Booms and Busts: the Burstiness of Star Formation in Nearby Dwarf Galaxies

In this review I summarise recent advances in our understanding of the importance of starburst events to the evolutionary histories of nearby galaxies. Ongoing bursts are easily diagnosed in emission-line surveys, but assessing the timing and intensity of fossil bursts requires more effort, usually demanding color-magnitude diagrams or spectroscopy of individual stars. For ages older than ~1 Gyr, this type of observation is currently limited to the Local Group and its immediate surroundings. However, if the Local Volume is representative of the Universe as a whole, then studies of the age and metallicity distributions of star clusters and resolved stellar populations should give statistical clues as to the frequency and importance of bursts to the histories of galaxies in general. Based on starburst statistics in the literature and synthetic colour-magnitude diagram studies of Local Group galaxies, I attempt to distinguish between systemic starbursts that strongly impact galaxy evolution and stochastic bursts that can appear impressive but are ultimately of little significance on gigayear timescales. As a specific case, it appears as though IC 10, the only starburst galaxy in the Local Group, falls into the latter category and is not fundamentally different from other nearby dwarf irregular galaxies.Comment: Accepted by the Publications of the Astronomical Society of Australia (PASA). Summary of a review talk given at the Southern Cross Astrophysics Conference on "Galaxy Metabolism" held in Sydney, 22-26 June 2009. 9 pages, 2 figure

Behavior of the Escape Rate Function in Hyperbolic Dynamical Systems

For a fixed initial reference measure, we study the dependence of the escape rate on the hole for a smooth or piecewise smooth hyperbolic map. First, we prove the existence and Holder continuity of the escape rate for systems with small holes admitting Young towers. Then we consider general holes for Anosov diffeomorphisms, without size or Markovian restrictions. We prove bounds on the upper and lower escape rates using the notion of pressure on the survivor set and show that a variational principle holds under generic conditions. However, we also show that the escape rate function forms a devil's staircase with jumps along sequences of regular holes and present examples to elucidate some of the difficulties involved in formulating a general theory.Comment: 21 pages. v2 differs from v1 only by additions to the acknowledgment

Alien Registration- Demers, Marie A. (Lewiston, Androscoggin County)

https://digitalmaine.com/alien_docs/29634/thumbnail.jp

Changes in Telecommunications Due to the 1996 Telecommunications Act

Telecommunications has gone through various stages of development since its conception in the late l 800\u27s. The most current event and the basis for this thesis, is the legislation that passed Congress titled the \u27\u27Telecommunications Act of 1996 . It is the purpose of this document to research the impact of this legislation to the user and the businesses involved in this industry. There were three main areas of focus for this research. The first area of study pertained to the current local and long distance companies in the telecommunications industry. The second area related to the users of the telecommunications products and what impact this change could have on them. And finally, the article addressed how this law would expand competition and bring in other industries not normally associated with telecommunications. To undertake this challenge, seventy-eight articles were obtained relating to these three categories. These articles were then sorted with the data classified into the three areas of investigation. This data was then analyzed lo eliminate biases that could impact the decision process to either substantiate or refute the hypothesis. It was hypothesized that deregulation of the telecommunications industry would not create opportunities for companies to expand into the national long distance business. Results of the analysis showed that the competition will be the strongest in the local access arena, and that this is already taking place through mergers and the entry of both utilities and cable television companies into telecommunications. These companies already have a consumer market in a particular region of the country and plan to expand their product lines to include telecommunications. Most of the mergers have been between local access providers merging with other local access providers to concentrate on that business. Based on the study, the hypothesis was supported that alt least initially !he focus will be in the local access markets. The existing long distance companies will have to compete with these providers in regions but not on a national basis. What can also be concluded from this research is that the telecommunications act will in fact create more competition and expand the type of products that will be produced in this new industry

A study to determine the factors involved in the development of students' attitudes toward chemistry and anatomy and physiology.

Thesis (M.S.)--Boston Universit

Kinematic design of a finger abduction mechanism for an anthropomorphic robotic hand

This paper presents the kinematic design of an abduction mechanism for the fingers of an underactuated anthropomorphic robotic hand. This mechanism will enhance the range of feasible grasps of the underactuated hand without significantly increasing its complexity. The analysis of the link between the index finger and the third finger is first assessed, where the parameters are studied in order to follow the amplitude constraint and to minimize the coordination error. Then, the study of the mechanism joining the third finger and the little finger is summarized. Finally, a prototype of the finger's abduction system is presented. <br><br> <i>This paper was presented at the IFToMM/ASME International Workshop on Underactuated Grasping (UG2010), 19 August 2010, Montréal, Canada.</i&gt

Deterministic models of the simplest chemical reactions

We present a general mathematical framework for constructing deterministic models of simple chemical reactions. In such a model, an underlying dynamical system drives a process in which a particle undergoes a reaction (changes color) when it enters a certain subset (the catalytic site) of the phase space and (possibly) some other conditions are satisfied. The framework we suggest allows us to define the entropy of reaction precisely and does not rely, as was the case in previous studies, on a stochastic mechanism to generate additional entropy. Thus our approach provides a natural setting in which to derive macroscopic chemical reaction laws from microscopic deterministic dynamics without invoking any random mechanisms