Showing papers by "Swedish Defence Research Agency published in 2020"

Globe-Trotting Aedes aegypti and Aedes albopictus: Risk Factors for Arbovirus Pandemics

Abstract: Introduction: Two species of Aedes (Ae.) mosquitoes (Ae. aegypti and Ae. albopictus) are primary vectors for emerging arboviruses that are a significant threat to public health and economic burden ...

Veracity assessment of online data

Abstract: Fake news, malicious rumors, fabricated reviews, generated images and videos, are today spread at an unprecedented rate, making the task of manually assessing data veracity for decision-making purposes a daunting task. Hence, it is urgent to explore possibilities to perform automatic veracity assessment. In this work we review the literature in search for methods and techniques representing state of the art with regard to computerized veracity assessment. We study what others have done within the area of veracity assessment, especially targeted towards social media and open source data, to understand research trends and determine needs for future research. The most common veracity assessment method among the studied set of papers is to perform text analysis using supervised learning. Regarding methods for machine learning much has happened in the last couple of years related to the advancements made in deep learning. However, very few papers make use of these advancements. Also, the papers in general tend to have a narrow scope, as they focus on solving a small task with only one type of data from one main source. The overall veracity assessment problem is complex, requiring a combination of data sources, data types, indicators, and methods. Only a few papers take on such a broad scope, thus, demonstrating the relative immaturity of the veracity assessment domain.

Transparent nanocellulose metamaterial enables controlled optical diffusion and radiative cooling

Abstract: Materials that provide independent control of infrared thermal radiation and haze in the visible could benefit many areas and applications, including clothing, packaging and photovoltaics. Here, we study this possibility for a metamaterial composite paper based on cellulose nanofibrils (CNF) and silicon dioxide (SiO2) microparticles with infrared (IR) Frohlich phonon resonances. This CNF–SiO2 composite shows outstanding transparency in the visible wavelength range, with the option of controlling light diffusion and haze from almost zero to 90% by varying the SiO2 microparticle concentration. We further show that the transparent metamaterial paper could maintain high thermal emissivity in the atmospheric IR window, as attributed to strong IR absorption of both the nanocellulose and the resonant SiO2 microparticles. The high IR emissivity and low visible absorption make the paper suitable for passive radiative cooling and we demonstrate cooling of the paper to around 3 °C below ambient air temperature by exposing it to the sky.

A longitudinal study of the development of the saliva microbiome in infants 2 days to 5 years compared to the microbiome in adolescents

Abstract: Understanding oral microbiota programming attracts increasing interest due to its importance for oral health and potential associations with systemic diseases. Here the oral microbiota was longitudinally characterized in children from 2 days (n = 206) to 5 years of age and in young adults (n = 175) by sequencing of the v3-v4 region of the 16S rRNA gene from saliva extracted DNA. Alpha diversity increased by age, with 2-day- and 3-month-old infants in one sub-group, and 18-month- and 3-year-old children in another. Firmicutes decreased up to 3 years of age, whereas Proteobacteria, Actinobacteria, Bacteroidetes and Fusobacteria abundances increased. Abiotrophia, Actinomyces, Capnocytophaga, Corynebacterium, Fusobacterium, Kingella, Leptotrichia, Neisseria and Porphyromonas appeared from 18-months of age. This was paralleled by expansions in the core microbiome that continued up to adulthood. The age-related microbiota transformation was paralleled by functional alterations, e.g., changed metabolic pathways that reflected e.g., breastfeeding and increasing proportions of anaerobic species. Oral microbiotas differed by feeding mode and weakly by mode of delivery, but not gender, pacifier use or cleaning method or probiotic intake. The study shows that the saliva microbiota is diverse 2 days after birth and under transformation up to 5 years of age and beyond, with fluctuations possibly reflecting age-related environmental influences.

Reclassification of francisella noatunensis subsp. Orientalis ottem et al. 2009 as francisella orientalis sp. nov., francisella noatunensis subsp. chilensis subsp. nov. and emended description of francisella noatunensis

