación, además de consultar una extensa bibliografía y fuentes muy diversas, hemos realizado múltiples entrevistas y encuestas de elaboración propia. En el trabajo, en primer lugar, se explica lo que significa otorgar un nombre a estas mascotas, con las que se convive y se establecen lazos afectivos. A continuación, se destaca la existencia de diferentes designaciones con las que se alude a un mismo animal de compañía, que alternan con la oficial. Finalmente, se indican los casos de redenominación de la mascota, como cambio de propietario, equivocación en cuanto al sexo, discordancia entre el nombre y el aspecto o la personalidad, dificultades en la pronunciación, confusión e incorrección desde el punto de vista político.  Finisterre (2005) is the literary recreation of Memorias by Manuel Baigorria, a unitarian exiled among the Ranquel Indians, from the perspective of Rosalind Kildare Neira, a Galician-Irish captive, who, later, became a machi o “doctor” in the indigenous community. Its structure as an epistolary novel –based on the letters written in Cape Finisterre by Rosalind for the young Elizabeth Armstrong, who resides in London– contributes to two parallel objectives: relating the “captive” experience in the Argentine Pampa of the sender and revealing the maternal identity of the receiver, erased intentionally by her own father. This “peripheral” voice, which feminizes the Memorias’ refl ections about war and anthropological matters, develops the question of the dichotomy “civilization” and “barbarism” through the condition and evaluation of the female figure in the “civilized” world and the “barbarian” one. 

    Sinónimos centros de atracción perenne en Martes de carnaval

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    El artículo se inscribe dentro del marco de la tendencia a comentar las características del rico lenguaje valleinclanesco. En concreto, se analiza en su obra un procedimiento retórico, la sinonimia, magistralmente utilizado por el autor. Los campos semánticos objeto de estudio son el diablo, la muerte, la embriaguez, el dinero y la prostitución, todos ellos vinculados al tabú lingüístico. This article features inside the tendency to comment the richness of Valle Inclán’s language. A rhetorical process is analyzed in its work: the use of synonyms, marvelously employed by the author. The semantic fields studied are the devil, death, drunkenness, money and prostitution, all of them related with linguistic taboo

    Quality of analgesic treatment in patients with advanced prostate cancer: do we do a better job now? The Swiss Group for Clinical Cancer Research (SAKK) experience

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    Goals of work: The aim of this study was to evaluate pain intensity and the application of the WHO guidelines for cancer pain treatment in patients with prostate cancer treated at Swiss cancer centers. Materials and methods: We analyzed a series of five multicenter phase II clinical trials which examined the palliative effect of different chemotherapies in patients with advanced hormone-refractory prostate carcinoma. Of 170 patients, 1,018 visits were evaluable for our purpose, including ratings of pain intensity by patients and prescribed analgesics. Main results: No or mild pain was indicated by patients in 36 to 55% of the visits, more than mild pain in 30 to 46%. In 21% of the visits, the WHO pain treatment criteria (treatment according to one of the three steps; oral, rectal or transdermal application of the main dose; administration on a regular schedule) were fulfilled, and the Cleeland index was positive according to all recommendations. In 6% of the visits, neither the WHO criteria were fulfilled nor was the Cleeland index positive. This indicates insufficient pain treatment not following the WHO guidelines and that the prescribed analgesics were not sufficiently potent for the rated pain intensity. Conclusions: In this selective Swiss sample, the standard of analgesic treatment is high. However, there is still scope for improvement. This cannot solely be solved by improving the knowledge of the physicians. Programs to change the patients' attitude towards cancer pain, training to improve the physicians' communication skills, and institutional changes may be promising strategie

    5-Fluorouracil as protracted continuous intravenous infusion can be added to full-dose docetaxel (Taxotere®)-cisplatin in advanced gastric carcinoma: a phase I-II trial

