Absolute Preference Research Articles

Information flow between derivatives and spot market; the reason of studies results divergence

This paper explains the lack of general consensus in previous studies on the direction of information flow between stocks and derivatives markets. We assume that informed traders do not develop absolute preference for one market; rather they react to private information as case by case. We provide theoretical and empirical proofs to validate this hypothesis. While deciding where trading, informed traders are attracted by higher liquidity and less transactions costs in spot market, and leverage effect offered by options market. We find that the use of leverage effect, which can largely compensate transactions costs and liquidity lack, depends on exceeding critical value of confidence in anticipation expressed as function of option value elasticity with respect to the underlying asset's price. We conclude that information flow between the stock and option markets depends on informed traders' confidence in anticipation based on private information quality and informed traders psychologies and abilities.

The Impact of Data Time Span on Forecast Accuracy through Calibrating the SLEUTH Urban Growth Model

Does the spacing of time intervals used for model input data have an impact on the model's subsequent calibration and so projections of land use change and urban growth? This study evaluated the performance of the SLEUTH urban growth and land use change model through two independent model calibrations with different temporal extents (1972 to 2006 vs. 2000 to 2006) for the historical Italian cities of Pisa Province and their surroundings. The goal in performing two calibrations was to investigate the sensitivity of SLEUTH forecasts to longer or shorter calibration timelines, that is does calibrating the model over a longer time period produce better model fits and therefore forecasts? The best fit parameters from each calibration were then used in forecasting urban growth in the area up to the year 2027. The authors findings show that the spatial growth estimated by the model was strongly influenced by the physical landscape and road networks. The forecast outputs over 100 Monte Carlo trials reflect the start of newly formed detached settlements towards and along existing roads, i.e., classic urban sprawl. The authors conclude that the short term calibration was a better model fit compared to the long term calibration. Nevertheless, the absolute preference for the short-term calibration over long-term implies that time-sensitivity in calibration remains a challenge for SLEUTH applications.

Activity in ventromedial prefrontal cortex during self-related processing: positive subjective value or personal significance?

Well-being and subjective experience of a coherent world depend on our sense of 'self' and relations between the self and the environment (e.g. people, objects and ideas). The ventromedial prefrontal cortex (vMPFC) is involved in self-related processing, and disrupted vMPFC activity is associated with disruptions of emotional/social functioning (e.g. depression and autism). Clarifying precise function(s) of vMPFC in self-related processing is an area of active investigation. In this study, we sought to more specifically characterize the function of vMPFC in self-related processing, focusing on two alternative accounts: (i) assignment of positive subjective value to self-related information and (ii) assignment of personal significance to self-related information. During functional magnetic resonance imaging (fMRI), participants imagined owning objects associated with either their perceived ingroup or outgroup. We found that for ingroup-associated objects, vMPFC showed greater activity for objects with increased than decreased post-ownership preference. In contrast, for outgroup-associated objects, vMPFC showed greater activity for objects with decreased than increased post-ownership preference. Our findings support the idea that the function of vMPFC in self-related processing may not be to represent/evaluate the 'positivity' or absolute preference of self-related information but to assign personal significance to it based on its meaning/function for the self.

The Employment of Veterans in State and Local Government Service

Has veterans’ preference been successful in increasing military veterans’ access to state and local government (SLG) jobs? U.S. Census data for 1980 through 2011 show that veterans are more likely than nonveterans to work for SLGs, despite some characteristics that would normally make them less likely to take SLG jobs. This is especially true in states that offer absolute preference or pay well relative to the private sector.