Abstract: Francisella noatunensis is a fastidious facultative intracellular bacterial pathogen that causes ‘piscine francisellosis’, a serious disease affecting both marine and fresh water farmed and wild fish worldwide. Currently two F. noatunensis subspecies are recognized, i.e. F. noatunensis subsp. noatunensis and F. noatunensis subsp. orientalis . In the present study, the taxonomy of F. noatunensis was revisited using a polyphasic approach, including whole genome derived parameters such as digital DNA–DNA hybridization, whole genome average nucleotide identity (wg-ANIm), whole genome phylogenetic analysis, whole genome G+C content, metabolic fingerprinting and chemotaxonomic analyses. The results indicated that isolates belonging to F. noatunensis subsp. orientalis represent a phenotypically and genetically homogenous taxon, clearly distinguishable from F. noatunensis subsp. noatunensis that fulfils requirements for separate species status. We propose, therefore, elevation of F. noatunensis subsp. orientalis to the species rank as Francisella orientalis sp. nov. with the type strain remaining as Ehime-1T (DSM 21254T=LMG 24544T). Furthermore, we identified sufficient phenotypic and genetic differences between F. noatunensis subsp. noatunensis recovered from diseased farmed Atlantic salmon in Chile and those isolated from wild and farmed Atlantic cod in Northern Europe to warrant proposal of the Chilean as a novel F. noatunensis subspecies, i.e. Francisella noatunensis subsp. chilensis subsp. nov. with strain PQ1106T (CECT 9798T=NCTC14375T) as the type strain. Finally, we emend the description of F. noatunensis by including further metabolic information and the description of atypical strains.

Operationalising resilience for disaster medicine practitioners: capability development through training, simulation and reflection

Abstract: Resilience has in recent decades been introduced as a term describing a new perspective within the domains of disaster management and safety management. Several theoretical interpretations and definitions of the essence of resilience have been proposed, but less work has described how to operationalise resilience and implement the concept within organisations. This case study describes the implementation of a set of general resilience management guidelines for critical infrastructure within a Swedish Regional Medical Command and Control Team. The case study demonstrates how domain-independent guidelines can be contextualised and introduced at an operational level, through a comprehensive capability development programme. It also demonstrates how a set of conceptual and reflective tools consisting of educational, training and exercise sessions of increasing complexity and realism can be used to move from high-level guidelines to practice. The experience from the case study demonstrates the value of combining (1) developmental learning of practitioners' cognitive skills through resilience-oriented reflection and interaction with dynamic complex open-ended problems; (2) contextualisation of generic guidelines as a basis for operational methodological support in the operational environment; and (3) the use of simulation-based training as part of a capability development programme with increasing complexity and realism across mixed educational, training and exercise sessions. As an actual example of a resilience implementation effort in a disaster medicine management organisation, the study contributes to the body of knowledge regarding how to implement the concept of resilience in operational practice.

Multilevel model for airborne transmission of foot-and-mouth disease applied to Swedish livestock

Abstract: The foot-and-mouth disease is an ever-present hazard to the livestock industry due to the huge economic consequences following an outbreak that necessitates culling of possibly infected animals in vast numbers. The disease is highly contagious and previous epizootics have shown that it spreads by many routes. One such route is airborne transmission, which has been investigated in this study by means of a detailed multilevel model that includes all scales of an outbreak. Local spread within an infected farm is described by a stochastic compartment model while the spread between farms is quantified by atmospheric dispersion simulations using a network representation of the set of farms. The model was applied to the Swedish livestock industry and the risk for an epizootic outbreak in Sweden was estimated using the basic reproduction number of each individual livestock-holding farm as the endpoint metric. The study was based on comprehensive official data sets for both the current livestock holdings and regional meteorological conditions. Three species of farm animals are susceptible to the disease and are present in large numbers: cattle, pigs and sheep. These species are all included in this study using their individual responses and consequences to the disease. It was concluded that some parts of southern Sweden are indeed preconditioned to harbor an airborne epizootic, while the sparse farm population of the north renders such events unlikely to occur there. The distribution of the basic reproduction number spans over several orders of magnitudes with low risk of disease spread from the majority of the farms while some farms may act as very strong disease transmitters. The results may serve as basic data in the planning of the national preparedness for this type of events.

Biophysical fingerprinting of single bacterial spores using laser Raman optical tweezers

Abstract: Spore-forming bacteria that cause diseases pose a danger in our society. When in spore form, bacteria can survive high temperatures and resist a plethora of disinfection chemicals. Effective disinf ...

Patch Size Evolution During Pulsating Aurora

Abstract: We report both decreasing and increasing trends in the patch sizes during pulsating aurora events. About 150 pulsating auroral events over the Fennoscandian Lapland have been successfully analyzed for their average patch size, total patch area, and number of patches as a function of event time, typically 1-2 hr. An automatic routine has been developed to detect patches in the all-sky camera images. In addition to events with decreasing and increasing average patch size evolution over the course of the pulsating aurora, events with no size trends and events with intermittently increasing and decreasing patch size trends were also found. In this study, we have analyzed a subset of events for which the average and total patch size systematically increase or decrease. The events with increasing patch size trend do not experience a decrease in the peak emission height, which was previously associated with the behavior of pulsating aurora precipitation. Furthermore, the events with increasing patch sizes have shorter lifetimes and twice as many substorm-injected energetic electrons at geosynchronous orbit as the events with decreasing patch sizes. Half of the events with increasing patch sizes occur during substorm expansion phases, while a majority (64%) of the ones with decreasing patch sizes take place during the recovery phase. These findings suggest that the visual appearance of pulsating aurora may be used as an indication of the pulsating aurora energy deposition to the atmosphere.

