Distributed computing system with dual independent communications paths between computers and employing split tokens

This is a distributed computing system providing flexible fault tolerance; ease of software design and concurrency specification; and dynamic balance of the loads. The system comprises a plurality of computers each having a first input/output interface and a second input/output interface for interfacing to communications networks each second input/output interface including a bypass for bypassing the associated computer. A global communications network interconnects the first input/output interfaces for providing each computer the ability to broadcast messages simultaneously to the remainder of the computers. A meshwork communications network interconnects the second input/output interfaces providing each computer with the ability to establish a communications link with another of the computers bypassing the remainder of computers. Each computer is controlled by a resident copy of a common operating system. Communications between respective ones of computers is by means of split tokens each having a moving first portion which is sent from computer to computer and a resident second portion which is disposed in the memory of at least one of computer and wherein the location of the second portion is part of the first portion. The split tokens represent both functions to be executed by the computers and data to be employed in the execution of the functions. The first input/output interfaces each include logic for detecting a collision between messages and for terminating the broadcasting of a message whereby collisions between messages are detected and avoided

Using a Grid-Enabled Wireless Sensor Network for Flood Management

Flooding is becoming an increasing problem. As a result there is a need to deploy more sophisticated sensor networks to detect and react to flooding. This paper outlines a demonstration that illustrates our proposed solution to this problem involving embedded wireless hardware, component based middleware and overlay networks

Abundant and equipotent founder cells establish and maintain acute lymphoblastic leukaemia

High frequencies of blasts in primary acute lymphoblastic leukaemia (ALL) samples have the potential to induce leukaemia and to engraft mice. However, it is unclear how individual ALL cells each contribute to drive leukaemic development in a bulk transplant and the extent to which these blasts vary functionally. We used cellular barcoding as a fate mapping tool to track primograft ALL blasts in vivo. Our results show that high numbers of ALL founder cells contribute at similar frequencies to leukaemic propagation over serial transplants, without any clear evidence of clonal succession. These founder cells also exhibit equal capacity to home and engraft to different organs, although stochastic processes may alter the composition in restrictive niches. Our findings enhance the stochastic stem cell model of ALL by demonstrating equal functional abilities of singular ALL blasts and show that successful treatment strategies must eradicate the entire leukaemic cell population

On transversally elliptic operators and the quantization of manifolds with ff-structure

An $f$-structure on a manifold $M$ is an endomorphism field \phi\in\Gamma(M,\End(TM)) such that $\phi^3+\phi=0$. Any $f$-structure $\phi$ determines an almost CR structure E_{1,0}\subset T_\C M given by the $+i$-eigenbundle of $\phi$. Using a compatible metric $g$ and connection $\nabla$ on $M$, we construct an odd first-order differential operator $D$, acting on sections of $\S=\Lambda E_{0,1}^*$, whose principal symbol is of the type considered in arXiv:0810.0338. In the special case of a CR-integrable almost $\S$-structure, we show that when $\nabla$ is the generalized Tanaka-Webster connection of Lotta and Pastore, the operator $D$ is given by D = \sqrt{2}(\dbbar+\dbbar^*), where \dbbar is the tangential Cauchy-Riemann operator. We then describe two "quantizations" of manifolds with $f$-structure that reduce to familiar methods in symplectic geometry in the case that $\phi$ is a compatible almost complex structure, and to the contact quantization defined in \cite{F4} when $\phi$ comes from a contact metric structure. The first is an index-theoretic approach involving the operator $D$; for certain group actions $D$ will be transversally elliptic, and using the results in arXiv:0810.0338, we can give a Riemann-Roch type formula for its index. The second approach uses an analogue of the polarized sections of a prequantum line bundle, with a CR structure playing the role of a complex polarization.Comment: 31 page

The Disproportionate Costs of Forming LLCs VS. Corporations: The Impact on Small Firm Liability Protection

The LLC is increasingly the ownership form of choice by nascent small business owners as it has some advantages over corporations and sole proprietorships and partnerships. Despite its advantages, some states have higher filing fees for LLCs than for corporations. Some states have significantly higher filing fees than other states for both LLCs and corporations. As a result, emerging companies are often discouraged from seeking liability protection, or they seek a corporation, reducing the flexibility that could be provided with an LLC. Our research shows that the disproportionate cost of starting an LLC is related to the percentage of LLCs formed in comparison with corporations. This can have significant implications to small business owners since they may be choosing ownership forms that are not advantageous to their particular venture strictly based on initial filing costs. These state policy decisions may lead to long-term tax revenue loss within states with higher filing fees

On certain surfaces in the Euclidean space E3{\mathbb{E}}^3

In the present paper we classify all surfaces in \E^3 with a canonical principal direction. Examples of these type of surfaces are constructed. We prove that the only minimal surface with a canonical principal direction in the Euclidean space ${\mathbb{E}}^3$ is the catenoid.Comment: 13 Latex page

Underwater Acoustic Imaging: One-bit Digitisation

In underwater acoustic imaging (UAI), the combination of a two-dimensional (2-D) array and replicate correlation can produce 3-D images, typically of objects at a range of 2 m. A system already developed achieves the high data acquisition rate needed through one-bit sampling (sensing only the sign of the received signal). Noise added before the one-bit sampling avoids the production of 'ghosts' in the image. By simulation and mathematical analysis, the effects of one-bit and added noise are studied for a chirp signal, with a restriction so far to 1-D images (image amplitude versus range). Conditions are given for the avoidance of ghosts and the minimisation of 'image noise' - noise in the image due to one-bit and added noise. A model of image noise is proposed, which is corroborated by the tests carried out to date. A general formula for the root-mean-square image noise is obtained. It has previously been suggested that filtering the singal after sampling would improve the image. However, it is shown that filtering is unnecessary and indeed makes the image worse. It is shown that a strong target can suppress evidence of a weak target because, when the strength of the return signal is raised, essentially the amplitude of the added noise must be raised to avoid 'ghosts'. A general formula, giving the ratio of target strengths such that the weak target has a 50% probability of detection, is obtained

Beam Profile Measurements and Simulations of the PETRA Laser-Wire

The Laser-wire will be an essential diagnostic tool at the International Linear Collider. It uses a finely focussed laser beam to measure the transverse profile of electron bunches by detecting the Compton-scattered photons (or degraded electrons) downstream of where the laser beam intersects the electron beam. Such a system has been installed at the PETRA storage ring at DESY, which uses a piezo-driven mirror to scan the laser-light across the electron beam. Lat- est results of experimental data taking are presented and compared to detailed simulations using the Geant4 based program BDSIM.Comment: 3 pagesm 4 figures. Submitted as a conference paper for the Particle Accelerator Conference 2005 (PAC05