Showing papers by "Swedish Defence Research Agency published in 2019"

Amyloid fibrils prepared using an acetylated and methyl amidated peptide model of the α-Synuclein NAC 71-82 amino acid stretch contain an additional cross-β structure also found in prion proteins.

Abstract: The 71-82 fragment of the non-amyloid-beta component (NAC) region of the Parkinson's disease (PD) and dementia with Lewy bodies (DLB) related protein alpha-Synuclein, has been reported to be import ...

Airborne concentrations and chemical considerations of radioactive ruthenium from an undeclared major nuclear release in 2017

Abstract: In October 2017, most European countries reported unique atmospheric detections of aerosol-bound radioruthenium (106Ru). The range of concentrations varied from some tenths of µBq·m−3 to more than 150 mBq·m−3. The widespread detection at such considerable (yet innocuous) levels suggested a considerable release. To compare activity reports of airborne 106Ru with different sampling periods, concentrations were reconstructed based on the most probable plume presence duration at each location. Based on airborne concentration spreading and chemical considerations, it is possible to assume that the release occurred in the Southern Urals region (Russian Federation). The 106Ru age was estimated to be about 2 years. It exhibited highly soluble and less soluble fractions in aqueous media, high radiopurity (lack of concomitant radionuclides), and volatility between 700 and 1,000 °C, thus suggesting a release at an advanced stage in the reprocessing of nuclear fuel. The amount and isotopic characteristics of the radioruthenium release may indicate a context with the production of a large 144Ce source for a neutrino experiment.

The Theory of Planned Behavior and Information Security Policy Compliance

Abstract: Much of the research on security policy compliance has tested the relationships posited by the theory of planned behavior. This theory explains far from all of the measurable variance in policy compliance intentions. However, it is associated with something called the sufficiency assumption, which essentially states that no variable is missing from the theory. This paper addresses this assumption in the context of information security policy compliance. A meta-analysis of published tests on information security behavior and a review of the literature in related fields are used to identify variables that have the potential to improve the theory’s predictions. These results are tested using a random sample of 645 white-collar workers. The results suggest that the variables anticipated regret and habit improve the predictions. The variables increase the explained variance by 3.4 and 2.6 percentage points, respectively, when they are added individually, and by 5.4 percentage points when both are added.

The toxic potential of a fourth-generation E-cigarette on human lung cell lines and tissue explants

Abstract: The use of electronic cigarettes (E‐cigs) is rapidly increasing. The latest generation of E‐cigs is highly customizable, allowing for high heating coil temperatures. The aim of this study was to as ...

An experimental and computational study of hydrogen–air combustion in the LAPCAT II supersonic combustor

Abstract: Dual-mode ramjet/scramjet engines are considered a promising propulsion system for the next generation commercial high-speed transport flight vehicles In this study we combine experimental measurements of high-speed (subsonic and supersonic) combustion at different operating conditions in the LAPCAT-II dual-mode ramjet/scramjet combustor with Large Eddy Simulations (LES) using finite rate chemistry models and skeletal H2–air combustion chemistry The combustor geometrically consists of four sections, and experiments have been realized for wall injection of H2 in a Mach = 2 vitiated air-flow for total pressures and temperatures of p0 = 040 MPa, 1414 K

A New Species of the γ-Proteobacterium Francisella, F. adeliensis Sp. Nov., Endocytobiont in an Antarctic Marine Ciliate and Potential Evolutionary Forerunner of Pathogenic Species.

Abstract: The study of the draft genome of an Antarctic marine ciliate, Euplotes petzi, revealed foreign sequences of bacterial origin belonging to the γ-proteobacterium Francisella that includes pathogenic and environmental species. TEM and FISH analyses confirmed the presence of a Francisella endocytobiont in E. petzi. This endocytobiont was isolated and found to be a new species, named F. adeliensis sp. nov.. F. adeliensis grows well at wide ranges of temperature, salinity, and carbon dioxide concentrations implying that it may colonize new organisms living in deeply diversified habitats. The F. adeliensis genome includes the igl and pdp gene sets (pdpC and pdpE excepted) of the Francisella pathogenicity island needed for intracellular growth. Consistently with an F. adeliensis ancient symbiotic lifestyle, it also contains a single insertion-sequence element. Instead, it lacks genes for the biosynthesis of essential amino acids such as cysteine, lysine, methionine, and tyrosine. In a genome-based phylogenetic tree, F. adeliensis forms a new early branching clade, basal to the evolution of pathogenic species. The correlations of this clade with the other clades raise doubts about a genuine free-living nature of the environmental Francisella species isolated from natural and man-made environments, and suggest to look at F. adeliensis as a pioneer in the Francisella colonization of eukaryotic organisms.

