1,033 research outputs found
Epigenetic aberrations and cancer
The correlation between epigenetic aberrations and disease underscores the importance of epigenetic mechanisms. Here, we review recent findings regarding chromatin modifications and their relevance to cancer
Raters as scale makers for an L2 Spanish speaking test: using paired test discourse to develop a rating scale for communicative interaction
This paper reports on the development of an evidence based rating scale to rate peer-peer L2 communicative interaction. The scale was based on experienced judges' comments on videoed student samples filmed during operational paired candidate tests of beginner level Spanish. Six trained and experienced raters generated criteria for communicative interaction which were incorporated into a tool for developing sample based rating scales, the Empirically-based, Binarychoice, Boundary-definition (EBB) method (Turner and Upshur, 1996), was adapted for the context. The findings reported on in this article examine the features of paired candidate interaction which raters used to define the boundary between performance levels. Three main criteria emerged as the boundaries used to define levels of interaction: non-verbal interpersonal communication, interactive listening and interactional management. These new notions are evidence of how peer-peer interaction can bee rated and also advance our understanding of the significant features of interaction in this rating context
Untangling Fine-Grained Code Changes
After working for some time, developers commit their code changes to a
version control system. When doing so, they often bundle unrelated changes
(e.g., bug fix and refactoring) in a single commit, thus creating a so-called
tangled commit. Sharing tangled commits is problematic because it makes review,
reversion, and integration of these commits harder and historical analyses of
the project less reliable. Researchers have worked at untangling existing
commits, i.e., finding which part of a commit relates to which task. In this
paper, we contribute to this line of work in two ways: (1) A publicly available
dataset of untangled code changes, created with the help of two developers who
accurately split their code changes into self contained tasks over a period of
four months; (2) a novel approach, EpiceaUntangler, to help developers share
untangled commits (aka. atomic commits) by using fine-grained code change
information. EpiceaUntangler is based and tested on the publicly available
dataset, and further evaluated by deploying it to 7 developers, who used it for
2 weeks. We recorded a median success rate of 91% and average one of 75%, in
automatically creating clusters of untangled fine-grained code changes
Framework for software architecture visualization assessment.
In order to assess software architecture visualisation strategies, we qualitatively characterize then construct an assessment framework with 7 key areas and 31 features. The framework is used for evaluation and comparison of various strategies from multiple stakeholder perspectives. Six existing software architecture visualisation tools and a seventh research tool were evaluated. All
tools exhibited shortcomings when evaluated in the framework
From image to technology: a multidisciplinary approach for improving the quality of organic bread.
This study is part of a research programme devoted to improving the quality of organic bread. It aims to identify and test prototypes of breads approved by consumers. This is achieved by analysing consumer representations and preferences and placing them within the framework of technological, sensory and nutritional dimensions of the products. The multidisciplinary approach implements an original qualitative approach that combines three consumer focus groups made up of both loyal and occasional consumers, and confrontation sessions with the programme scientific partners. Four prototypes of organic breads have thus been formalised and subsequently tested on a sample of 120 consumers from two sites (Angers and Strasbourg). From an operational point of view, proposals for organic breads approved by consumers are formulated. In terms of methodology, the contributions of a multidisciplinary study are discussed
Scissors resonance in the quasi-continuum of Th, Pa and U isotopes
The gamma-ray strength function in the quasi-continuum has been measured for
231-233Th, 232,233Pa and 237-239U using the Oslo method. All eight nuclei show
a pronounced increase in gamma strength at omega_SR approx 2.4 MeV, which is
interpreted as the low-energy M1 scissors resonance (SR). The total strength is
found to be B_SR = 9-11 mu_N^2 when integrated over the 1 - 4 MeV gamma-energy
region. The SR displays a double-hump structure that is theoretically not
understood. Our results are compared with data from (gamma, gamma') experiments
and theoretical sum-rule estimates for a nuclear rigid-body moment of inertia.Comment: 11 pages, 9 figure
Insulator-Metal Transition in One Dimension Induced by Long-Range Electronic Interactions
The effects of a long range electronic potential on a one dimensional
commensurate Charge Density Wave (CDW) state are investigated. Using numerical
techniques it is shown that a transition to a metallic ground state is reached
as the range of the electron-electron repulsion increases. In this metallic
state, the optical conductivity exhibits a large Drude weight. Possible
interpretations of our results are discussed.Comment: 5 pages, Revtex, minor misprints corrected and a reference to earlier
work by V. Emery and C. Noguera adde
Deducing correlation parameters from optical conductivity in the Bechgaard salts
Numerical calculations of the kinetic energy of various extensions of the
one-dimensional Hubbard model including dimerization and repulsion between
nearest neighbours are reported. Using the sum rule that relates the kinetic
energy to the integral of the optical conductivity, one can determine which
parameters are consistent with the reduction of the infrared oscillator
strength that has been observed in the Bechgaard salts. This leads to improved
estimates of the correlation parameters for both the TMTSF and TMTTF series.Comment: 12 pages, latex, figures available from the author
Antiferromagnetic Phases of One-Dimensional Quarter-Filled Organic Conductors
The magnetic structure of antiferromagnetically ordered phases of
quasi-one-dimensional organic conductors is studied theoretically at absolute
zero based on the mean field approximation to the quarter-filled band with
on-site and nearest-neighbor Coulomb interaction. The differences in magnetic
properties between the antiferromagnetic phase of (TMTTF)X and the spin
density wave phase in (TMTSF)X are seen to be due to a varying degrees of
roles played by the on-site Coulomb interaction. The nearest-neighbor Coulomb
interaction introduces charge disproportionation, which has the same spatial
periodicity as the Wigner crystal, accompanied by a modified antiferromagnetic
phase. This is in accordance with the results of experiments on (TMTTF)Br
and (TMTTF)SCN. Moreover, the antiferromagnetic phase of (DI-DCNQI)Ag
is predicted to have a similar antiferromagnetic spin structure.Comment: 8 pages, LaTeX, 4 figures, uses jpsj.sty, to be published in J. Phys.
Soc. Jpn. 66 No. 5 (1997
Coexistent State of Charge Density Wave and Spin Density Wave in One-Dimensional Quarter Filled Band Systems under Magnetic Fields
We theoretically study how the coexistent state of the charge density wave
and the spin density wave in the one-dimensional quarter filled band is
enhanced by magnetic fields. We found that when the correlation between
electrons is strong the spin density wave state is suppressed under high
magnetic fields, whereas the charge density wave state still remains. This will
be observed in experiments such as the X-ray measurement.Comment: 7 pages, 15 figure
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