In vitro glucuronidation of five rhubarb anthraquinones by intestinal and liver microsomes from humans and rats

Anthraquinones naturally distribute in many plants including rhubarb and have widespread applications throughout industry and medicine. Recent studies provided new insights in potential applications of these traditional laxative constituents. Glucuronidation was the main metabolic pathway of rhubarb anthraquinones in vivo. This study examined the activity and regioselectivity of glucuronidation of rhubarb anthraquinones (aloe-emodin, emodin, chrysophanol, physcion, rhein) in liver and intestinal microsomes from rats and humans, by comparing with the core structure danthron. All anthraquinones formed mono-glucuronides and, except for rhein, the conjugation sites of the main metabolites were unambiguously identified. Two minor glucuronides of emodin were first reported together with the dominant emodin-3-O-β-d-glucuronide. The substitution on the anthraquinone ring was crucial to the activity and regioselectivity of glucuronidation. In general, the activity was decreased greatly with a β-COOH (rhein), while enhanced dramatically with a β-OH (emodin). Glucuronidation showed an absolute preference towards β-OH, followed by α-OH and β-alcoholic OH. The glucuronidation activity and regioselectivity also varied slightly with organs and species. All glucuronides of aloe-emodin, emodin, chrysophanol and physcion were formed by multiple human UGT isoforms with 1A9 being the most prominent in most cases. The UGT2B subfamily (2B7 and 2B15) only showed high activity towards a β-OH. In conclusion, the substitution at the anthraquinone ring was crucial to the rate and preference of glucuronidation. The high glucuronidation activity of UGT1A9 towards anthraquinones highlighted potential drug interactions.

Power Law with Exponential Cut‐off Utility

Most of the utility functions studied earlier concentrated on properties of risk aversion. In this article, the authors have introduced a new class of utility function called the Power Law with Exponential Cut-off (PLEC) utility function, which exhibits all the absolute and relative risk aversion and risk loving preferences of individuals, under various conditions. It generalises and encompasses other systems of utility functions like that of exponential power. Certain properties of this utility function are discussed. Sensitivity analysis exhibits different portfolio allocations for various risk preferences. The analysis also shows that arbitrary risk preferences may lead to biased risk response estimates. Performance of PLEC utility function in portfolio allocation problem is demonstrated through numerical examples. This is evaluated through optimal solutions.

Why the first provider takes it all: the consequences of a low trust culture on pricing and ratings in online sourcing markets

Electronic markets are ruled by price and reputation, and, at least in the case of Online Sourcing Markets (OSM), also by preference for providers the buyer already contracted with. OSM are online markets for software development. Adding Fukuyama's notion of a low trust culture, an argument is advanced why buyers in OSM may give absolute preference to providers with whom they had previous contracts, presenting a special case of neoclassical contracting. Examining all the transactions in one calendar year at a leading OSM supports this proposition. All it took to be given the tender was to be the only bidding provider with at least one successful previous contract with the buyer, rendering pricing and ratings immaterial to bid choice. Only when none of the bidding providers had previous successful projects with the buyer did pricing and rating affect bid choice. The proposition is also consistent with the buyers’ comments about their providers. Implications are discussed about how a low trust culture affects OSM behavior.

Local pronouns in ditransitive scenarios: Corpus perspectives from English and Polish

Abstract While there is no doubt that the Rs (recipients) of ditransitive clauses are much more likely to be rendered by LPs (local persons) than Ts (themes), as reflected in the Person Role Constraint (see e.g., Perlmutter 1971; Bonet 1991, 1995; Haspelmath 2004), this paper sets out to determine whether the preference for LP Rs holds only relative to Ts or is in fact an absolute preference, i.e., a general property of Rs in ditransitive clauses. The investigation is based on a consideration of corpus data from two languages, English and Polish, both of which have a rich array of ditransitive predicates and together cover a good range of ditransitive constructions differing in degrees of grammaticalization. The investigation reveals that distribution of LPs is strongly affected by the degree of grammaticalization of a ditransitive construction and the encoding of the person forms, the levels of LP Rs and the frequency effects of the Person Role Constraint being strongest in double object constructions (DOC), less strong in the dative-accusative construction (DAC) and weakest in the prepositional construction (Prep-Cs), as shown in the cline: DOC > DAC > Prep-C. Significant differences are also noted in the distribution of LPs between different classes of ditransitive predicates, the highest level of LP Rs being with communicated message predicates and the lowest with ballistic and accompanying motion predicates.

