61 research outputs found

    Measurement in Research on Perceptions of Probability and Risk

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    Die Dissertation umfasst vier unabhĂ€ngige, jedoch thematisch verwandte Artikel. Der Schwerpunkt liegt auf Fragen der Messung in der Erforschung von Wahrscheinlichkeits- und Risikourteilen. Ausgangspunkt waren Studien zum sogenannten Einzelfalleffekt—einer systematischen Verzerrung von Urteilen ĂŒber statistisch vermittelte Risiken durch persönliche Erfahrungsberichte. Der erste Artikel ist ein Beispiel hierfĂŒr. Er zeigt, dass der Effekt nicht von der GlaubwĂŒrdigkeit der Informationsquellen moderiert wird. Ferner fand sich, dass die beiden Risikokomponenten, Wahrscheinlichkeit und Schweregrad, nicht unabhĂ€ngig voneinander wahrgenommen werden. In dieser und vergleichbaren Studien sind die subjektive Wahrscheinlichkeit und das wahrgenommene Risiko zentrale abhĂ€ngige Variablen. In der Forschung herrscht jedoch wenig Einigkeit darĂŒber, wie beide Konstrukte am besten zu messen sind. Daher beschĂ€ftigt sich der zweite Artikel unter anderem mit der Frage, ob der Einzelfalleffekt vom verwendeten Messinstrument abhĂ€ngig ist. In zwei Experimenten wurde gezeigt, dass der Einfluss von Narrativen auf einem nichtnumerischen Risikomaß am stĂ€rksten ist, wĂ€hrend zwei Skalen fĂŒr subjektive Wahrscheinlichkeit hauptsĂ€chlich Manipulationen der statistischen Information abbildeten. Besonders bemerkenswert ist daher der zweite wichtige Befund in Artikel 2: Der Einzelfalleffekt beruht auf einer ReprĂ€sentation von relativer HĂ€ufigkeit, d.h. Wahrscheinlichkeit. Artikel 3 und 4 sind methodisch ausgerichtet. In insgesamt vier Experimenten wurden verschiedene Messformate zur Erfassung subjektiver Wahrscheinlichkeitsurteile unter streng kontrollierten Bedingungen hinsichtlich der psychometrischen Eigenschaften SensitivitĂ€t und KontextabhĂ€ngigkeit evaluiert. In Experiment 1 erwiesen sich numerische Maße verschiedenen Ratingskalen in allen Kriterien als grundsĂ€tzlich ĂŒberlegen. Jedoch zeigten die Befunde auch, dass Unterschiede der Skalenleistung nicht nur von inhĂ€renten Eigenschaften der Instrumente abhĂ€ngen, sondern auch von der Genauigkeit der den Urteilen zugrundeliegenden ReprĂ€sentationen. In Experimenten 2 bis 4 konnte gezeigt werden, dass ein großer Fehler in den ReprĂ€sentationen sogar in einem within-subjects Design zu vermeintlichen Kontexteffekten auf niedrig aufgelösten Ratingskalen fĂŒhren kann. Solche Messinstrumente erlauben weder eine sinnvolle Quantifizierung noch einen sinnvollen Vergleich von Wahrscheinlichkeitsurteilen und sollten fĂŒr diesen Zweck nicht verwendet werden. Numerische Maße lassen sich hingegen eindeutig interpretieren, sie erfassen jedoch auch die Ungenauigkeiten in den zugrundeliegenden ReprĂ€sentationen und können daher zu klassischen RegressionsfehlschlĂŒssen fĂŒhren.The dissertation comprises four independent though thematically related research articles. The principal focus is on questions of measurement in research of probability and risk perception. These questions were inspired by studies of the biasing effect of single-case narratives on perceptions of statistically conveyed risks. Article 1 serves as an example and shows that the bias is not affected by cues regarding the credibility of either information source. Additional analyses revealed that the two assumed constituents of risk, that is, probability and severity, were not perceived independently. In this and comparable studies subjective probability and perceived risk are central dependent variables. However, there is no agreement on how to assess either one. Therefore, the experiments in Article 2 investigated, among other things, whether the bias is task-dependent, that is, whether it changes as a function of the instrument that is used to measure it. Narratives had the strongest effect on a non-numerical risk measure, whereas two scales for subjective probability reflected primarily statistical variations. In light of this, the second major finding in these studies was especially remarkable: The narrative bias is driven by a representation of relative frequency, that is, probability. Articles 3 and 4 are yet more methodological. Across altogether four experiments, various self-report formats for judgments of subjective probability were evaluated under highly controlled conditions in terms of the psychometric properties sensitivity and context dependency. However, differences in performance between scales were caused only in part by characteristics of the scales themselves—they also depended on the error in the underlying representations. Experiments 2–4 showed that highly imprecise representation can lead to apparent context effects on low-resolution rating scales. Such instruments do not allow for a meaningful quantification or meaningful comparisons between experimental conditions and should not be used in research on subjective probability. Numeric formats, on the other hand, are unambiguously interpretable but also very sensitive to noise and can lead to classic regression fallacies

