12,085 research outputs found
Innovative Hybridisation of Genetic Algorithms and Neural Networks in Detecting Marker Genes for Leukaemia Cancer
Methods for extracting marker genes that trigger the growth
of cancerous cells from a high level of complexity microarrays are of much interest from the computing community. Through the identified genes, the pathology of cancerous cells can be revealed and early precaution
can be taken to prevent further proliferation of cancerous cells. In this paper, we propose an innovative hybridised gene identification framework based on genetic algorithms and neural networks to identify marker genes for leukaemia disease. Our approach confirms that high classification
accuracy does not ensure the optimal set of genes have been identified and our model delivers a more promising set of genes even with a lower classification accurac
Anatomical Studies of Cca Penetration Associated With Conventional (Tooth) and With Micro (Needle) Incising
Individual tooth and needle incisions were made on radial and tangential surfaces of white spruce and jack pine heartwood test samples. The samples were pressure-treated with CCA preservative and then dissected in various planes to examine patterns of preservative penetration. Lateral movement of preservative from incisions was generally greater in the radial than in the tangential direction (average R/T ratio about 1.5). Longitudinal movement was in the range of 15 to 20 times that of lateral movement. Ray tissue facilitates movement in the radial plane, but difficulty is encountered in traversing latewood bands. An individual tooth incision resulted in a larger zone of treated wood but also in a greater amount of wood tissue damage than a needle incision. When compared as ratios of treated wood area to damaged wood area at a depth of 9 mm beneath the original treated surface, needle incisions were decidedly superior. For an equivalent degree of preservative treatment, conventional incising teeth damaged about ten times the amount of wood tissue as did incising needles
Quantitative spectroscopy of extreme helium stars - Model atmospheres and a non-LTE abundance analysis of BD+102179?
Extreme helium stars (EHe stars) are hydrogen-deficient supergiants of
spectral type A and B. They are believed to result from mergers in double
degenerate systems. In this paper we present a detailed quantitative non-LTE
spectral analysis for BD+102179, a prototype of this rare class of
stars, using UVES and FEROS spectra covering the range from 3100 to 10
000 {\AA}. Atmosphere model computations were improved in two ways. First,
since the UV metal line blanketing has a strong impact on the
temperature-density stratification, we used the Atlas12 code. Additionally, We
tested Atlas12 against the benchmark code Sterne3, and found only small
differences in the temperature and density stratifications, and good agreement
with the spectral energy distributions. Second, 12 chemical species were
treated in non-LTE. Pronounced non-LTE effects occur in individual spectral
lines but, for the majority, the effects are moderate to small. The
spectroscopic parameters give = 17 300300 K and
= 2.800.10, and an evolutionary mass of 0.550.05 . The star
is thus slightly hotter, more compact and less massive than found in previous
studies. The kinematic properties imply a thick-disk membership, which is
consistent with the metallicity Fe/H and -enhancement.
The refined light-element abundances are consistent with the white dwarf merger
scenario. We further discuss the observed helium spectrum in an appendix,
detecting dipole-allowed transitions from about 150 multiplets plus the most
comprehensive set of known/predicted isolated forbidden components to date.
