Evidence for changes in the radiative efficiency of transient black hole X-ray binaries

We have used pointed RXTE data to examine the long-term X-ray light curves of six transient black hole X-ray binaries during their decay from outburst to quiescence. In most cases there is a period of exponential decay as the source approaches the soft-to-hard state transition, and another period of exponential decay following this transition as the source decays in the hard state. The e-folding times change around the time of the state transition, from typically approx 12 days at the end of the soft state to approx 7 days at the beginning of the hard state. This factor ~2 change in the decay timescale is expected if there is a change from radiatively efficient emission in the soft state to radiatively inefficient emission in the hard state, overlying an exponential decay in the mass accretion rate. This adds support to the idea that the X-ray emitting region is governed by radiatively inefficient accretion (such as an advection-dominated or jet-dominated accretion flow) during the fading hard state.Comment: 9 pages, 18 figures, accepted for publication in MNRAS, minor changes following proo

APPR Teacher Appeals Process Report

[Excerpt] The Annual Professional Performance Review (APPR) is the new teacher evaluation system adopted by New York State in 2012. Through APPR, each New York State teacher’s performance is evaluated annually. If a teacher is rated Ineffective, he or she must take part in a Teacher Improvement Plan (TIP). If a teacher is rated Ineffective for two consecutive years, the teacher may be dismissed even if that teacher has tenure. Given these potential consequences, the ability to appeal APPR ratings and how those ratings are conducted has been a major issue for teachers and their unions. Under New York Education Law 3012-c, which establishes APPR, each school district negotiates its own APPR procedure with its local teachers union, including any procedures for appealing the performance review. This report examines the APPR appeals procedures established by school districts in order to investigate the following: Which aspects of the APPR process can teachers appeal? Who has the fi nal say in that appeals process? How much time do appeals processes take? Can teachers appeal APPR issues through the regular contractual grievance-arbitration procedure? This report addresses these questions by analyzing APPR appeal procedures for all New York State school districts. The data analyzed was gathered by coding the provisions of the APPR appeal procedures, which are publicly available on the New York State Department of Education website (1)

Mesiodens preventing eruption of a permanent central incisor

A maxillary midline supernumerary tooth is the most common type of supernumerary tooth. We present a case of a mesiodens, preventing eruption of a permanent central incisor. The aetiology, diagnosis and the effect of these developmental anomalies upon the dentition are discussed.peer-reviewe

The Analytic Theory of Matrix Orthogonal Polynomials

We give a survey of the analytic theory of matrix orthogonal polynomials.Comment: 85 page