Continuous but not intermittent noise has a negative impact on mating success in a marine fish with paternal care

Abstract: Anthropogenic underwater noise is a global pollutant of increasing concern but its impact on reproduction in fish is largely unknown. Hence, a better understanding of its consequences for this important link to fitness is crucial. Working in aquaria, we experimentally tested the impact of broadband noise exposure (added either continuously or intermittently), compared to a control, on the behaviour and reproductive success of the common goby (Pomatoschistus microps), a vocal fish with exclusive paternal care. Compared to the intermittent noise and control treatments, the continuous noise treatment increased latency to female nest inspection and spawning and decreased spawning probability. In contrast, many other female and male pre-spawning behaviours, and female ventilation rate (proxies for stress levels) did not differ among treatments. Therefore, it is likely that female spawning decisions were delayed by a reduced ability to assess male acoustic signals, rather than due to stress per se and that the silent periods in the intermittent noise treatment provided a respite where the females could assess the males. Taken together, we show that noise (of similar frequency range as anthropogenic boat noise) negatively affects reproductive success, particularly under a continuous noise exposure.

Feasibility Study of Mesoporous Silica Particles for Pulmonary Drug Delivery: Therapeutic Treatment with Dexamethasone in a Mouse Model of Airway Inflammation

Abstract: Diseases in the respiratory tract rank among the leading causes of death in the world, and thus novel and optimized treatments are needed. The lungs offer a large surface for drug absorption, and the inhalation of aerosolized drugs are a well-established therapeutic modality for local treatment of lung conditions. Nanoparticle-based drug delivery platforms are gaining importance for use through the pulmonary route. By using porous carrier matrices, higher doses of especially poorly soluble drugs can be administered locally, reducing their side effects and improving their biodistribution. In this study, the feasibility of mesoporous silica particles (MSPs) as carriers for anti-inflammatory drugs in the treatment of airway inflammation was investigated. Two different sizes of particles on the micron and nanoscale (1 µm and 200 nm) were produced, and were loaded with dexamethasone (DEX) to a loading degree of 1:1 DEX:MSP. These particles were further surface-functionalized with a polyethylene glycol–polyethylene imine (PEG–PEI) copolymer for optimal aqueous dispersibility. The drug-loaded particles were administered as an aerosol, through inhalation to two different mice models of neutrophil-induced (by melphalan or lipopolysaccharide) airway inflammation. The mice received treatment with either DEX-loaded MSPs or, as controls, empty MSPs or DEX only; and were evaluated for treatment effects 24 h after exposure. The results show that the MEL-induced airway inflammation could be treated by the DEX-loaded MSPs to the same extent as free DEX. Interestingly, in the case of LPS-induced inflammation, even the empty MSPs significantly down-modulated the inflammatory response. This study highlights the potential of MSPs as drug carriers for the treatment of diseases in the airways.

Trajectory representation and landmark projection for continuous-time structure from motion

Abstract: This paper revisits the problem of continuous-time structure from motion, and introduces a number of extensions that improve convergence and efficiency. The formulation with a C2-continuous spline ...

Large eddy simulation of CH4-air and C2H4-air combustion in a model annular gas turbine combustor

Abstract: Combustion instabilities are one of the major challenges in developing and operating propulsion and power generating gas-turbine engines More specifically, techniques for managing the increasingly stringent emissions regulations and efficiency demands have often given rise to thermo-acoustic instabilities, particularly for annular combustors operating in a lean premixed mode In this paper, we combine experimental and computational methods to examine unsteady gas turbine combustion in a full annular model gas turbine combustor installed at NTNU, operating both methane- and ethylene-air blends The experimental data consists of flame images, high-speed OH* chemiluminescence images, as well as pressure and heat-release time-series at discrete locations for the ethylene-air case The computational set-up consists of the 18 inlet tubes and swirlers, and the full annular combustor placed in a large external domain The computational model consists of a compressible finite rate chemistry LES model using skeletal methane-air and ethylene-air combustion chemistry The combustor is simulated in its self-excited state, without external forcing From the experiments and simulations the methane and ethylene cases are found to behave differently: The ethylene-air flames are much smaller than the methane-air flames, resulting in different interaction between adjacent flames The LES predictions show good qualitative agreement with the measurements in terms of instantaneous and time-averaged flame structure Comparing measured and predicted time-series of pressure and heat-release also shows good quantitative agreement with respect to the dynamics and structure for the ethylene-air case Investigating the predicted combustion dynamics using Proper Orthogonal Decomposition (POD) confirms the importance of the self-excited azimuthal mode on the behavior of the flame: the presence of nodes and anti-nodes of pressure induced fluctuations of the swirler mass-flow, which then, in turn, influence the heat-release These events occur shifted in time

