4,937 research outputs found
On the scalar nonet in the extended Nambu Jona-Lasinio model
We discuss the lightest scalar resonances, , ,
and in the extended Nambu Jona-Lasinio model. We find
that the model parameters can be tuned, but unnaturally, to accommodate for
those scalars except the . We also discuss problems encountered in
the K Matrix unitarization approximation by using counting technique.Comment: 23 pages 3 eps figures, To appear in Nucl. Phys.
PTEN inhibitor bisperoxovanadium protects oligodendrocytes and myelin and prevents neuronal atrophy in adult rats following cervical hemicontusive spinal cord injury
Cervical spinal cord injury (SCI) damages axons and motor neurons responsible for ipsilateral forelimb function and causes demyelination and oligodendrocyte death. Inhibition of the phosphatase and tensin homologue, PTEN, promotes neural cell survival, neuroprotection and regeneration in vivo and in vitro. PTEN inhibition can also promote oligodendrocyte-mediated myelination of axons in vitro likely through Akt activation. We recently demonstrated that acute treatment with phosphatase PTEN inhibitor, bisperoxovanadium (bpV)-pic reduced tissue damage, neuron death, and promoted functional recovery after cervical hemi-contusion SCI. Evidence suggests bpV can promote myelin stability; however, bpV effects on myelination and oligodendrocytes in contusive SCI models are unclear. We hypothesized that bpV could increase myelin around the injury site through sparing or remyelination, and that bpV treatment may promote increased numbers of oligodendrocytes. Using histological and immunofluorescence labeling, we found that bpV treatment promoted significant spared white matter (30%; p < 0.01) and Luxol Fast Blue (LFB)+ myelin area rostral (Veh: 0.56 ± 0.01 vs. bpV: 0.64 ± 0.02; p < 0.05) and at the epicenter (Veh: 0.4175 ± 0.03 vs. bpV: 0.5400 ± 0.03; p < 0.05). VLF oligodendrocytes were also significantly greater with bpV therapy (109 ± 5.3 vs. Veh: 77 ± 2.7/mm2; p < 0.01). In addition, bpV increased mean motor neuron soma area versus vehicle-treatment (1.0 ± 0.02 vs. Veh: 0.77 ± 0.02) relative to Sham neuron size. This study provides key insight into additional cell and tissue effects that could contribute to bpV-mediated functional recovery observed after contusive cervical SCI
Thermalization of quark-gluon matter by 2-to-2 and 3-to-3 elastic scatterings
Thermalization of quark-gluon matter is studied with a transport equation
that includes contributions of 2-to-2 and 3-to-3 elastic scatterings.
Thermalization time is related to the squared amplitudes for the elastic
scatterings that are calculated in perturbative QCD.Comment: LaTex, 6 pages, 3 figures, talk presented at the 19th international
conference on ultra-relativistic nucleus-nucleus collisions, Shanghai, China,
Nov. 200
Depth-aware neural style transfer
Neural style transfer has recently received significant attention and demonstrated amazing results. An efficient solution proposed by Johnson et al. trains feed-forward convolutional neural networks by defining and optimizing perceptual loss functions. Such methods are typically based on high-level features extracted from pre-trained neural networks, where the loss functions contain two components: style loss and content loss. However, such pre-trained networks are originally designed for object recognition, and hence the high-level features often focus on the primary target and neglect other details. As a result, when input images contain multiple objects potentially at different depths, the resulting images are often unsatisfactory because image layout is destroyed and the boundary between the foreground and background as well as different objects becomes obscured. We observe that the depth map effectively reflects the spatial distribution in an image and preserving the depth map of the content image after stylization helps produce an image that preserves its semantic content. In this paper, we introduce a novel approach for neural style transfer that integrates depth preservation as additional loss, preserving overall image layout while performing style transfer
Changes in endogenous hormone concentrations during inflorescence induction and development in pineapple (Ananas comosus cv. Smooth Cayenne) by ethephon
This study investigated the changes of five endogenous hormones in the shoot apex and the white bases of D-leaf during the inflorescence induction and development of ‘Smooth Cayenne’ pineapple, using 14-month-old pot-grown plants as material and ethephon as flower forcing agent. Results showed that application of ethephon increased the level of endogenous ethylene (C2H4), abscisic acid (ABA) and 2-isopentyl adenine (2-iP) while it decreased the concentration of indole-3-acetic acid (IAA), gibberellic acid (GA3) and zeatin (ZT), and led to the transition of vegetative growth to inflorescence initiation. After inflorescence initiation, the contents of C2H4, ABA and 2-iP declined but the contents of IAA, ABA and ZT increased. These results indicated that low levels of IAA, GA3 and ZT and high levels of C2H4, ABA and 2-iP facilitated inflorescence initiation, while high levels of ZT, IAA and GA3 and low levels of C2H4 and ABA facilitated inflorescence development.Key words: Pineapple, inflorescence initiation, inflorescence development, endogenous hormone
