275 research outputs found
Unselective regrowth of 1.5-μm InGaAsP multiple-quantum-well distributed-feedback buried heterostructure lasers
Unselective regrowth for fabricating 1.5-μm InGaAsP multiple-quantum well (MQW) distributed-feedback (DFB) buried heterostructure (BH) lasers is developed. The experimental results exhibit superior characteristics, such as a low threshold of 8.5mA, high slope efficiency of 0.55mW∕mA, circular-like far-field patterns, the narrow linewidth of 2.5MHz, etc. The high performance of the devices effectively proves the feasibility of the new method to fabricate buried heterostructure lasers
Video Object Segmentation using Point-based Memory Network
Recent years have witnessed the prevalence of memory-based methods for Semi-supervised Video Object Segmentation (SVOS) which utilise past frames efficiently for label propagation. When conducting feature matching, fine-grained multi-scale feature matching has typically been performed using all query points, which inevitably results in redundant computations and thus makes the fusion of multi-scale results ineffective. In this paper, we develop a new Point-based Memory Network, termed as PMNet, to perform fine-grained feature matching on hard samples only, assuming that easy samples can already obtain satisfactory matching results without the need for complicated multi-scale feature matching. Our approach first generates an uncertainty map from the initial decoding outputs. Next, the fine-grained features at uncertain locations are sampled to match the memory features on the same scale. Finally, the matching results are further decoded to provide a refined output. The point-based scheme works with the coarsest feature matching in a complementary and efficient manner. Furthermore, we propose an approach to adaptively perform global or regional matching based on the motion history of memory points, making our method more robust against ambiguous backgrounds. Experimental results on several benchmark datasets demonstrate the superiority of our proposed method over state-of-the-art methods
Periostin Is Essential for the Integrity and Function of the Periodontal Ligament During Occlusal Loading in Mice
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141255/1/jper1480.pd
In vivo impact of a 4Â bp deletion mutation in the DLX3 gene on bone development
AbstractDistal-less 3 (DLX3) gene mutations are etiologic for Tricho-Dento-Osseous syndrome. To investigate the in vivo impact of mutant DLX3 on bone development, we established transgenic (TG) mice expressing the c.571_574delGGGG DLX-3 gene mutation (MT-DLX3) driven by a mouse 2.3 Col1A1 promoter. Microcomputed tomographic analyses demonstrated markedly increased trabecular bone volume and bone mineral density in femora from TG mice. In ex vivo experiments, TG mice showed enhanced differentiation of bone marrow stromal cells to osteoblasts and increased expression levels of bone formation markers. However, TG mice did not show enhanced dynamic bone formation rates in in vivo fluorochrome double labeling experiments. Osteoclastic differentiation capacities of bone marrow monocytes were reduced in TG mice in the presence of osteoclastogenic factors and the numbers of TRAP(+) osteoclasts on distal metaphyseal trabecular bone surfaces were significantly decreased. TRACP 5b and CTX serum levels were significantly decreased in TG mice, while IFN-γ levels were significantly increased. These data demonstrate that increased levels of IFN-γ decrease osteoclast bone resorption activities, contributing to the enhanced trabecular bone volume and mineral density in these TG mice. These data suggest a novel role for this DLX-3 mutation in osteoclast differentiation and bone resorption
The fermion dynamical symmetry model for the even--even and even--odd nuclei in the Xe--Ba region
The even--even and even--odd nuclei Xe-Xe and
Ba-Ba are shown to have a well-realized fermion dynamical symmetry. Their low-lying energy levels can be
described by a unified analytical expression with two (three) adjustable
parameters for even--odd (even--even) nuclei that is derived from the fermion
dynamical symmetry model. Analytical expressions are given for wavefunctions
and for transition rates that agree well with data. The distinction
between the FDSM and IBM limits is discussed. The experimentally
observed suppression of the the energy levels with increasing quantum
number can be explained as a perturbation of the pairing interaction on
the symmetry, which leads to an Pairing effect for nuclei.Comment: submitted to Phys. Rev. C, LaTeX, 31 pages, 8 figures with postscript
files available on request at [email protected]
Time-Dependent Partition-Free Approach in Resonant Tunneling Systems
An extended Keldysh formalism, well suited to properly take into account the
initial correlations, is used in order to deal with the time-dependent current
response of a resonant tunneling system. We use a \textit{partition-free}
approach by Cini in which the whole system is in equilibrium before an external
bias is switched on. No fictitious partitions are used. Besides the
steady-state responses one can also calculate physical dynamical responses. In
the noninteracting case we clarify under what circumstances a steady-state
current develops and compare our result with the one obtained in the
partitioned scheme. We prove a Theorem of asymptotic Equivalence between the
two schemes for arbitrary time-dependent disturbances. We also show that the
steady-state current is independent of the history of the external perturbation
(Memory Loss Theorem). In the so called wide-band limit an analytic result for
the time-dependent current is obtained. In the interacting case we propose an
exact non-equilibrium Green function approach based on Time Dependent Density
Functional Theory. The equations are no more difficult than an ordinary Mean
Field treatment. We show how the scattering-state scheme by Lang follows from
our formulation. An exact formula for the steady-state current of an arbitrary
interacting resonant tunneling system is obtained. As an example the
time-dependent current response is calculated in the Random Phase
Approximation.Comment: final version, 18 pages, 9 figure
Dark Energy and Neutrino CPT Violation
In this paper we study the dynamical CPT violation in the neutrino sector
induced by the dark energy of the Universe. Specifically we consider a dark
energy model where the dark energy scalar derivatively interacts with the
right-handed neutrinos. This type of derivative coupling leads to a
cosmological CPT violation during the evolution of the background field of the
dark energy. We calculate the induced CPT violation of left-handed neutrinos
and find the CPT violation produced in this way is consistent with the present
experimental limit and sensitive to the future neutrino oscillation
experiments, such as the neutrino factory.Comment: 10 pages, 2 figures. Typos corrected and references added. To be
published in EPJ
NMR and Mossbauer study of spin dynamics and electronic structure of Fe{2+x}V{1-x}Al and Fe2VGa
In order to assess the magnetic ordering process in Fe2VAl and the related
material Fe2VGa, we have carried out nuclear magnetic resonance (NMR) and
Mossbauer studies. 27Al NMR relaxation measurements covered the temperature
range 4 -- 500 K in Fe(2+x)V(1-x)Al samples. We found a peak in the NMR
spin-lattice relaxation rate, 27T1^-1, corresponding to the magnetic
transitions in each of these samples. These peaks appear at 125 K, 17 K, and
165 K for x = 0.10, 0, and - 0.05 respectively, and we connect these features
with critical slowing down of the localized antisite defects. Mossbauer
measurements for Fe2VAl and Fe2VGa showed lines with no hyperfine splitting,
and isomer shifts nearly identical to those of the corresponding sites in Fe3Al
and Fe3Ga, respectively. We show that a model in which local band filling leads
to magnetic regions in the samples, in addition to the localized antisite
defects, can account for the observed magnetic ordering behavior.Comment: 5 pages, 3 figure
- …