Semicrossed products of the disk algebra and the Jacobson radical

We consider semicrossed products of the disk algebra with respect to endomorphisms defined by finite Blaschke products. We characterize the Jacobson radical of these operator algebras. Furthermore, in the case the finite Blaschke product is elliptic, we show that the semicrossed product contains no nonzero quasinilpotent elements. However, if the finite Blaschke product is hyperbolic or parabolic with zero hyperbolic step, the Jacobson radical is nonzero and a proper subset of the set of quasinilpotent elements.Comment: 12 page

Gaseous Air Pollutants and Hospitalization for Respiratory Disease in the Neonatal Period

OBJECTIVE: Current levels of ambient air pollution are associated with morbidity and mortality in the general population. To determine the influence of gaseous air pollutants on neonatal respiratory morbidity, we tested the association between daily respiratory hospitalizations and daily concentrations of ambient air pollution gases: ozone, carbon monoxide, sulfur dioxide, and nitrogen dioxide, in 11 large Canadian cities. STUDY DESIGN: Daily time-series analyses were employed and results were adjusted for day of the week, temperature, barometric pressure, and relative humidity. RESULTS: The percent increases in hospitalization associated with an increase in air pollution equivalent to its interquartile range were 3.35 [95% confidence interval (CI), 1.73–4.77] for O(3), 2.85 (95% CI, 1.68–4.02) for NO(2), 1.66 (95% CI, 0.63–2.69) for SO(2), and 1.75 (95% CI, 0.48–3.02) for CO. The independent effect of all pollutants combined was 9.61% (95% CI, 4.52–14.7%). CONCLUSION: Our results suggest that neonates are experiencing adverse effects of air pollution at current levels in Canada, and that accounts for a significant proportion of hospitalizations in this subgroup

An analysis of Australia's carbon pollution reduction scheme

The authors review the decision-making since the Labour Government came into office (November 2007). The Australian Government’s ‘Carbon Pollution Reduction Scheme’ White Paper (15 December 2008) proposes that an Australian Emissions Trading Scheme (AETS) be implemented in mid-2010. Acknowledging that the scheme is comprehensive, the paper finds that in many cases, Australia will take a softer approach to climate change through the AETS than the European Union ETS(EUETS). The paper assesses key issues in the White Paper such as emissions reduction targets, GHG coverage, sectoral coverage, inclusion of unlimited quantities of offsets from Kyoto international markets and exclusion of deforestation activities

Amenability of algebras of approximable operators

We give a necessary and sufficient condition for amenability of the Banach algebra of approximable operators on a Banach space. We further investigate the relationship between amenability of this algebra and factorization of operators, strengthening known results and developing new techniques to determine whether or not a given Banach space carries an amenable algebra of approximable operators. Using these techniques, we are able to show, among other things, the non-amenability of the algebra of approximable operators on Tsirelson's space.Comment: 20 pages, to appear in Israel Journal of Mathematic

Campus Mental Health: Implications for Instructors Supporting Students

The recent escalation in student suicides due to mental health problems has encouraged higher education institutions to not only modify their overall support structures, but to also (re)define the role of faculty and staff. Despite the increased attention given to student mental health in Canadian higher education institutions, little is known and understood about how instructors view their role as supporters or promoters of student mental health. The purpose of this study was to explore the role of college instructors in supporting students with mental health problems or illnesses. Participants were 42 instructors between the ages of 25 to 64 from Molize College in Toronto, Ontario. Qualitative ethnography was employed to gather data from participants, specifically through a survey questionnaire and interviews. A constructivist framework was adopted to analyze and understand the values, perceptions, meanings, and practices post-secondary instructors carry around notions of student mental health and intervention. Findings revealed that instructors were generally aware of student mental health concerns in post-secondary institutions, but that greater awareness was still warranted, namely in the areas of instructor mental health and location of support services. Findings also demonstrated that most instructors evaluated their knowledge and confidence in relation to student mental health as poor, which was often credited to limited relevant professional development and training. Additionally, data indicated that instructors carried skepticism towards the role of some student support services departments, as well as towards their own role when supporting the mental health and well-being of students. On a final note, findings revealed that instructors commonly employed four practices to support the mental health and well-being of students: conversation, referral, accommodations, and curricular inclusion and instruction. Future studies are encouraged to acknowledge the narratives of instructors through ethnographic inquiry, to allow for greater insights into their awareness, knowledge/confidence, responsibilities, and practices when it comes to supporting the mental health and well-being of students in higher education settings. Incorporating the instructor may not be a panacea for the shortcomings of current mental health policies and practices in higher education settings, but it can certainly represent a colossal step in that direction. KEYWORDS: student mental health, higher education, instructor

How UK climate change policy has been made sustainable

UK climate change policy is based on the advice of the Committee on Climate Change established under the Climate Change Act 2008. This Committee is an independent, expert agency established as part of the reconceiving of the regulatory state as a response to the neo-liberal critique of older forms of regulation. But the quality of the advice given in the Committee’s recent Fourth Carbon Budget Review is so tendentious as to barely be able to be described as advice at all. This grave shortcoming poses the most serious questions for contemporary constitutional and regulatory processes

Stabilising Lyme Regis – a strategic approach

Coastal erosion and landslides have been a constant threat to Lyme Regis in West Dorset, UK for over 250 years. By the 1980s, the frequency and scale of coastal erosion and land instability had reached a point whereby the local council realised that a change from the previous ad hoc repair and protection approach was needed to secure the long-term future of the town. An environmental improvements initiative was developed from then onwards to provide a strategic and integrated programme of coast protection and cliff stabilisation measures designed to mitigate the increasing threat of climate change, coastal erosion and landslides, while respecting the site’s unique heritage and environmental interests. This paper outlines the background and principal phases of the project that have been successfully delivered over the period 1990–2015

A magnetic shield/dual purpose mission

The objective of this work is to design, build, and fly a dual-purpose payload whose function is to produce a large volume, low intensity magnetic field and to test the concept of using such a magnetic field to protect manned spacecraft against particle radiation. An additional mission objective is to study the effect of this moving field on upper atmosphere plasmas. Both mission objectives appear to be capable of being tested using the same superconducting coil. The potential benefits of this magnetic shield concept apply directly to both earth-orbital and interplanetary missions. This payload would be a first step in assessing the true potential of large volume magnetic fields in the U.S. space program. Either converted launch systems or piggyback payload opportunities may be appropriate for this mission. The use of superconducting coils for magnetic shielding against solar flare radiation during manned interplanetary missions has long been contemplated and was considered in detail in the years preceding the Apollo mission. With the advent of new superconductors, it has now become realistic to reconsider this concept for a Mars mission. Even in near-earth orbits, large volume magnetic fields produced using conventional metallic superconductors allow novel plasma physics experiments to be contemplated. Both deployed field-coil and non-deployed field-coil shielding arrangements have been investigated, with the latter being most suitable for an initial test payload in a polar orbit