Impact of measured and simulated tundra snowpack properties on heat transfer

Snowpack microstructure controls the transfer of heat to, as well as the temperature of, the underlying soils. In situ measurements of snow and soil properties from four field campaigns during two winters (March and November 2018, January and March 2019) were compared to an ensemble of CLM5.0 (Community Land Model) simulations, at Trail Valley Creek, Northwest Territories, Canada. Snow micropenetrometer profiles allowed for snowpack density and thermal conductivity to be derived at higher vertical resolution (1.25 mm) and a larger sample size (n=1050) compared to traditional snowpit observations (3 cm vertical resolution; n=115). Comparing measurements with simulations shows CLM overestimated snow thermal conductivity by a factor of 3, leading to a cold bias in wintertime soil temperatures (RMSE=5.8 ∘C). Two different approaches were taken to reduce this bias: alternative parameterisations of snow thermal conductivity and the application of a correction factor. All the evaluated parameterisations of snow thermal conductivity improved simulations of wintertime soil temperatures, with that of Sturm et al. (1997) having the greatest impact (RMSE=2.5 ∘C). The required correction factor is strongly related to snow depth () and thus differs between the two snow seasons, limiting the applicability of such an approach. Improving simulated snow properties and the corresponding heat flux is important, as wintertime soil temperatures are an important control on subnivean soil respiration and hence impact Arctic winter carbon fluxes and budgets

Simulating net ecosystem exchange under seasonal snow cover at an Arctic tundra site

Estimates of winter (snow-covered non-growing season) CO2 fluxes across the Arctic region vary by a factor of 3.5, with considerable variation between measured and simulated fluxes. Measurements of snow properties, soil temperatures, and net ecosystem exchange (NEE) at Trail Valley Creek, NWT, Canada, allowed for the evaluation of simulated winter NEE in a tundra environment with the Community Land Model (CLM5.0). Default CLM5.0 parameterisations did not adequately simulate winter NEE in this tundra environment, with near-zero NEE (< 0.01 gCm^-2d^-1) simulated between November and mid-May. In contrast, measured NEE was broadly positive (indicating net CO2 release) from snow-cover onset until late April. Changes to the parameterisation of snow thermal conductivity, required to correct for a cold soil temperature bias, reduced the duration for which no NEE was simulated. Parameter sensitivity analysis revealed the critical role of the minimum soil moisture threshold of decomposition (Ψmin) in regulating winter soil respiration. The default value of this parameter (Ψmin) was too high, preventing simulation of soil respiration for the vast majority of the snow-covered season. In addition, the default rate of change of soil respiration with temperature (Q10) was too low, further contributing to poor model performance during winter. As Ψmin and Q10 had opposing effects on the magnitude of simulated winter soil respiration, larger negative values of Ψmin and larger positive values of Q10 are required to simulate wintertime NEE more adequately.Natural Environment Research CouncilPeer Reviewe

Outcomes after gastrectomy according to the Gastrectomy Complications Consensus Group (GCCG) in the Dutch Upper GI Cancer Audit (DUCA)

Background: In 2019, the Gastrectomy Complications Consensus Group (GCCG) published a standardized set of complications aiming toward uniform reporting of post-gastrectomy complications. This study aimed to report outcomes after gastrectomy in the Netherlands according to GCCG definitions and compare them to previously reported national results and the European database reported by the GCCG. Methods: This nationwide, population-based cohort study included all patients undergoing gastrectomy for gastric cancer registered in the DUCA in 2020–2021. Postoperative morbidity and 30-day/in-hospital mortality were analyzed according to the GCCG definitions. For all patients, baseline characteristics and outcomes were compared with the GCCG cohort consisting of 27 European expert centers (GASTRODATA; 2017–2018). Results: In 2020–2021, 782 patients underwent gastrectomy in the Netherlands. Variation was seen in baseline characteristics between the Dutch and the GCCG cohort (N = 1349), most notably in minimally invasive surgery (80.6% vs 19.6%, p < 0.001). In the Netherlands, 223 (28.5%) patients developed a total of 407 complications, the most frequent being non-surgical infections (28.5%) and anastomotic leakage (13.4%). The overall complication and 30-day mortality rates were similar between the Dutch and GCCG cohort (28.5% vs 29.8%, p = 0.563; 3.7% vs 3.6%, p = 0.953). Higher surgical and endoscopic/radiologic reintervention rates were observed in the Netherlands compared to the GCCG cohort (10.7% vs 7.8%, p = 0.025; 10.9% vs 2.9%, p < 0.001). Conclusion: Reporting outcomes according to the standardized GCCG definitions allows for international benchmarking. Postoperative outcomes were comparable between Dutch and GCCG cohorts, but both exceed the international benchmark for expert gastrectomy care, highlighting targets for national and international quality improvement