    SoK: SCA-secure ECC in software – mission impossible?

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    This paper describes an ECC implementation computing the X25519 keyexchange protocol on the Arm Cortex-M4 microcontroller. For providing protections against various side-channel and fault attacks we first review known attacks and countermeasures, then we provide software implementations that come with extensive mitigations, and finally we present a preliminary side-channel evaluation. To our best knowledge, this is the first public software claiming affordable protection against multiple classes of attacks that are motivated by distinct real-world application scenarios. We distinguish between X25519 with ephemeral keys and X25519 with static keys and show that the overhead to our baseline unprotected implementation is about 37% and 243%, respectively. While this might seem to be a high price to pay for security, we also show that even our (most protected) static implementation is at least as efficient as widely-deployed ECC cryptographic libraries, which offer much less protection

    The alignment of the C3 Accelerator Structures with the Rasnik alignment system

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    The Rasnik 3-point alignment system, now widely applied in particle physics experiments and in the instrumentation of gravitational wave experiments, can be used as N-point alignment system by daisy chain N individual 3-point systems. The conceptual implementation of Rasnik chains in C3 is presented. The proper operation of a laser diode and a CMOS image sensor in liquid nitrogen has been verified. Next plans for testing a small but complete system, immersed in liquid nitrogen, are presented

    Opportunities and challenges of Web 2.0 for vaccination decisions.

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    A growing number of people use the Internet to obtain health information, including information about vaccines. Websites that allow and promote interaction among users are an increasingly popular source of health information. Users of such so-called Web 2.0 applications (e.g. social media), while still in the minority, represent a growing proportion of online communicators, including vocal and active anti-vaccination groups as well as public health communicators. In this paper, the authors: define Web 2.0 and examine how it may influence vaccination decisions; discuss how anti-vaccination movements use Web 2.0 as well as the challenges Web 2.0 holds for public health communicators; describe the types of information used in these different settings; introduce the theoretical background that can be used to design effective vaccination communication in a Web 2.0 environment; make recommendations for practice and pose open questions for future research. The authors conclude that, as a result of the Internet and Web 2.0, private and public concerns surrounding vaccinations have the potential to virally spread across the globe in a quick, efficient and vivid manner. Web 2.0 may influence vaccination decisions by delivering information that alters the perceived personal risk of vaccine-preventable diseases or vaccination side-effects. It appears useful for public health officials to put effort into increasing the effectiveness of existing communication by implementing interactive, customized communication. A key step to providing successful public health communication is to identify those who are particularly vulnerable to finding and using unreliable and misleading information. Thus, it appears worthwhile that public health websites strive to be easy to find, easy to use, attractive in its presentation and readily provide the information, support and advice that the searcher is looking for. This holds especially when less knowledgeable individuals are in need of reliable information about vaccination risks and benefits

    Cause and Effect Analysis between Influencing Factors Related to Environmental Conditions, Hunting and Handling Practices and the Initial Microbial Load of Game Carcasses

