3,131 research outputs found
Constraining the bulk Lorentz factor from the photosphere emission
We propose a direct and model-independent method to constrain the Lorentz
factor of a relativistically expanding object, like gamma-ray bursts. Only the
measurements, such as thermal component of the emission, the distance and the
variable time scale of the light curve, are used. If the uncertainties are
considered, we will obtain lower limits of the Lorentz factor instead. We apply
this method to GRB 090618 and get a lower limit of the Lorentz factor to be 22.
The method can be used to any relativistically moving object, such as gamma-ray
bursts, blazars, and soft gamma-ray repeaters, providing the thermal component
of the emission being observed.Comment: 10 pages, 1 figur
Delay Reduction in Multi-Hop Device-to-Device Communication using Network Coding
This paper considers the problem of reducing the broadcast decoding delay of
wireless networks using instantly decodable network coding (IDNC) based
device-to-device (D2D) communications. In a D2D configuration, devices in the
network can help hasten the recovery of the lost packets of other devices in
their transmission range by sending network coded packets. Unlike previous
works that assumed fully connected network, this paper proposes a partially
connected configuration in which the decision should be made not only on the
packet combinations but also on the set of transmitting devices. First, the
different events occurring at each device are identified so as to derive an
expression for the probability distribution of the decoding delay. The joint
optimization problem over the set of transmitting devices and the packet
combinations of each is, then, formulated. The optimal solution of the joint
optimization problem is derived using a graph theory approach by introducing
the cooperation graph and reformulating the problem as a maximum weight clique
problem in which the weight of each vertex is the contribution of the device
identified by the vertex. Through extensive simulations, the decoding delay
experienced by all devices in the Point to Multi-Point (PMP) configuration, the
fully connected D2D (FC-D2D) configuration and the more practical partially
connected D2D (PC-D2D) configuration are compared. Numerical results suggest
that the PC-D2D outperforms the FC-D2D and provides appreciable gain especially
for poorly connected networks
Desktop Robot Based Rapid Prototyping System: An Advanced Extrusion Based Processing of Biopolymers into 3D Tissue Engineering Scaffolds
The Friedmann equation in modified entropy-area relation from entropy force
According to the formal holographic principle, a modification to the
assumption of holographic principle in Verlinder's investigation of entropy
force is obtained. A more precise relation between entropy and area in the
holographic system is proposed. With the entropy corrections to the
area-relation, we derivate Newton's laws and Einstein equation with a static
spherically symmetric holographic screen. Furthermore we derived the correction
terms to the modified Friedmann equation of the FRW universe starting from the
holographic principle and the Debye model.Comment: Mod. Phys. Lett. A26, 489-500 (2011
Use Text Mining Approach to Generate the Draft of Indictment for Prosecutor
Motivation: The quantity of criminal cases year 2009 in Taiwan is up to 1.8 millions, Each prosecutor must handle over 211 cases per month, complaints on over loading is laud and clear. While 70 % of criminal cases are drug Abuse, public danger, larceny and fraud, these types of criminal cases may have different story though, the complexity are relative simple than cases of killing, corruption etc., but prosecutors still spend costly time on these cases handling. In this paper we try to use text mining technology to provide solution on this issue. Approach: We use the police’s investigation document of criminal case to compare with judgment history of court, and use Cosine Similarity algorithm to calculate coefficient of similarity, base on the highest coefficient, we find the closest judgment of this type of criminal case, that can be used to decide and generate the draft of indictment for prosecutor
I=2 Pion scattering length with improved actions on anisotropic lattices
scattering length in the I=2 channel is calculated within quenched
approximation using improved gauge and improved Wilson fermion actions on
anisotropic lattices. The results are extrapolated towards the chiral, infinite
volume and continuum limit. This result improves our previous result on the
scattering length. In the chiral, infinite volume and continuum limit, we
obtain , which is consistent with the result from
Chiral Perturbation Theory, the experiment and results from other lattice
calculations.Comment: 7 pages, 2 figures, typeset wit elsart.cl
Regulation and accumulation of secondary metabolites in plant-fungus symbiotic system
Plants have evolved adaptive strategies to mutualistic microbes penetration for both mycorrhizal fungi and endophytic fungi. Subsequently, an array of host plant defense responses and signal transduction is generated. A group of secondary metabolites are accumulated inducibly or enhanced constitutively in plant tissues during the process. Symbiotic fungi usually perform compatible and friendly interactions with host plants, which contribute to growth promotion and secondary metabolites accumulation simultaneously, such as alkaloids and terpenoid with pharmacological characteristics. Especially, some secondary metabolites derived from root exudation act as signal molecules, which induce the spore germination and hypha branching in mycorrhizal fungi. However, the precise mechanisms in some cases remain unclear so far and need to be further investigated. Above exciting and interesting results shed light on our understanding of the mystery of fungal elicitation of secondary metabolitesaccumulation in plant kingdom. Therefore a deeper insight in mutualistic symbiosis is of great importance for biological applications: (1) the plant/microbial co-culture system in vitro may be perfectly useful to guide the cultivation of medicinal plants for obtaining high level of bioactive compounds; (2) manipulating plant released signal molecules and isoprenoid metabolism will be effective to optimize and improve the function of mycorrhizae in forestry, agriculture and horticulture
Molecular cloning of a novel GSK3/shaggy-like gene from Triticum monococcum L. and its expression in response to salt, drought and other abiotic stresses
The glycogen synthase kinase 3 (GSK3)/SHAGGY-like kinases are nonreceptor serine/threonine protein kinases that are involved in a variety of biological processes. Here, a novel GSK-3-like kinase encoding cDNA was isolated from Triticum monococcum L. seedlings by reverse transcriptase polymerase chain reaction (RT-PCR). Sequence analysis showed that the full length of cDNA consist of 1,543 bp with an open reading frame of 1,068 bp, which encodes 355 amino acid residues. The deduced amino acid sequence showed a high homology with shaggy-like kinases from Triticum aestivum, Zea mays, Trifolium repens, Nicotine tabacum, Medicago sativa and Arabidopsis thaliana; therefore, the gene was named TmGSK1 (Triticum monococcum Glycogen Synthase Kinase 1,GenBank Accession No. DQ443471). Southern blot analysis indicated that there was only one copy of TmGSK1 in the einkorn wheat genome. Quantitative real-time RT-PCR studies showed that the expression of TmGSK1 in the einkorn wheat was induced by salt stress, mechanical wounding, ABA hormone, cold and drought. These results suggest that cells accumulate more TmGSK1 mRNA response to those abiotic stresses. TmGSK1 was shown to be a positive regulator commonly involved in the tolerance to salt, mechanical injury, ABA hormone, cold and drought in einkorn wheat.Key words: TmGSK1, abiotic stress, shaggy-like kinase, signal transduction, Triticum monococcum L
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