PURPOSE This work is a preliminary study of a stationary cardiac SPECT system. The goal of this research is to propose a stationary cardiac SPECT system using segmented slant-hole collimators and to perform computer simulations to test the feasibility. Compared to the rotational SPECT, a stationary system has a benefit of acquiring temporally consistent projections. The most challenging issue i...

One of the most basic tools in the theory of automorphic forms is the truncation operator, first defined in [Langlands: 1966] but elaborated in later work of Jim Arthur (particularly [Arthur: 1978] and [Arthur: 1980]). In spite of its fundamental nature, there are many mysteries about it. In this article I’ll not dispel many of these, but I’ll at least motivate its definition by relating it to ...

Nerve growth factor (NGF) induces neurite outgrowth and differentiation in a process that involves NGF binding to its receptor TrkA and endocytosis of the NGF-TrkA complex into signaling endosomes. Here, we find that biogenesis of signaling endosomes requires inactivation of Rab5 to block early endosome fusion. Expression of dominant-negative Rab5 mutants enhanced NGF-mediated neurite outgrowth...

We present a numerical method which accurately computes the discrete spectrum and associated bound states of semi-infinite Hamiltonians model electronic “edge” localized at boundaries one- two-dimensional crystalline materials. The problem is nontrivial since arbitrarily large finite “hard” (Dirichlet) truncations Hamiltonian in infinite bulk direction tend to produce spurious partially support...

Abstract A scattering plate consisting of multiple lead strips is an effective tool for scatter correction and dose reduction in cone-beam CT(CBCT). Existing methods take advantage data redundancy by partially blocking cone beam from a single scan to make up perform correction. However, geometric objects with large angles during CBCT scans, existing backprojection-filteration(BPF) algorithms ca...

kernel density estimators are the basic tools for density estimation in non-parametric statistics.  the k-nearest neighbor kernel estimators represent a special form of kernel density estimators, in  which  the  bandwidth  is varied depending on the location of the sample points. in this paper‎, we  initially introduce the k-nearest neighbor kernel density estimator in the random left-truncatio...

In this paper, we introduce a new concept of volumes difference function of the projection and intersection bodies. Following this, we establish the Minkowski and Brunn-Minkowski inequalities for volumes difference function of the projection and intersection bodies.

Transmission scans are an important part of the process of obtaining patient attenuation maps for accurate SPECT (single photon emission computed tomography) imaging. In order to avoid truncation of the projection data, asymmetric cone-beam imaging geometries were investigated. By using the BeaconTM SPECT system, it was shown that in the acquisition process transmission and emission imaging geo...

In this article, we propose an adaptive grid based on mesh equidistribution principle for two-parameter convection-diffusion boundary value problems with continuous and discontinuous data. A numerical algorithm based on an upwind finite difference operator and an appropriate adaptive grid is constructed. Truncation errors are derived for both continuous and discontinuous problems. Parameter uni...

We consider experimental design for the prediction of a realization of a second-order random field Z with known covariance function, or kernel, K. When the mean of Z is known, the integrated mean squared error of the best linear predictor, approximated by spectral truncation, coincides with that obtained with a Bayesian linear model. The machinery of approximate design theory is then available ...