Antiprotonic Potentials from Global Fits to the PS209 Data

The experimental results for strong interaction effects in antiprotonic atoms by the PS209 collaboration consist of high quality data for several sequences of isotopes along the periodic table. Global analysis of these data in terms of a $\bar p$-nucleus optical potential achieves good description of the data using a s-wave finite-range \bar p N interaction. Equally good fits are also obtained with a poorly-defined zero-range potential containing a p-wave term.Comment: 6 pages, 1 figure, talk at LEAP03, to appear in NIM(B

Reaction time and incident cancer: 25 years of follow-up of study members in the UK Health and Lifestyle Survey

<b>Objectives</b><p></p> To investigate the association of reaction time with cancer incidence.<p></p> <b>Methods</b><p></p> 6900 individuals aged 18 to 94 years who participated in the UK Health and Lifestyle Survey in 1984/1985 and were followed for a cancer registration for 25 years.<p></p> <b>Results</b><p></p> Disease surveillance gave rise to 1015 cancer events from all sites. In general, there was essentially no clear pattern of association for either simple or choice reaction time with cancer of all sites combined, nor specific malignancies. However, selected associations were found for lung cancer, colorectal cancer and skin cancer.<p></p> <b>Conclusions</b><p></p> In the present study, reaction time and its components were not generally related to cancer risk

The discrete dynamics of small-scale spatial events: agent-based models of mobility in carnivals and street parades

Small-scale spatial events are situations in which elements or objects vary in such away that temporal dynamics is intrinsic to their representation and explanation. Someof the clearest examples involve local movement from conventional traffic modelingto disaster evacuation where congestion, crowding, panic, and related safety issue arekey features of such events. We propose that such events can be simulated using newvariants of pedestrian model, which embody ideas about how behavior emerges fromthe accumulated interactions between small-scale objects. We present a model inwhich the event space is first explored by agents using ?swarm intelligence?. Armedwith information about the space, agents then move in an unobstructed fashion to theevent. Congestion and problems over safety are then resolved through introducingcontrols in an iterative fashion and rerunning the model until a ?safe solution? isreached. The model has been developed to simulate the effect of changing the route ofthe Notting Hill Carnival, an annual event held in west central London over 2 days inAugust each year. One of the key issues in using such simulation is how the processof modeling interacts with those who manage and control the event. As such, thischanges the nature of the modeling problem from one where control and optimizationis external to the model to one where this is intrinsic to the simulation

Traffic, urban growth and suburban sprawl

Cities are still getting bigger in the western world. Even though urbanpopulations are barely reproducing themselves and migration from thecountryside to the town has slowed to a trickle, the demand for more livingspace shows no sign of abating as cities continue to expand their bordersthrough suburban sprawl. The automobile, of course, makes this possiblebut we show no signs of moving to other forms of transport that mightenable our cities to become a little more compact. The problems of sprawlare pervasive. Besides congestion, time wasted, and the long term costs ofusing non-renewable energy, the lack of good social infrastructure inrapidly growing suburban areas together with the erosion of agriculturalland, often of high environmental quality, has focused the debate onwhether or not such forms of development are sustainable. In this paper,we begin by noting that suburban sprawl is an age-old phenomenon whichrepresents a fine balance between the forces that are pushing peopletogether in cities and those that are forcing them out. These lead todifferent types of sprawl in different places and at different times butwhatever the variety, there are costs to be borne. We briefly review these,noting how these affect suburban sprawl in Europe, and the efforts of theEuropean Commission to understand the problem. We conclude not with aplea that cities should be compacted and all automobile traffic removedbut that we should engage in policies for ?smart growth? such as thosebeing adopted in North America

Narrow deeply bound K−K^- atomic states

Using optical potentials fitted to a comprehensive set of strong interaction level shifts and widths in $K^-$ atoms, we predict that the $K^-$ atomic levels which are inaccessible in the atomic cascade process are generally narrow, spanning a range of widths about 50 - 1500 keV over the entire periodic table. The mechanism for this narrowing is different from the mechanism for narrowing of pionic atom levels. Examples of such `deeply bound' $K^-$ atomic states are given, showing that in many cases these states should be reasonably well resolved. Several reactions which could be used to form these `deeply bound' states are mentioned. Narrow deeply bound states are expected also in $\bar{p}$ atoms.Comment: Revised, Phys. Lett B. in pres

On the determination of the pion effective mass in nuclei from pionic atoms

The binding energies of the deeply bound 1s and 2p states in pionic atoms of $^{207}$Pb, recently established experimentally in the $^{208}$Pb(d,$^3$He) reaction, have been used by several groups to derive the pion effective mass in nuclear matter. We show that these binding energies are fully consistent with `normal' pionic atoms and that the real part of the pion-nucleus potential at the center of $^{207}$Pb is 28$\pm$3 MeV and not 20 MeV as suggested previously.Comment: 8 pages, Revtex, 2 figures, accepted by Physics Letters

Macro and Micro Dynamics of City Size Distributions: The Case of Israel

We study the distribution of sizes in the Israeli system of cities, using a rank-size representation of population distributions from 1950 to 2005. Based on a multiplicative model of proportionate growth, we develop a quantitative comparison relating the change in the rank-size curves to the change in the real data of Israeli cities during this period. At the level of macro dynamics, there is good agreement between the model and the real data. At the micro level, however, the model is less successful as the mean variation of the cities’ rank during the period studied is much larger in the model than in the real data. To illustrate this difference, we use the rankclock representation

Thermodynamics and kinetics of heterogeneous reactions

Thermodynamics and kinetics of sublimation, catalytic, and oxidation reaction

Representing multifunctional cities: density and diversity in space and time

In this paper, we define measures of urban diversity, density and segregation using newdata and software systems based on GIS. These allow us to visualise the meaning of themultifunctional city. We begin with a discussion of how cities have become moresegregated in their land uses and activities during the last 200 years and how the currentfocus is on reversing this trend through limiting urban sprawl and bringing new lifeback to the inner and central city. We define various indices which show how diversityand density manifest themselves spatially. We argue that multifunctionalism is a relativeconcept, dependent upon the spatial and temporal scale that we use to think about themixing and concentration of urban land uses. We present three examples using spatiallysmoothed indicators of diversity: for a world city ? London, for a highly controlledpolycentric urban region ? Randstad Holland, and for a much more diffusely populatedsemi-urban region ? Venice-Padua-Teviso. We conclude by illustrating that urbandiversity varies as people engage in different activities associated with different landuses throughout the day, as well as through the vertical, third dimension of the city. Thisimpresses the point that we need to understand multifunctional cities in all theirdimensions of space and time