Daniel Hall

We report measurements of the de Haas-van Alphen effect on a series of compounds, LaMIn5. The results show that each of the Co and Ir Fermi surfaces exhibits some portions that are two dimensional and some portions that are three dimensional. The most two-dimensional character is exhibited in LaCoIn5, less two-dimensional behavior is seen in LaIrIn5, and no part of Fermi surface of LaRhIn5 is found to have a two-dimensional character. Thus the two dimensionality of portions of the FSs is largely determined by the d character of the energy bands while all of the effective masses remain ≤1.2. This fact has implications for the causes of the heavy fermion nature of superconductivity and magnetism in the Ce-based compounds having similar composition and structure. © 2009 The American Physical Society.

The results of a de Haas-van Alphen study on the alloy series Ce xLa 1-xMIn 5, with M = Co, Rh, or Ir, are presented. It was suggested that 4f-electron localization is the primary driving factor for quantum criticality in the p, M phase diagram of Ce compounds. The close correspondence between ferromagnetism and f-electron localization were suggested to be similar to that observed between ferromagnetism and f-electron localization reported in systems such as CeRu 2Si 2. Fermi-liquid state to form for any x in the case of M = Rh was found to be inconsistent with theoretical models that propose antiferromagnetism to result from spin-density-wave formation.

Alisdair MacIntyre argues that the virtues necessary for good work are everywhere and always embodied by particular communities of practice. As a general surgeon, MacIntyre’s work has deeply influenced my own understanding of the practice of good surgery. The task of this essay is to describe how the guild of surgeons functions as a more-or-less coherent tradition of moral enquiry, embodying and transmitting the virtues necessary for the practice of good surgery. Beginning with an example of surgeons engaged in a process of moral discernment, I describe how the practice of surgery depends on the cultivation of a certain kind of practical wisdom (phronesis) that effectively orders the techniques of surgery toward particular notions of human flourishing within the limits of what is possible with the particular body on which the surgeon operates. I then argue that one reason why surgeons train in an apprenticeship model of "residency" is to cultivate not only the technical skill but also the practical wisdom to perform good surgery. I conclude by noting that the surgical profession is enduring necessary, but unprecedented, changes in the way it practices and transmits its art; and without deliberate and sustained attention to the character formation of surgeons, the profession runs the risk of creating excellent technicians who are nonetheless ill-equipped to practice wise and good surgery