A brief overview of surgery for atrial fibrillation

The Maze procedure was the first surgical technique developed to ablate, rather than isolate, atrial fibrillation and was first performed clinically in 1987. The experimental and clinical electrophysiological maps on which the Maze procedure was based demonstrated the presence of two or more large (5-6 cm diameter) macro-reentrant circuits during established atrial fibrillation (AF). Eleven years later, focal triggers were identified, primarily in and around the pulmonary veins, and were shown to be responsible for the induction of individual episodes of AF. Thus, it became clear that episodes of paroxysmal AF could be treated in most patients by isolating or ablating the region of the pulmonary veins, but that once AF became non-paroxysmal and thus dependent upon the macro-reentrant circuits for its maintenance, it would still be necessary to perform some type of additional procedure to interrupt those circuits. Approximately 100,000 patients who undergo coronary artery bypass grafting (CABG), aortic valve replacement (AVR) or mitral valve surgery in the US also have associated AF, but only 20% of them undergo a concomitant procedure to ablate the AF. However, multiple studies have demonstrated that treating the AF at the time of these other primary operations results in an improved quality of life, fewer long-term strokes and improved long-term survival while adding no risk to the overall surgical procedure. Moreover, the major cardiology and surgery societies recommend that concomitant AF surgery be performed in all cases when feasible. Patients undergoing CABG and AVR who have paroxysmal AF should undergo pulmonary vein isolation, while those with non-paroxysmal AF (persistent or long-standing persistent AF) should have a Maze procedure. Patients undergoing mitral valve surgery who have either paroxysmal AF or non-paroxysmal AF should undergo a Maze procedure

An Analysis of the Payback Potential of New Lighting Technology

Recent, energy saving improvements in lighting technology have been made involving the use of more efficient lamps, silver coated light reflectors, and electronic light ballasts. Research indicates that it is economically feasible to retrofit existing light fixtures to utilize the advantages of these developments. This process consists of the removal of all standard lamps and ballasts in each light fixture, the installation of a highly refined light reflector and the replacement of the existing lamps with brighter, more efficient ones. Standard magnetic ballasts are exchanged for more efficient electronic ballasts. Resulting is a light fixture that produces a comparable amount of light, generates less heat, and uses much less energy than regular light fixtures. The purpose of this study was to define the cost-versus-savings involved with this type of retrofit as applied to the Westville School District. The district\u27s light fixtures were counted and utility costs were determined for both present, and retrofitted lighting. This study found that a retrofit of this type would be cost effective for the district

An Analysis of the Payback Potential of New Lighting Technology

Recent, energy saving improvements in lighting technology have been made involving the use of more efficient lamps, silver coated light reflectors, and electronic light ballasts. Research indicates that it is economically feasible to retrofit existing light fixtures to utilize the advantages of these developments. This process consists of the removal of all standard lamps and ballasts in each light fixture, the installation of a highly refined light reflector and the replacement of the existing lamps with brighter, more efficient ones. Standard magnetic ballasts are exchanged for more efficient electronic ballasts. Resulting is a light fixture that produces a comparable amount of light, generates less heat, and uses much less energy than regular light fixtures. The purpose of this study was to define the cost-versus-savings involved with this type of retrofit as applied to the Westville School District. The district\u27s light fixtures were counted and utility costs were determined for both present, and retrofitted lighting. This study found that a retrofit of this type would be cost effective for the district

Researching religious communities in the twenty-first century : the phenomenology of religion, local agency and the joint ownership of knowledge

The phenomenology of religion increasingly is being criticized as outdated. This chapter argues that phenomenology retains relevance to contemporary research methods, as illustrated by two differing projects in Australia on the repatriation of Indigenous knowledge. After presenting these cases, they are analyzed in light of the contrasting arguments of the phenomenologist Wilfred Cantwell Smith and the philosopher Wayne Proudfoot about the influence of believers on research findings. The chapter concludes that the phenomenological method, when re-configured in terms of relationality, local agency and the joint ownership of knowledge, can play a decisive role in determining future directions in religious studies

What makes an experience 'religious'? : the necessity of defining religion

In this paper, I build on Peggy Morgan’s work on religious experience by arguing that in order to identify experiences that qualify as ‘religious’, we first must know what we mean by ‘religion’. Building on my prior writings in which I define religion non-theologically, I suggest that religious experience has no necessary connection to encounters with postulated supernatural or divine entities. Rather, religion results from how authoritative traditions mould individual or group behaviour. This contention results from defining religion as limited to three necessary conditions: identifiable communities (whether explicitly or implicitly comprised), authority and tradition. I compare this application of religion to religious experience with that formulated by Ann Taves, who defines religion as that which people ‘deem religious’ and religious experience as reflecting encounters with ‘specialness’. I argue that Taves’s use of religion and religious experience proposes a theory incorporating unreflective, common sense understandings that inadvertently suppress critical thinking. By defining religion in socio-cultural terms, I have distanced the academic study of religious experience from theological or quasi-theological assumptions and established it firmly within the social sciences