Scalability evaluation of VPN technologies for secure container networking

For years, containers have been a popular choice for lightweight virtualization in the cloud. With the rise of more powerful and flexible edge devices, container deployment strategies have arisen that leverage the computational power of edge devices for optimal workload distribution. This move from a secure data center network to heterogenous public and private networks presents some issues in terms of security and network topology that can be partially solved by using a Virtual Private Network (VPN) to connect edge nodes to the cloud. In this paper, the scalability of VPN software is evaluated to determine if and how it can be used in large-scale clusters containing edge nodes. Benchmarks are performed to determine the maximum number of VPN-connected nodes and the influence of network degradation on VPN performance, primarily using traffic typical for edge devices generating IoT data. Some high level conclusions are drawn from the results, indicating that WireGuard is an excellent choice of VPN software to connect edge nodes in a cluster. Analysis of the results also shows the strengths and weaknesses of other VPN software

FUSE : a microservice approach to cross-domain federation using docker containers

In crisis situations, it is important to be able to quickly gather information from various sources to form a complete and accurate picture of the situation. However, the different policies of participating companies often make it difficult to connect their information sources quickly, or to allow software to be deployed on their networks in a uniform way. The difficulty in deploying software is exacerbated by the fact that companies often use different software platforms in their existing networks. In this paper, Flexible federated Unified Service Environment (FUSE) is presented as a solution for joining multiple domains into a microservice based ad hoc federation, and for deploying and managing container-based software on the devices of a federation. The resource requirements for setting up a FUSE federation are examined, and a video streaming application is deployed to demonstrate the performance of software deployed on an example federation. The results show that FUSE can be deployed in 10 minutes or less, and that it can support multiple video streams under normal network conditions, making it a viable solution for the problem of quick and easy cross-domain federation

Radiosynthesis, in vitro and preliminary in vivo evaluation of the novel glutamine derived PET tracers [18F]fluorophenylglutamine and [18F]fluorobiphenylglutamine

INTRODUCTION: Glucose has been deemed the driving force of tumor growth for decades. However, research has shown that several tumors metabolically shift towards glutaminolysis. The development of radiolabeled glutamine derivatives could be a useful molecular imaging tool for visualizing these tumors. We elaborated on the glutamine-derived PET tracers by developing two novel probes, namely [(18)F]fluorophenylglutamine and [(18)F]fluorobiphenylglutamine MATERIALS AND METHODS: Both tracers were labelled with fluorine-18 using our recently reported ruthenium-based direct aromatic fluorination method. Their affinity was evaluated with a [(3)H]glutamine inhibition experiment in a human PC-3 and a rat F98 cell line. The imaging potential of [(18)F]fluorophenylglutamine and [(18)F]fluorobiphenylglutamine was tested using a mouse PC-3 and a rat F98 tumor model. RESULTS: The radiosynthesis of both tracers was successful with overall non-decay corrected yields of 18.46 ± 4.18 % (n=10) ([(18)F]fluorophenylglutamine) and 8.05 ± 3.25 % (n=5) ([(18)F]fluorobiphenylglutamine). In vitro inhibition experiments showed a moderate and low affinity of fluorophenylglutamine and fluorobiphenylglutamine, respectively, towards the human ASCT-2 transporter. Both compounds had a low affinity towards the rat ASCT-2 transporter. These results were endorsed by the in vivo experiments with low uptake of both tracers in the F98 rat xenograft, low uptake of [(18)F]FBPG in the mice PC-3 xenograft and a moderate uptake of [(18)F]FPG in the PC-3 tumors. CONCLUSION: We investigated the imaging potential of two novel PET radiotracers [(18)F]FPG and [(18)F]FBPG. [(18)F]FPG is the first example of a glutamine radiotracer derivatized with a phenyl group which enables the exploration of further derivatization of the phenyl group to increase the affinity and imaging qualities. We hypothesize that increasing the affinity of [(18)F]FPG by optimizing the substituents of the arene ring can result in a high-quality glutamine-based PET radiotracer. ADVANCES IN KNOWLEDGE AND IMPLICATIONS FOR PATIENT CARE: We hereby report novel glutamine-based PET-tracers. These tracers are tagged on the arene group with fluorine-18, hereby preventing in vivo defluorination, which can occur with alkyl labelled tracers (e.g. (2S,4R)4-[(18)F]fluoroglutamine). [(18)F]FPG shows clear tumor uptake in vivo, has no in vivo defluorination and has a straightforward production. We believe this tracer is a good starting point for the development of a high-quality tracer which is useful for the clinical visualization of the glutamine transport

Presence of low virulence chytrid fungi could protect European amphibians from more deadly strains