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    Background: A phase I-II multicenter trial was conducted to define the maximum tolerated dose (MTD) according to tolerance and toxicity (primary objective), as well as to describe the clinical activity, in terms of response and survival (secondary objectives), of a combination of 5-fluorouracil (5-FU) in protracted continuous intravenous infusion (p.i.v.) with docetaxel and cisplatin for patients with advanced gastric cancer. Patients and methods: Patients with measurable unresectable and/or metastatic gastric carcinoma, World Health Organization performance status ≤1, normal hematological and renal functions, adequate hepatic function and not pretreated for advanced disease by chemotherapy, received up to eight cycles of a combination of docetaxel on day 1, cisplatin on day 1 and 5-FU p.i.v. on days 1-14 (TCF) every 3 weeks, which was escalated up to the MTD, defined by the occurrence of dose-limiting toxicity in two patients in one dose level. Results: Fifty-two patients were accrued and treated (43 in the phase I part of the trial and nine additional at the recommended dose level). A median of five cycles/patient was given. The recommended dose of TCF was docetaxel 85 mg/m2 on day 1, cisplatin 75 mg/m2 on day 1 and 5-FU p.i.v. 300 mg/m2/day on days 1-14. Grade ≥3 toxicities were neutropenia 79%, alopecia 46%, fatigue 23%, mucositis 10%, diarrhea 19%, nausea/vomiting 13%, neurological 4% and palmar-plantar 2%. Ten non-fatal febrile neutropenia episodes were recorded in eight patients. There were no treatment-related deaths. Among 41 patients with measurable disease (79%), we observed one complete and 20 partial responses for an overall intent-to-treat response rate of 51% (95% confidence interval 35-67%). Five patients (20%) had stable disease for ≥12 weeks (four cycles). The median overall survival was 9.3 months. Conclusions: 5-FU p.i.v. at 300 mg/m2/day for 2 weeks out of three could be safely added to the docetaxel-cisplatin (TC) combination, but the dose of docetaxel had to be reduced to 75 mg/m2 in a subsequent phase II trial. This drug regimen seems to be very active in advanced gastric cancer. Comparison with both TC and ECF in a randomized SAKK trial is ongoin

    Recovery from recurrent depression with mindfulness-based cognitive therapy and antidepressants: a qualitative study with illustrative case studies

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    Objectives: This study aimed to describe the recovery journeys of people with a history of recurrent depression who took part in a psychosocial programme designed to teach skills to prevent depressive relapse (mindfulness-based cognitive therapy (MBCT)), alongside maintenance antidepressant medication (ADM). Design: A qualitative study embedded within a multicentre, single blind, randomised controlled trial (the PREVENT trial). Setting: Primary care urban and rural settings in the UK. Participants 42 people who participated in the MBCT arm of the parent trial were purposively sampled to represent a range of recovery journeys. Interventions: MBCT involves eight weekly group sessions, with four refresher sessions offered in the year following the end of the programme. It was adapted to offer bespoke support around ADM tapering and discontinuation. Methods: Written feedback and structured in-depth interviews were collected in the 2 years after participants undertook MBCT. Data were analysed using thematic analysis and case studies constructed to illustrate the findings. Results: People with recurrent depression have unique recovery journeys that shape and are shaped by their pharmacological and psychological treatment choices. Their journeys typically include several over-arching themes: (1) beliefs about the causes of depression, both biological and psychosocial; (2) personal agency, including expectations about their role in recovery and treatment; (3) acceptance, both of depression itself and the recovery journey; (4) quality of life; (5) experiences and perspectives on ADM and ADM tapering-discontinuation; and (6) the role of general practitioners, both positive and negative. Conclusions: People with recurrent depression describe unique, complex recovery journeys shaped by their experiences of depression, treatment and interactions with health professionals. Understanding how several themes coalesce for each individual can both support their recovery and treatment choices as well as health professionals in providing more accessible, collaborative, individualised and empowering care. :Trial registration number: Clinical trial number ISRCTN26666654; post results.</p
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