Decontamination efficacy of soapy water and water washing following exposure of toxic chemicals on human skin

Abstract: Aim of the study: Following exposure to toxic chemicals, skin uptake is a potential route of intoxication. Therefore, efficient methods for rapid skin decontamination to mitigate systemic effects are of utmost importance. In operational guidelines, skin decontamination is recommended to be performed by dry absorption and washing with water or soapy water. In the present study, evaluation of decontamination efficacy using water or soapy water was performed for five chemicals, three toxic industrial chemicals and two simulants for chemical warfare agents.Materials and methods: Decontamination was initiated at time points 5, 15, 45 and 120 min after exposure in order to evaluate the time window for efficient decontamination. Experiments were conducted utilizing an in vitro skin penetration model to allow exposure of toxic chemicals on human skin. Results: For all test substances, it was clearly demonstrated that decontamination had greater efficacy when initiated at the earliest time-point while decontamination after 120 min was less efficient. Adding soap to the water showed no significant improvement for any of the tested substances.Conclusion: These results are of reledvance for the development of efficient operational decontamination procedures.

Wall-Modeled LES for Ship Hydrodynamics in Model Scale

Abstract: A complete approach for wall-modeled large-eddy simulation (WMLES) is demonstrated for the simulation of the flow around a bulk carrier in the model scale. Essential components of the method are an a-priori estimate of the thickness of the turbulent boundary layer (TBL) over the hull and to use an unstructured grid with the appropriate resolution relative to this thickness. Expressions from the literature for the scaling of the computational cost, in terms of the grid size, with Reynolds number, are adapted in this application. It is shown that WMLES is possible for model scale ship hydrodynamics, with ∼108 grid cells, which is a gain of at least one order of magnitude as compared with wall-resolving LES. For the canonical case of a flat-plate TBL, the effects of wall model parameters and grid cell topology on the predictive accuracy of the method are investigated. For the flat-plate case, WMLES results are compared with results from direct numerical simulation, RANS (Reynolds-averaged Navier-Stokes), and semi-empirical formulas. For the bulk carrier flow, WMLES and RANS are compared, but further validation is needed to assess the predictive accuracy of the approach.

High resolution and sensitivity up-conversion mid-infrared photon-counting LIDAR.

Abstract: A single-photon-counting mid-infrared LIDAR is presented. 2.4 µm mid-infrared photons were up-converted to 737 nm by intra-cavity mixing in a periodically poled rubidium-doped KTiOPO4 crystal inside a Nd:YVO4 laser. The up-converted photons were detected by a Si single-photon avalanche photodiode (SPAD). A temporal resolution of 42 ps and a dark count rate of 500 Hz were achieved, limited by the SPAD and ambient light leakage. It allowed for detection of two targets separated by only a few millimeters. This technique is easily extendable to longer wavelengths, limited primarily by the nonlinear crystal transparency.

Identification of Degradation Products of Sea-Dumped Chemical Warfare Agent-Related Phenylarsenic Chemicals in Marine Sediment.

Abstract: Previously unknown phenylarsenic chemicals that originated from chemical warfare agents (CWAs) have been detected and identified in sediment samples collected from the vicinity of chemical munition dumpsites. Nontargeted screening by ultrahigh-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS) was used for detection of 14 unknown CWA-related phenylarsenic chemicals. Methylated forms of Clark I/II, Adamsite, and phenyldichloroarsine were detected in all analyzed sediment samples, and their identification was based on synthesized chemicals. In addition, other previously unknown CWA-related phenylarsenic chemicals were detected, and their structures were elucidated using MS/HRMS technique. On the basis of relative isotope ratios of protonated molecules and measures of exact masses of formed fragment ions, it could be concluded that some of these unknown chemicals contained a sulfur atom attached to an arsenic atom. In addition to that, some of the samples contained chemicals that had formed via addition of an OH group to the aromatic ring. However, it is not possible to say how these chemicals are formed, but the most plausible cause is activities of marine microbes in the sediment. To our knowledge, these chemicals have not been detected from sediment samples previously. Sensitive analytical methods are needed for these novel chemicals to assess the total CWA burden in marine sediments, and this information is essential for the risk assessment.

CRATE Exercise Control – A cyber defense exercise management and support tool

Abstract: The growing dependency on computerized systems in society causes an increased need for a high level of cyber security competence among the professionals tasked with operating and protecting such systems. Cyber defense exercises are important for experience-based learning to train professionals working with critical computer systems. However, arranging realistic exercises require skilled instructors and technicians with the right set of tools. In this paper, we describe an exercise management and support tool called CRATE Exercise Control (CEC). The tool was developed by the Swedish Defence Research Agency (FOI), based on empirical experiences from arranging cyber defense exercises in the cyber range CRATE (Cyber Range And Training Environment), and best practices published by other organizations. We also share experiences made while using CEC during cyber defense exercises, as well as recommendations to consider when designing exercise management and support tools.

