Induced matter: Curved N-manifolds encapsulated in Riemann-flat N+1 dimensional space

Liko and Wesson have recently introduced a new 5-dimensional induced matter solution of the Einstein equations, a negative curvature Robertson-Walker space embedded in a Riemann flat 5-dimensional manifold. We show that this solution is a special case of a more general theorem prescribing the structure of certain N+1-dimensional Riemann flat spaces which are all solutions of the Einstein equations. These solutions encapsulate N-dimensional curved manifolds. Such spaces are said to "induce matter" in the sub-manifolds by virtue of their geometric structure alone. We prove that the N-manifold can be any maximally symmetric space.Comment: 3 page

BRAVO economic study of LANDSAT follow-on

The LANDSAT Follow-On satellite consists of two major systems: the instrument module and the Multi-Mission Modular Spacecraft (MMS). The instrument module contains the thematic mapper and the five-band multispectral scanner instruments. The instrument module also includes the solar array, the tracking and data relay satellite (TDRS) antenna, and the wideband data module. The MMS contains the modularized and standardized power, propulsion, attitude control, and command and data handling subsystems. The Shuttle will be supporting the LANDSAT Follow-On system. The LANDSAT Follow-On Project plans two Delta 3910 launches. The first is scheduled for 1981; the second Delta launch will occur as needed to keep one satellite operational on orbit. The second satellite will be ready six months after the first. It could be launched any time after that. Shuttle support of the system could begin in early 1983 but would be scheduled to start after the second Delta launch

Notes on dairy bacteriology.

It is a well known fact that milk varies greatly in quality. Some of it will make butter of the highest quality, some again, owing to injurious organisms, will not make prime butter. The injurious fermentations are much worse at times than at others. Milk as it is received at the creamery, is often “off” in odor. It is, therefore, desirable to know what patron is responsible for this tainted milk. It was supposed by patrons that these odors had their origin in weeds, etc. Some years ago Mr. Monrad gave, at one of the meetings of the Iowa State Dairy Association, a simple test for detecting these odors which is largely used in European dairies. Samples of milk from different patrons are placed in glass tubes and then allowed to stand for a day or less, in a warm place to allow the bacteria to develop. The odors and gaseous fermentations may easily be detected

The chemical composition of food preservatives. Solutions for testing cream and milk.

There are many substances which are found on the market at the present time intended for preserving food products under various brands and names. The claims made for these substances by the manufacturers would lead one to believe that the brand of substance for which the claim is made possessed a wonderful power for preserving food products. When these mixtures are examined it is found that they are composed of common substances and such that any one could readily prepare for a small part of the price charged for them. In the development of the dairy industry from the farm dairy to the creamery, it has been found that the processes connected with the industry must be controlled in an intelligent manner in order that success may resul

Explorations, Vol. 1, No. 2

The cover print is a multi-plate colored etching entitled Skull and Sun Dial, by Susan Groce, Associate Professor of Art at the University of Maine at Orono, where she teaches Printmaking and Drawing. Articles include: The Quaternary Ice Age Plants and Animals: Secrets of the Colorado Plateau, by Jim I. Mead and Emilee M. Mead Finding the Facts: Pieces of the Puzzle On Location: In Search of the First Americans A Temporal Vegetational Continuum: From Tundra to Forest, by Carole J. Bombard for Ronald B. Davis Anatomy of an Excavation, by Robson Bonnichsen What the Bones Tell Us, by Marcella H. Sorg People of the Americas Publication Program, by Emilee M. Mea

Modelling and simulation of biased agonism dynamics at a G protein-coupled receptor.