Effects of sound exposure from a seismic airgun on heart rate, acceleration and depth use in free-swimming Atlantic cod and saithe.

Abstract: Airguns used for offshore seismic exploration by the oil and gas industry contribute to globally increasing anthropogenic noise levels in the marine environment. There is concern that the omnidirectional, high intensity sound pulses created by airguns may alter fish physiology and behaviour. A controlled short-term field experiment was performed to investigate the effects of sound exposure from a seismic airgun on the physiology and behaviour of two socioeconomically and ecologically important marine fishes: the Atlantic cod (Gadus morhua) and saithe (Pollachius virens). Biologgers recording heart rate and body temperature and acoustic transmitters recording locomotory activity (i.e. acceleration) and depth were used to monitor free-swimming individuals during experimental sound exposures (18-60 dB above ambient). Fish were held in a large sea cage (50 m diameter; 25 m depth) and exposed to sound exposure trials over a 3-day period. Concurrently, the behaviour of untagged cod and saithe was monitored using video recording. The cod exhibited reduced heart rate (bradycardia) in response to the particle motion component of the sound from the airgun, indicative of an initial flight response. No behavioural startle response to the airgun was observed; both cod and saithe changed both swimming depth and horizontal position more frequently during sound production. The saithe became more dispersed in response to the elevated sound levels. The fish seemed to habituate both physiologically and behaviourally with repeated exposure. In conclusion, the sound exposures induced over the time frames used in this study appear unlikely to be associated with long-term alterations in physiology or behaviour. However, additional research is needed to fully understand the ecological consequences of airgun use in marine ecosystems.

Spatial and Temporal Variability of Ambient Underwater Sound in the Baltic Sea.

Abstract: During last decades, anthropogenic underwater sound and its chronic impact on marine species have been recognised as an environmental protection challenge. At the same time, studies on the spatial and temporal variability of ambient sound, and how it is affected by biotic, abiotic and anthropogenic factors are lacking. This paper presents analysis of a large-scale and long-term underwater sound monitoring in the Baltic Sea. Throughout the year 2014, sound was monitored in 36 Baltic Sea locations. Selected locations covered different natural conditions and ship traffic intensities. The 63 Hz, 125 Hz and 2 kHz one-third octave band sound pressure levels were calculated and analysed. The levels varied significantly from one monitoring location to another. The annual median sound pressure level of the quietest and the loudest location differed almost 50 dB in the 63 Hz one-third octave band. Largest difference in the monthly medians was 15 dB in 63 Hz one-third octave band. The same monitoring locations annual estimated probability density functions for two yearly periods show strong similarity. The data variability grows as the averaging time period is reduced. Maritime traffic elevates the ambient sound levels in many areas of the Baltic Sea during extensive time periods.

Target Detection and Classification of Small Drones by Deep Learning on Radar Micro-Doppler

Abstract: Small drones, also called mini-UAVs (Unmanned Aerial Vehicles), have become very wide-spread. In security applications it is often desirable to detect and classify them. In this paper we employ radar micro-Doppler for detection and classification of small drones. Micro-Doppler are Doppler shifts generated by the movements of parts of the target. We have used radar measurements of small drones and birds, generated TVDs (Time Velocity Diagrams), and used a deep learning classifier to distinguish between drones and birds (target detection) and types of drones (target classification) with very good results. Our deep learning classifier is an improvement in classification performance compared to our earlier boosting and SVM (Support Vector Machine) classifiers on the same data.

Highly interacting regions of the human genome are enriched with enhancers and bound by DNA repair proteins.

