Transfigurings: Beauty, wonder and the noumenal

Encounter (1) The ash tree at twilight – an epiphany explored. I was simply standing in the garden one evening looking at the late spring sky above me, through the canopy of a large ash tree whose every leaf and twig was picked out in black against the indigo sky. As my eyes adjusted to the dwindling light, the three dimensional array of the tree’s infinitely elaborate structure fixated me, and I was able to savour its precise and almost granular penetration of the air around it. The space it occupied in turn seemed to take on the quality of a mould, a mould of minute intricacy whose every hollow channel was perfectly fitted by the filigree of tree-stuff that had, as it were, been poured or breathed into it. Although in one sense a more unscientific view of the tree’s actual growth could hardly be imagined, the perception of the tree’s infusing a space that was ready to receive it does have a picturesque relation to the Darwinian thought that living things exist simply and precisely because they can, and that every grain of organic nature occupies that location to which it is, at the time of occupation, most perfectly fitted. Finally, like so much aspect-perception, this perception too could after a while be switched at will with the ordinary perception of the tree as fixed, the fluid air flowing and wrapping gently around it. It was, if you like, an altered conception of space and form, and it was most definitely wonderful while it lasted

A semantic comparison of the conclusion of LXX Tobit and Semitic 4QTobit

At the beginning of the 20th century, the shorter Greek version of the book of Tobit, GI, which is included in the Catholic Bible, was thought to be the oldest version. It was defined as ‘a lesson on almsgiving and its redeeming powers’. As the discoveries of the Semitic copies of Tobit at Qumran, GI is recognised to be a reworking of the longer version GII, most probably originally written in Aramaic, between 225 and 175 BCE. In all versions of Tobit, the theme of almsgiving is introduced as specifically directed to Jewish kinsmen, but towards the end, is to be directed to all poor, suggesting that it may have been written by a Hellenistic Jew. Although the surface context of the narrative of Tobit is the Jewish tradition of proper observation of mitzvot and sacrifice and eventual reward, the various versions contain varying degrees of ancient Near Eastern wisdom, and an ironic, subversive reflection of hypocritical righteousness. This article questioned why the endings differ markedly in different versions. To try to find answers, a semantic comparison was made between GI and the most complete Aramaic version 4Q196. Contribution: This article considered the implications of source criticism in the reception of the various versions of Tobit. The possibility was examined that the pre-Christian, Aramaic version 4Q196Tobit does not confirm the excessive focus on almsgiving as righteousness apparent in the GI version of LXX Tobit

Pattern matching and pattern discovery algorithms for protein topologies

We describe algorithms for pattern matching and pattern learning in TOPS diagrams (formal descriptions of protein topologies). These problems can be reduced to checking for subgraph isomorphism and finding maximal common subgraphs in a restricted class of ordered graphs. We have developed a subgraph isomorphism algorithm for ordered graphs, which performs well on the given set of data. The maximal common subgraph problem then is solved by repeated subgraph extension and checking for isomorphisms. Despite the apparent inefficiency such approach gives an algorithm with time complexity proportional to the number of graphs in the input set and is still practical on the given set of data. As a result we obtain fast methods which can be used for building a database of protein topological motifs, and for the comparison of a given protein of known secondary structure against a motif database

The Third Wave of science studies: studies of expertise and experience

Science studies has shown us why science and technology cannot always solve technical problems in the public domain. In particular, the speed of political decision-making is faster than the speed of scientific consensus formation. A predominant motif over recent years has been the need to extend the domain of technical decision-making beyond the technically qualified elite so as to enhance political legitimacy. We argue, however, that the `Problem of Legitimacy' has been replaced the `Problem of Extension.' This is a tendency to dissolve the boundary between experts and the public so that there are no longer any grounds for limiting the indefinite extension of technical decision-making rights. We argue that a Third Wave of science studies -- Studies of Expertise and Experience (SEE) -- is needed to solve the Problem of Extension. SEE will include a normative theory of expertise and will disentangle expertise from political rights in technical decision-making. The theory builds categories of expertise starting with the key distinction between interactive expertise and contributory expertise. A new categorisation of types of science is also needed. We illustrate the potential of the approach by re-examining existing case studies including Wynne's study of Cumbrian sheep farmers. Sometimes the new theory argues for more public involvement, sometimes for less. An Appendix describes existing contributions to the problem of technical decision-making in the public domain

