24 research outputs found
Lights, Camera, Action! Exploring Effects of Visual Distractions on Completion of Security Tasks
Human errors in performing security-critical tasks are typically blamed on
the complexity of those tasks. However, such errors can also occur because of
(possibly unexpected) sensory distractions. A sensory distraction that produces
negative effects can be abused by the adversary that controls the environment.
Meanwhile, a distraction with positive effects can be artificially introduced
to improve user performance.
The goal of this work is to explore the effects of visual stimuli on the
performance of security-critical tasks. To this end, we experimented with a
large number of subjects who were exposed to a range of unexpected visual
stimuli while attempting to perform Bluetooth Pairing. Our results clearly
demonstrate substantially increased task completion times and markedly lower
task success rates. These negative effects are noteworthy, especially, when
contrasted with prior results on audio distractions which had positive effects
on performance of similar tasks. Experiments were conducted in a novel (fully
automated and completely unattended) experimental environment. This yielded
more uniform experiments, better scalability and significantly lower financial
and logistical burdens. We discuss this experience, including benefits and
limitations of the unattended automated experiment paradigm
Airborne biological hazards and dust in fattening pig facilities with and without straw
Against the background of a high prevalence of respiratory diseases among the workers with the housing of fattening pigs as well as conspicuous negative pulmonary results among the fattening pigs it will be necessary to determine within the framework of an interdisciplinary cooperating project the impact of and hazards for humans, animals and the environment wherever it occurred in fattening pig facilities. To achieve this research has been carried out in representative systems of housing fattening pigs especially taking into account organic systems with the use of straw in deep litter or minimal litter systems in comparison to conventional systems, where the straw was used as on occupation material. In correspondence with the current discussion in the field of occupational medicine and the occupational safety and health area the impact through micro organisms and their metabolic products (so-called biological hazards) as well as the effects of dust and harmful gases are central in this research. The objective of this project is on one hand to describe the status quo concerning the level of biological hazards in different housing system for fattening pigs. On the other hand causeâeffect relationships and influencing factors on the level and dynamics of the registered parameters should be described
StallluftqualitÀt und Arbeitsplatzbelastungen in unterschiedlichen Mastschweinehaltungsverfahren
Der aktuellen Diskussion in der Arbeitsmedizin entsprechend standen beider Untersuchung unterschiedlicher Mastschweinehaltungsverfahren dieBelastungen durch Mikroorganismen und deren Stoffwechselprodukte(sog. biologische Belastungen) ergĂ€nzt um Staub- und Schadgaseinwir-kungen im Vordergrund. Anhand der umfassenden Untersuchungenkonnten keine deutlichen haltungssystemspezifischen Unterschiede imHinblick auf Schadgas- und Staubkonzentrationen ermittelt werden. Diebiologischen Belastungen wie auch Parameter der Tiergesundheit diffe-rierten zwischen den StĂ€llen. Die gewonnenen Ergebnisse legen dieSchlussfolgerung nahe, dass das AusmaĂ der Belastungen nicht ursĂ€ch-lich einem spezifischen Haltungssystem zugeschrieben werden kann,sondern in erster Linie von dessen individueller Ausgestaltung und derspezifischen BetriebsfĂŒhrung bestimmt wird
Indoor Air Quality and Biological Impacts on the Workplace in Housing Systems for Fattening pigs
In this research of a variety of housing systems for fattening pigs, the impact by microorganisms and their metabolic products, as well as the effects of dust and harmful gases, was central. No distinct differences between the housing systems could be determined regarding the dust and gas concentrations. The biological hazards as well as the impact on animal health varies between the different housing systems
Surface charge of polyoxometalates modulates polymerization of the scrapie prion protein
Prions are composed solely of an alternatively folded isoform of the prion protein (PrP), designated PrPSc. N-terminally truncated PrPSc, denoted PrP 27â30, retains infectivity and polymerizes into rods with the ultrastructural and tinctorial properties of amyloid. We report here that some polyoxometalates (POMs) favor polymerization of PrP 27-30 into prion rods, whereas other POMs promote assembly of the protein into 2D crystals. Antibodies reacting with epitopes in denatured PrP 27-30 also bound to 2D crystals treated with 3 M urea. These same antibodies did not bind to either native PrPSc or untreated 2D crystals. By using small, spherical POMs with Keggin-type structures, the central heteroatom was found to determine whether prion rods or 2D crystals were preferentially formed. An example of a Keggin-type POM with a phosphorous heteroatom is the phosphotungstate anion (PTA). Both PTA and a Keggin-type POM with a silicon heteratom have low-charge densities and favor formation of prion rods. In contrast, POMs with boron or hydrogen heteroatoms exhibiting higher negative charges encouraged 2D crystal formation. The 2D crystals of PrP 27-30 produced by selective precipitation with POMs were larger and more well ordered than those obtained by sucrose gradient centrifugation. Our findings argue that the negative charge of Keggin-type POMs determines the quaternary structure adopted by PrP 27-30. The mechanism by which POMs function in competing prion polymerization pathwaysâone favoring 2D crystals and the other, amyloid fibrilsâremains to be established