Lüders and Pauli proved the $\mathcal{CPT}$ theorem based on Lagrangian quantum field theory almost half a century ago. Jost gave a more general proof based on “axiomatic” field theory nearly as long ago. The axiomatic point of view has two advantages over the Lagrangian one. First, the axiomatic point of view makes clear why $\mathcal{CPT}$ is fundamental—because it is intimately related to Lorentz invariance. Secondly, the axiomatic proof gives a simple way to calculate the $\mathcal{CPT}$ transform of any relativistic field (...) without calculating $\mathcal{C}$ , $\mathcal{P}$ and $\mathcal{T}$ separately and then multiplying them. The purpose of this pedagogical paper is to “deaxiomatize” the $\mathcal{CPT}$ theorem by explaining it in a few simple steps. We use theorems of distribution theory and of several complex variables without proof to make the exposition elementary. (shrink)

This paper studies the model of the quantum electrodynamics (QED) of a single nonrelativistic electron due to W. Pauli and M. Fierz and studied further by P. Blanchard. This model exhibits infrared divergence in a very simple context. The infrared divergence is associated with the inequivalence of the Hilbert spaces associated with the free Hamiltonian and with the complete Hamiltonian. Infrared divergences that are visible in the perturbative description disappear in the space of the clothed electrons. In this model when (...) the Hamiltonian is expressed in terms of the “physical” fields that create the electron together with its cloud of soft photons, the variational principle suggested earlier can be applied. At finite time the Heisenberg field of the model acts in the space of the perturbative electron together with a finite number of perturbative photons, while the “physical” field can be chosen to act in the space of the exact (“physical”) electron eigenstates together with a finite number of physical photons. The space of the physical (or clothed) electron states can be chosen to be a Fock space. (shrink)

Quons are particles characterized by the parameter q, which permits smooth interpolation between Bose and Fermi statistics; q = 1 gives bosons, q = -1 gives fermions. In this paper we give a heuristic argument for an extension of conservation of statistics to quons with trilinear couplings of the form ffb, where f is fermion-like and b is boson-like. We show that q f 2 = qb. In particular, we relate the bound on qγ for photons to the bound on (...) qe for electrons, allowing the very precise bound for electrons to be carried over to photons. An extension of this argument suggests that all particles are fermions or bosons to a high precision. (shrink)

A Christian approach to the issues that constitute bioethics is inevitable for us who cherish the truth of historic, creedal, trinitarian Christianity. Scripture teaches and the Greek and Latin Church Fathers as well as the Reformers aver that man, created in the image of God, has an inherent, if vestigial, sense of right and wrong and a conscience however marred by the fall and by rebellion. We must believe that we share this most basic ecumenism with all humanity, not because (...) of rational observation and analysis of nature, but because Scripture reveals it. We who are convinced of the truth of historic, creedal, trinitarian Christianity have a high view of Scripture and hold it to be infallible and utterly trustworthy irrespective of the importance we assign to our specific post-biblical traditional distinctives. This is a narrower but much more vital ecumenism than the first. Faithful adherence to Scripture inevitably manifests itself in remarkably similar priorities and values, often, lamentably, not because of, but in spite of, ourselves. (shrink)

Things and Their Place in Theories Our talk of external things, our very notion of things, is just a conceptual apparatus that helps us to foresee and ...

The present study tested the hypothesis that centrality of religiosity as defined as the position of an individual’s religious construct system in personality moderates the relationship between the experience of forgiveness by God and forgivingness for others. Participants completed measures of forgiveness by God, forgivingness, and centrality of religiosity. The moderating hypothesis was tested by treating centrality of religiosity both as a continuous variable and as a categorical variable with reference to a typological distinction. Results indicate that centrality of religiosity (...) moderates the positive relationship between forgiveness by God and forgivingness for others, implying that this relation only occurs if the religious construct system is in a central position in personality, but not if it is in a subordinate position. These results underline the importance of considering centrality of religiosity as an individual difference variable. (shrink)

The aim of the study was to determine the acceptance and perception of Nigerian patients to medical photography. A self-administered questionnaire was distributed among Nigerian patients attending oral and maxillofacial surgery and plastic surgery clinics of 3 tertiary health institutions. Information requested included patients' opinion about consent process, capturing equipment, distribution and accessibility of medical photographs. The use of non-identifiable medical photographs was more acceptable than identifiable to respondents for all purposes (P = 0.003). Most respondents were favourably disposed to (...) photographs being taken for inclusion in the case note, but opposed to identifiable photographs being used for other purposes most especially in medical websites and medical journals. Female respondents preferred non-identifiable medical photographs to identifiable ones (P = 0.001). Most respondents (78%) indicated that their consent be sought for each of the outline needs for medical photography. Half of the respondents indicated that identifiable photographs may have a negative effect on their persons; and the most commonly mentioned effects were social stigmatization, bad publicity and emotional/psychological effects. Most of the respondents preferred the use of hospital-owned camera to personal camera/personal camera-phone for their medical photographs. Most respondents (67.8%) indicated that they would like to be informed about the use of their photographs on every occasion, and 74% indicated that they would like to be informed of the specific journal in which their medical photographs are to be published. In conclusion, non-identifiable rather than identifiable medical photography is acceptable to most patients in the studied Nigerian environment. The use of personal camera/personal camera-phone should be discouraged as its acceptance by respondents is very low. Judicious use of medical photography is therefore advocated to avoid breach of principle of privacy and confidentiality in medical practice. (shrink)

Lifestyle diseases constitute an increasing proportion of health problems and this trend is likely to continue. A better understanding of the responsibility argument is important for the assessment of policies aimed at meeting this challenge. Holding individuals accountable for their choices in the context of health care is, however, controversial. There are powerful arguments both for and against such policies. In this article the main arguments for and the traditional arguments against the use of individual responsibility as a criterion for (...) the distribution of scarce health resources will be briefly outlined. It is argued that one of the most prominent contemporary normative traditions, liberal egalitarianism, presents a way of holding individuals accountable for their choices that avoids most of the problems pointed out by the critics. The aim of the article is to propose a plausible interpretation of liberal egalitarianism with respect to responsibility and health care and assess it against reasonable counter-arguments. (shrink)