Volume 24, Issue 7, July 2024, Page 6-12.

Atomic-scale computer simulation has been used to study the thermally activated atomic transport of self-interstitial atoms in the form of planar clusters in pure Cu and f -Fe. There is strong evidence that such clusters are commonly formed in metals during irradiation with high-energy particles and play an important role in accumulation and spatial distribution of surviving defects. An extensive study of the mobility of SIA clusters containing two to 331 interstitials has been carried out using the molecular dynamics simulation (...) technique for the temperature range from 180 to 1200 K. The results obtained show that clusters larger than three to four SIAs are one-dimensionally mobile in both Cu and Fe. Large clusters of more than 100 SIAs in Cu and 300 SIAs in Fe have significantly reduced mobility. The problem of describing one-dimensional motion in three-dimensional space is discussed. An attempt is made to describe the mobility of SIA clusters within the approximation of 1D diffusion. For clusters in both metals the effective migration energy of 1D diffusion as estimated via the jump frequency of the cluster centre of mass is found to be independent of the number of SIAs in the clusters, although the cluster jump frequency decreases with increasing cluster size. Mechanisms of 1D mobility of interstitial clusters are discussed. (shrink)

Gluten ataxia is a rare immune-mediated neurological disorder caused by the ingestion of gluten. The diagnosis is not straightforward as antibodies are present in only up to 38% of patients, but often at lower titers. The symptoms of ataxia may be mild at the onset but lead to permanent damage if remain untreated. It is characterized by damage to the cerebellum however, the pathophysiology of the disease is not clearly understood. The present study investigated the neurochemical profile of vermis and (...) right cerebellum and structural changes in various brain regions of patients with gluten ataxia and compared it with healthy controls. Volumetric 3-D T1 and T1-weighted magnetic resonance imaging in the three planes of the whole brain and single-voxel 1H- magnetic resonance spectroscopy of the vermis and right cerebellum were acquired on 3 T human MR scanner. The metabolite concentrations were estimated using LC Model while brain volumes were estimated using the online tool volBrain pipeline and CERES and corrected for partial volumes. The levels of neuro-metabolites were found to be significantly lower in vermis, while N-acetyl aspartate + N-acetyl aspartate glutamate and glycerophosphocholine + phosphocholine was lower in cerebellum regions in the patients with gluten ataxia compared to healthy controls. A significant reduction in the white matter of ; reduction in the volumes of cerebellum lobe and thalamus while lateral ventricles were increased in the patients with gluten ataxia compared to healthy controls. The reduced neuronal metabolites along with structural changes in the brain suggested neuronal degeneration in the patients with gluten ataxia. Our preliminary findings may be useful in understanding the gluten-induced cerebral damage and indicated that MRI and MRS may serve as a non-invasive useful tool in the early diagnosis, thereby enabling better management of these patients. (shrink)

It has been suggested in the literature that spatial coherence of the wave function can be dynamically suppressed by fluctuations in the spacetime geometry. These fluctuations represent the minimal uncertainty that is present when one probes spacetime geometry with a quantum probe. Two similar models have been proposed, one by Diósi and one by Karolyhazy and collaborators, based on apparently unrelated minimal spacetime bounds. The two models arrive at somewhat different expressions for the dependence of the localization coherence length on (...) the mass and size of the quantum object. In the present article we compare and contrast the two models from three aspects: comparison of the spacetime bounds, method of calculating decoherence time, comparison of noise correlation. We show that under certain conditions the minimal spacetime bounds in the two models can be derived one from the other. We argue that the methods of calculating the decoherence time are equivalent. We re-derive the two-point correlation for the fluctuation potential in the K-model, and confirm the earlier result of Diósi and Lukács that it is non-white noise, unlike in the D-model, where the corresponding correlation is white noise in time. This seems to be the origin of the different results in the two models. We derive the non-Markovian master equation for the K-model. We argue that the minimal spacetime bound cannot predict the noise correlation uniquely, and additional criteria are necessary to accurately determine the effects of gravitationally induced decoherence. (shrink)