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    Environmental, hunting and handling factors affect the microbial load of hunted game and the resulting meat products. The aim of this study was to systematically investigate the influence of several factors on the initial microbial load (IML) of game carcasses during the early hunting chain. Eviscerated roe deer body cavities (n = 24) were investigated in terms of total viable count and the levels of Pseudomonas spp., Lactobacillus spp., Enterobacteriaceae and Escherichia coli (E. coli). Furthermore, a risk analysis based on the obtained original IML data, literature search and a Failure Mode and Effects Analysis (FMEA) was performed. The IML could be explained in a regression model by factors including the higher body weight (BW), damaged gastrointestinal tract by the shot, ambient temperature or rain. The levels of Lactobacillus spp. (p = 0.0472), Enterobacteriaceae (p = 0.0070) and E. coli (p = 0.0015) were lower on the belly flap surface when gloves were used during evisceration. The literature search revealed that studies examining influencing factors (IF) on the IML of game carcasses found contradictory effects of the comparable IF on IML. Potential handling failures may lead to a higher IML of game carcasses during the early hunting chain ranked by FMEA. Several handling practices for game carcasses are recommended, such as ensuring efficient cooling of heavier BW carcasses to limit bacterial growth or eviscerating heavier carcasses before lighter ones

    Workshop on accounting for fishers and other stakeholders’ perceptions of the dynamics of fish stocks in ICES advice (WKAFPA)

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    The objective of the Workshop on accounting for fishers and other stakeholders’ perceptions of the dynamics of fish stocks in ICES advice (WKAFPA) was to identify where and how stake- holder information could be incorporated in the ICES fisheries advice process. It adopted an operational definition of the concept of perception, where perceptions result from observations, interpreted in light of experience, that can be supported by data, information and knowledge to generate evidence about them. Stakeholder information can be either structured (e.g. routinely collected information in a standardized format) or unstructured (e.g. experiential information) and either of those can inform decisions made during the production of ICES advice. Most notably, the group identified there was a need to engage with stakeholders earlier in the process, i.e. before benchmarks meetings take place and before preliminary assessment results are used as the basis to predict total allowable catches for upcoming advice (Figure 4.2). It was therefore recommended to include in the ICES process the organisation of pre-bench- mark/roadmap workshops where science and data needs of upcoming benchmarks can be iden- tified, followed by making arrangements how scientists and stakeholders can collaborate to ac- cess, prepare for use (where relevant) and document the structured and unstructured infor- mation well ahead of the benchmark meetings. It was also recommended to organise ‘sense-checking’ sessions with stakeholders when prelim- inary assessments are available but not yet used as the basis for advisory production. This would allow stakeholders and assessment scientists to verify available knowledge and data against stock perceptions and provide additional considerations relevant for the production of TAC ad- vice. Next to these two additional activities, it is recommended that communication on differ- ences in stakeholder perception or data derived perceptions are communicated within the ICES assessment reports as well as in the ICES advice in a transparent manner. Not only should dif- ferences or similarities be documented and communicated, in those cases where there are differ- ences in perception between ICES stock assessments and stakeholders, a working group, external to the assessment working groups, should evaluate these differences and describe whether these differences can be logically explained or require further investigation. This outcome of this pro- cess may potentially lead to new data collection or additional analyses suitable for input to benchmarks. Essential in this entire process is making sure the same language is spoken between scientists and stakeholders, that there are clear and transparent processes in place on how to deal with stakeholder information and communicate clearly how this information is used in the prepara- tion of ICES advice.info:eu-repo/semantics/publishedVersio

    Changes over time in characteristics, resource use and outcomes among ICU patients with COVID-19-A nationwide, observational study in Denmark

