Clinical and radiographic observation of the periodontium in patients undergoing orthodontic therapy: first twenty-seven months

Thesis (MSD) --Boston University (Periodontics).Includes bibliographic references: leaves 84-89.Twenty-two male patients from 12-14 years of age were selected prior to active orthodontic therapy at Boston University School of Graduate Dentistry's Departmant of Orthodontics. These patients were projected to undergo full-banded orthodontic treatnent. The objective of this investigation was designed as a long tenn project to document the quantitative and qualitative changes occurring in the periodontium during and following orthodontic therapy. The patients were examined for the first 9 month period by Dr. Stuart Sears and Dr. Sergio Tejedor-Leon. Relocation of two families reduced the number of patients to twenty which were examined for the second 9 nonth period by Dr. Robert E. Roe and Dr. Robert P. Rubins. [TRUNCATED

GOVERNMENT REVENUES AND EXPENDITURES IN GUINEA-BISSAU: CAUSALITY AND COINTEGRATION

The paper establishes empirically the temporal causality and long run relationship between government expenditures and government revenues for the case of Guinea-Bissau - a low income country under stress (LICUS) in Africa. A macroeconomic model is developed to lay out the hypothesis of a spend-tax behavior in the country¡¯s public finances management system. Empirical validation is carried out by means of a traditional Granger-causality test and the estimation of an error correction model between expenditures and revenues.Public Finances, Causality Tests, Cointegration Analysis

The Political Control of Bureaucracies under Asymmetric Information

We analyze a model of interest group influence where this influence arises from a group's ability to provide relevant information to political actors about regulatory performance. The model rests on three premises: (I) bureaucrats possess an informational advantage, vis-à-vis their political overseers, concerning policy relevant variables; (2) this informational advantage is potentially exploitable by the agency; and (3) politicians anticipate this exploitation and adapt to it in their design of agencies. We show that a major consequence of this anticipation and adaptation is service to organized interest groups

Classical Physics and Quantum Loops

The standard picture of the loop expansion associates a factor of h-bar with each loop, suggesting that the tree diagrams are to be associated with classical physics, while loop effects are quantum mechanical in nature. We discuss examples wherein classical effects arise from loop contributions and display the relationship between the classical terms and the long range effects of massless particles.Comment: 15 pages, 3 figure

A ring trap for ultracold atoms

We propose a new kind of toroidal trap, designed for ultracold atoms. It relies on a combination of a magnetic trap for rf-dressed atoms, which creates a bubble-like trap, and a standing wave of light. This new trap is well suited for investigating questions of low dimensionality in a ring potential. We study the trap characteristics for a set of experimentally accessible parameters. A loading procedure from a conventional magnetic trap is also proposed. The flexible nature of this new ring trap, including an adjustable radius and adjustable transverse oscillation frequencies, will allow the study of superfluidity in variable geometries and dimensionalities.Comment: 4 figures, 10 pages ; the order of the sections has been changed ; to appear in Phys. Rev.

Self-pulsation at 480 GHz from a two-color discrete mode laser diode

A discrete mode Fabry-Pérot laser is designed and fabricated to achieve two-color lasing. We demonstrate beating between the two laser modes and self-pulsation at 480 GHz