Topological Background Fields as Quantum Degrees of Freedom of Compactified Strings

It is shown that background fields of a topological character usually introduced as such in compactified string theories correspond to quantum degrees of freedom which parametrise the freedom in choosing a representation of the zero mode quantum algebra in the presence of non-trivial topology. One consequence would appear to be that the values of such quantum degrees of freedom, in other words of the associated topological background fields, cannot be determined by the nonperturbative string dynamics.Comment: 1+10 pages, no figure

Exploring the biophysical and socio-economic barriers to carbon sequestration in viticultural soils

To avoid catastrophic changes in the climate system by the end of the 21st century, the world must pursue drastic climate change mitigation strategies. All scenarios for containing the increase in global surface temperatures to below 1.5 or 2 ℃ by 2100 involve the large-scale deployment of carbon sequestration technologies. If properly managed, agricultural soils may sequester substantial amounts of atmospheric carbon dioxide in the form of soil organic carbon. However, there is a focus on arable land and grassland with regard to soil organic carbon sequestration, and research has overlooked other types of agricultural land, especially vineyards. There is a lack of evidence on the potential of vineyards to sequester carbon and participate in the global efforts to mitigate climate change via soil organic carbon sequestration. This thesis aims to quantify the carbon sink potential of vineyard agroecosystems under different soil management practices and identify the winegrowing regions where it is the highest. It also seeks to investigate the different factors that play a role in the adoption of soil organic carbon sequestration practices by winegrowers. An interdisciplinary approach was used, combining literature review, meta-analysis, machine learning and surveys to investigate the biophysical and socio-economic barriers to soil organic carbon sequestration in vineyards. A meta-analysis was performed to estimate, at the global level, the soil organic carbon sequestration rates associated with the use of different soil management practices in vineyards, based on field experiments. Results show that, under the same management practices, vineyards may sequester similar or larger amounts of organic carbon per hectare compared to other types of agricultural land. The data gathered in the meta-analysis was then used to build a model that predicts, using a random forest regression, changes in soil organic carbon stocks in vineyards under specific management practices, based on soil and climatic characteristics. The model was applied to six winegrowing countries located in Europe (Spain, France, Italy, Portugal, Germany and Austria) for a period of twenty years. The results indicate that the ability of vineyards to sequester carbon in these countries is high, though it varies greatly depending on the winegrowing regions and practices considered. To further understand the decision-making process of implementing soil organic carbon sequestration practices in vineyards, a questionnaire was circulated to winegrowers in France. It enquired about the adoption of different soil management practices, as well as vineyard attributes and winegrowers’ socio-economic characteristics, access to information, involvement in policy instruments, resources, confidence and attitudes towards soil organic carbon sequestration practices. The results from a binary logistic regression indicate that many of these factors (e.g., winegrower’s and vine’s age, farm size, certifications, use of irrigation, etc.) are involved in the adoption process of soil organic carbon sequestration practices. To complement these results, a second questionnaire was circulated to French winegrowers to investigate the motives and barriers to the adoption of soil organic carbon sequestration practices as perceived by winegrowers. Results identify the desire to achieve biophysical outcomes (e.g., returning organic matter to the soil) as a key motivation for the adoption of these practices and biophysical and technical barriers as the main barriers preventing winegrowers from adopting the practices. The findings of this thesis suggest that vineyards have an important role to play in climate change mitigation and should not be overlooked by soil organic carbon sequestration strategies, especially in countries or regions where vineyards represent an important share of the total agricultural land. However, this potential will only be realised if soil organic carbon sequestration practices are adopted by winegrowers. Further policy instruments should be developed at the local, regional, national and European levels to overcome some of the barriers currently hindering the uptake of these practices in the viticulture sector

Why do French winegrowers adopt soil organic carbon sequestration practices? Understanding motivations and barriers

Soil carbon sequestration (SCS) practices on French agricultural land are part of the portfolio of actions available to policymakers in the field of climate change mitigation and are central to the success of the “4 per 1,000” initiative, launched by France in 2015. To date, there has been limited research considering their applicability to vineyards. A survey was circulated to 506 French winegrowers to identify the adoption rate of six SCS practices in the viticultural sector (applying organic amendments, using biochar, returning pruning residues to the soil, no-tillage, cover cropping, and introducing or preserving hedges in the vineyard) and to explore motives and barriers to adoption. The survey also investigated ways of overcoming barriers to adoption and winegrowers' perception of agri-environment measures. Differences in motivations and barriers between SCS practices were found, and winegrowers themselves suggested a need for improved communication of evidence about SCS practices and better-targeted policy incentives to support adoption

Why do French winegrowers adopt soil organic carbon sequestration practices? Understanding motivations and barriers

Soil carbon sequestration (SCS) practices on French agricultural land are part of the portfolio of actions available to policymakers in the field of climate change mitigation and are central to the success of the “4 per 1,000” initiative, launched by France in 2015. To date, there has been limited research considering their applicability to vineyards. A survey was circulated to 506 French winegrowers to identify the adoption rate of six SCS practices in the viticultural sector (applying organic amendments, using biochar, returning pruning residues to the soil, no-tillage, cover cropping, and introducing or preserving hedges in the vineyard) and to explore motives and barriers to adoption. The survey also investigated ways of overcoming barriers to adoption and winegrowers' perception of agri-environment measures. Differences in motivations and barriers between SCS practices were found, and winegrowers themselves suggested a need for improved communication of evidence about SCS practices and better-targeted policy incentives to support adoption.</p

