390 research outputs found
Assessing vulnerabilities in IoT-based ambient assisted living systems
Ambient Assisted Living systems aim at providing automated support to humans with special needs. Smart Homes equipped with Internet of Things infrastructure supporting the development of Ambient Intelligence which can look after humans is being widely investigated worldwide. As any IT based system, these have strengths and also weaknesses. One dimension of these systems developers want to strengthen is security, eliminating or at least reducing as much as possible potential threats. The motivation is clear, as these systems gather sensitive information about the health of an individual there is potential for harm if that information is accessed and used by the wrong person. This chapter starts by providing an analysis of stakeholders in this area. Then explains the IoT infrastructure used as a testbed for the main security analysis methods and tools. Finally it explains a process to assess the likelihood of certain vulnerabilities in the system. This process is mainly focused on the design stage of a system. It can be iteratively combined with development to inform a developing team which system architectures may be safer and worth given development priority
Distribution of the Object Oriented Databases. A Viewpoint of the MVDB Model's Methodology and Architecture
In databases, much work has been done towards extending models with advanced tools such as view technology, schema evolution support, multiple classification, role modeling and viewpoints. Over the past years, most of the research dealing with the object multiple representation and evolution has proposed to enrich the monolithic vision of the classical object approach in which an object belongs to one hierarchy class. In particular, the integration of the viewpoint mechanism to the conventional object-oriented data model gives it flexibility and allows one to improve the modeling power of objects. The viewpoint paradigm refers to the multiple descriptions, the distribution, and the evolution of object. Also, it can be an undeniable contribution for a distributed design of complex databases. The motivation of this paper is to define an object data model integrating viewpoints in databases and to present a federated database architecture integrating multiple viewpoint sources following a local-as-extended-view data integration approach.object-oriented data model, OQL language, LAEV data integration approach, MVDB model, federated databases, Local-As-View Strategy.
A breach in plant defences: Pseudomonas syringae pv. actinidiae targets ethylene signalling to overcome Actinidia chinensis pathogen responses
Ethylene interacts with other plant hormones to modulate many aspects of plant metabolism, including defence and stomata regulation. Therefore, its manipulation may allow plant pathogens to overcome the host’s immune responses. This work investigates the role of ethylene as a virulence factor for Pseudomonas syringae pv. actinidiae (Psa), the aetiological agent of the bacterial canker of kiwifruit. The pandemic, highly virulent biovar of this pathogen produces ethylene, whereas the biovars isolated in Japan and Korea do not. Ethylene production is modulated in planta by light/dark cycle. Exogenous ethylene application stimulates bacterial virulence, and restricts or increases host colonisation if performed before or after inoculation, respectively. The deletion of a gene, unrelated to known bacterial biosynthetic pathways and putatively encoding for an oxidoreductase, abolishes ethylene production and reduces the pathogen growth rate in planta. Ethylene production by Psa may be a recently and independently evolved virulence trait in the arms race against the host. Plantand pathogen-derived ethylene may concur in the activation/suppression of immune responses, in the chemotaxis toward a suitable entry point, or in the endophytic colonisation
Cryogenic bath-type heat exchangers for ultra-pure noble gas applications
Two cryogenic bath-type heat exchangers for ultra-pure noble gas applications were developed with particular emphasis on noble gas liquefaction in cryogenic distillation systems. The main objective was to construct heat exchangers for xenon from materials that do not emanate radon and that fulfill ultra-high vacuum standards. Therefore, only high-quality copper and stainless steel materials were used. Especially, large-area oxygen-free copper fins with high conductivity in a new design ensure efficient heat transfer. One bath-type Xe-Xe heat exchanger was designed with a diameter of 50 cm to achieve a xenon condensing capacity of at least 100 kg/h. In order to guarantee the necessary heat transfer between the two xenon reservoirs, this heat exchanger features a specially manufactured stainless steel flange with a copper plate welded inside. We first tested our concept on a dedicated bath-type heat exchanger with a reduced diameter of 30 cm using liquid nitrogen to liquefy the xenon. A model based on conservative assumptions such as film boiling on the nitrogen side and film condensation on the xenon side was developed and applied to caluclate the expected heat transfer for our design. We were able to demonstrate an adjustable xenon liquefaction rate of up to 113 kg/h limited only by our measurement procedure at a cooling efficiency of (0.98 ± 0.03) for the LN-Xe heat exchanger
Transcriptional profiling of vaccine-induced immune responses in humans and non-human primates
There is an urgent need for pre-clinical and clinical biomarkers predictive of vaccine immunogenicity, efficacy and safety to reduce the risks and costs associated with vaccine development. Results emerging from immunoprofiling studies in non-human primates and humans demonstrate clearly that (i) type and duration of immune memory are largely determined by the magnitude and complexity of the innate immune signals and (ii) genetic signatures highly predictive of B-cell and T-cell responses can be identified for specific vaccines. For vaccines with similar composition, e.g. live attenuated viral vaccines, these signatures share common patterns. Signatures predictive of vaccine efficacy have been identified in a few experimental challenge studies. This review aims to give an overview of the current literature on immunoprofiling studies in humans and also presents some of our own data on profiling of licensed and experimental vaccines in non-human primates
Event structure semantics of (controlled) reversible CCS
CCSK is a reversible form of CCS which is causal, meaning that ac- tions can be reversed if and only if each action caused by them has already been reversed; there is no control on whether or when a computation reverses. We pro- pose an event structure semantics for CCSK. For this purpose we define a cat- egory of reversible bundle event structures, and use the causal subcategory to model CCSK. We then modify CCSK to control the reversibility with a rollback primitive, which reverses a specific action and all actions caused by it. To define the event structure semantics of rollback, we change our reversible bundle event structures by making the conflict relation asymmetric rather than symmetric, and we exploit their capacity for non-causal reversibility
Taxonomic classification of asteroids based on MOVIS near-infrared colors
We aim to provide a taxonomic classification for asteroids observed by
VISTA-VHS survey. We derive a method for assigning a compositional type to an
object based on its (Y-J), (J-Ks), and (H-Ks) colors. We present a taxonomic
classification for 18\,265 asteroids from the MOVIS catalog, using a
probabilistic method and the k-nearest neighbors algorithm. Because our
taxonomy is based only on NIR colors, several classes from Bus-DeMeo were
clustered into groups and a slightly different notation was used (i.e. the
superscript indicates that the classification was obtained based on the NIR
colors and the subscript indicates possible miss-identifications with other
types). Our results are compared with the information provided by the Sloan
Digital Sky Survey (SDSS) and Wide-field Infrared Survey Explorer (WISE). The
two algorithms used in this study give a taxonomic type for all objects having
at least (Y-J) and (J-Ks) observed colors. A final classification is reported
for a set of 6\,496 asteroids based on the criteria that KNN and probabilistic
algorithms gave the same result, (Y-J) 0.118 and
(J-Ks)0.136. This set includes 144 bodies classified as ,
613 as , 197 as , 91 as , 440 as , 665
as , 233 as , 3\,315 as , and 798 as . We
report the albedo distribution for each taxonomic group and we compute new
median values for the main types. We found that V-type and A-type candidates
have identical size frequency distributions, but the V-types are five times
more common than the A-types. Several particular cases, such as the A-type
asteroid (11616) 1996 BQ2 and the S-type (3675) Kematsch, both in the Cybele
population, are discussed. Files and codes available at:
https://github.com/marcelpopescu/MOVIS-TaxonomyComment: 18 pages, 10 figures, accepted for publication in Astronomy &
Astrophysics (A&A
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