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    BACKGROUND: Characteristics and care of intensive care unit (ICU) patients with COVID‐19 may have changed during the pandemic, but longitudinal data assessing this are limited. We compared patients with COVID‐19 admitted to Danish ICUs in the first wave with those admitted later. METHODS: Among all Danish ICU patients with COVID‐19, we compared demographics, chronic comorbidities, use of organ support, length of stay and vital status of those admitted 10 March to 19 May 2020 (first wave) versus 20 May 2020 to 30 June 2021. We analysed risk factors for death by adjusted logistic regression analysis. RESULTS: Among all hospitalised patients with COVID‐19, a lower proportion was admitted to ICU after the first wave (13% vs. 8%). Among all 1374 ICU patients with COVID‐19, 326 were admitted during the first wave. There were no major differences in patient's characteristics or mortality between the two periods, but use of invasive mechanical ventilation (81% vs. 58% of patients), renal replacement therapy (26% vs. 13%) and ECMO (8% vs. 3%) and median length of stay in ICU (13 vs. 10 days) and in hospital (20 vs. 17 days) were all significantly lower after the first wave. Risk factors for death were higher age, larger burden of comorbidities (heart failure, pulmonary disease and kidney disease) and active cancer, but not admission during or after the first wave. CONCLUSIONS: After the first wave of COVID‐19 in Denmark, a lower proportion of hospitalised patients with COVID‐19 were admitted to ICU. Among ICU patients, use of organ support was lower and length of stay was reduced, but mortality rates remained at a relatively high level

    A deletion in GDF7 is associated with a heritable forebrain commissural malformation concurrent with ventriculomegaly and interhemispheric cysts in cats

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    Publisher Copyright: © 2020 by the authors.An inherited neurologic syndrome in a family of mixed-breed Oriental cats has been characterized as forebrain commissural malformation, concurrent with ventriculomegaly and interhemispheric cysts. However, the genetic basis for this autosomal recessive syndrome in cats is unknown. Forty-three cats were genotyped on the Illumina Infinium Feline 63K iSelect DNA Array and used for analyses. Genome-wide association studies, including a sib-transmission disequilibrium test and a case-control association analysis, and homozygosity mapping, identified a critical region on cat chromosome A3. Short-read whole genome sequencing was completed for a cat trio segregating with the syndrome. A homozygous 7 bp deletion in growth differentiation factor 7 (GDF7) (c.221_227delGCCGCGC [p.Arg74Profs]) was identified in affected cats, by comparison to the 99 Lives Cat variant dataset, validated using Sanger sequencing and genotyped by fragment analyses. This variant was not identified in 192 unaffected cats in the 99 Lives dataset. The variant segregated concordantly in an extended pedigree. In mice, GDF7 mRNA is expressed within the roof plate when commissural axons initiate ventrally-directed growth. This finding emphasized the importance of GDF7 in the neurodevelopmental process in the mammalian brain. A genetic test can be developed for use by cat breeders to eradicate this variant.Peer reviewe

    Werewolf, there wolf : Variants in hairless associated with hypotrichia and roaning in the lykoi cat breed

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    Publisher Copyright: © 2020 by the authors. Licensee MDPI, Basel, Switzerland.A variety of cat breeds have been developed via novelty selection on aesthetic, dermatological traits, such as coat colors and fur types. A recently developed breed, the lykoi (a.k.a. werewolf cat), was bred from cats with a sparse hair coat with roaning, implying full color and all white hairs. The lykoi phenotype is a form of hypotrichia, presenting as a significant reduction in the average numbers of follicles per hair follicle group as compared to domestic shorthair cats, a mild to severe perifollicular to mural lymphocytic infiltration in 77% of observed hair follicle groups, and the follicles are often miniaturized, dilated, and dysplastic. Whole genome sequencing was conducted on a single lykoi cat that was a cross between two independently ascertained lineages. Comparison to the 99 Lives dataset of 194 non‐lykoi cats suggested two variants in the cat homolog for Hairless (HR) (HR lysine demethylase and nuclear receptor corepressor) as candidate causal gene variants. The lykoi cat was a compound heterozygote for two loss of function variants in HR, an exon 3 c.1255_1256dupGT (chrB1:36040783), which should produce a stop codon at amino acid 420 (p.Gln420Serfs*100) and, an exon 18 c.3389insGACA (chrB1:36051555), which should produce a stop codon at amino acid position 1130 (p.Ser1130Argfs*29). Ascertainment of 14 additional cats from founder lineages from Canada, France and different areas of the USA identified four additional loss of function HR variants likely causing the highly similar phenotypic hair coat across the diverse cats. The novel variants in HR for cat hypotrichia can now be established between minor differences in the phenotypic presentations.Peer reviewe
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