86 research outputs found

    Correlation of Isotope Count With Sentinel Node Positivity in Vulvar Cancer

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    Objective: Sentinel node biopsy (SNB) has become standard of care in early stage vulvar cancer. As the correlation of isotope count with the presence of metastases remains unclear, often several active nodes are excised per groin. This can result in increased morbidity in node-negative disease despite of SNB. In the current analysis, we assess whether resection of the hottest node could be sufficient to detect sentinel lymph node (SLN) metastasis. Methods: Patients with primary vulvar cancer receiving an SNB with radioactive tracer at the University Medical Center Hamburg-Eppendorf between 2008 and 2015 were evaluated. Results: A total of 145 patients with SNB were analyzed;thereof, 144 underwent bilateral SNB, resulting in 289 analyzed groins. A median of 2 SLNs (range, 1-7) per groin were removed. From 94 (32.5%) of 289 groins, more than 2 SLNs were excised. Median overall SLN isotope count was 1400 cps. In 50 groins, a positive SLN was detected (unilateral in 38 patients, bilateral in 6). The median number of positive SLN per groin was 1 (range, 1-4). The SLN with the highest isotope count carried metastases in 36 (78.3%) of 46 groins (in 4 cases, the highest count was unknown). In 10 (21.7%) of 46 positive groins, the SLN with the highest count was not the metastatic SLN (9/10 second highest count). Median count of these 10 SLN was 60% of the highest count with a range from 11.0% to 74.0%. Conclusions: The highest isotope count does not reliably detect the positive SLN in vulvar cancer. To prevent mostly fatal groin recurrences, surgeons should continue to remove all SLN accumulating relevant radioactive tracer over background activity

    Correlation functions near Modulated and Rough Surfaces

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    In a system with long-ranged correlations, the behavior of correlation functions is sensitive to the presence of a boundary. We show that surface deformations strongly modify this behavior as compared to a flat surface. The modified near surface correlations can be measured by scattering probes. To determine these correlations, we develop a perturbative calculation in the deformations in height from a flat surface. Detailed results are given for a regularly patterned surface, as well as for a self-affinely rough surface with roughness exponent ζ\zeta. By combining this perturbative calculation in height deformations with the field-theoretic renormalization group approach, we also estimate the values of critical exponents governing the behavior of the decay of correlation functions near a self-affinely rough surface. We find that for the interacting theory, a large enough ζ\zeta can lead to novel surface critical behavior. We also provide scaling relations between roughness induced critical exponents for thermodynamic surface quantities.Comment: 31 pages, 2 figure

    From the development of an open-source energy modelling tool to its application and the creation of communities of practice: The example of OSeMOSYS

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    In the last decades, energy modelling has supported energy planning by offering insights into the dynamics between energy access, resource use, and sustainable development. Especially in recent years, there has been an attempt to strengthen the science-policy interface and increase the involvement of society in energy planning processes. This has, both in the EU and worldwide, led to the development of open-source and transparent energy modelling practices. This paper describes the role of an open-source energy modelling tool in the energy planning process and highlights its importance for society. Specifically, it describes the existence and characteristics of the relationship between developing an open-source, freely available tool and its application, dissemination and use for policy making. Using the example of the Open Source energy Modelling System (OSeMOSYS), this work focuses on practices that were established within the community and that made the framework's development and application both relevant and scientifically grounded

    From the development of an open-source energy modelling tool to its application and the creation of communities of practice: The example of OSeMOSYS.

    Get PDF
    In the last decades, energy modelling has supported energy planning by offering insights into the dynamics between energy access, resource use, and sustainable development. Especially in recent years, there has been an attempt to strengthen the science-policy interface and increase the involvement of society in energy planning processes. This has, both in the EU and worldwide, led to the development of open-source and transparent energy modelling practices. This paper describes the role of an open-source energy modelling tool in the energy planning process and highlights its importance for society. Specifically, it describes the existence and characteristics of the relationship between developing an open-source, freely available tool and its application, dissemination and use for policy making. Using the example of the Open Source energy Modelling System (OSeMOSYS), this work focuses on practices that were established within the community and that made the framework's development and application both relevant and scientifically grounded

    Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

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    Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