Impact of measured and simulated tundra snowpack properties on heat transfer

Snowpack microstructure controls the transfer of heat to, as well as the temperature of, the underlying soils. In situ measurements of snow and soil properties from four field campaigns during two winters (March and November 2018, January and March 2019) were compared to an ensemble of CLM5.0 (Community Land Model) simulations, at Trail Valley Creek, Northwest Territories, Canada. Snow micropenetrometer profiles allowed for snowpack density and thermal conductivity to be derived at higher vertical resolution (1.25 mm) and a larger sample size (n = 1050) compared to traditional snowpit observations (3 cm vertical resolution; n = 115). Comparing measurements with simulations shows CLM overestimated snow thermal conductivity by a factor of 3, leading to a cold bias in wintertime soil temperatures (RMSE = 5.8 °C). Two different approaches were taken to reduce this bias: alternative parameterisations of snow thermal conductivity and the application of a correction factor. All the evaluated parameterisations of snow thermal conductivity improved simulations of wintertime soil temperatures, with that of Sturm et al. (1997) having the greatest impact (RMSE = 2.5 °C). The required correction factor is strongly related to snow depth (R2 = 0.77, RMSE = 0.066) and thus differs between the two snow seasons, limiting the applicability of such an approach. Improving simulated snow properties and the corresponding heat flux is important, as wintertime soil temperatures are an important control on subnivean soil respiration and hence impact Arctic winter carbon fluxes and budgets

Simulating net ecosystem exchange under seasonal snow cover at an Arctic tundra site

Estimates of winter (snow-covered non-growing season) CO2 fluxes across the Arctic region vary by a factor of 3.5, with considerable variation between measured and simulated fluxes. Measurements of snow properties, soil temperatures, and net ecosystem exchange (NEE) at Trail Valley Creek, NWT, Canada, allowed for the evaluation of simulated winter NEE in a tundra environment with the Community Land Model (CLM5.0). Default CLM5.0 parameterisations did not adequately simulate winter NEE in this tundra environment, with near-zero NEE (< 0.01 ) simulated between November and mid-May. In contrast, measured NEE was broadly positive (indicating net CO2 release) from snow-cover onset until late April. Changes to the parameterisation of snow thermal conductivity, required to correct for a cold soil temperature bias, reduced the duration for which no NEE was simulated. Parameter sensitivity analysis revealed the critical role of the minimum soil moisture threshold of decomposition (Ψmin) in regulating winter soil respiration. The default value of this parameter (Ψmin) was too high, preventing simulation of soil respiration for the vast majority of the snow-covered season. In addition, the default rate of change of soil respiration with temperature (Q10) was too low, further contributing to poor model performance during winter. As Ψmin and Q10 had opposing effects on the magnitude of simulated winter soil respiration, larger negative values of Ψmin and larger positive values of Q10 are required to simulate wintertime NEE more adequately

Liver Resection for Hepatic Metastases from Soft Tissue Sarcoma: A Nationwide Study

Abstract Background: This study aims to evaluate the feasibility and safety of resection of sarcoma liver metastases, and to identify possible prognostic factors for long-term survival. Methods: All patients who underwent resection of liver metastases of sarcoma in the Netherlands from 1998 to 2014 were included. Study data was retrospectively collected from patient files. Survival rates were calculated using Kaplan-Meier survival analysis. Results: Some 38 patients treated in 16 hospitals were included (15 male, 23 female). The median age was 57 years (37–80 years). The most common histological subtype was leiomyosarcoma (63%). The predominant site of primary tumour was the abdomen (59%). R0 resection was achieved in 16 patients. Mortality was 3 and 16% of included patients had 1 or more complications. The median follow-up period was 18 months (range 1–161). After liver resection, 1-, 3-, and 5-year survival were 88, 54, and 42% respectively. Median overall survival was 46 months (1– 161 months). One- and three-year progression-free survival (PFS) after liver resection were 54 and 19% respectively. Median PFS was 16 months (1–61 months). Conclusions: Liver surgery for sarcoma metastases is safe and leads to a relatively good survival. The choice for surgical treatment should always be discussed in a multidisciplinary sarcoma and liver team

Integrative policy development for healthier people and ecosystems : a European case analysis

