6,147 research outputs found

    Stability and Invariant Random Subgroups

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    Consider Sym(n)\operatorname{Sym}(n), endowed with the normalized Hamming metric dnd_n. A finitely-generated group Γ\Gamma is \emph{P-stable} if every almost homomorphism ρnk ⁣:ΓSym(nk)\rho_{n_k}\colon \Gamma\rightarrow\operatorname{Sym}(n_k) (i.e., for every g,hΓg,h\in\Gamma, limkdnk(ρnk(gh),ρnk(g)ρnk(h))=0\lim_{k\rightarrow\infty}d_{n_k}( \rho_{n_k}(gh),\rho_{n_k}(g)\rho_{n_k}(h))=0) is close to an actual homomorphism φnk ⁣:ΓSym(nk)\varphi_{n_k} \colon\Gamma\rightarrow\operatorname{Sym}(n_k). Glebsky and Rivera observed that finite groups are P-stable, while Arzhantseva and P\u{a}unescu showed the same for abelian groups and raised many questions, especially about P-stability of amenable groups. We develop P-stability in general, and in particular for amenable groups. Our main tool is the theory of invariant random subgroups (IRS), which enables us to give a characterization of P-stability among amenable groups, and to deduce stability and instability of various families of amenable groups.Comment: 24 pages; v2 includes minor updates and new reference

    Economic and Environmental Consequences of the ECJ Genome Editing Judgment in Agriculture

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    Genome-edited crops are on the verge of being placed on the market and their agricultural and food products will thus be internationally traded soon. National regulations, however, diverge regarding the classification of genome-edited crops. Major countries such as the US and Brazil do not specifically regulate genome-edited crops, while in the European Union, they fall under GMO legislation, according to the European Court of Justice (ECJ). As it is in some cases impossible to analytically distinguish between products from genome-edited plants and those from non-genome-edited plants, EU importers may fear the risk of violating EU legislation. They may choose not to import any agricultural and food products based on crops for which genome-edited varieties are available. Therefore, crop products of which the EU is currently a net importer would become more expensive in the EU, and production would intensify. Furthermore, an intense substitution of products covered and not covered by genome editing would occur in consumption, production, and trade. We analyzed the effects of such a cease of EU imports for cereals and soy in the EU agricultural sector with the comparative static agricultural sector equilibrium model CAPRI. Our results indicate dramatic effects on agricultural and food prices as well as on farm income. The intensification of EU agriculture may result in negative net environmental effects in the EU as well as in an increase in global greenhouse gas (GHG) emissions. This suggests that trade effects should be considered when developing domestic regulation for genome-edited crops.Peer Reviewe

    Attention Allocation Aid for Visual Search

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    This paper outlines the development and testing of a novel, feedback-enabled attention allocation aid (AAAD), which uses real-time physiological data to improve human performance in a realistic sequential visual search task. Indeed, by optimizing over search duration, the aid improves efficiency, while preserving decision accuracy, as the operator identifies and classifies targets within simulated aerial imagery. Specifically, using experimental eye-tracking data and measurements about target detectability across the human visual field, we develop functional models of detection accuracy as a function of search time, number of eye movements, scan path, and image clutter. These models are then used by the AAAD in conjunction with real time eye position data to make probabilistic estimations of attained search accuracy and to recommend that the observer either move on to the next image or continue exploring the present image. An experimental evaluation in a scenario motivated from human supervisory control in surveillance missions confirms the benefits of the AAAD.Comment: To be presented at the ACM CHI conference in Denver, Colorado in May 201

    The Excess Costs of Depression and the Influence of Sociodemographic and Socioeconomic Factors: Results from the German Health Interview and Examination Survey for Adults (DEGS)

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    Introduction The aim of this study was to estimate excess costs of depression in Germany and to examine the influence of sociodemographic and socioeconomic determinants. Methods Annual excess costs of depression per patient were estimated for the year 2019 by comparing survey data of individuals with and without self-reported medically diagnosed depression, representative for the German population aged 18–79 years. Differences between individuals with depression (n = 223) and without depression (n = 4540) were adjusted using entropy balancing. Excess costs were estimated using generalized linear model regression with a gamma distribution and log-link function. We estimated direct (inpatient, outpatient, medication) and indirect (sick leave, early retirement) excess costs. Subgroup analyses by social determinants were conducted for sex, age, socioeconomic status, first-generation or second-generation migrants, partnership, and social support. Results Total annual excess costs of depression amounted to €5047 (95% confidence interval [CI] 3214–6880) per patient. Indirect excess costs amounted to €2835 (1566–4103) and were higher than direct excess costs (€2212 [1083–3341]). Outpatient (€498), inpatient (€1345), early retirement (€1686), and sick leave (€1149) excess costs were statistically significant, while medication (€370) excess costs were not. Regarding social determinants, total excess costs were highest in the younger age groups (€7955 for 18–29-year-olds, €9560 for 30–44-year-olds), whereas total excess costs were lowest for the oldest age group (€2168 for 65+) and first-generation or second-generation migrants (€1820). Conclusions Depression was associated with high excess costs that varied by social determinants. Considerable differences between the socioeconomic and sociodemographic subgroups need further clarification as they point to specific treatment barriers as well as varying treatment needs.Peer Reviewe
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