9,158 research outputs found

    Entanglement-Assisted Quantum Error Correction with Linear Optics

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    We construct a theory of continuous-variable entanglement-assisted quantum error correction. We present an example of a continuous-variable entanglement-assisted code that corrects for an arbitrary single-mode error. We also show how to implement encoding circuits using passive optical devices, homodyne measurements, feedforward classical communication, conditional displacements, and off-line squeezers.Comment: 8 pages, 1 figure, major expansion of paper with detailed exampl

    A Framework for Data Warehousing Research

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    This paper proposes a framework for data warehousing research. The framework includes environmental, organizational, personal, data and technological variables, which influence the development and use of a data warehouse, and dependent variables, which are useful in evaluating system success. The framework attempts to provide directions for future data warehousing research and development

    Evaluations of co-brands: a two-country comparison

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    This paper explores consumer reactions to a brand alliance, with perceptions of the parent brands, perceived fit between the brands and fit between product categories as the drivers. Drawing on previous work on co-brands (Simonin and Ruth, 1998; Baumgarth, 2000), two simultaneous studies of four consumer brand pairings were conducted in the UK (n=122) and Italy (n=125) using respondents from an online panel. Important differences between the studies are identified and possible cultural explanations for deviant outcomes are discussed

    Evaluating Web Data for Data Mining

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    Organizations’ operational data constructs the major data source for their data warehouse. The exponential development of WWW has made Internet an immense database containing all kinds of information with various types of data structures. Organizations are increasingly interested in capturing web data into their data warehousing systems to enlarge their data source for decision supporting, therefore improving accuracy and effectiveness of their decision making. This research thoroughly analyzes the data value of web data to data warehousing as well as business decision making, discusses the feasibility and potential problem of loading web data into data warehouse system, and provides a framework for evaluating web data for data warehousing purpose. Web data analysis and evaluation is regarded as a prerequisite for Web Integration - a breakthrough approach in furnishing data warehouse input: extracting, scrubbing, transforming web data and loading it into data warehouse systems to support organization decision making

    The Role of Information Technology in One-to-One Marketing

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    The short, fifty or so year history of modern information technology is replete with examples, large and small, of how IT has enabled changes in business organizations, business practices, and, indeed, entire business models. Without IT there would be no just-in- time inventory management, no instant credit card verification, and no email. IT has been credited with helping to eliminate levels of management and providing executives with the data they need for decision making. Indeed, business process re-engineering is predicated on the use of IT as the driver for organizational change. The purpose of this tutorial will be to discuss the role of IT in the exciting changes taking place in the field of marketing and, in particular, in what is becoming known as one-to- one marketing

    Complex CatSper-dependent and independent [Ca2<sup>+</sup>]i signalling in human spermatozoa induced by follicular fluid

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    STUDY QUESTION: Does progesterone in human follicular fluid (hFF) activate CatSper and do other components of hFF modulate this effect and/or contribute separately to hFF-induced Ca2+ signaling?SUMMARY ANSWER: hFF potently stimulates CatSper and increases [Ca2+]i, primarily due to high concentrations of progesterone, however,other components of hFF also contribute to [Ca2+]i signaling, including modulation of CatSper channel activity and inhibition of [Ca2+]i oscillations.WHAT IS KNOWN ALREADY: CatSper, the principal Ca2+ channel in spermatozoa, is progesterone-sensitive and essential for fertility. Both hFF and progesterone, which is present in hFF, influence sperm function and increase their [Ca2+]i.STUDY DESIGN, SIZE, DURATION: This basic medical research study used semen samples from &gt;40 donors and hFF from &gt;50 patients who were undergoing surgical oocyte retrieval for IVF/ICSI.PARTICIPANTS/MATERIALS, SETTING, METHODS: Semen donors and patients were recruited in accordance with local ethics approval (13/ES/0091) from the East of Scotland Research Ethics Service REC1. Activities of CatSper and KSper were assessed by patch clamp electrophysiology. Sperm [Ca2+]i responses were examined in sperm populations and single cells. Computer-assisted sperm analysis (CASA) parameters and penetration into viscous media were used to assess functional effects.MAIN RESULTS AND THE ROLE OF CHANCE: hFF and progesterone significantly potentiated CatSper currents. Under quasiphysiologicalconditions, hFF (up to 50%) failed to alter membrane K+ conductance or current reversal potential. hFF and progesterone (at an equivalent concentration) stimulated similar biphasic [Ca2+]i signals both in sperm populations and single cells. At a high hFF concentration (10%), the sustained (plateau) component of the [Ca2+]i signal was consistently greater than that induced by progesterone alone. In single cell recordings, 1% hFF-induced [Ca2+]i oscillations similarly to progesterone but with 10% hFF generation of [Ca2+]i oscillations was suppressed. After treatment to ‘strip’ lipid-derived mediators, hFF failed to significantly stimulate CatSper currents but induced small [Ca2+]i responsesthat were greater than those induced by the equivalent concentration of progesterone after stripping. Similar [Ca2+]i responses were observed when sperm pretreated with 3 μM progesterone (to desensitize progesterone responses) were stimulated with hFF or stripped hFF. hFF stimulated viscous media penetration and was more effective than the equivalent does of progesterone.LARGE SCALE DATA: N/A.LIMITATIONS, REASONS FOR CAUTION: This was an in vitro study. Caution must be taken when extrapolating these results in vivo.WIDER IMPLICATIONS OF THE FINDINGS: This study directly demonstrates that hFF activates CatSper and establishes that the biologically important effects of hFF reflect, at least in part, action on this channel, primarily via progesterone. However, these experiments also demonstrate that other components of hFF both contribute to the [Ca2+]i signal and modulate the activation of CatSper. Simple in vitro experiments performed out of the context of the complex in vivo environment need to be interpreted with caution