Characterising the biophysical, economic and social impacts of soil carbon sequestration as a greenhouse gas removal technology

To limit warming to well below 2°C, most scenario projections rely on greenhouse gas removal technologies (GGRTs); one such GGRT uses soil carbon sequestration (SCS) in agricultural land. In addition to their role in mitigating climate change, SCS practices play a role in delivering agroecosystem resilience, climate change adaptability, and food security. Environmental heterogeneity and differences in agricultural practices challenge the practical implementation of SCS, and our analysis addresses the associated knowledge gap. Previous assessments have focused on global potentials, but there is a need among policy makers to operationalise SCS. Here, we assess a range of practices already proposed to deliver SCS, and distil these into a subset of specific measures. We provide a multi‐disciplinary summary of the barriers and potential incentives toward practical implementation of these measures. First, we identify specific practices with potential for both a positive impact on SCS at farm level, and an uptake rate compatible with global impact. These focus on: a. optimising crop primary productivity (e.g. nutrient optimisation, pH management, irrigation) b. reducing soil disturbance and managing soil physical properties (e.g. improved rotations, minimum till) c. minimising deliberate removal of C or lateral transport via erosion processes (e.g. support measures, bare fallow reduction) d. addition of C produced outside the system (e.g. organic manure amendments, biochar addition) e. provision of additional C inputs within the cropping system (e.g. agroforestry, cover cropping) We then consider economic and non‐cost barriers and incentives for land managers implementing these measures, along with the potential externalised impacts of implementation. This offers a framework and reference point for holistic assessment of the impacts of SCS. Finally, we summarise and discuss the ability of extant scientific approaches to quantify the technical potential and externalities of SCS measures, and the barriers and incentives to their implementation in global agricultural systems

Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI): A Prospective Longitudinal Observational Study

BACKGROUND: Current classification of traumatic brain injury (TBI) is suboptimal, and management is based on weak evidence, with little attempt to personalize treatment. A need exists for new precision medicine and stratified management approaches that incorporate emerging technologies. OBJECTIVE: To improve characterization and classification of TBI and to identify best clinical care, using comparative effectiveness research approaches. METHODS: This multicenter, longitudinal, prospective, observational study in 22 countries across Europe and Israel will collect detailed data from 5400 consenting patients, presenting within 24 hours of injury, with a clinical diagnosis of TBI and an indication for computed tomography. Broader registry-level data collection in approximately 20 000 patients will assess generalizability. Cross sectional comprehensive outcome assessments, including quality of life and neuropsychological testing, will be performed at 6 months. Longitudinal assessments will continue up to 24 months post TBI in patient subsets. Advanced neuroimaging and genomic and biomarker data will be used to improve characterization, and analyses will include neuroinformatics approaches to address variations in process and clinical care. Results will be integrated with living systematic reviews in a process of knowledge transfer. The study initiation was from October to December 2014, and the recruitment period was for 18 to 24 months. EXPECTED OUTCOMES: Collaborative European NeuroTrauma Effectiveness Research in TBI should provide novel multidimensional approaches to TBI characterization and classification, evidence to support treatment recommendations, and benchmarks for quality of care. Data and sample repositories will ensure opportunities for legacy research. DISCUSSION: Comparative effectiveness research provides an alternative to reductionistic clinical trials in restricted patient populations by exploiting differences in biology, care, and outcome to support optimal personalized patient management

The European Reference Genome Atlas: piloting a decentralised approach to equitable biodiversity genomics.

ABSTRACT: A global genome database of all of Earth’s species diversity could be a treasure trove of scientific discoveries. However, regardless of the major advances in genome sequencing technologies, only a tiny fraction of species have genomic information available. To contribute to a more complete planetary genomic database, scientists and institutions across the world have united under the Earth BioGenome Project (EBP), which plans to sequence and assemble high-quality reference genomes for all ∼1.5 million recognized eukaryotic species through a stepwise phased approach. As the initiative transitions into Phase II, where 150,000 species are to be sequenced in just four years, worldwide participation in the project will be fundamental to success. As the European node of the EBP, the European Reference Genome Atlas (ERGA) seeks to implement a new decentralised, accessible, equitable and inclusive model for producing high-quality reference genomes, which will inform EBP as it scales. To embark on this mission, ERGA launched a Pilot Project to establish a network across Europe to develop and test the first infrastructure of its kind for the coordinated and distributed reference genome production on 98 European eukaryotic species from sample providers across 33 European countries. Here we outline the process and challenges faced during the development of a pilot infrastructure for the production of reference genome resources, and explore the effectiveness of this approach in terms of high-quality reference genome production, considering also equity and inclusion. The outcomes and lessons learned during this pilot provide a solid foundation for ERGA while offering key learnings to other transnational and national genomic resource projects.info:eu-repo/semantics/publishedVersio

Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.

RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)

An Action For Chan-Paton Factors

We show that Chan-Paton factors can be derived from a classical action describing the dynamics of a new group-valued degree of freedom attached to the boundary of an open bosonic string. We discuss the free and the interacting string in the oriented and unoriented cases, as well as the coupling of the string to an external Yang-Mills gauge field, and recover by this approach well-known results. Comment: 1+9 pages, no figure