Theoretical models of G protein-coupled receptor (GPCR) concentration-response relationships often assume an agonist producing a single functional response via a single active state of the receptor. These models have largely been analysed assuming steady-state conditions. There is now much experimental evidence to suggest that many GPCRs can exist in multiple receptor conformations and elicit numerous functional responses, with ligands having the potential to activate different signalling pathways to varying extents-a concept referred to as biased agonism, functional selectivity or pluri-dimensional efficacy. Moreover, recent experimental results indicate a clear possibility for time-dependent bias, whereby an agonist's bias with respect to different pathways may vary dynamically. Efforts towards understanding the implications of temporal bias by characterising and quantifying ligand effects on multiple pathways will clearly be aided by extending current equilibrium binding and biased activation models to include G protein activation dynamics. Here, we present a new model of time-dependent biased agonism, based on ordinary differential equations for multiple cubic ternary complex activation models with G protein cycle dynamics. This model allows simulation and analysis of multi-pathway activation bias dynamics at a single receptor for the first time, at the level of active G protein (αGTP), towards the analysis of dynamic functional responses. The model is generally applicable to systems with NG G proteins and N* active receptor states. Numerical simulations for NG=N*=2 reveal new insights into the effects of system parameters (including cooperativities, and ligand and receptor concentrations) on bias dynamics, highlighting new phenomena including the dynamic inter-conversion of bias direction. Further, we fit this model to 'wet' experimental data for two competing G proteins (Gi and Gs) that become activated upon stimulation of the adenosine A1 receptor with adenosine derivative compounds. Finally, we show that our model can qualitatively describe the temporal dynamics of this competing G protein activation

Searching for degeneracies of real Hamiltonians using homotopy classification of loops in SO(nn)

Topological tests to detect degeneracies of Hamiltonians have been put forward in the past. Here, we address the applicability of a recently proposed test [Phys. Rev. Lett. {\bf 92}, 060406 (2004)] for degeneracies of real Hamiltonian matrices. This test relies on the existence of nontrivial loops in the space of eigenbases SO$(n)$. We develop necessary means to determine the homotopy class of a given loop in this space. Furthermore, in cases where the dimension of the relevant Hilbert space is large the application of the original test may not be immediate. To remedy this deficiency, we put forward a condition for when the test is applicable to a subspace of Hilbert space. Finally, we demonstrate that applying the methodology of [Phys. Rev. Lett. {\bf 92}, 060406 (2004)] to the complex Hamiltonian case does not provide any new information.Comment: Minor changes, journal reference adde

Lyapunov exponent and natural invariant density determination of chaotic maps: An iterative maximum entropy ansatz

We apply the maximum entropy principle to construct the natural invariant density and Lyapunov exponent of one-dimensional chaotic maps. Using a novel function reconstruction technique that is based on the solution of Hausdorff moment problem via maximizing Shannon entropy, we estimate the invariant density and the Lyapunov exponent of nonlinear maps in one-dimension from a knowledge of finite number of moments. The accuracy and the stability of the algorithm are illustrated by comparing our results to a number of nonlinear maps for which the exact analytical results are available. Furthermore, we also consider a very complex example for which no exact analytical result for invariant density is available. A comparison of our results to those available in the literature is also discussed.Comment: 16 pages including 6 figure

The Quantum Adiabatic Approximation and the Geometric Phase

A precise definition of an adiabaticity parameter $\nu$ of a time-dependent Hamiltonian is proposed. A variation of the time-dependent perturbation theory is presented which yields a series expansion of the evolution operator $U(\tau)=\sum_\ell U^{(\ell)}(\tau)$ with $U^{(\ell)}(\tau)$ being at least of the order $\nu^\ell$. In particular $U^{(0)}(\tau)$ corresponds to the adiabatic approximation and yields Berry's adiabatic phase. It is shown that this series expansion has nothing to do with the $1/\tau$-expansion of $U(\tau)$. It is also shown that the non-adiabatic part of the evolution operator is generated by a transformed Hamiltonian which is off-diagonal in the eigenbasis of the initial Hamiltonian. Some related issues concerning the geometric phase are also discussed.Comment: uuencoded LaTeX file, 19 page