4,633 research outputs found
Innovative molecular diagnosis of Trichinella species based on β-carbonic anhydrase genomic sequence
Trichinellosis is a helminthic infection where different species of Trichinella nematodes are the causative agents. Several molecular assays have been designed to aid diagnostics of trichinellosis. These assays are mostly complex and expensive. The genomes of Trichinella species contain certain parasite-specific genes, which can be detected by polymerase chain reaction (PCR) methods. We selected -carbonic anhydrase (-CA) gene as a target, because it is present in many parasites genomes but absent in vertebrates. We developed a novel -CA gene-based method for detection of Trichinella larvae in biological samples. We first identified a -CA protein sequence from Trichinella spiralis by bioinformatic tools using -CAs from Caenorhabditis elegans and Drosophila melanogaster. Thereafter, 16 sets of designed primers were tested to detect -CA genomic sequences from three species of Trichinella, including T.spiralis, Trichinellapseudospiralis and Trichinellanativa. Among all 16 sets of designed primers, the primer set No. 2 efficiently amplified -CA genomic sequences from T.spiralis, T.pseudospiralis and T.nativa without any false-positive amplicons from other parasite samples including Toxoplasma gondii, Toxocara cati and Parascaris equorum. This robust and straightforward method could be useful for meat inspection in slaughterhouses, quality control by food authorities and medical laboratories.Peer reviewe
Tversky loss function for image segmentation using 3D fully convolutional deep networks
Fully convolutional deep neural networks carry out excellent potential for
fast and accurate image segmentation. One of the main challenges in training
these networks is data imbalance, which is particularly problematic in medical
imaging applications such as lesion segmentation where the number of lesion
voxels is often much lower than the number of non-lesion voxels. Training with
unbalanced data can lead to predictions that are severely biased towards high
precision but low recall (sensitivity), which is undesired especially in
medical applications where false negatives are much less tolerable than false
positives. Several methods have been proposed to deal with this problem
including balanced sampling, two step training, sample re-weighting, and
similarity loss functions. In this paper, we propose a generalized loss
function based on the Tversky index to address the issue of data imbalance and
achieve much better trade-off between precision and recall in training 3D fully
convolutional deep neural networks. Experimental results in multiple sclerosis
lesion segmentation on magnetic resonance images show improved F2 score, Dice
coefficient, and the area under the precision-recall curve in test data. Based
on these results we suggest Tversky loss function as a generalized framework to
effectively train deep neural networks
NMR Evidence for Antiferromagnetic Transition in the Single-Component Molecular Conductor, [Au(tmdt)_{2}] at 110 K
We present the results of a ^{1}H NMR study of the single-component molecular
conductor, [Au(tmdt)_{2}].
A steep increase in the NMR line width and a peak formation of the nuclear
spin-lattice relaxation rate, 1/T_{1}, were observed at around 110 K.
This behavior provides clear and microscopic evidences for a magnetic phase
transition at considerably high temperature among organic conductors.
