6,784 research outputs found

    Photonic quantum memory in two-level ensembles based on modulating the refractive index in time: equivalence to gradient echo memory

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    We present a quantum memory protocol that allows to store light in ensembles of two-level atoms, e.g. rare-earth ions doped into a crystal, by modulating the refractive index of the host medium of the atoms linearly in time. We show that under certain conditions the resulting dynamics is equivalent to that underlying the gradient echo memory protocol, which relies on a spatial gradient of the atomic resonance frequencies. We discuss the prospects for an experimental implementation.Comment: 5 pages, 2 figure

    Toxicological approach to setting spacecraft maximum allowable concentrations for carbon monoxide

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    The Spacecraft Maximum Allowable Concentrations (SMACs) are exposure limits for airborne chemicals used by NASA in spacecraft. The aim of these SMACs is to protect the spacecrew against adverse health effects and performance decrements that would interfere with mission objectives. Because of the 1 and 24 hr SMACs are set for contingencies, minor reversible toxic effects that do not affect mission objectives are acceptable. The 7, 30, or 180 day SMACs are aimed at nominal operations, so they are established at levels that would not cause noncarcinogenic toxic effects and more than one case of tumor per 1000 exposed individuals over the background. The process used to set the SMACs for carbon monoxide (CO) is described to illustrate the approach used by NASA. After the toxicological literature on CO was reviewed, the data were summarized and separated into acute, subchronic, and chronic toxicity data. CO's toxicity depends on the formation of carboxyhemoglobin (COHb) in the blood, reducing the blood's oxygen carrying capacity. The initial task was to estimate the COHb levels that would not produce toxic effects in the brain and heart

    What is the Best Way to Produce Consensus and Buy in to Guidelines for Rectal Cancer?

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    Evidence-based guidelines are important tools and common pathways for translating evidence into clinical practice. It is most urgently needed when significant heterogeneity in practice exist. Actively engaging opinion leaders in the process of evidence-based guidelines development is important for several reasons. These include allowing the collective views of the practice communities to be represented, resolving heterogeneity in practice through discussion, and allowing credible recommendations to be formulated. Most importantly, the process itself is a tool for facilitating dissemination and implementation. Recognizing the gap between practice pattern and guideline recommendations, and devising strategies to address it represent an important step toward maximizing concordance between guideline and practice. Evidence-based recommendations serve as important reference points, against which we can measure, debate, and innovate from

    Review Essay: Deepening Deliberative Democracy – Experimentation vs. Naturalization

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    Hélène Landemore and Ana Tanasoca have recently proposed two different approaches to deepening the deliberative dimension of democracy. In Open Democracy (2020), Landemore introduces a novel paradigm of democracy—open democracy—which grants ordinary citizens access to an actual exercise of political power through innovative forms of democratic representation. In Deliberation Naturalized (2020), Tanasoca develops a naturalized normative theory of deliberative democracy which stresses the role of citizen deliberation in what she refers to as ‘naturalistic’ settings, i.e., the public sphere. Both texts invite us to stretch our imaginations of how contemporary democracy can be deepened in deliberative ways

    Bowel dysfunction after transposition of intestinal segments into the urinary tract : 8-year prospective cohort study

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    Purpose Bowel function may be disturbed after intestinal segments are transposed into the urinary tract to reconstruct or replace the bladder. In 1997, our group were the first to report major bowel dysfunction in a cohort of such patients: up to 42% of those who were asymptomatic preoperatively describing new bowel symptoms postoperatively including explosive diarrhoea, nocturnal diarrhoea, faecal urgency, faecal incontinence and flatus leakage . We now describe bowel symptoms in this same cohort eight years later (2005). Materials and Methods 116 patients were evaluable. Of the remaining 37 from the original report: 30 had died, five no longer wished to be involved, and two could not be traced. Patients were asked to complete postal questionnaires identical to those used in the first follow-up, assessing the severity of bowel symptoms and quality of life using two validated instruments. Responses were compared with those from the original study. The Nottingham Health Profile quality of life scores were also compared to age and sex matched norms. Results 96 (83%) completed eight-year follow-up questionnaires: 43 after ileal conduit diversion (Group 1), 17 after clam enterocystoplasty for overactive bladder (Group 2), 18 after reconstructed bladder for neurogenic bladder dysfunction (Group 3), and 18 with bladder replacement for non-neurogenic causes (Group 4). High prevalence rates of bowel symptoms persisted with no statistically significant differences between the two time points. Of those with symptoms in 2005, around 50% had reported similar symptoms in 1997. Clam enterocystoplasty patients (Group 2) still reported the highest prevalence (59%) of troublesome diarrhoea with one in two on regular anti-diarrhoeal medication. They also had high rates of faecal incontinence (47%), faecal urgency (41%) and nocturnal bowel movement (18%); with high proportions reporting a moderate or severe adverse effect on work (36%), social life (50%) and sex life (43%). High rates were also reported by neurogenic bladder dysfunction patients, including 50% with troublesome diarrhoea. This symptom was reported by 19% after ileal conduit and by 17% after bladder replacement for non-neurogenic causes. The impact of bowel symptoms on every-day activities and quality of life persisted, remaining most severe after clam enterocystoplasty, with 24% regretting undergoing the procedure because of subsequent bowel symptoms. Conclusions: After more than eight years, operations involving transposition of intestinal segments continue to be associated with high rates of bowel symptoms, which impact on everyday activities. These are particularly troublesome following enterocystoplasty for overactive bladder and bladder reconstruction for neurogenic bladder dysfunction. These risks should influence patient selection and potential patients should be warned prior to surgery