What to wear? The influence of attire on the perceived professionalism of dentists and lawyers.

Using a sample of 201 participants and a between-subjects design, the perceived professionalism—suitability, capability, ease to talk to and friendliness—of male and female dentists and lawyers in various attires was examined. Results showed an absolute preference for male dentists and lawyers in professional and formal attire, respectively. Male dentists and lawyers in professional and formal attire were further rated as more suitable, capable, easier to talk to, and friendlier than female professionals, and than those dressed in smart or casual attire. Results are discussed in terms of positive dental outcomes and legal representation. Limitations are considered.

Mate choice in Mus musculus is relative and dependent on the estrous state.

Mate choice is a critical behavioral decision process with profound impact on evolution. However, the mechanistic basis of mate choice is poorly understood. In this study we focused on assortative mate choice, which is known to contribute to the reproductive isolation of the two European subspecies of house mouse, Mus musculus musculus and Mus musculus domesticus. To understand the decision process, we developed both full mating and limited-contact paradigms and tested musculus females' preference for musculus versus domesticus males, mimicking the natural musculus/domesticus contact zone. As hypothesized, when allowed to mate we found that sexually receptive musculus females exhibited a robust preference to mate with musculus males. In contrast, when non-receptive, females did not exhibit a preference and rather alternated between males in response to male mount attempts. Moreover in a no-choice condition, females mated readily with males from both subspecies. Finally, when no physical contact was allowed, and therefore male's behavior could not influence female's behavior, female's preference for its own subspecies was maintained independently of the estrous state. Together, our results suggest that the assortative preference is relative and based on a comparison of the options available rather than on an absolute preference. The results of the limited-contact experiments highlight the interplay between female's internal state and the nature of the interaction with prospective mates in the full mating conditions. With these experiments we believe we established an assortative mate preference assay that is appropriate for the investigation of its underlying substrates.

An evaluation of the robustness of the visual air quality “preference study” method

In 2012, the U.S. Environmental Protection Agency (EPA) considered setting a secondary National Ambient Air Quality Standard (NAAQS) for particulate matter (PM) to maintain urban visual air quality (VAQ) above the level that EPA believes results in adverse effects on public welfare. EPA is relying on a type of survey it calls a “VAQ preference study” to determine this level. Individuals are shown photographs of the same vista under a range of different visibility conditions and asked to state whether the VAQ in each photograph is “acceptable” or “unacceptable.” EPA considers the effect on public welfare to be adverse at the VAQ level that at least 50% of respondents deem unacceptable (the “VAQ cutpoint”). Given its central role in setting a NAAQS, the scientific validity of this method is an important question. This study tests the robustness of the VAQ preference study method by replicating the survey instrument from a prior VAQ preference study, and by applying two variants in which the only change was use of a different range of VAQ levels. Tested on split samples, these three variants produced statistically significantly different VAQ cutpoint estimates. In contrast, all three variants produced comparable results for a calibration task at the start of each survey in which respondents were asked to rate the VAQ in each photograph on a scale of 1–7 (without any opinion on the acceptability of each level). The significantly different estimates of VAQ cutpoints across survey variants cannot be attributed to inability on the part of respondents to discern whether they were being shown the entire range of actual visibility conditions. This suggests that VAQ preference surveys do not actually estimate individuals' enduring preferences regarding VAQ, because absolute preferences would not be influenced by the particular levels of VAQ over which their preferences are elicited. Implications: In setting its particulate matter secondary National Ambient Air Quality Standard for urban visibility, the U.S. Environmental Protection Agency is relying on a survey method that has people rate a range of urban visibility levels as “acceptable” or “unacceptable.” A test of that survey method using split samples finds its results are not robust to variations in the range of visibility it shows to respondents. This implies that the visibility preference survey method needs more scientific evaluation before it can be assumed to be measuring individual preferences for visibility in a valid manner.