Abstract: In specific cases, chromatin clearly forms long-range loops that place distant regulatory elements in close proximity to transcription start sites, but we have limited understanding of many loops identified by Chromosome Conformation Capture (such as Hi-C) analyses. In efforts to elucidate their characteristics and functions, we have identified highly interacting regions (HIRs) using intra-chromosomal Hi-C datasets with a new computational method based on looking at the eigenvector that corresponds to the smallest eigenvalue (here unity). Analysis of these regions using ENCODE data shows that they are in general enriched in bound factors involved in DNA damage repair and have actively transcribed genes. However, both highly transcribed regions as well as transcriptionally inactive regions can form HIRs. The results also indicate that enhancers and super-enhancers in particular form long-range interactions within the same chromosome. The accumulation of DNA repair factors in most identified HIRs suggests that protection from DNA damage in these regions is essential for avoidance of detrimental rearrangements.

Experimental Infection and Transmission Competence of Sindbis Virus in Culex torrentium and Culex pipiens Mosquitoes from Northern Sweden

Abstract: Introduction: Sindbis virus (SINV) is a mosquito-borne Alphavirus known to infect birds and cause intermittent outbreaks among humans in Fenno-Scandia. In Sweden, the endemic area has mainly been i ...

RICS-el: Building a national testbed for research and training on SCADA security (short paper)

Abstract: Trends show that cyber attacks targeting critical infrastructures are increasing, but security research for protecting such systems are challenging. There is a gap between the somewhat simplified models researchers at universities can sustain contra the complex systems at infrastructure owners that seldom can be used for direct research. There is also a lack of common datasets for research benchmarking. This paper presents a national experimental testbed for security research within supervisory control and data acquisition systems (SCADA), accessible for both research training and experiments. The virtualized testbed has been designed and implemented with both vendor experts and security researchers to balance the goals of realism with specific research needs. It includes a real SCADA product for energy management, a number of network zones, substation nodes, and a simulated power system. This environment enables creation of scenarios similar to real world utility scenarios, attack generation, development of defence mechanisms, and perhaps just as important: generating open datasets for comparative research evaluation.

Phylogeographic Distribution of Human and Hare Francisella Tularensis Subsp. Holarctica Strains in the Netherlands and Its Pathology in European Brown Hares (Lepus Europaeus).

Abstract: Sequence-based typing of Francisella tularensis has led to insights in the evolutionary developments of tularemia. In Europe, two major basal clades of F. tularensis subsp. holarctica exist, with a distinct geographical distribution. Basal clade B.6 is primarily found in Western Europe, while basal clade B.12 occurs predominantly in the central and eastern parts of Europe. There are indications that tularemia is geographically expanding and that strains from the two clades might differ in pathogenicity, with basal clade B.6 strains being potentially more virulent than basal clade B.12. This study provides information on genotypes detected in the Netherlands during 2011–2017. Data are presented for seven autochthonous human cases and for 29 European brown hares (Lepus europaeus) with laboratory confirmed tularemia. Associated disease patterns are described for 25 European brown hares which underwent post-mortem examination. The basal clades B.6 and B.12 are present both in humans and in European brown hares in the Netherlands, with a patchy geographical distribution. For both genotypes the main pathological findings in hares associated with tularemia were severe (sub)acute necrotizing hepatitis and splenitis as well as necrotizing lesions and hemorrhages in several other organs. Pneumonia was significantly more common in the B.6 than in the B.12 cases. In conclusion, the two major basal clades present in different parts in Europe are both present in the Netherlands. In hares found dead, both genotypes were associated with severe acute disease affecting multiple organs. Hepatitis and splenitis were common pathological findings in hares infected with either genotype, but pneumonia occurred significantly more frequently in hares infected with the B.6 genotype compared to hares infected with the B.12 genotype.

An a priori analysis of a DNS database of turbulent lean premixed methane flames for LES with finite-rate chemistry

Abstract: An a priori analysis of a DNS database of turbulent lean premixed methane flames is presented considering the relative effects of turbulence and LES filtering, along with a potential modelling approach for LES with finite-rate chemistry. The leading-order effect was found to be due to the filter operation; flame response to turbulence was a secondary effect, and manifested primarily as an increase in standard deviations about conditional means. It was found that the radicals O, H and OH were less impacted by the filter than other high-temperature radicals, which were significantly reduced in magnitude by the filter. By considering reaction path diagrams, key reactions have been identified that are responsible for disparities between the desired filtered reaction rates and the reaction rates evaluated using quantities available in LES calculations (i.e. the filtered species and temperature). More specifically, the hydrogen abstraction reactions that take CH 4 to CH 3 (by O, H and OH) were found to have particularly enhanced reaction rates, and dominate the reaction path. Under the conditions presented, reaction paths were found to be independent of turbulence intensity. In general, the filtered reaction rates from the DNS were found to align more closely with the filtered laminar profile than the reaction rate of filtered species and temperature, (but disparities were found to decrease with increasing Karlovitz number). A simple model for scaling reaction rates is considered based on filtered laminar flame profiles, and the resulting reaction paths demonstrate proof-of-concept of a simple approach for formulating a reaction rate model for LES with finite-rate chemistry.