Nav1.3 and FGF14 are primary determinants of the TTX-sensitive sodium current in mouse adrenal chromaffin cells
Adrenal chromaffin cells (CCs) in rodents express rapidly inactivating, tetrodotoxin (TTX)-sensitive sodium channels. The resulting current has generally been attributed to Nav1.7, although a possible role for Nav1.3 has also been suggested. Nav channels in rat CCs rapidly inactivate via two independent pathways which differ in their time course of recovery. One subpopulation recovers with time constants similar to traditional fast inactivation and the other ∼10-fold slower, but both pathways can act within a single homogenous population of channels. Here, we use Nav1.3 KO mice to probe the properties and molecular components of Nav current in CCs. We find that the absence of Nav1.3 abolishes all Nav current in about half of CCs examined, while a small, fast inactivating Nav current is still observed in the rest. To probe possible molecular components underlying slow recovery from inactivation, we used mice null for fibroblast growth factor homology factor 14 (FGF14). In these cells, the slow component of recovery from fast inactivation is completely absent in most CCs, with no change in the time constant of fast recovery. The use dependence of Nav current reduction during trains of stimuli in WT cells is completely abolished in FGF14 KO mice, directly demonstrating a role for slow recovery from inactivation in determining Nav current availability. Our results indicate that FGF14-mediated inactivation is the major determinant defining use-dependent changes in Nav availability in CCs. These results establish that Nav1.3, like other Nav isoforms, can also partner with FGF subunits, strongly regulating Nav channel function
Characterization and Modulation of PI3K-Akt Signaling Following Contusive SCI
poster abstractSpinal cord injury (SCI) is devastating, with most injuries being contusive/compressive injuries at the cervical spinal level. There are two mechanisms of damage after acute contusive SCI: a primary mechanical insult to the cord, and secondary injury induced by many biological events, including inflammation and signal-mediated cell death. The extent of tissue damage correlates with functional loss after SCI, therefore it is critical to protect neural tissue for preservation of functional ability. Focusing on cellular signaling events following SCI is a promising direction of investigation, as modulation of such pathways can promote neuroprotection or regeneration following injury. Two particular signaling pathways have been highlighted as mediators of cellular survival post-central nervous system (CNS) injury, the MEK-Erk and PI3K-Akt pathways. Reducing Erk activity has been shown to promote neuroprotection and reduced reactive gliosis, while reduction of PI3K-Akt signaling likely results in initiation of cellular death. Recent studies have demonstrated promotion of regrowth of adult corticospinal (CST) neurons and protection of motor neuron atrophy by disinhibition of PI3K via PTEN deletion or knock-down in these cells. Understanding the signal pathways and mechanisms involved in different cell types, when such response occurs, and the potential interaction between pathways is essential for maximizing development of optimal approaches to treatment following SCI. This study highlights PI3K-Akt signaling involvement following injury, with future directions aimed at better understanding this pathway for targeting therapies to mediate anatomical and functional preservation and recovery following SCI
Non-Abelian Quantum Hall States and their Quasiparticles: from the Pattern of Zeros to Vertex Algebra
In the pattern-of-zeros approach to quantum Hall states, a set of data
{n;m;S_a|a=1,...,n; n,m,S_a in N} (called the pattern of zeros) is introduced
to characterize a quantum Hall wave function. In this paper we find sufficient
conditions on the pattern of zeros so that the data correspond to a valid wave
function. Some times, a set of data {n;m;S_a} corresponds to a unique quantum
Hall state, while other times, a set of data corresponds to several different
quantum Hall states. So in the latter cases, the patterns of zeros alone does
not completely characterize the quantum Hall states. In this paper, We find
that the following expanded set of data {n;m;S_a;c|a=1,...,n; n,m,S_a in N; c
in R} provides a more complete characterization of quantum Hall states. Each
expanded set of data completely characterize a unique quantum Hall state, at
least for the examples discussed in this paper. The result is obtained by
combining the pattern of zeros and Z_n simple-current vertex algebra which
describes a large class of Abelian and non-Abelian quantum Hall states
\Phi_{Z_n}^sc. The more complete characterization in terms of {n;m;S_a;c}
allows us to obtain more topological properties of those states, which include
the central charge c of edge states, the scaling dimensions and the statistics
of quasiparticle excitations.Comment: 42 pages. RevTeX
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