625 research outputs found
Multidimensional generalized Gini indices.
The axioms used to characterize the generalized Gini social evaluation orderings for one-dimensional distributions are extended to the multidimensional attributes case. A social evaluation ordering is shown to have a two-stage aggregation representation if these axioms and a separability assumption are satisfied. In the first stage, the distributions of each attribute are aggregated using generalized Gini social evaluation functions. The functional form of the second-stage aggregator depends on the number of attributes and on which version of a comonotonic additivity axiom is used. The implications of these results for the corresponding multidimensional indices of relative and absolute inequality are also considered.Generalized Gini; multidimensional inequality
Reasons and Means to Model Preferences as Incomplete
Literature involving preferences of artificial agents or human beings often
assume their preferences can be represented using a complete transitive binary
relation. Much has been written however on different models of preferences. We
review some of the reasons that have been put forward to justify more complex
modeling, and review some of the techniques that have been proposed to obtain
models of such preferences
Elicitation of Preferences under Ambiguity
This paper is about behaviour under ambiguity ‒ that is, a situation in which probabilities either do not exist or are not known. Our objective is to find the most empirically valid of the increasingly large number of theories attempting to explain such behaviour. We use experimentally-generated data to compare and contrast the theories. The incentivised experimental task we employed was that of allocation: in a series of problems we gave the subjects an amount of money and asked them to allocate the money over three accounts, the payoffs to them being contingent on a ‘state of the world’ with the occurrence of the states being ambiguous. We reproduced ambiguity in the laboratory using a Bingo Blower. We fitted the most popular and apparently empirically valid preference functionals [Subjective Expected Utility (SEU), MaxMin Expected Utility (MEU) and α-MEU], as well as Mean-Variance (MV) and a heuristic rule, Safety First (SF). We found that SEU fits better than MV and SF and only slightly worse than MEU and α-MEU
Thermal Plasma of Electric Arc Discharge Between Composite Cu-Cr Electrsodes: Optical Emission and Electrode Surface Interaction
This work deals with investigations of thermal plasma of electric arc discharge between sintered composite Cu-Cr electrodes, which can be used in electrical contacts of vacuum circuit breakers. Breaking arcs between composite Cu-Cr as well as single-component copper electrodes were used to study the electrical properties, plasma optical emission and electrodes surface modification behavior. In particular, the temporal evolution of plasma emission spectra of electric breaking arcs in air atmosphere was investigated by Optical Emission Spectroscopy (OES). Scanning Electron Microscopy (SEM) with Energy-dispersive X-ray Spectroscopy (EDXS) were applied to analyze the cross-section of working layer of electrodes surface modified by the heat flux from the discharge
Measuring loss aversion under ambiguity: a method to make prospect theory completely observable
We propose a simple, parameter-free method that, for the first time, makes it possible to completely observe Tversky and Kahneman’s (1992) prospect theory. While methods exist to measure event weighting and the utility for gains and losses separately, there was no method to measure loss aversion under ambiguity. Our method allows this and thereby it can measure prospect theory’s entire utility function. Consequently, we can properly identify properties of utility and perform new tests of prospect theory. We implemented our method in an experiment and obtained support for prospect theory. Utility was concave for gains and convex for losses and there was substantial loss aversion. Both utility and loss aversion were the same for risk and ambiguity, as assumed by prospect theory, and sign-comonotonic trade-off consistency, the central condition of prospect theory, held
A Primary Retroperitoneal Mucinous Tumor
A twenty-five-year-old female presented with a large retroperitoneal mass. Workup included history and physical exam, imaging, biopsy, colonoscopy, and gynecologic exam. After surgical resection, the mass was determined to be a primary retroperitoneal mucinous tumor (PRMT). Clinically and histologically, these tumors are similar pancreatic and ovarian mucinous neoplasms. PRMTs are rare and few case reports have been published. PRMTs are divided into mucinous cystadenomas, mucinous borderline tumors of low malignant potential, and mucinous carcinoma. These tumors have malignant potential so resection is indicated and in some cases adjuvant chemotherapy and/or surveillance imaging
Neutron crystallography reveals mechanisms used by Pseudomonas aeruginosa for host-cell binding
Pseudomonas aeruginosa employs lectins to bind to its host cells, and is known to be the major cause of lung infections. Lectin B (LecB) from Pseudomonas aeruginosa binds specifically to galactose and fucose and is important for pathogenicity, adhesion and biofilm formation. In this work, the neutron crystal structure (1.9 angstrom) of the deuterated LecB/Ca/fucose complex is reported. The structure, in combination with perdeuteration of the ligand and the receptor allowed the observation of hydrogen atoms, protonation states and hydrogen bonds involved in the interaction between pathogenic bacteria and host cells. Thus the study provides structural insights into the mechanism of high affinity binding of LecB to its targets.
The opportunistic pathogen Pseudomonas aeruginosa, a major cause of nosocomial infections, uses carbohydrate-binding proteins (lectins) as part of its binding to host cells. The fucose-binding lectin, LecB, displays a unique carbohydrate-binding site that incorporates two closely located calcium ions bridging between the ligand and protein, providing specificity and unusually high affinity. Here, we investigate the mechanisms involved in binding based on neutron crystallography studies of a fully deuterated LecB/fucose/calcium complex. The neutron structure, which includes the positions of all the hydrogen atoms, reveals that the high affinity of binding may be related to the occurrence of a low-barrier hydrogen bond induced by the proximity of the two calcium ions, the presence of coordination rings between the sugar, calcium and LecB, and the dynamic behaviour of bridging water molecules at room temperature. These key structural details may assist in the design of anti-adhesive compounds to combat multi-resistance bacterial infections
Candidate biomarkers of antibiotic resistance for the monitoring of wastewater and the downstream environment
Urban wastewater treatment plants (UWTPs) are essential for reducing the pollutants load and protecting water bodies. However, wastewater catchment areas and UWTPs emit continuously antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs), with recognized impacts on the downstream environments. Recently, the European Commission recommended to monitor antibiotic resistance in UWTPs serving more than 100 000 population equivalents. Antibiotic resistance monitoring in environmental samples can be challenging. The expected complexity of these systems can jeopardize the interpretation capacity regarding, for instance, wastewater treatment efficiency, impacts of environmental contamination, or risks due to human exposure. Simplified monitoring frameworks will be essential for the successful implementation of analytical procedures, data analysis, and data sharing. This study aimed to test a set of biomarkers representative of ARG contamination, selected based on their frequent human association and, simultaneously, rare presence in pristine environments. In addition to the 16S rRNA gene, ten potential biomarkers (intI1, sul1, ermB, ermF, aph(3′’)-Ib, qacEΔ1, uidA, mefC, tetX, and crAssphage) were monitored in DNA extracts (n = 116) from raw wastewater, activated sludge, treated wastewater, and surface water (upstream and downstream of UWTPs) samples collected in the Czech Republic, Denmark, Israel, the Netherlands, and Portugal. Each biomarker was sensitive enough to measure decreases (on average by up to 2.5 log-units gene copy/mL) from raw wastewater to surface water, with variations in the same order of magnitude as for the 16S rRNA gene. The use of the 10 biomarkers allowed the typing of water samples whose origin or quality could be predicted in a blind test. The results show that, based on appropriate biomarkers, qPCR can be used for a cost-effective and technically accessible approach to monitoring wastewater and the downstream environment.info:eu-repo/semantics/publishedVersio
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