Moreover, a so far unreported series of pronounced forbidden He I components is
detected in the optical-UV.Comment: Accepted for publication in MNRAS, 26 pages, 19 Figure
Fixation of Juvenile Cambium from Two Coniferous Species for Ultrastructural Study
Samples of dormant and of actively growing cambial-zone tissue collected in June and March, respectively, from plantations of young white spruce (Picea glauca [Moench] Voss) and red pine (Pinus resinosa Ait.) near Ottawa, Canada, were fixed in five different solutions at three temperatures. Fixation quality was evaluated by electron microscopy.Not all cellular organelles were preserved equally well by the same fixative in the active and in the dormant conditions, or in both spruce and pine. In general, our best results were obtained with Karnovsky's fixative solution. Somewhat less satisfactory results were obtained with a glutaraldehyde-acrolein mixture followed by straight glutaraldehyde. Poorer results were obtained with a trialdehyde solution while a glutaraldehyde-osmium tetroxide cocktail undoubtedly provided the worst fixation.Different fixative temperatures had a marked effect on fixation quality only when phosphate buffer was used. There was little gained by prolonging the period of fixation beyond a few hours
Time-domain Brillouin Scattering as a Local Temperature Probe in Liquids
We present results of time-domain Brillouin scattering (TDBS) to determine
the local temperature of liquids in contact to an optical transducer. TDBS is
based on an ultrafast pump-probe technique to determine the light scattering
frequency shift caused by the propagation of coherent acoustic waves in a
sample. Since the temperature influences the Brillouin scattering frequency
shift, the TDBS signal probes the local temperature of the liquid. Results for
the extracted Brillouin scattering frequencies recorded at different liquid
temperatures and at different laser powers - i.e. different steady state
background temperatures- are shown to demonstrate the usefulness of TDBS as a
temperature probe. This TDBS experimental scheme is a first step towards the
investigation of ultrathin liquids measured by GHz ultrasonic probing.Comment: arXiv admin note: substantial text overlap with arXiv:1702.0107
Response to comment on "solid recovered fuel: Materials flow analysis and fuel property development during the mechanical processing of biodried waste"
Laner and Cencic1 comment on Velis et al. (2013)2 clarifying certain points on the use of the material flow analysis (MFA) software STAN3. We welcome the correspondence and the opportunity this exchange provides to discuss optimal approaches to using STAN. In keeping with Velis et al.2 these physically impossible, and otherwise insignificant, negative flows have enabled improvements to STAN. Here, we elaborate on the practicalities of using STAN in our research and on the correctness and validation of our results, notwithstanding the inclusion of negative flows. We explain the contribution of our approach to solid waste management and resource recovery
Quintessence Models and the Cosmological Evolution of alpha
The cosmological evolution of a quintessence-like scalar field, phi, coupled
to matter and gauge fields leads to effective modifications of the coupling
constants and particle masses over time. We analyze a class of models where the
scalar field potential V(phi) and the couplings to matter B(phi) admit common
extremum in phi, as in the Damour-Polyakov ansatz. We find that even for the
simplest choices of potentials and B(phi), the observational constraints on
delta alpha/alpha coming from quasar absorption spectra, the Oklo phenomenon
and Big Bang nucleosynthesis provide complementary constraints on the
parameters of the model. We show the evolutionary history of these models in
some detail and describe the effects of a varying mass for dark matter.Comment: 26 pages, 20 eps figure
Strain and field modulation in bilayer graphene band structure
Using an external electric field, one can modulate the bandgap of Bernal
stacked bilayer graphene by breaking A-~B symmetry. We analyze strain effects
on the bilayer graphene using the extended Huckel theory and find that reduced
interlayer distance results in higher bandgap modulation, as expected.
Furthermore, above about 2.5 angstrom interlayer distance, the bandgap is
direct, follows a convex relation to electric field and saturates to a value
determined by the interlayer distance. However, below about 2.5 angstrom, the
bandgap is indirect, the trend becomes concave and a threshold electric field
is observed, which also depends on the stacking distance.Comment: 3 pages, 5 figures - v1 and v2 are the same, uploaded twice - v3,
some typos fixed and a reference adde
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Serving GODAE Data and Products to the Ocean Community
The Global Ocean Data Assimilation Experiment (GODAE [http://
www.godae.org]) has spanned a decade of rapid technological development. The ever-increasing volume and diversity of oceanographic data produced by in situ instruments, remote-sensing platforms, and computer simulations have driven
the development of a number of innovative technologies that are essential for connecting scientists with the data that they need. This paper gives an overview of the technologies that have been developed and applied in the course of GODAE, which now provide users of oceanographic data with the capability to discover, evaluate, visualize, download, and analyze data from all over the world. The key to this
capability is the ability to reduce the inherent complexity of oceanographic data by providing a consistent, harmonized view of the various data products. The challenges of data serving have been addressed over the last 10 years through the cooperative skills and energies of many individuals
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