ALL STIMULI ARE EQUAL, BUT SOME ARE MORE EQUAL THAN OTHERS: MEASURING RELATIONAL PREFERENCES WITHIN AN EQUIVALENCE CLASS

Two experiments used post-class formation within-class relational assessment test performances to evaluate whether participants demonstrated preference for certain members of an equivalence class based on the type of relation that existed between class members. In Experiment 1, two 5-node 7-member equivalence classes, consisting entirely of nonsense syllables, were established using the simultaneous protocol. Only 1 of the 6 participants in Experiment 1 formed classes. After class formation, the effects of the different relations between stimuli were evaluated using within-class relational assessment tests, and the 1 participant showed an absolute preference for transitive over equivalence relations, and for baseline over symmetrical relations. Experiment 2 was identical to Experiment 1, except that one of the nonsense syllable stimuli in each class was replaced by a pictorial stimulus. Under these conditions, classes were formed by 5 of 13 participants. During the relational assessment tests, the 5 participants who formed classes demonstrated almost exclusive preferences for transitive relations over equivalence relations and for trained baseline relations over symmetrical relations. Thus, this research demonstrates that the members of equivalence classes are differentially related to each other based on relational type.

Mode of Action of a Family 75 Chitosanase from Streptomyces avermitilis

Chitooligosaccharides (CHOS) are oligomers composed of glucosamine and N-acetylglucosamine with several interesting bioactivities that can be produced from enzymatic cleavage of chitosans. By controlling the degree of acetylation of the substrate chitosan, the enzyme, and the extent of enzyme degradation, CHOS preparations with limited variation in length and sequence can be produced. We here report on the degradation of chitosans with a novel family 75 chitosanase, SaCsn75A from Streptomyces avermitilis . By characterizing the CHOS preparations, we have obtained insight into the mode of action and subsite specificities of the enzyme. The degradation of a fully deacetylated and a 31% acetylated chitosan revealed that the enzyme degrade these substrates according to a nonprocessive, endo mode of action. With the 31% acetylated chitosan as substrate, the kinetics of the degradation showed an initial rapid phase, followed by a second slower phase. In the initial faster phase, an acetylated unit (A) is productively bound in subsite -1, whereas deacetylated units (D) are bound in the -2 subsite and the +1 subsite. In the slower second phase, D-units bind productively in the -1 subsite, probably with both acetylated and deacetylated units in the -2 subsite, but still with an absolute preference for deacetylated units in the +1 subsite. CHOS produced in the initial phase are composed of deacetylated units with an acetylated reducing end. In the slower second phase, higher amounts of low DP fully deacetylated oligomers (dimer and trimer) are produced, while the higher DP oligomers are dominated by compounds with acetylated reducing ends containing increasing amounts of internal acetylated units. The degradation of chitosans with varying degrees of acetylation to maximum extents of degradation showed that increasingly longer oligomers are produced with increasing degree of acetylation, and that the longer oligomers contain sequences of consecutive acetylated units interspaced by single deacetylated units. The catalytic properties of SaCsn75A differ from the properties of a previously characterized family 46 chitosanase from S. coelicolor (ScCsn46A).

Role of four-membered rings in C32fullerene stability and mechanisms of generalized Stone-Wales transformation: a density functional theory investigation