Experimental Evaluation of Group Communications Protocols for Data Dissemination at the Tactical Edge

Abstract: Data dissemination is one of the fundamental requirements for any military network. Types of data include Situation Awareness data such as position reports, sensor data, and Commander’s Operational Orders and Intelligence Reports. Different data types have different dissemination patterns and requirements. Some data types such as position reports are generated by each node and need to be received by every other node. On the other hand, sensor data is generated by a handful of nodes and may be needed by a subset of other nodes. Finally, orders and reports are generated by higher echelon nodes (e.g., a Headquarters node) and need to be disseminated down the command hierarchy. Group communications protocols typically handle dissemination of such data from multiple senders to multiple recipients. In this paper, we evaluate the performance of a number of different group communications protocols for data dissemination. In particular, we evaluate the performance over an emulated tactical edge network using the Anglova scenario. Such an evaluation helps identify the relative strengths and weaknesses of these protocols when they operate in a challenged communications environment with limited capacity, variable latency, and unstable links.

“We want to know where the line is”: comparing current planning for future sea-level rise with three core principles of robust decision support approaches

Abstract: Handling uncertainties is a major challenge in climate change adaptation. A variety of robust decision support approaches that aim for better management of uncertainty have recently been emerging a...

A meta-analysis of field experiments on phishing susceptibility

Abstract: Phishing is a serious threat to any organization allowing their employees to use messaging systems and computers connected to the internet. Consequently, researchers have undertaken a large number of studies to identify the variables that determine this threat, i.e. variables that influence users' susceptibility to phishing emails. This paper presents a meta-analysis of the findings in 48 papers describing field experiments. The mean susceptibility rate to phishing emails across all studies and measurements was 21 percent. A majority (116 of 140) of the association tests reported, concerned variables related to the recipient. Most of these reported insignificant results. Both relative risks and association tests showed that technical warning systems, email personalization, training, and the use of established deceptive tactics influence the susceptibility rate. The type of scam as such also appears to be important, with some types of scams being orders of magnitude more successful than other types. Many of the results had limitations in control and sampling, which may explain unexpected and contradictory results.

Understanding practical challenges to risk and vulnerability assessments: the case of Swedish municipalities

Abstract: Assessing risks and vulnerabilities in the multifaceted context of a municipality is challenging. There is a plethora of methods and tools to support this task. However, to achieve successful outco...

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 ...

EMC challenges for the era of massive Internet of Things

Abstract: The technical development towards the full vision of the Internet of Things (IoT) is expected to reach its full potential by the coming 5G wireless technologies. This will open up for so called massive IoT characterized by very large co-location densities. This development will affect the area of Electromagnetic Compatibility (EMC) in a number of ways and may even be the most challenging issue for the EMC area since it was born for over 100 years ago. The challenges that emerge as a result of the mass increase of wirelessly consumer devices, dense co-located, working in new frequency bands and in scenarios characterized by being highly dynamic, flexible and non-predictable, will be complex and will require new EMC equipment, theoretical models and methodologies for EMC analysis and testing to be developed. In this paper, some of these new challenges are highlighted and discussed. Furthermore, numerical results from some dense co-location scenarios are presented to show examples of interference challenges to be handled.

Levels of hate in online environments

Abstract: Hate speech in online environments is a severe problem for many reasons. The space for reasoning and argumentation shrinks, individuals refrain from expressing their opinions, and polarization of views increases. Hate speech contributes to a climate where threats and even violence are increasingly regarded as acceptable. The amount and the intensity of hate expressions vary greatly between different digital environments. To analyze the level of hate in a given online environment, to study the development over time and to compare the level of hate within online environments we have developed the notion of a hate level. The hate level encapsulates the level of hate in a given digital environment. We present methods to automatically determine the hate level, utilizing transfer learning on pre-trained language models with annotated data to create automated hate detectors. We evaluate our approaches on a set of websites and discussion forums.