6,518 research outputs found
Is Rewarding Beneficial to Behavior?
What effect does a reward system have on ninth grade student behavior? Is there a way to have my students behave better than they currently are? There is plenty of research that has been conducted on different types of distracting behavior as well as different types of systems and programs that try to influence that behavior. A ninth grade class has been selected, observed, and data has been recorded on any disruptive or unwanted behavior for three weeks. The first three weeks the student had no clue they were being checked for behavior. For the second three weeks, a reward system was implanted for the class. The class was given the opportunity to earn a “free day” in physical education class by decreasing their disruptive behavior during class. In this study the students proved that if given the chance to work towards something they would work harder and behave better
Tools for managing manure nutrients
Manures are a valuable source of nutrients (and organic matter), and can be seen as a method of transferring nutrients around the farm (for homeproduced manures) or as a method of importing fertility (imported manures or composts). Good manure management offers a ‘win-win’ opportunity: benefits to soil fertility and benefits to the environment (less pollution). This paper describes two tools for manure nutrient planning: the use of look-up tables to assess nutrient content, and the development of a Decision Support Tool for describing nutrient transformations during manure management
Evaluating the New Automatic Method for the Analysis of Absorption Spectra Using Synthetic Spectra
We recently presented a new "artificial intelligence" method for the analysis
of high-resolution absorption spectra (Bainbridge and Webb, Mon. Not. R.
Astron. Soc. 2017, 468,1639-1670). This new method unifies three established
numerical methods: a genetic algorithm (GVPFIT); non-linear least-squares
optimisation with parameter constraints (VPFIT); and Bayesian Model Averaging
(BMA). In this work, we investigate the performance of GVPFIT and BMA over a
broad range of velocity structures using synthetic spectra. We found that this
new method recovers the velocity structures of the absorption systems and
accurately estimates variation in the fine structure constant. Studies such as
this one are required to evaluate this new method before it can be applied to
the analysis of large sets of absorption spectra. This is the first time that a
sample of synthetic spectra has been utilised to investigate the analysis of
absorption spectra. Probing the variation of nature's fundamental constants
(such as the fine structure constant), through the analysis of absorption
spectra, is one of the most direct ways of testing the universality of physical
laws. This "artificial intelligence" method provides a way to avoid the main
limiting factor, i.e., human interaction, in the analysis of absorption
spectra.Comment: 9 pages, 5 figures, published on 5 April 2017 in Univers
Keck constraints on a varying fine-structure constant: wavelength calibration errors
The Keck telescope's HIRES spectrograph has previously provided evidence for
a smaller fine-structure constant, alpha, compared to the current laboratory
value, in a sample of 143 quasar absorption systems:
da/a=(-0.57+/-0.11)x10^{-5}. This was based on a variety of metal-ion
transitions which, if alpha varies, experience different relative velocity
shifts. This result is yet to be robustly contradicted, or confirmed, by
measurements on other telescopes and spectrographs; it remains crucial to do
so. It is also important to consider new possible instrumental systematic
effects which may explain the Keck/HIRES results. Griest et al. (2009,
arXiv:0904.4725v1) recently identified distortions in the echelle order
wavelength scales of HIRES with typical amplitudes +/-250m/s. Here we
investigate the effect such distortions may have had on the Keck/HIRES varying
alpha results. We demonstrate that they cause a random effect on da/a from
absorber to absorber because the systems are at different redshifts, placing
the relevant absorption lines at different positions in different echelle
orders. The typical magnitude of the effect on da/a is ~0.4x10^{-5} per
absorber which, compared to the median error on da/a in the sample,
~1.9x10^{-5}, is relatively small. Consequently, the weighted mean value
changes by less than 0.05x10^{-5} if the corrections we calculate are applied.
Nevertheless, we urge caution, particularly for analyses aiming to achieve high
precision da/a measurements on individual systems or small samples, that a much
more detailed understanding of such intra-order distortions and their
dependence on observational parameters is important if they are to be avoided
or modelled reliably. [Abridged]Comment: 9 pages, 2 figures, 2 tables. Invited contribution to Proc. IAU
XXVIIth General Assembly, Joint Discussion 9, "Are the fundamental constants
varying with time?". To appear in P. Molaro, E. Vangioni-Flam, eds, Memorie
della Societa Astronomica Italiana (MmSAIt), Vol. 80. Complete version of
Table 1 available at http://astronomy.swin.edu.au/~mmurphy/pub.htm
Sparse SCN Projections to the PVN Indicate Paracrine Signaling
From the Washington University Senior Honors Thesis Abstracts (WUSHTA), 2017. Published by the Office of Undergraduate Research. Joy Zalis Kiefer, Director of Undergraduate Research and Associate Dean in the College of Arts & Sciences; Lindsey Paunovich, Editor; Helen Human, Programs Manager and Assistant Dean in the College of Arts and Sciences Mentor: Erik D. Herzo
Modelling cell movement and chemotaxis pseudopod based feedback
A computational framework is presented for the simulation of eukaryotic cell migration and chemotaxis. An empirical pattern formation model, based on a system of non-linear reaction-diffusion equations, is approximated on an evolving cell boundary using an Arbitrary Lagrangian Eulerian surface finite element method (ALE-SFEM). The solution state is used to drive a mechanical model of the protrusive and retractive forces exerted on the cell boundary. Movement of the cell is achieved using a level set method. Results are presented for cell migration with and without chemotaxis. The simulated behaviour is compared with experimental results of migrating Dictyostelium discoideum cells
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