Wildlife diseases are contributing to the current Earth’s sixth mass extinction; one disease, chytridiomycosis, has caused mass amphibian die-offs. While global spread of a hypervirulent lineage of the fungus Batrachochytrium dendrobatidis (BdGPL) causes unprecedented loss of vertebrate diversity by decimating amphibian populations, its impact on amphibian communities is highly variable across regions. Here, we combine field data with in vitro and in vivo trials that demonstrate the presence of a markedly diverse variety of low virulence isolates of BdGPL in northern European amphibian communities. Pre-exposure to some of these low virulence isolates protects against disease following subsequent exposure to highly virulent BdGPL in midwife toads (Alytes obstetricans) and alters infection dynamics of its sister species B. salamandrivorans in newts (Triturus marmoratus), but not in salamanders (Salamandra salamandra). The key role of pathogen virulence in the complex host-pathogen-environment interaction supports efforts to limit pathogen pollution in a globalized world

Multi-decadal improvements in the ecological quality of European rivers are not consistently reflected in biodiversity metrics

Humans impact terrestrial, marine and freshwater ecosystems, yet many broad-scale studies have found no systematic, negative biodiversity changes (for example, decreasing abundance or taxon richness). Here we show that mixed biodiversity responses may arise because community metrics show variable responses to anthropogenic impacts across broad spatial scales. We first quantified temporal trends in anthropogenic impacts for 1,365 riverine invertebrate communities from 23 European countries, based on similarity to least-impacted reference communities. Reference comparisons provide necessary, but often missing, baselines for evaluating whether communities are negatively impacted or have improved (less or more similar, respectively). We then determined whether changing impacts were consistently reflected in metrics of community abundance, taxon richness, evenness and composition. Invertebrate communities improved, that is, became more similar to reference conditions, from 1992 until the 2010s, after which improvements plateaued. Improvements were generally reflected by higher taxon richness, providing evidence that certain community metrics can broadly indicate anthropogenic impacts. However, richness responses were highly variable among sites, and we found no consistent responses in community abundance, evenness or composition. These findings suggest that, without sufficient data and careful metric selection, many common community metrics cannot reliably reflect anthropogenic impacts, helping explain the prevalence of mixed biodiversity trends.We thank J. England for assistance with calculating ecological quality and the biomonitoring indices in the UK. Funding for authors, data collection and processing was provided by the European Union Horizon 2020 project eLTER PLUS (grant number 871128). F.A. was supported by the Swiss National Science Foundation (grant numbers 310030_197410 and 31003A_173074) and the University of Zurich Research Priority Program Global Change and Biodiversity. J.B. and M.A.-C. were funded by the European Commission, under the L‘Instrument Financier pour l’Environnement (LIFE) Nature and Biodiversity program, as part of the project LIFE-DIVAQUA (LIFE18 NAT/ES/000121) and also by the project ‘WATERLANDS’ (PID2019-107085RB-I00) funded by the Ministerio de Ciencia, Innovación y Universidades (MCIN) and Agencia Estatal de Investigación (AEI; MCIN/AEI/10.13039/501100011033/ and by the European Regional Development Fund (ERDF) ‘A way of making Europe’. N.J.B. and V.P. were supported by the Lithuanian Environmental Protection Agency (https://aaa.lrv.lt/) who collected the data and were funded by the Lithuanian Research Council (project number S-PD-22-72). J.H. was supported by the Academy of Finland (grant number 331957). S.C.J. acknowledges funding by the Leibniz Competition project Freshwater Megafauna Futures and the German Federal Ministry of Education and Research (Bundesministerium für Bildung und Forschung or BMBF; 033W034A). A.L. acknowledges funding by the Spanish Ministry of Science and Innovation (PID2020-115830GB-100). P.P., M.P. and M.S. were supported by the Czech Science Foundation (GA23-05268S and P505-20-17305S) and thank the Czech Hydrometeorological Institute and the state enterprises Povodí for the data used to calculate ecological quality metrics from the Czech surface water monitoring program. H.T. was supported by the Estonian Research Council (number PRG1266) and by the Estonian national program ‘Humanitarian and natural science collections’. M.J.F. acknowledges the support of Fundação para a Ciência e Tecnologia, Portugal, through the projects UIDB/04292/2020 and UIDP/04292/2020 granted to the Marine and Environmental Sciences Centre, LA/P/0069/2020 granted to the Associate Laboratory Aquatic Research Network (ARNET), and a Call Estímulo ao Emprego Científico (CEEC) contract.Peer reviewe

Impact de la géométrie du segment initial de l'axone sur les propriétés électriques des neurones