Density functional theory (DFT) methods have been applied to study C(32) fullerenes built from four-, five-, and six-membered rings. The relative energies of pure C(32) fullerenes have been evaluated to locate three most stable structures, 32:D(4d) with two squares, 1:D(3) without square and 5:C(s) with one square. Structural analysis reveals that there is a rearrangement pathway between the lowest energy classical isomer 1:D(3) and the lowest energy non-classical isomer 32:D(4d), and 5:C(s) behaves just as an intermediate between them. The kinetic processes of generalized Stone-Wales transformation (GSWT) with four-membered rings have been explored and two distinct reaction mechanisms are determined by all the transition states and intrinsic reaction coordinates with PBE1PBE/6-31G(d) approach for the first time. One mechanism is the concerted reaction with a rotating dimer closed to the cage surface and another is the stepwise reaction with a carbene-like sp(3) structure, whereas the latter is sorted into two paths based on four-membered ring vanishing before or after the formation of the carbene-like structure. It is indicated that there is no absolute preference for any mechanism, which depends on the adaptability of different reactants on the diverse mechanisms. Furthermore, it's found that the interconversion process with the participation of squares is more reactive than the rearrangement between C(60)_I(h) and C(60)_C(2v), implying some potential importance of non-classical small fullerenes in the fullerene isomerization.

Degradation of Chitosans with a Family 46 Chitosanase from Streptomyces coelicolor A3(2)

We have studied the degradation of well-characterized soluble heteropolymeric chitosans by a novel family 46 chitosanase, ScCsn46A from Streptomyces coelicolor A3(2), to obtain insight into the enzyme's mode of action and to determine its potential for production of different chitooligosaccharides. The degradation of both a fully deacetylated chitosan and a 32% acetylated chitosan showed a continuum of oligomeric products and a rapid disappearance of the polymeric fraction, which is diagnostic for a nonprocessive endomode of action. The kinetics of the degradation of the 32% acetylated chitosan demonstrated an initial rapid phase and a slower second phase, in addition to a third and even slower kinetic phase. The first phase reflects the cleavage of the glycosidic linkage between two deacetylated units (D-D), the primary products being fully deacetylated dimers, trimers, and tetramers, as well as longer oligomers with increasing degrees of acetylation. In the subsequent slower kinetic phases, oligomers with a higher degree of acetylated units (A) appear, including oligomers with A's at the reducing or nonreducing end, which indicate that there are no absolute preferences for D in subsites -1 and +1. After maximum degradation of the chitosan, the dimers DA and DD were the dominant products. The degradation of chitosans with varying degrees of acetylation to a maximum degree of scission showed that ScCsn46A could degrade all chitosan substrates extensively, although to decreasing degrees of scission with increasing F(A). The potential use of ScCsn46A to prepare fully deacetylated oligomers and more highly acetylated oligomers from chitosan substrates with varying degrees of acetylation is discussed.

Single-Molecule Study of Human Topoisomerase II

Topoisomerase II is an essential enzyme that maintains genomic integrity by simplifying global DNA topology through supercoil relaxation, decatenation of linked chromosomal DNA, and DNA unknoting. This is achieved by generating a transient double-stranded break in one DNA segment through which a second double-stranded segment is passed prior to religation of the break. Failure or prevention of DNA religation leads to double stranded DNA breaks and fragmentation of the genome. Thus, the DNA cleavage reaction of human topoisomerase II (hTopo II) is one of the most successful targets for anti-cancer drugs. In order to develop effective anti-cancer drugs, it is critical to understand the detailed mechanism of DNA supercoil relaxation driven by hTopo II. One of the two isoforms of human Topoisomerase II, hTopo IIα, preferentially relaxes positive supercoils, a feature it shares with only one other type II topoisomerase; E. coli topoisomerase IV. Here, we have investigated the mechanism of DNA supercoil relaxation by hTopo IIα using single molecule magnetic tweezers experiments. We measured the DNA relaxation rate of positive and negative supercoils and found that positive supercoil relaxation was ∼2 times faster than negative supercoil relaxation. This result indicates that the relaxation mechanism of hTopo IIα is different from that of topoisomerase IV, which displays an almost absolute preference for positively supercoiled DNA in single-molecule experiments. Our data further suggest that there is a small, ∼30%, difference in the processivity of hTopo IIα relaxing positive versus negative supercoils. These data, together with twist dependent relaxation rate measurements, allow a detailed comparison with the mechanism of chiral discrimination by E. coli topoisomerase IV, and suggest possible mechanisms of chiral discrimination by type II topoisomerases.

