The quantum cryptographic switch

We illustrate using a quantum system the principle of a cryptographic switch, in which a third party (Charlie) can control to a continuously varying degree the amount of information the receiver (Bob) receives, after the sender (Alice) has sent her information. Suppose Charlie transmits a Bell state to Alice and Bob. Alice uses dense coding to transmit two bits to Bob. Only if the 2-bit information corresponding to choice of Bell state is made available by Charlie to Bob can the latter recover Alice's information. By varying the information he gives, Charlie can continuously vary the information recovered by Bob. The performance of the protocol subjected to the squeezed generalized amplitude damping channel is considered. We also present a number of practical situations where a cryptographic switch would be of use.Comment: 7 pages, 4 Figure

The Study on RFID Security Method for Entrance Guard System

The RFID technology has been used by industries in recent years, for examples, replacing the traditional two-dimensional barcode, logistics management, military applications, identification. In fact, RFID technology has become one of the new killer technologies. The RFID uses radio frequency to convey information which involves, however, many security problems; Current RFID guidelines do not present solutions to these security problems. The methods put forward in published paper fail to offer complete solutions, either. This study identifies RFID security method for Entrance Guard system. The algorithms used include Hash, AES, random values, XOR four item technology, and use the three-way authentication structure to solve the safety problems of the certification of Entrance Guard system. The experiment showed the algorithms provided better protection on the current RFID systems against attack methods such as Eavesdropping, Traceability, Spoofing and Replay attacking

Ab initio study of ferroelectric domain walls in PbTiO3

We have investigated the atomistic structure of the 180-degree and 90-degree domain boundaries in the ferroelectric perovskite compound PbTiO3 using a first-principles ultrasoft-pseudopotential approach. For each case we have computed the position, thickness and creation energy of the domain walls, and an estimate of the barrier height for their motion has been obtained. We find both kinds of domain walls to be very narrow with a similar width of the order of one to two lattice constants. The energy of the 90-dergree domain wall is calculated to be 35 mJ/m^2, about a factor of four lower than the energy of its 180-degree counterpart, and only a miniscule barrier for its motion is found. As a surprising feature we detected a small offset of 0.15-0.2 eV in the electrostatic potential across the 90-degree domain wall.Comment: 12 pages, with 9 postscript figures embedded. Uses REVTEX and epsf macros. Also available at http://www.physics.rutgers.edu/~dhv/preprints/bm_dw/index.htm

A straw drift chamber spectrometer for studies of rare kaon decays

We describe the design, construction, readout, tests, and performance of planar drift chambers, based on 5 mm diameter copperized Mylar and Kapton straws, used in an experimental search for rare kaon decays. The experiment took place in the high-intensity neutral beam at the Alternating Gradient Synchrotron of Brookhaven National Laboratory, using a neutral beam stop, two analyzing dipoles, and redundant particle identification to remove backgrounds

Synthesis of Cobalt Nanowires on Porous Anodic Alumina Template Using Electrochemical Deposition

Electrochemical deposition has been widely used for synthesis of metal nanowires (NWs) on the porous template. In this paper, the effect of potential and electrolyte concentration on cobalt (Co) NWs formation through porous anodic alumina template has been investigated using direct-current electrodepostion at 0.75~2 V together with the high 0.5 M and low 0.1 M cobalt sulfurate based electrolyte. Scanning electron microscopy and grazing incidence X-ray diffraction were used to examine the nanostructure, morphology and phase of Co NWs. The current vs time curve was recorded for understanding the growth behavior. Too low potential of 0.75 V is not favored for Co NWs formation due to insufficient driving force while too high potential of 2 V ruins the NWs growth owing to hydrogen generation in reduction reaction. The uniform crystalline Co NWs can be obtained by the proper potential of 1V and concentration of 0.5 M at an average growth rate of 964 nm/min

Phylogenetics and Biogeography of the Phalaenopsis violacea (Orchidaceae) Species Complex Based on Nuclear and Plastid DNA

The Phalaenopsis violacea complex includes two species P violacea Witte and Phalaenopsis bellina (Rchb f) E A Christ However three forms of P violacea have been found in different areas including Sumatra the Malay Peninsula and Mentawai Island The phylogenetic tree inferred from the internal transcribed spacer (ITS) region of nuclear ribosomal DNA (nrDNA) the trnL intron and the atpB rbcL spacer of plastid DNA were used to clarify the phylogenetics and biogeography of the P violacea complex Analyses of the trnL intron sequences and of the atpB rbcL spacer did not allow for apparent discrimination among these three species of the P violacea complex Based on the phylogenetic tree inferred from th

Three-dimensional random Voronoi tessellations: From cubic crystal lattices to Poisson point processes