In a previous paper by Pollock and Singh, it was proven that the total entropy of de Sitter space-time is equal to zero in the spatially flat case K=0. This result derives from the fundamental property of classical thermodynamics that temperature and volume are not necessarily independent variables in curved space-time, and can be shown to hold for all three spatial curvatures K=0,±1. Here, we extend this approach to Schwarzschild space-time, by constructing a non-vacuum interior space with line element (...) ds 2=e2λ(r) dt 2−e−2λ(r) dr 2−r 2(dθ 2+sin2 θdϕ 2), where $\mathrm{e}^{2{\lambda }(r)}=-\frac{1}{2}(1-\frac{r^{2}}{R_{0}^{2}})$ , which matches onto the vacuum exterior Schwarzschild metric in such a way that e2λ and d(e2λ )/dr are both continuous at the Schwarzschild radius R 0=2M. Then we show that the volume entropy is equal to A/4, where $A\equiv 4\pi R_{0}^{2}$ is the area of the apparent horizon, as found by Hawking. (shrink)

The authors use the term “principlism” to refer to the practice of using “principles” to replace both moral theory and particular moral rules and ideals in dealing with the moral problems that arise in medical practice. The authors argue that these “principles” do not function as claimed, and that their use is misleading both practically and theoretically. The “principles” are in fact not guides to action, but rather they are merely names for a collection of sometimes superficially related matters for (...) consideration when dealing with a moral problem. The “principles” lack any systematic relationship to each other, and they often conflict with each other. These conflicts are unresolvable, since there is no unified moral theory from which they are all derived. For comparison the authors sketch the advantages of using a unified moral theory. (shrink)

In the Severan period the proconsulship of Africa or Asia was normally held some 15 to 17 years after die consulship. Although there are comparatively few consuls in this period whose ages can be firmly established, what evidencethere is suggests that the consulship was normally held in the early forties, on occasions as early as the mid thirties: a consularis could, therefore, hope to attain a premier proconsulship aged about 60. Thus the future emperor P.Helvius Pertinax, who was born on (...) 1st August 126, held the proconsulship of Africa, probably in 188/9, at the age of 62. M. Didius Julianus, the imperial successor to Pertinax, also succeeded him in Africa aged about 56. C. Vettius Sabinianus was born before 136 and his proconsulship fell about 192/37 whenhe was at least 56 years old. (shrink)

The goal is to isolate points of philosophical interest in the preceding articles on narrative medical ethics in order to focus subsequent dialogue between the two disciplines. Ethics is an enterprise that has over the centuries developed a somewhat malleable structure, comprising characteristics, methods, lines of reasoning, rules, principles, assumptions, and arguments. This structure provides the framework within which many disciplines contribute to ethics through the exercise of their particular interests, skills, and methods. Challenging or changing the structural components requires (...) arguments of a traditional sort appropriate to the discipline of ethics. Three tenets are proposed as comprising the “received view” or credo of the literature and ethics movement. Each is examined. Then the individual articles in this issue are explored to the end of ferreting out points that would be fruitful points of discussion between philosophy and literature folks pursuing their mutual interest in ethics. (shrink)

This paper examines some of the background social and institutional practices involved in the production of official statistics about crime and criminal justice. It documents how a host of micropolitical considerations impinge on what studies are conducted, which agencies control official data, and how measures are standardized. The communication of statistical facts is also shown to be influenced by a concern to prospectively manage the political symbolism of popular accounts about crime and criminal justice statistics.

Based on the writings of D.S. Kothari; includes his brief biographical sketch and review of his four books.

According to the interface theory of perception, our perceptual systems have evolved to provide a species-specific interface to guide adaptive behaviour, and not to provide veridical representations of an observer-independent world. Results of simulations of evolutionary resource games, genetic algorithms, and multiple mathematical theorems have supported and fleshed out this claim in various ways. They indicate that the probability is zero that any perceptual system has been shaped by natural selection to represent the true structure of an observer-independent world. Bagwell (...) (2023) thinks that this argument is self-defeating because it implies that organisms, resources, genes, etc. that are essential constituents of Darwin's theory do not provide an insight into the nature of observerindependent reality. Bagwell's argument relies on a false premise, however — namely, that the mathematical formulation of a scientific theory cannot dethrone its fundamental concepts. More broadly, his argument involves a fundamental misunderstanding of the nature of scientific theories — of their explanatory scope and their necessary limits. (shrink)

The essays in this Journal issue offer examples of how textual analysis, literary theory, and the reading and writing of literature can contribute to an understanding of ethical issues in medicine. The editors' purpose in such an issue is to stimulate discussion between philosopher-ethicists and literary scholars whose work concerns this topic. With the concluding essays by editors Clouser and Hawkins, this discussion begins.

This edited collection focuses on the problem of social justice, or, more particularly, how the demand for social justice was articulated and implemented in ...