Slow relaxation in granular compaction

Experimental studies show that the density of a vibrated granular material evolves from a low density initial state into a higher density final steady state. The relaxation towards the final density value follows an inverse logarithmic law. We propose a simple stochastic adsorption-desorption process which captures the essential mechanism underlying this remarkably slow relaxation. As the system approaches its final state, a growing number of beads have to be rearranged to enable a local density increase. In one dimension, this number grows as $N=\rho/(1-\rho)$, and the density increase rate is drastically reduced by a factor $e^{-N}$. Consequently, a logarithmically slow approach to the final state is found $\rho_{\infty}-\rho(t)\cong 1/\ln t$.Comment: revtex, 4 pages, 3 figures, also available from http://arnold.uchicago.edu/~ebn

Ab initio calculation of the neutron-proton mass difference

The existence and stability of atoms rely on the fact that neutrons are more massive than protons. The measured mass difference is only 0.14\% of the average of the two masses. A slightly smaller or larger value would have led to a dramatically different universe. Here, we show that this difference results from the competition between electromagnetic and mass isospin breaking effects. We performed lattice quantum-chromodynamics and quantum-electrodynamics computations with four nondegenerate Wilson fermion flavors and computed the neutron-proton mass-splitting with an accuracy of $300$ kilo-electron volts, which is greater than $0$ by $5$ standard deviations. We also determine the splittings in the $\Sigma$, $\Xi$, $D$ and $\Xi_{cc}$ isospin multiplets, exceeding in some cases the precision of experimental measurements.Comment: 57 pages, 15 figures, 6 tables, revised versio

Reversible Random Sequential Adsorption of Dimers on a Triangular Lattice

We report on simulations of reversible random sequential adsorption of dimers on three different lattices: a one-dimensional lattice, a two-dimensional triangular lattice, and a two-dimensional triangular lattice with the nearest neighbors excluded. In addition to the adsorption of particles at a rate K+, we allow particles to leave the surface at a rate K-. The results from the one-dimensional lattice model agree with previous results for the continuous parking lot model. In particular, the long-time behavior is dominated by collective events involving two particles. We were able to directly confirm the importance of two-particle events in the simple two-dimensional triangular lattice. For the two-dimensional triangular lattice with the nearest neighbors excluded, the observed dynamics are consistent with this picture. The two-dimensional simulations were motivated by measurements of Ca++ binding to Langmuir monolayers. The two cases were chosen to model the effects of changing pH in the experimental system.Comment: 9 pages, 10 figure

Some flows in shape optimization

Geometric flows related to shape optimization problems of Bernoulli type are investigated. The evolution law is the sum of a curvature term and a nonlocal term of Hele-Shaw type. We introduce generalized set solutions, the definition of which is widely inspired by viscosity solutions. The main result is an inclusion preservation principle for generalized solutions. As a consequence, we obtain existence, uniqueness and stability of solutions. Asymptotic behavior for the flow is discussed: we prove that the solutions converge to a generalized Bernoulli exterior free boundary problem

Groups and individuals: conformity and diversity in the performance of gendered identities

The nature and role of social groups is a central tension in sociology. On the one hand, the idea of a group enables sociologists to locate and describe individuals in terms of characteristics that are shared with others. On the other, emphasizing the fluidity of categories such as gender or ethnicity undermines their legitimacy as ways of classifying people and, by extension, the legitimacy of categorization as a goal of sociological research. In this paper, we use a new research method known as the Imitation Game to defend the social group as a sociological concept. We show that, despite the diversity of practices that may be consistent with self‐identified membership of a group, there are also shared normative expectations – typically narrower in nature than the diversity displayed by individual group members – that shape the ways in which category membership can be discussed with, and performed to, others. Two claims follow from this. First, the Imitation Game provides a way of simultaneously revealing both the diversity and ‘groupishness’ of social groups. Second, that the social group, in the quasi‐Durkheimian sense of something that transcends the individual, remains an important concept for sociology

Early stage morphology of quench condensed Ag, Pb and Pb/Ag hybrid films

Scanning Tunneling Microscopy (STM) has been used to study the morphology of Ag, Pb and Pb/Ag bilayer films fabricated by quench condensation of the elements onto cold (T=77K), inert and atomically flat Highly Oriented Pyrolytic Graphite (HOPG) substrates. All films are thinner than 10 nm and show a granular structure that is consistent with earlier studies of QC films. The average lateral diameter, $\bar {2r}$, of the Ag grains, however, depends on whether the Ag is deposited directly on HOPG ($\bar {2r}$ = 13 nm) or on a Pb film consisting of a single layer of Pb grains ($\bar {2r}$ = 26.8 nm). In addition, the critical thickness for electrical conduction ($d_{G}$) of Pb/Ag films on inert glass substrates is substantially larger than for pure Ag films. These results are evidence that the structure of the underlying substrate exerts an influence on the size of the grains in QC films. We propose a qualitative explanation for this previously unencountered phenomenon.Comment: 11 pages, 3 figures and one tabl