The observed variation in 1/T_{1} with respect to temperature indicates the
highly correlated nature of the metallic phase.Comment: 5pages, 6figures to be published in J. Phys. Soc. Jp
Improved Scalable Green Synthesis of Noble Metallic Polygonal Micro/Nano particles from Waste Macadamia Nut Shells
RA2 Research Attachment
Using neuroevolution for predicting mobile marketing conversion
This paper addresses user Conversion Rate (CVR) prediction within the context of Mobile Performance Marketing. Specifically, we adapt two main neuroevolution methods: Neuroevolution of Augmenting Topologies (NEAT) and Hypercube-based NEAT (HyperNEAT). First, we discuss two mechanisms for increasing execution speed (parallelism and data sampling); a strategy for preventing excessive network complexity with NEAT; and a rolling window scheme for performing an online learning. Then, we present experimental results, using distinct datasets and testing both offline and online learning environments.ThisarticleisaresultoftheprojectNORTE-01-0247-FEDER-017497,supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This work was also supported by FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2019
Singlet Stripe Phases in the planar t-J Model
The energies of singlet stripe phases in which a plane is broken up into spin
liquid ladders by lines of holes, is examined. If the holes were static then
patterns containing spin liquids with a finite spin gap are favored. The case
of dynamic holes is treated by assembling t-J ladders oriented perpendicular to
the stripes. For a wide region around the hole-hole
correlations in a single ladder are found to be predominantly charge density
wave type but an attraction between hole pairs on adjacent ladders leads to a
stripe phase. A quantum mechanical melting of the hole lines at smaller
values leads to a Bose condensate of hole pairs, i.e. a superconducting phase.Comment: 5 pages, uuencoded compressed PostScript file including 5 figures,
ETH-TH/942
Electronic Structure of Stripes in Two-Dimensional Hubbard Model
Focusing on La_{2-x}Sr_{x}CuO_{4}, we study the stripe structure by the
self-consistent mean-field theory of the Hubbard model. By introducing the
realistic Fermi surface topology, the SDW-gapped insulator is changed to
metallic. The solitonic features of the stripe structure and the contribution
of the mid-gap states are presented. We consider the band dispersion, the local
density of states, the spectral weight, and the optical conductivity,
associated with the solitonic structure. These results may provide important
information for the experimental research of the stripe structure, such as the
angle-resolved photoemission experiments. The ``Fermi surface'' shape is
changed depending on the ratio of the incommensurability delta and the hole
density n_h. In real space, only the stripe region is metallic when delta/n_h
is large.Comment: LaTeX 12 pages (using jpsj macros) with 16 figure
Spin and charge excitations in incommensurate spin density waves
Collective excitations both for spin- and charge-channels are investigated in
incommensurate spin density wave (or stripe) states on two-dimensional Hubbard
model. By random phase approximation, the dynamical susceptibility
\chi(q,\omega) is calculated for full range of (q,\omega) with including all
higher harmonics components. An intricate landscape of the spectra in
\chi(q,\omega) is obtained. We discuss the anisotropy of the dispersion cones
for spin wave excitations, and for the phason excitation related to the motion
of the stripe line. Inelastic neutron experiments on Cr and its alloys and
stripe states of underdoped cuprates are proposed
Magnetic phase diagram of cubic perovskites SrMn_1-xFe_xO_3
We combine the results of magnetic and transport measurements with Mossbauer
spectroscopy and room-temperature diffraction data to construct the magnetic
phase diagram of the new family of cubic perovskite manganites SrMn_1-xFe_xO_3.
We have found antiferromagnetic ordering for lightly and heavily Fe-substituted
material, while intermediate substitution leads to spin-glass behavior. Near
the SrMn_0.5Fe_0.5O_3 composition these two types of ordering are found to
coexist and affect one another. The spin glass behavior may be caused by
competing ferro- and antiferromagnetic interactions among Mn^4+ and observed
Fe^3+ and Fe^5+ ions.Comment: 8 pages, 10 figures, revtex, accepted to Phys. Rev.
Searching for the Slater Transition in the Pyrochlore CdOsO with Infrared Spectroscopy
Infrared reflectance measurements were made on the single crystal pyrochlore
CdOsO in order to examine the transformations of the
electronic structure and crystal lattice across the boundary of the metal
insulator transition at . All predicted IR active phonons are
observed in the conductivity over all temperatures and the oscillator strength
is found to be temperature independent. These results indicate that charge
ordering plays only a minor role in the MIT and that the transition is strictly
electronic in nature. The conductivity shows the clear opening of a gap with
. The gap opens continuously, with a temperature
dependence similar to that of BCS superconductors, and the gap edge having a
distinct dependence. All of these
observables support the suggestion of a Slater transition in CdOsO.Comment: 4 pages, 4 figure
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