Dans la plupart des neurones, les potentiels d’action (PA) sont générés dans un compartiment sous-cellulaire situé au début de l'axone, le segment initial de l'axone (SIA). La position et la longueur du SIA varient d'un type de neurone à l'autre, au cours du développement ou en réponse à un changement d'activité afférente. Ce travail combine une approche théorique avec des expériences pour éclairer la pertinence des aspects géométriques du SIA pour différentes fonctions électriques des neurones. Premièrement, nous étudions l'excitabilité sous un angle théorique et montrons que le seuil d’initiation diminue si l'AIS est éloigné du soma. Deuxièmement, nous allions modélisation et électrophysiologie pour étudier la transmission du PA du SIA au soma en enregistrant le courant axial à l'initiation des PAs. Nous montrons que la charge électrique transmise du SIA au soma est ajustée à la taille du soma de façon à suffisamment dépolariser le soma pour y régénérer le PA. En outre, nous avons observé que le seuil d'initiation s'adapte au potentiel de membrane. En parallèle, le courant axial est atténué, un phénomène en partie compensé par un élargissement du courant, de façon à transmettre la charge nécessaire à la régénération du PA. Nos résultats démontrent que la géométrie du SIA influence de façon distincte différentes propriétés électriques des neurones.In most neurons, action potentials (APs) are initiated in the axon initial segment (AIS), a subcellular compartment located at the start of the axon. The position and length of the AIS vary substantially across and within neuron types, during development and in response to a change in afferent activity. This work combines a theoretical approach with experiments to shed light on the geometrical aspects of the AIS that are relevant for distinct electrical functions. First, we focus on excitability and we relate theoretically the voltage threshold with AIS geometry. We find that the neuron is more excitable if the AIS is located further away from the soma. Second, combining modelling and patch-clamp recording, we study the AP transmission to the soma by recording the axial current at spike initiation. We show that the charge transferred by the AIS matches the size of the soma to produce a sufficient depolarization to regenerate the spike at the soma. Furthermore, we observed that threshold adapts to the membrane potential, and that the axial current attenuates concomitantly. It is partly compensated by current broadening to ensure the right amount of charge is transferred to the soma. Altogether, our results show that the geometry of the AIS has a multidimensional impact, as it affects distinct electrical properties differently

Theoretical relation between axon initial segment geometry and excitability

International audienceIn most vertebrate neurons, action potentials are triggered at the distal end of the axon initial segment (AIS). Both position and length of the AIS vary across and within neuron types, with activity, development and pathology. What is the impact of AIS geometry on excitability? Direct empirical assessment has proven difficult because of the many potential confounding factors. Here, we carried a principled theoretical analysis to answer this question. We provide a simple formula relating AIS geometry and sodium conductance density to the somatic voltage threshold. A distal shift of the AIS normally produces a (modest) increase in excitability, but we explain how this pattern can reverse if a hyperpolarizing current is present at the AIS, due to resistive coupling with the soma. This work provides a theoretical tool to assess the significance of structural AIS plasticity for electrical function

Developing public management expertise in the Belgian federal administration. A partnership between multiple stakeholders

Since 2001 the Belgian federal public sector has organised an educational programme in public management to encounter the growing need for public management expertise. At that same moment a huge reform project within the administration took place, and automatically both projects were connected. This specific administrative context generated at first a partnership between two actors, and evolved later on towards a partnership between multiple actors. It is the purpose of this paper to provide insight into the development of the educational programme within its specific context and to analyze the way the partnership developed in order to ensure the continuation of the programme and the achievement of the educational goals. This article is written by two major actors, i.e. the two universities which organize the programme and their commissioner, the Training Institute of the Federal Administration, an organisation within the Belgian federal public sector. It is based on the experiences of the three institutes, formal and informal documents, and 22 qualitative in-depth interviews taken within the federal administration between April 2007 and January 2008.status: publishe

Developing public management expertise in the Belgian federal administration. A partnership between multiple stakeholders

Since 2001 the Belgian federal public sector has organised an educational programme in public management to encounter the growing need for public management expertise. At that same moment a huge reform project within the administration took place, and automatically both projects were connected. This specific administrative context generated at first a partnership between two actors, and evolved later on towards a partnership between multiple actors. It is the purpose of this paper to provide insight into the development of the educational programme within its specific context and to analyze the way the partnership developed in order to ensure the continuation of the programme and the achievement of the educational goals.This article is written by two major actors, i.e. the two universities which organize the programme and their commissioner, the Training Institute of the Federal Administration, an organisation within the Belgian federal public sector. It is based on the experiences of the three institutes, formal and informal documents, and 22 qualitative in-depth interviews taken within the federal administration between April 2007 and January 2008.info:eu-repo/semantics/publishe