Adaptive Demodulation in Symmetric Alpha-Stable Impulse Noise Channels

Abstract: In this work, we propose a novel algorithm for adaptive demodulation in impulse noise channels The proposed method computes appropriate log-likelihood ratios (LLR) based on four previously established parameter estimation techniques of Symmetric $\alpha -$Stable noise The methods are evaluated with Monte Carlo simulations and shown to outperform the compared demodulators Simulations show that the methods perform close to the theoretical limit in different proportions of impulse noise and in pure, randomized $\alpha -$Stable interference The proposed adaptive demodulation technique can be used to improve decoding or demodulation performance in many real-world situations where non-Gaussian interference commonly occurs

Genotyping of Francisella tularensis subsp. holarctica from Hares in Germany.

Abstract: Francisella tularensis is the causative agent of the zoonotic disease tularemia. In Germany, most human infections are caused by contact with infected hares. The aim of this study was to characterize Francisella tularensis subsp. holarctica strains isolated from hares in Germany and to develop bioinformatics tools to analyze their genetic relatedness. In total, 257 German isolates—obtained mainly from hares (n = 233), other vertebrate animals, and ticks, but also from humans (n = 3)—were analyzed within this study. Publically available sequence data from 49 isolates were used to put our isolates into an epidemiological context and to compare isolates from natural foci and humans. Whole-genome sequences were analyzed using core-genome Multi-Locus-Sequence-Typing, canonical Single Nucleotide Polymorphism (SNP) typing and whole-genome SNP typing. An overall conformity of genotype clustering between the typing methods was found, albeit with a lower resolution for canonical single SNP typing. The subclade distribution, both on local and national levels, among strains from humans and hares was similar, suggesting circulation of the same genotypes both in animals and humans. Whilst close to identical isolates of the same subclade were found distributed over large areas, small geographical foci often harbored members of different subclades. In conclusion, although genomic high-resolution typing was shown to be robust, reproducible and allowed the identification of highly closely related strains, genetic profiling alone is not always conclusive for epidemiological linkage of F. tularensis strains.

Emulating Synchronized Cooperative Broadcast in the Anglova Scenario and EMANE

Abstract: Emulation environments are an effective approach to experimenting with and evaluating network protocols, algorithms, and components. However, implementing a complete waveform for an emulation environment requires a significant effort. This paper describes two simplified approaches to implement and include a Synchronized Cooperative Broadcast (SCB) waveform within the Anglova scenario and the EMANE network emulation framework. The result is two different implementations of SCB, having different levels of abstraction regarding the specific details of SCB and offering different capabilities. The SCB implementations are tested and compared in the militarily-realistic Anglova scenario. The performance of SCB is also theoretically estimated within the Anglova scenario as a baseline for comparison purposes. The results show that the approaches taken to emulate SCB within EMANE and the Anglova scenario perform as expected when compared to the theoretical results.

Autonomous UAV-based Forest Mapping Below the Canopy

Abstract: We present a system for forest mapping from an autonomous UAV, flying below the tree canopy. The UAV is equipped with four stereo cameras, which provide information for navigation, mapping, and collision avoidance. The main focus of the paper is positioning and forest mapping, but the full system, including both hardware and algorithms, is described.

Full Duplex Based Digital Out-of-Band Interference Cancellation for Collocated Radios

Abstract: In this work, a novel out-of-band interference cancellation (OOBIC) method, based on a full duplex interference cancellation technique, is proposed The aim of the OOBIC is to counteract the interference that may occur when collocated radios transmit and receive in closely located frequency bands The main advantage of the method is that the cancellation can be performed directly on the data signal, with the desired signal present, without complex nonlinear modeling, and without additional synchronization between the collocated radios The method is validated both analytically and through simulations, and is shown to successfully increase the signal quality in OOB interference situations where the signal otherwise would have been unrecoverable

Laser sensing from small UAVs

Abstract: Currently there is a considerable development of small, lightweight, lidar systems, for applications in autonomous cars. The development gives possibilities to equip small UAVs with this type of sensor. Adding an active sensor component, beside the more common passive UAV sensors, can give additional capabilities. This paper gives experimental examples of lidar data and discusses applications and capabilities for the platform and sensor concept including the combination with data from other sensors. The lidar can be used for accurate 3D measurements and has a potential for detection of partly occluded objects. Additionally, positioning of the UAV can be obtained by a combination of lidar data and data from other low-cost sensors (such as inertial measurement units). The capabilities are attainable both for indoor and outdoor shortrange applications.