    A Stochastic MPEC Approach for Grid Tariff Design with Demand-Side Flexibility

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    As the end-users increasingly can provide fexibility to the power system, it is important to consider how this fexibility can be activated as a resource for the grid. Electricity network tarifs is one option that can be used to activate this fexibility. Therefore, by designing efcient grid tarifs, it might be possible to reduce the total costs in the power system by incentivizing a change in consumption patterns. This paper provides a methodology for optimal grid tarif design under decentralized decision-making and uncertainty in demand, power prices, and renewable generation. A bilevel model is formulated to adequately describe the interaction between the end-users and a distribution system operator. In addition, a centralized decisionmaking model is provided for benchmarking purposes. The bilevel model is reformulated as a mixed-integer linear problem solvable by branch-and-cut techniques. Results based on both deterministic and stochastic settings are presented and discussed. The fndings suggest how electricity grid tarifs should be designed to provide an efcient price signal for reducing aggregate network peaks.publishedVersio

    A Stochastic MPEC Approach for Grid Tariff Design with Demand-Side Flexibility

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    As the end-users increasingly can provide fexibility to the power system, it is important to consider how this fexibility can be activated as a resource for the grid. Electricity network tarifs is one option that can be used to activate this fexibility. Therefore, by designing efcient grid tarifs, it might be possible to reduce the total costs in the power system by incentivizing a change in consumption patterns. This paper provides a methodology for optimal grid tarif design under decentralized decision-making and uncertainty in demand, power prices, and renewable generation. A bilevel model is formulated to adequately describe the interaction between the end-users and a distribution system operator. In addition, a centralized decisionmaking model is provided for benchmarking purposes. The bilevel model is reformulated as a mixed-integer linear problem solvable by branch-and-cut techniques. Results based on both deterministic and stochastic settings are presented and discussed. The fndings suggest how electricity grid tarifs should be designed to provide an efcient price signal for reducing aggregate network peaks

    Effect of hydrological factors on temperature and oxygen distribution in floodplain lakes a case study of the Drwęca floodplain

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    Starorzecza stanowią integralny element w dolinach rzek meandrujących. Kluczową rolą w funkcjonowaniu wszystkich ekosystemów wodnych w dolinach rzek jest reżim hydrologiczny. Badania nad rozkładem termiczno-tlenowym starorzeczy przeprowadzono w latach 2007-2009 na podstawie sezonowego rytmu profilowania hydrochemicznego w 6 starorzeczach doliny Drwęcy w północnej Polsce. W wyniku przeprowadzonych obserwacji stwierdzono, że fluktuacje zwierciadła wody rzecznej znacznie wpływają na skład fizykochemiczny wód starorzeczy. Wyjaśniają one zwiększone korelacje między stanami wód a natlenieniem. Szczególnym okresem w tym względzie jest wiosenne przesycenie wód tym gazem, gdy po długim okresie utrzymywania się pokrywy lodowej starorzecza odświeżają swe wody, biorąc „głęboki oddech” przed tlenowym deficytem letnim.Oxbow lakes are an integral element in meandering rivers valleys. A key role in the functioning of all floodplain water bodies is hydrological regime. The study on temperature and oxygen distribution in oxbow lakes was carried out in the years 2007-2009 based on seasonal sampling and vertical profiling of 6 oxbow lakes located along the Drweca River in northern Poland. Based on the investigations, it was found that river water-table fluctuations as well as alluvial groundwater movements modify chemical budget of floodplain lakes. The impact of hydrological connectivity in relation to the site specific hydrological conditions on the vertical profiles showed also differences between measurement sites within each water body

    A Stochastic MPEC Approach for Grid Tariff Design with Demand-Side Flexibility

    No full text
    As the end-users increasingly can provide fexibility to the power system, it is important to consider how this fexibility can be activated as a resource for the grid. Electricity network tarifs is one option that can be used to activate this fexibility. Therefore, by designing efcient grid tarifs, it might be possible to reduce the total costs in the power system by incentivizing a change in consumption patterns. This paper provides a methodology for optimal grid tarif design under decentralized decision-making and uncertainty in demand, power prices, and renewable generation. A bilevel model is formulated to adequately describe the interaction between the end-users and a distribution system operator. In addition, a centralized decisionmaking model is provided for benchmarking purposes. The bilevel model is reformulated as a mixed-integer linear problem solvable by branch-and-cut techniques. Results based on both deterministic and stochastic settings are presented and discussed. The fndings suggest how electricity grid tarifs should be designed to provide an efcient price signal for reducing aggregate network peaks
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