299 research outputs found

    VHF discharges in storm cells producing microbursts

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    An experiment was carried out in which 3-D mapping of VHF sources was compared to a 3-D description of the reflectivity and dynamics of associated cloud cells observed by a radar network. Data from 61 microbursts were analyzed and it was found that, in 93 pct. of the cases, electrical activity precedes outflow development. The results confirm that the peak in intracloud activity precedes the maximum value of the outflow

    Single-frequency, pulsed Yb3+-doped multicomponent phosphate power fiber amplifier

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    High-power, single-frequency, pulsed fiber amplifiers are required in light detection and ranging, coherent laser detection, and remote sensing applications to reach long range within a short acquisition time. However, the power-scaling of these amplifiers is limited by nonlinearities generated in the optical fibers, in particular by stimulated Brillouin scattering (SBS). In this regard, the use of multicomponent phosphate glasses maximizes the energy extraction and minimizes nonlinearities. Here, we present the development of a single-stage, hybrid, pulsed fiber amplifier using a custom-made multicomponent Yb-doped phosphate fiber. The performance of the phosphate fiber was compared to a commercial Yb-doped silica fiber. While the latter showed SBS limitation at nearly 6.5 kW for 40 cm length, the maximum achieved output peak power for the multicomponent Yb-doped phosphate fiber was 11.7 kW for 9 ns pulses using only 20 cm with no sign of SBS

    Avoidable cancers in the Nordic countries-the potential impact of increased physical activity on postmenopausal breast, colon and endometrial cancer

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    Background: Physical activity has been shown to reduce the risk of colon, endometrial and postmenopausal breast cancer. The aim of this study was to quantify the proportion of the cancer burden in the Nordic countries linked to insufficient levels of leisure time physical activity and estimate the potential for cancer prevention for these three sites by increasing physical activity levels. Methods: Using the Prevent macrosimulation model, the number of cancer cases in the Nordic countries over a 30-year period (2016-2045) was modelled, under different scenarios of increasing physical activity levels in the population, and compared with the projected number of cases if constant physical activity prevailed. Physical activity (moderate and vigorous) was categorised according to metabolic equivalents (MET) hours in groups with sufficient physical activity (15+ MET-hours/week), low deficit (9 to Results: If no one had insufficient levels of physical activity, about 11,000 colon, endometrial and postmenopausal breast cancer cases could be avoided in the Nordic countries in a 30-year period, which is 1% of the expected cases for the three cancer types. With a 50% reduction in all deficit groups by 2025 or a 100% reduction in the group of high deficit, approximately 0.5% of the expected cases for the three cancer types could be avoided. The number and percentage of avoidable cases was highest for colon cancer. Conclusion: 11,000 cancer cases could be avoided in the Nordic countries in a 30-year period, if deficit in physical activity was eliminated. (C) 2019 Elsevier Ltd. All rights reserved.Peer reviewe

    A visual summary of the EUROCARE-4 results: a UK perspective.

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    BACKGROUND: This paper provides a one-page visual summary of the previously published relative survival estimates for 42 types of cancers in 23 countries in Europe. METHODS: The cancer patients in these analyses were 15 years or older at the time of their diagnosis in the period 1995-1999. Follow-up was to the end of 2003 and relative survival estimates were computed by the cohort method. RESULTS: The analysis of 1-year survival had good discriminatory power and visibly separated a group of countries with consistently high survival estimates (Switzerland, France, Sweden, Belgium and Italy) and another group of countries with lower estimates (Poland, Czech Republic, Ireland, Denmark and United Kingdom-Northern Ireland). After the first year, there was less variation between the countries. CONCLUSION: To more fully understand the UK situation, a rational comparison would select countries with data-quality, prosperity and healthcare systems that are similar to the United Kingdom. In otherwise comparable populations, a pronounced difference in 1-year survival is most likely to be due to variation in a strong prognostic factor, which exerts its effect in the short term. A likely explanation for the short-term survival deficit in the United Kingdom compared with the Nordic countries is a less favourable stage distribution in the United Kingdom. However, the present superficial analysis does not exclude possible functions for other factors relating to the organisation and quality of cancer care services

    Survival trends in patients diagnosed with colon and rectal cancer in the nordic countries 1990-2016 : The NORDCAN survival studies

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    Background: Survival of patients with colon and rectal cancer has improved in all Nordic countries during the past decades. The aim of this study was to further assess survival trends in patients with colon and rectal cancer in the Nordic countries by age at diagnosis and to present additional survival measures. Methods: Data on colon and rectal cancer cases diagnosed in the Nordic countries between 1990 and 2016 were obtained from the NORDCAN database. Relative survival was estimated using flexible parametric models. Both age-standardized and age-specific measures for women and men were estimated from the models, as well as reference-adjusted crude probabilities of death and life-years lost. Results: The five-year age-standardized relative survival of colon and rectal cancer patients continued to improve for women and men in all Nordic countries, from around 50% in 1990 to about 70% at the end of the study period. In general, survival was similar across age and sex. The largest improvement was seen for Danish men and women with rectal cancer, from 41% to 69% and from 43% to 71%, respectively. The age-standardized and reference-adjusted five-year crude probability of death in colon cancer ranged from 30% to 36% across countries, and for rectal cancer from 20% to 33%. The average number of age-standardized and reference-adjusted life-years lost ranged between six and nine years. Conclusion: There were substantial improvements in colon and rectal cancer survival in all Nordic countries 1990-2016. Of special note is that the previously observed survival disadvantage in Denmark is no longer present. (C) 2022 The Author(s). Published by Elsevier Ltd.Peer reviewe
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