There is growing evidence of the inter‐relationships between ecosystems and public health. This creates opportunities for the development of cross‐sectoral policies and interventions that provide dual benefits to public health and to the natural environment. These benefits are increasingly articulated in strategy documents at national and regional level, yet implementation of integrative policies on the ground remains limited and fragmented. Here, we use a workshop approach to identify some features of this evidence–implementation gap based on policy and practice within a number of western European countries. The driving forces behind some recent moves towards more integrative policy development and implementation show important differences between countries, reflecting the non‐linear and complex nature of the policy‐making process. We use these case studies to illustrate some of the key barriers to greater integrative policy development identified in the policy analysis literature. Specific barriers we identify include: institutional barriers; differing time perspectives in public health and ecosystem management; contrasting historical development of public health and natural environment disciplinary policy agendas; an incomplete evidence base relating investment in the natural environment to benefits for public health; a lack of appropriate outcome measures including benefit–cost trade‐offs; and finally a lack of integrative policy frameworks across the health and natural environment sectors. We also identify opportunities for greater policy integration and examples of good practice from different countries. However, we note there is no single mechanism that will deliver integrative policy for healthier people and ecosystems in all countries and situations. National governments, national public agencies, local governments, research institutions, and professional bodies all share a responsibility to identify and seize opportunities for influencing policy change, whether incremental or abrupt, to ensure that ecosystems and the health of society are managed so that the interests of future generations, as well as present generations, can be protected

The Experiment for Space Radiation Analysis: Probing the Earth\u27s Radiation Belts Using a CubeSat Platform

The Experiment for Space Radiation Analysis (ESRA) is the latest of a series of Demonstration and Validation missions built by the Los Alamos National Laboratory, with the focus on testing a new generation of plasma and energetic particle sensors. The primary motivation for the ESRA payloads is to minimize size, weight, power, and cost while still providing necessary mission data. These new instruments will be demonstrated by ESRA through testing and on-orbit operations to increase their technology readiness level such that they can support the evolution of technology and mission objectives. This project will leverage a commercial off-the-shelf CubeSat avionics bus and commercial satellite ground networks to reduce the cost and timeline associated with traditional DemVal missions. The system will launch as a ride share with the DoD Space Test Program to be inserted in Geosynchronous Transfer Orbit (GTO) and allow observations of the Earth’s radiation belts. The ESRA CubeSat consists of two science payloads and several subsystems: the Wide-field-of-view Plasma Spectrometer, the Energetic Charged Particle telescope, high voltage power supply, payload processor, flight software architecture, and distributed processor module. The ESRA CubeSat will provide measurements of the plasma and energetic charged particle populations in the GTO environment for ions ranging from ~100 eV to ~1000 MeV and electrons with energy ranging from 100 keV to 20 MeV. ESRA will utilize a commercial 12U bus and demonstrate a low-cost, rapidly deployable spaceflight platform with sufficient SWAP to enable efficient measurements of the energetic particle populations in the dynamic radiation belts

Virology under the microscope—a call for rational discourse

Viruses have brought humanity many challenges: respiratory infection, cancer, neurological impairment and immunosuppression to name a few. Virology research over the last 60+ years has responded to reduce this disease burden with vaccines and antivirals. Despite this long history, the COVID-19 pandemic has brought unprecedented attention to the field of virology. Some of this attention is focused on concern about the safe conduct of research with human pathogens. A small but vocal group of individuals has seized upon these concerns – conflating legitimate questions about safely conducting virus-related research with uncertainties over the origins of SARS-CoV-2. The result has fueled public confusion and, in many instances, ill-informed condemnation of virology. With this article, we seek to promote a return to rational discourse. We explain the use of gain-of-function approaches in science, discuss the possible origins of SARS-CoV-2 and outline current regulatory structures that provide oversight for virological research in the United States. By offering our expertise, we – a broad group of working virologists – seek to aid policy makers in navigating these controversial issues. Balanced, evidence-based discourse is essential to addressing public concern while maintaining and expanding much-needed research in virology

Voluntary disclosure of corporate strategy: determinants and outcomes. An empirical study into the risks and payoffs of communicating corporate strategy.

Business leaders increasingly face pressure from stakeholders to be transparent. There appears however little consensus on the risks and payoffs of disclosing vital information such as corporate strategy. To fill this gap, this study analyzes firm-specific determinants and organisational outcomes of voluntary disclosure of corporate strategy. Stakeholder theory and agency theory help to understand whether companies serve their interest to engage with stakeholders and overcome information asymmetries. I connect these theories and propose a comprehensive approach to measure voluntary disclosure of corporate strategy. Hypotheses from the theoretical framework are empirically tested through panel regression of data on identified determinants and outcomes and of disclosed strategy through annual reports, corporate social responsibility reports, corporate websites and corporate press releases by the 70 largest publicly listed companies in the Netherlands from 2003 through 2008. I found that industry, profitability, dual-listing status, national ranking status and listing age have significant effects on voluntary disclosure of corporate strategy. No significant effects are found for size, leverage and ownership concentration. On outcomes, I found that liquidity of stock and corporate reputation are significantly influenced by voluntary disclosure of corporate strategy. No significant effect is found for volatility of stock. My contributions to theory, methodology and empirics offers a stepping-stone for further research into understanding how companies can use transparency to manage stakeholder relations