We perturb the SC, BCC, and FCC crystal structures with a spatial Gaussian noise whose adimensional strength is controlled by the parameter a, and analyze the topological and metrical properties of the resulting Voronoi Tessellations (VT). The topological properties of the VT of the SC and FCC crystals are unstable with respect to the introduction of noise, because the corresponding polyhedra are geometrically degenerate, whereas the tessellation of the BCC crystal is topologically stable even against noise of small but finite intensity. For weak noise, the mean area of the perturbed BCC and FCC crystals VT increases quadratically with a. In the case of perturbed SCC crystals, there is an optimal amount of noise that minimizes the mean area of the cells. Already for a moderate noise (a>0.5), the properties of the three perturbed VT are indistinguishable, and for intense noise (a>2), results converge to the Poisson-VT limit. Notably, 2-parameter gamma distributions are an excellent model for the empirical of of all considered properties. The VT of the perturbed BCC and FCC structures are local maxima for the isoperimetric quotient, which measures the degre of sphericity of the cells, among space filling VT. In the BCC case, this suggests a weaker form of the recentluy disproved Kelvin conjecture. Due to the fluctuations of the shape of the cells, anomalous scalings with exponents >3/2 is observed between the area and the volumes of the cells, and, except for the FCC case, also for a->0. In the Poisson-VT limit, the exponent is about 1.67. As the number of faces is positively correlated with the sphericity of the cells, the anomalous scaling is heavily reduced when we perform powerlaw fits separately on cells with a specific number of faces

Promoter prediction using physico-chemical properties of DNA

The ability to locate promoters within a section of DNA is known to be a very difficult and very important task in DNA analysis. We document an approach that incorporates the concept of DNA as a complex molecule using several models of its physico-chemical properties. A support vector machine is trained to recognise promoters by their distinctive physical and chemical properties. We demonstrate that by combining models, we can improve upon the classification accuracy obtained with a single model. We also show that by examining how the predictive accuracy of these properties varies over the promoter, we can reduce the number of attributes needed. Finally, we apply this method to a real-world problem. The results demonstrate that such an approach has significant merit in its own right. Furthermore, they suggest better results from a planned combined approach to promoter prediction using both physicochemical and sequence based techniques

Identification of differentially expressed genes induced by Bamboo mosaic virus infection in Nicotiana benthamiana by cDNA-amplified fragment length polymorphism

Background: The genes of plants can be up- or down-regulated during viral infection to influence the replication of viruses. Identification of these differentially expressed genes could shed light on the defense systems employed by plants and the mechanisms involved in the adaption of viruses to plant cells. Differential gene expression in Nicotiana benthamiana plants in response to infection with Bamboo mosaic virus (BaMV) was revealed using cDNA-amplified fragment length polymorphism (AFLP). Results: Following inoculation with BaMV, N. benthamiana displayed differential gene expression in response to the infection. Isolation, cloning, and sequencing analysis using cDNA-AFLP furnished 90 cDNA fragments with eight pairs of selective primers. Fifteen randomly selected genes were used for a combined virus-induced gene silencing (VIGS) knockdown experiment, using BaMV infection to investigate the roles played by these genes during viral infection, specifically addressing the means by which these genes influence the accumulation of BaMV protein. Nine of the 15 genes showed either a positive or a negative influence on the accumulation of BaMV protein. Six knockdown plants showed an increase in the accumulation of BaMV, suggesting that they played a role in the resistance to viral infection, while three plants showed a reduction in coat protein, indicating a positive influence on the accumulation of BaMV in plants. An interesting observation was that eight of the nine plants showing an increase in BaMV coat protein were associated with cell rescue, defense, death, aging, signal transduction, and energy production. Conclusions: This study reports an efficient and straightforward method for the identification of host genes involved in viral infection. We succeeded in establishing a cDNA-AFLP system to help track changes in gene expression patterns in N. benthamiana plants when infected with BaMV. The combination of both DNA-AFLP and VIGS methodologies made it possible to screen a large number of genes and identify those associated with infections of plant viruses. In this report, 9 of the 15 analyzed genes exhibited either a positive or a negative influence on the accumulation of BaMV in N. benthamiana plants

Estrogen receptor alpha polymorphism is associated with pelvic organ prolapse risk

Estrogen and estrogen receptors are known to play important roles in the pathophysiology of pelvic organ prolapse (POP). We investigated whether estrogen receptor alpha (ER alpha) gene polymorphisms were associated with POP risk by conducting a case-control association study in 88 women with POP and 153 women without POP. Genotypes of the ER alpha (ESR1) gene polymorphisms (rs17847075, rs2207647, rs2234693, rs3798577, and rs2228480) were determined by polymerase chain reaction, followed by restriction fragment length polymorphism analysis. There was significant difference between women with and those without POP in the distribution of the ESR1 rs2228480 genotypes evaluated. By using multivariable logistic regression, age and ESR1 rs2228480 genotype GA were significantly associated with POP risk. Although the sample size of women with POP studied is small, the present study shows that ER alpha genotype may be associated with POP risk