    Bowel dysfunction after transposition of intestinal segments into the urinary tract : 8-year prospective cohort study

    Get PDF
    Purpose Bowel function may be disturbed after intestinal segments are transposed into the urinary tract to reconstruct or replace the bladder. In 1997, our group were the first to report major bowel dysfunction in a cohort of such patients: up to 42% of those who were asymptomatic preoperatively describing new bowel symptoms postoperatively including explosive diarrhoea, nocturnal diarrhoea, faecal urgency, faecal incontinence and flatus leakage . We now describe bowel symptoms in this same cohort eight years later (2005). Materials and Methods 116 patients were evaluable. Of the remaining 37 from the original report: 30 had died, five no longer wished to be involved, and two could not be traced. Patients were asked to complete postal questionnaires identical to those used in the first follow-up, assessing the severity of bowel symptoms and quality of life using two validated instruments. Responses were compared with those from the original study. The Nottingham Health Profile quality of life scores were also compared to age and sex matched norms. Results 96 (83%) completed eight-year follow-up questionnaires: 43 after ileal conduit diversion (Group 1), 17 after clam enterocystoplasty for overactive bladder (Group 2), 18 after reconstructed bladder for neurogenic bladder dysfunction (Group 3), and 18 with bladder replacement for non-neurogenic causes (Group 4). High prevalence rates of bowel symptoms persisted with no statistically significant differences between the two time points. Of those with symptoms in 2005, around 50% had reported similar symptoms in 1997. Clam enterocystoplasty patients (Group 2) still reported the highest prevalence (59%) of troublesome diarrhoea with one in two on regular anti-diarrhoeal medication. They also had high rates of faecal incontinence (47%), faecal urgency (41%) and nocturnal bowel movement (18%); with high proportions reporting a moderate or severe adverse effect on work (36%), social life (50%) and sex life (43%). High rates were also reported by neurogenic bladder dysfunction patients, including 50% with troublesome diarrhoea. This symptom was reported by 19% after ileal conduit and by 17% after bladder replacement for non-neurogenic causes. The impact of bowel symptoms on every-day activities and quality of life persisted, remaining most severe after clam enterocystoplasty, with 24% regretting undergoing the procedure because of subsequent bowel symptoms. Conclusions: After more than eight years, operations involving transposition of intestinal segments continue to be associated with high rates of bowel symptoms, which impact on everyday activities. These are particularly troublesome following enterocystoplasty for overactive bladder and bladder reconstruction for neurogenic bladder dysfunction. These risks should influence patient selection and potential patients should be warned prior to surgery

    Capecitabine as Salvage Treatment for Lymphoepithelioma-Like Carcinoma of Lung

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    AbstractLymphoepithelioma-like carcinoma (LELC) of lung has previously demonstrated good clinical response to 5-fluorouracil containing chemotherapy regimen, similar to the observation in undifferentiated nasopharyngeal carcinoma. Capecitabine, which is converted into active 5-fluorouracil within tumor cells, has been found effective in colorectal, breast, and recently nasopharyngeal carcinomas. We report our experience in five patients with advanced or metastatic LELC of lung who were treated with single agent capecitabine as salvage chemotherapy. The finding of disease control in three of five patients, especially with exceptionally durable stable disease (14.8 months) in one patient, suggests the potential clinical activity of capecitabine in LELC of lung. Future studies on capecitabine-containing chemotherapy regimens in LELC of lung are warranted

    Ensemble Sales Forecasting Study in Semiconductor Industry

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    Sales forecasting plays a prominent role in business planning and business strategy. The value and importance of advance information is a cornerstone of planning activity, and a well-set forecast goal can guide sale-force more efficiently. In this paper CPU sales forecasting of Intel Corporation, a multinational semiconductor industry, was considered. Past sale, future booking, exchange rates, Gross domestic product (GDP) forecasting, seasonality and other indicators were innovatively incorporated into the quantitative modeling. Benefit from the recent advances in computation power and software development, millions of models built upon multiple regressions, time series analysis, random forest and boosting tree were executed in parallel. The models with smaller validation errors were selected to form the ensemble model. To better capture the distinct characteristics, forecasting models were implemented at lead time and lines of business level. The moving windows validation process automatically selected the models which closely represent current market condition. The weekly cadence forecasting schema allowed the model to response effectively to market fluctuation. Generic variable importance analysis was also developed to increase the model interpretability. Rather than assuming fixed distribution, this non-parametric permutation variable importance analysis provided a general framework across methods to evaluate the variable importance. This variable importance framework can further extend to classification problem by modifying the mean absolute percentage error(MAPE) into misclassify error. Please find the demo code at : https://github.com/qx0731/ensemble_forecast_methodsComment: 14 pages, Industrial Conference on Data Mining 2017 (ICDM 2017
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