1,903 research outputs found
Fractional constant elasticity of variance model
This paper develops a European option pricing formula for fractional market
models. Although there exist option pricing results for a fractional
Black-Scholes model, they are established without accounting for stochastic
volatility. In this paper, a fractional version of the Constant Elasticity of
Variance (CEV) model is developed. European option pricing formula similar to
that of the classical CEV model is obtained and a volatility skew pattern is
revealed.Comment: Published at http://dx.doi.org/10.1214/074921706000001012 in the IMS
Lecture Notes Monograph Series
(http://www.imstat.org/publications/lecnotes.htm) by the Institute of
Mathematical Statistics (http://www.imstat.org
Automation System for Single Photon Generation and Detection
Single photon source can be produced by using spontaneous parametric down conversion or quantum emitter such as ions, molecules, atoms, quantum dots and colour centres. Main objective of current research is to automate single photon generation module and detection module based on nitrogen vacancy colour centre in diamond into one system. In single photon generation, diamond sample is held at a holder mounted on a 3D piezo translation stage. Laser source with wavelength 527nm is focused using a standard microscope objective to a spot size at the nitrogen vacancy centre to produce fluorescence.
Since a single photon is generated by exciting an isolated nitrogen vacancy in a diamond crystal, it is critical that position of nitrogen vacancies in the crystal to be known. For this purpose, a scanning system was designed and constructed to determine the 3D position of nitrogen vacancy and identified their coordinates for later use. The system consists of a high precision 3D piezo translation stage and was controlled by a scanning programme built using LabVIEW. This programme will map the location of the vacancies in an intensity graph where axis X and Y show the scanning position while the bright colour spots determine the position of the vacancies.
In single photon detection which is based on the Hanbury-Brown-Twiss setup, the fluorescence emitted from the nitrogen vacancy is split by a beamsplitter and directed to single photon detectors. A digital pulse is produced for each photocount detected. At the same time, output from the detectors is fed into a time to amplitude converter/single channel analyzer to produce coincidence counts. In order to read and record the number of photon counts and number of coincidences, a detection system was designed and built. This detection system interfaces a series of high performance single photon detectors to the same computer that controls the scanning system via a detection programme. Besides reading and recording data, the detection programme can also calculate the second order correlation function, g2(τ) from a subVI written in LabVIEW 8.2
Dendritic cell based cancer vaccines using adenovirally mediated expression of the HER-2/neu gene and apoptotic tumor cells expressing heat shock protein 70
Human Epidermal Growth Factor Receptor 2 (HER-2/neu) is a breast tumor antigen (Ag) commonly overexpressed in 30% of breast cancer cases. Both HER-2/neu-targeted DNA-based and transgene modified dendritic cell (DC)-based vaccines are potent elements in eliciting HER-2/neu specific antitumor immune responses; however, there has been no side-by-side comparison of these two different immunization methods. We utilized an in vivo murine tumor model expressing the rat neu Ag to compare the immunization efficacy between DC transduced with replication-deficient adenovirus containing neu (AdVneu), to form DCneu, and plasmid DNA (pcDNA) vaccine. DCneu displayed an upregulation of immunologically important molecules and inflammatory cytokines expression such as IL-6 that partially mediated conversion of the regulatory T (Tr) cell suppression. Wildtype FVB/N mice immunized with DCneu induced stronger HER-2/neu-specific humoral and cellular immune responses compared to plasmid DNA immunized mice. Furthermore, mice immunized with DCneu remained completely protected from tumor challenge compared to partial or no protection observed in DNA immunized mice in two tumor animal models. In FVBneuN transgenic mice, which develop spontaneous breast tumors at 4-8 months of age, DCneu significantly delayed tumor onset when immunization conducted in mice at a younger age. Taken together, we demonstrated that a HER-2/neu-gene modified DC vaccine is more potent than a plasmid DNA vaccine in inducing neu specific immune responses resulting in greater protective and preventative effects in the tumor models examined. In another study, we examined the use of a DC-based cancer vaccine involving the phagocytosis of apoptotic tumor cells expressing heat shock protein 70 (HSP70). The dual role of HSP70, as an antigenic peptide chaperone and danger signal, makes it especially important in DC-based vaccination. In this study, we investigated the impacts of apoptotic transgenic MCA/HSP tumor cells expressing HSP70 on DC maturation, T cell stimulation and overall vaccine efficacy. We found that DC with phagocytosis of MCA/HSP in the early phase of apoptosis expressed more peptide-major histocompatibility class (pMHC) I complexes, stimulated stronger cytotoxic T lymphocytes (CTL) responses and induced greater immune protection against MCA tumor cell challenge, compared to mice immunized with DC that phagocytosed MCA/HSP cells in the late phase of apoptosis. Taken together, our data demonstrated that HSP70 expression on apoptotic tumor cells stimulated DC maturation and DC with phagocytosis of apoptotic tumor cells expressing HSP70 in early phase of apoptosis more efficiently induced tumor-specific CTL responses and immunity than DC with phagocytosis of apoptotic tumor cells in late phase of apoptosis. Overall, we have examined variations in designing DC-based cancer vaccines in two completely different model systems. Taken together, our results may have an important impact in designing DC-based antitumor vaccines
The "Lord Cooke Project": Reviewing Lord Cooke's Extrajudicial Writing
This note discusses key themes arising from Lord Cooke's published extrajudicial writing. These themes cover Lord Cooke's conception of the common law, the interpretation of the Treaty of Waitangi, the development of bill of rights jurisprudence in New Zealand and overseas, and the role of judges. This note arises out of the authors' involvement in the Lord Cooke project, a Victoria University of Wellington initiative that will make a complete collection of Lord Cooke's extrajudicial writings available online
Interactions Of Dimethylbenz(c)acridines And Polycyclic Hydrocarbons With Dna And Their Effects On Its Template Activity
Strictly local Union-Find
Fault-tolerant quantum computing requires classical hardware to perform the
decoding necessary for error correction. The Union-Find decoder is one of the
best candidates for this. It has remarkably organic characteristics, involving
the growth and merger of data structures through nearest-neighbour steps; this
naturally suggests the possibility of realising Union-Find using a lattice of
very simple processors with strictly nearest-neighbour links. In this way the
computational load can be distributed with near-ideal parallelism. Here we
build on earlier work to show for the first time that this strict (rather than
partial) locality is practical, with a worst-case runtime and
mean runtime subquadratic in where is the surface code distance. A
novel parity-calculation scheme is employed, which can also simplify previously
proposed architectures. We compare our strictly local realisation with one
augmented by long-range links; while the latter is of course faster, we note
that local asynchronous logic could largely negate the difference.Comment: 15 pages, 12 figure
- …