Testing Models of Pure Exchange

We reanalyze the experimental data of Michener et al. (1975, 1977) to explain behavior in pure exchange situations. The data were compared to predictions of various cooperative bargaining models and to the predictions of a bilateral exchange model developed in the present paper. The bilateral exchange model fitted well and performed best. The model could explain asymmetries in actors' exchange outcomes as commonly observed in exchange networks, and that generalized exchange hardly occurred in the experiments. However, systematic deviations from predictions of the bilateral exchange model and other models of rational behavior were observed; actors tend to focus on their absolute preferences rather than on their relative preferences. These deviations could be explained by a boundedly rational model of exchange, assuming that actors use heuristics to detect profitable exchange opportunities.

Female preference for male phenotypic traits in a fiddler crab: do females use absolute or comparative evaluation?

While mate choice is often assumed to be based on an absolute value that may reflect underlying male quality, many mating systems facilitate the comparative evaluation of males. Females can encounter a number of potential mates, either sequentially or simultaneously, before making a mate choice decision. Consequently, the attractiveness of one male may depend on the attractiveness of other males a female has previously encountered. To examine whether female choice in the fiddler crab Uca mjoebergi is based on the comparative evaluation of males, I altered the social context in which a set of males were encountered. Using a robotic crab system to manipulate claw size and wave rate directly, I determined female preference for two male options in the absence and presence of an asymmetrically dominating decoy option. The decoy male option was designed to change the relative attractiveness of the initial two male options. The presence of the decoy significantly altered the absolute preference, but not the relative preference, for the two male options. While this study clearly demonstrates that female U. mjoebergi are not using strict absolute preferences when ranking each male's attractiveness, it does not conclusively support comparative evaluation mechanisms. One possibility is that sexually selected traits in a complex signalling system often vary in how reliably they reflect male quality, and females may use a combination of absolute and comparative measures when assessing male quality.

Context-dependent mate choice in relation to social composition in green swordtails Xiphophorus helleri

Comparative evaluation mechanisms of mate choice in relation to social composition of potential mates have not been considered in nonhuman animals. Models of rational decision making suggest that when choice is based on absolute values, the addition of a third option should take choices from the original 2 options in proportion to their original shares and not result in an increase in the absolute preference for any of the 3 options in the set. However, studies of foraging behavior have shown that choice alternatives are often not irrelevant, specifically when preference is based on 2 or more dimensions (multiple cues) and when the third option is an asymmetrically dominated “decoy” (i.e., it has a lower value than both original options on one dimension but is only lower than one of the 2 original options on the other dimension). Asymmetrically dominated decoys are predicted to increase preference for the option that dominates it on both dimensions if mate choice is context dependent. We tested whether mate choice is dependent on or independent of social context in green swordtails, a species where females commonly use multiple cues in mate choice decisions. Addition of a third, decoy, male to the set of options resulted in females shifting preference away from the phenotype of male that each preferred in binary comparisons. Consequently, although mate choice was context dependent, the asymmetrically dominated decoy effect was not observed. Instead, females showed negative frequency-dependent preference for the rare-male phenotype, which may act to maintain genetic variation under sexual selection.

Heterogeneity in Post-materialist Value Priorities. Evidence from a Latent Class Discrete Choice Approach

should be conceived of as relative priorities rather than absolute preferences. As such they insist on using ranking techniques of measurement which generates choice data. In this study, we aim at validating the measurement of Inglehart’s (post-)materialism by means of a latent class discrete choice model. We argue that from a statistical point of view this is the appropriate way of dealing with ranking data. Furthermore, the analyses revealed a heterogeneity in (post-)materialist value priorities that has previously been left unobserved. Consistent with Inglehart’s research a post-materialist class is discerned irrespective of the number of latent classes that is selected. However, as far as materialism is concerned three different types of materialist concerns can be distinguished. The validity of the empirical typology is further demonstrated by linking it to key covariates and political attitudes.