    Single-cell analysis of [Ca<sup>2+</sup>]i signalling in sub-fertile men:characteristics and relation to fertilization outcome

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    STUDY QUESTIONWhat are the characteristics of progesterone-induced (CatSper-mediated) single cell [Ca2+]i signals in spermatozoa from sub-fertile men and how do they relate to fertilizing ability?SUMMARY ANSWERSingle cell analysis of progesterone-induced (CatSper-mediated) [Ca2+]i showed that reduced progesterone-sensitivity is a common feature of sperm from sub-fertile patients and is correlated with fertilization rate.WHAT IS KNOWN ALREADYStimulation with progesterone is a widely used method for assessing [Ca2+]i mobilization by activation of CatSper in human spermatozoa. Although data are limited, sperm population studies have indicated an association of poor [Ca2+]i response to progesterone with reduced fertilization ability.STUDY DESIGN, SIZE, DURATIONThis was a cohort study using semen samples from 21 donors and 101 patients attending the assisted conception unit at Ninewells Hospital Dundee who were undergoing ART treatment. Patients were recruited from January 2016 to June 2017.PARTICIPANTS/MATERIALS, SETTING, METHODSSemen donors and patients were recruited in accordance with local ethics approval (13/ES/0091) from the East of Scotland Research Ethics Service (EoSRES) REC1. [Ca2+]i responses were examined by single cell imaging and motility parameters assessed by computer-assisted sperm analysis (CASA).MAIN RESULTS AND THE ROLE OF CHANCEFor analysis, patient samples were divided into three groups IVF(+ve) (successful fertilization; 62 samples), IVF-FF (failed fertilization; eight samples) and ICSI (21 samples). A further 10 IVF samples showed large, spontaneous [Ca2+]i oscillations and responses to progesterone could not be analysed. All patient samples loaded with the [Ca2+]i-indicator fluo4 responded to progesterone stimulation with a biphasic increase in fluorescence (transient followed by plateau) which resembled that seen in progesterone-stimulated donor samples. The mean normalized response (progesterone-induced increase in fluorescence normalized to resting level) was significantly smaller in IVF-FF and ICSI patient groups than in donors. All samples were further analysed by plotting, for each cell, the relationship between resting fluorescence intensity and the progesterone-induced fluorescence increment. In donor samples these plots overlaid closely and had a gradient of ≈ 2 and plots for most IVF(+ve) samples closely resembled the donor distribution. However, in a subset (≈ 10%) of IVF(+ve) samples, 3/8 IVF-FF samples and one-third of ICSI samples the gradient of the plot was significantly lower, indicating that the response to progesterone of the cells in these samples was abnormally small. Examination of the relationship between gradient (regression coefficient of the plot) in IVF samples and fertilization rate showed a positive correlation. In IVF-FF and ICSI groups, the proportion of cells in which a response to progesterone could be detected was significantly lower than in donors and IVF (+ve) patients. Approximately 20% of cells in donor, IVF(+ve) and ICSI samples generated [Ca2+]i oscillations when challenged with progesterone but in IVF-FF samples only ≈ 10% of cells generated oscillations and there was a significantly greater proportion of samples where no oscillations were observed. Levels of hyperactivated motility were lower in IVF(+ve) and IVF-FF groups compared to controls, IVF-FF also having lower levels than IVF(+ve).LIMITATIONS, REASONS FOR CAUTIONThis is an in vitro study and caution must be taken when extrapolating these results in vivo.WIDER IMPLICATIONS OF THE FINDINGSThis study reveals important details of impaired [Ca2+]i signalling in sperm from sub-fertile men that cannot be detected in population studies

    Calgary, Edmonton and the University of Alberta: the extraordinary medical mobilization by Canada’s newest province

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    The Canadian contribution of medical services to the British Empire during the First World War was a national endeavour. Physicians from across the country enlisted in local regiments to join. No other region provided more physicians per capita than the newly formed province of Alberta. Largely org anized through the Medical School of the University of Alberta, the No. 11 Canadian Field Ambulance out of Edmonton and the No. 8 Canadian Field Ambulance out of Calgary ultimately enlisted between one-third and half of the province’s doctors to the war campaign. Many individuals from this region distinguished themselves, including LCol J.N. Gunn from Calgary, who commanded the No. 8 Canadian Field Ambulance; Maj Heber Moshier, one of the founders of the School of Pharmacy at the University of Alberta; and Dr. A.C. Rankin, who would go on to be the first Dean of Medicine at the University of Alberta. These Canadian heroes, and the many others like them who served with the No. 8 and 11 Field Ambulances, personify the sacrifice, strength and resilience of the medical community in Alberta and should not be forgotten
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