3,712 research outputs found
Social influence protects collective decision making from equality bias
A basic tenet of research on wisdom of the crowds ā and key assumption of Condorcetās Jury Theorem ā is the independence of votersā opinions before votes are aggregated. However, we often look for othersā opinions before casting our vote. Such social influence can push groups towards herding, leading to āmadness of the crowdsā. To investigate the role of social influence in joint decision making, we had dyads of participants perform a visual odd-ball search task together. In the Independent (IND) condition participants initially made a private decision. If disagreeing, discussion and collective decision ensued. In the Influence (INF) condition no private decisions were made and collective decision was immediately negotiated. Dyads that did not accrue collective benefit under IND condition improved with added social influence under INF condition. In Experiment 2, covertly, we added noise to one of the dyad membersā visual search display. The resulting increased heterogeneity in dyad membersā performances impaired the dyadic performance under IND condition (Bahrami et al., 2010). Importantly, dyadic performance improved with social influence under INF, replicating Experiment 1. Further analyses revealed that under IND condition, dyads exercised equality bias (Mahmoodi et al., 2015) by granting undue credit to the less reliable partner. Under INF condition, however, the more reliable partner (correctly) dominated the joint decisions. While social influence may impede collective success under ideal conditions, our results demonstrate how it can help the group members overcome factors such as equality bias, which could potentially lead to catastrophic failure
The dynamics of quasi-isometric foliations
If the stable, center, and unstable foliations of a partially hyperbolic
system are quasi-isometric, the system has Global Product Structure. This
result also applies to Anosov systems and to other invariant splittings.
If a partially hyperbolic system on a manifold with abelian fundamental group
has quasi-isometric stable and unstable foliations, the center foliation is
without holonomy. If, further, the system has Global Product Structure, then
all center leaves are homeomorphic.Comment: 18 pages, 1 figur
Design of Copolymeric Materials
We devise a method for designing materials that will have some desired
structural characteristics. We apply it to multiblock copolymers that have two
different types of monomers, A and B. We show how to determine what sequence of
A's and B's should be synthesised in order to give a particular structure and
morphology. %For example in a melt of such %polymers, one may wish to engineer
a body-centered %cubic structure. Using this method in conjunction with the
theory of microphase separation developed by Leibler, we show it is possible to
efficiently search for a desired morphology. The method is quite general and
can be extended to design isolated heteropolymers, such as proteins, with
desired structural characteristics. We show that by making certain
approximations to the exact algorithm, a method recently proposed by
Shakhnovich and Gutin is obtained. The problems with this method are discussed
and we propose an improved approximate algorithm that is computationally
efficient.Comment: 15 pages latex 2.09 and psfig, 1 postscript figure
A New Algorithm for Protein Design
We apply a new approach to the reverse protein folding problem. Our method
uses a minimization function in the design process which is different from the
energy function used for folding. For a lattice model, we show that this new
approach produces sequences that are likely to fold into desired structures.
Our method is a significant improvement over previous attempts which used the
energy function for designing sequences.Comment: 10 pages latex 2.09 no figures. Use uufiles to decod
Non-analytic microscopic phase transitions and temperature oscillations in the microcanonical ensemble: An exactly solvable 1d-model for evaporation
We calculate exactly both the microcanonical and canonical thermodynamic
functions (TDFs) for a one-dimensional model system with piecewise constant
Lennard-Jones type pair interactions. In the case of an isolated -particle
system, the microcanonical TDFs exhibit (N-1) singular (non-analytic)
microscopic phase transitions of the formal order N/2, separating N
energetically different evaporation (dissociation) states. In a suitably
designed evaporation experiment, these types of phase transitions should
manifest themselves in the form of pressure and temperature oscillations,
indicating cooling by evaporation. In the presence of a heat bath (thermostat),
such oscillations are absent, but the canonical heat capacity shows a
characteristic peak, indicating the temperature-induced dissociation of the
one-dimensional chain. The distribution of complex zeros (DOZ) of the canonical
partition may be used to identify different degrees of dissociation in the
canonical ensemble.Comment: version accepted for publication in PRE, minor additions in the text,
references adde
A Hierarchically-Organized Phase Diagram near a Quantum Critical Point in URu2Si2
A comprehensive transport study, as a function of both temperature and
magnetic field in continuous magnetic fields up to 45 T reveals that URu2Si2
possesses all the essential hallmarks of quantum criticality at temperatures
above 5.5 K and fields around 38 T, but then collapses into multiple low
temperature phases in a hierarchically-organized phase diagram as the
temperature is reduced. Although certain generic features of the phase diagram
are very similar to those in the cuprates and heavy fermion superconductors,
the existence of multiple ordered hysteretic phases near the field-tuned
quantum critical point is presently unique to URu2Si2. This finding suggests
the existence of many competing order parameters separated by small energy
difference in URu2Si2.Comment: 6 pages, twocolum texts, 3 coloured figure included, submitted to PR
Self-reported pregnancy exposures and placental DNA methylation in the MARBLES prospective autism sibling study.
Human placenta is a fetal-derived tissue that offers a unique sample of epigenetic and environmental exposures present in utero. In the MARBLES prospective pregnancy study of high-risk younger siblings of children with autism spectrum disorder (ASD), pregnancy and environmental factors collected by maternal interviews were examined as predictors of placental DNA methylation, including partially methylated domains (PMDs), an embryonic feature of the placental methylome. DNA methylation data from MethylC-seq analysis of 47 placentas of children clinically diagnosed at 3 years with ASD or typical development using standardized assessments were examined in relation to: child's gestational age, birth-weight, and diagnosis; maternal pre-pregnancy body mass index, smoking, education, parity, height, prenatal vitamin and folate intake; home ownership; pesticides professionally applied to lawns or gardens or inside homes, pet flea/tick pouches, collars, or soaps/shampoos used in the 3 months prior to or during pregnancy. Sequencing run, order, and coverage, and child race and sex were considered as potential confounders. Akaike information criterion was used to select the most parsimonious among candidate models. Final prediction models used sandwich estimators to produce homoscadisticity-robust estimates of the 95% confidence interval (CI) and P-values controlled the false discovery rate at 5%. The strongest, most robust associations were between pesticides professionally applied outside the home and higher average methylation over PMDs [0.45 (95% CI 0.17, 0.72), P = 0.03] and a reduced proportion of the genome in PMDs [-0.42 (95% CI - 0.67 to -0.17), P = 0.03]. Pesticide exposures could alter placental DNA methylation more than other factors
PIH24 Cost Impact Of A Comprehensive Sti Screening Strategy, Including Chlamydia, Gonorrhea And Trichomoniasis: A Us Payer Perspective
Critical Exponents of the Metal-Insulator Transition in the Two-Dimensional Hubbard Model
We study the filling-controlled metal-insulator transition in the
two-dimensional Hubbard model near half-filling with the use of zero
temperature quantum Monte Carlo methods. In the metallic phase, the
compressibility behaves as where
is the critical chemical potential. In the insulating phase, the
localization length follows with . Under the assumption of hyperscaling, the compressibility
data leads to a correlation length exponent . Our
results show that the exponents and agree within
statistical uncertainty. This confirms the assumption of hyperscaling with
correlation length exponent and dynamical exponent . In
contrast the metal-insulator transition in the generic band insulators in all
dimensions as well as in the one-dimensional Hubbard model satisfy the
hyperscaling assumption with exponents and .Comment: Two references added. The DVI file and PS figure files are also
available at http://www.issp.u-tokyo.ac.jp/labs/riron/imada/furukawa/; to
appear in J. Phys. Soc. Jpn 65 (1996) No.
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