6,147 research outputs found
Stability and Invariant Random Subgroups
Consider , endowed with the normalized Hamming metric
. A finitely-generated group is \emph{P-stable} if every almost
homomorphism (i.e.,
for every , ) is close to an actual
homomorphism .
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
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Multireference Stochastic Coupled Cluster.
We describe a modification of the stochastic coupled cluster algorithm that
allows the use of multiple reference determinants. By considering the secondary
references as excitations of the primary reference and using them to change the
acceptance criteria for selection and spawning, we obtain a simple form of
stochastic multireference coupled cluster which preserves the appealing aspects
of the single reference approach. The method is able to successfully describe
strongly correlated molecular systems using few references and low cluster
truncation levels, showing promise as a tool to tackle strong correlation in
more general systems. Moreover, it allows simple and comprehensive control of
the included references and excitorsthereof, and this flexibility can be taken
advantage of to gain insight into some of the inner workings of established
electronic structure methods
Economic and Environmental Consequences of the ECJ Genome Editing Judgment in Agriculture
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
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)
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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