2,264 research outputs found
The magnetic form factor of the deuteron in chiral effective field theory
We calculate the magnetic form factor of the deuteron up to O(eP^4) in the
chiral EFT expansion of the electromagnetic current operator. The two LECs
which enter the two-body part of the isoscalar NN three-current operator are
fit to experimental data, and the resulting values are of natural size. The
O(eP^4) description of G_M agrees with data for momentum transfers Q^2 < 0.35
GeV^2.Comment: 4 pages, 2 figure
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Visual Analytics for Understanding Spatial Situations from Episodic Movement Data
Continuing advances in modern data acquisition techniques result in rapidly growing amounts of geo-referenced data about moving objects and in emergence of new data types. We define episodic movement data as a new complex data type to be considered in the research fields relevant to data analysis. In episodic movement data, position measurements may be separated by large time gaps, in which the positions of the moving objects are unknown and cannot be reliably reconstructed. Many of the existing methods for movement analysis are designed for data with fine temporal resolution and cannot be applied to discontinuous trajectories. We present an approach utilizing Visual Analytics methods to explore and understand the temporal variation of spatial situations derived from episodic movement data by means of spatio-temporal aggregation. The situations are defined in terms of the presence of moving objects in different places and in terms of flows (collective movements) among the places. The approach, which combines interactive visual displays with clustering of the spatial situations, is presented by example of a real dataset collected by Bluetooth sensors
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Body Ideals and Weight Bias: Does Ethnicity Make a Difference?
The current study investigates whether there are there ethnic differences between Caucasian, African American, and Hispanic women in (a) weight bias, (b) body ideals, (c) social awareness and internalization of appearance standards and (d) physical activity in relation to these constructs. Participants included 130 Caucasian, 103 African American, and 52 Hispanic undergraduate female students. Participants completed a demographic survey, the Antifat Attitudes Test, the Figure Rating Scale, the Sociocultural Attitudes toward Appearance Questionnaire, and the Multiethnic Identity Measure questionnaire. No significant ethnic group differences in weight bias emerged. Differences were found for participants' perceptions of the culturally ideal female body shape, as well as awareness and internalization. No relationship was found between physical activity and weight bias, body ideals, and appearance standards. Future researchers should use health weight classifications, in addition to ethnicity, to examine weight bias, body ideals, and physical activity
Simulator for Microlens Planet Surveys
We summarize the status of a computer simulator for microlens planet surveys.
The simulator generates synthetic light curves of microlensing events observed
with specified networks of telescopes over specified periods of time.
Particular attention is paid to models for sky brightness and seeing,
calibrated by fitting to data from the OGLE survey and RoboNet observations in
2011. Time intervals during which events are observable are identified by
accounting for positions of the Sun and the Moon, and other restrictions on
telescope pointing. Simulated observations are then generated for an algorithm
that adjusts target priorities in real time with the aim of maximizing planet
detection zone area summed over all the available events. The exoplanet
detection capability of observations was compared for several telescopes.Comment: Proc. IAU Symp. No. 293 "Formation, detection, and characterization
of extrasolar habitable planets", ed. by N. Haghighipour. 4 pages, in pres
Cellular Automaton Study of Time-Dynamics of Avalanche Breakdown in IMPATT Diodes
Employing a recently developed efficient cellular automaton technique for solving
Boltzmann's transport equation for realistic devices, we present a detailed study of the
carrier dynamics in GaAs avalanche p-i-n (IMPATT) diodes. We find that the impact
ionization in reverse bias p-i-n diodes with ultrathin (less than 50 nm) intrinsic regions is
triggered by Zener tunneling rather than by thermal generation. The impact generation
of hot carriers occurs mainly in the low-field junction regions rather than in the high
field intrinsic zone. The calculations predict significantly more minority carriers on the
n-side than on the p-side
Specialized odorant receptors in social insects that detect cuticular hydrocarbon cues and candidate pheromones.
Eusocial insects use cuticular hydrocarbons as components of pheromones that mediate social behaviours, such as caste and nestmate recognition, and regulation of reproduction. In ants such as Harpegnathos saltator, the queen produces a pheromone which suppresses the development of workers' ovaries and if she is removed, workers can transition to a reproductive state known as gamergate. Here we functionally characterize a subfamily of odorant receptors (Ors) with a nine-exon gene structure that have undergone a massive expansion in ants and other eusocial insects. We deorphanize 22 representative members and find they can detect cuticular hydrocarbons from different ant castes, with one (HsOr263) that responds strongly to gamergate extract and a candidate queen pheromone component. After systematic testing with a diverse panel of hydrocarbons, we find that most Harpegnathos saltator Ors are narrowly tuned, suggesting that several receptors must contribute to detection and discrimination of different cuticular hydrocarbons important in mediating eusocial behaviour.Cuticular hydrocarbons (CHC) mediate the interactions between individuals in eusocial insects, but the sensory receptors for CHCs are unclear. Here the authors show that in ants such as H. saltator, the 9-exon subfamily of odorant receptors (HsOrs) responds to CHCs, and ectopic expression of HsOrs in Drosophila neurons imparts responsiveness to CHCs
Regression analysis of the results of examinations of students in probability theory
In this paper, is carried a study of the dependence of the results of tests with the help of linear and nonlinear regression analysis. As a result of an earlier statistical analysis with the same data, was found the relationship between them
Low-energy neutron-deuteron reactions with N3LO chiral forces
We solve three-nucleon Faddeev equations with nucleon-nucleon and
three-nucleon forces derived consistently in the framework of chiral
perturbation theory at next-to-next-to-next-to-leading order in the chiral
expansion. In this first investigation we include only matrix elements of the
three-nucleon force for partial waves with the total two-nucleon
(three-nucleon) angular momenta up to 3 (5/2). Low-energy neutron-deuteron
elastic scattering and deuteron breakup reaction are studied. Emphasis is put
on Ay puzzle in elastic scattering and cross sections in symmetric-space-star
and neutron-neutron quasi-free-scattering breakup configurations, for which
large discrepancies between data and theory have been reported.Comment: 22 pages, 7 figure
Few-nucleon systems with state-of-the-art chiral nucleon-nucleon forces
We apply improved nucleon-nucleon potentials up to fifth order in chiral
effective field theory, along with a new analysis of the theoretical truncation
errors, to study nucleon-deuteron (Nd) scattering and selected low-energy
observables in 3H, 4He, and 6Li. Calculations beyond second order differ from
experiment well outside the range of quantified uncertainties, providing truly
unambiguous evidence for missing three-nucleon forces within the employed
framework. The sizes of the required three-nucleon force contributions agree
well with expectations based on Weinberg's power counting. We identify the
energy range in elastic Nd scattering best suited to study three-nucleon force
effects and estimate the achievable accuracy of theoretical predictions for
various observables.Comment: 5 pages, 5 figure
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