Can cells solve mazes? Understanding cells responses to wound healing

Wound healing is a complex process that occurs after the body\u27s tissue has been damaged or impaled by a foreign object. Cells must travel from all over the body to the site of injury. The goal of this project is to understand what affects the migration of fibroblast cells in order to develop more effective wound treatments. Our research has aimed to develop a way to map the decision-making processes of fibroblasts that drive their migration to a wound site. We have addressed this by asking the question: can cells solve mazes? Our team has developed several methodologies by which we have been able to study the responsiveness of fibroblasts to certain cues. Specifically the migration of the cells has been tracked relative to physical barriers created by the walls of the maze and chemical concentration gradients. Preliminary results have demonstrated the feasibility of this apparatus for a mode of studying cell proliferation and migration

Neutron recognition in the LAND detector for large neutron multiplicity

The performance of the LAND neutron detector is studied. Using an event-mixing technique based on one-neutron data obtained in the S107 experiment at the GSI laboratory, we test the efficiency of various analytic tools used to determine the multiplicity and kinematic properties of detected neutrons. A new algorithm developed recently for recognizing neutron showers from spectator decays in the ALADIN experiment S254 is described in detail. Its performance is assessed in comparison with other methods. The properties of the observed neutron events are used to estimate the detection efficiency of LAND in this experiment.Comment: 16 pages, 8 figure

Comment on Benjamin Smith (2004): 'Oil Wealth and Regime Survival in the Developing World, 1960-1999'

In “Oil Wealth and Regime Survival in the Developing World, 1960-1999“ Benjamin Smith examines the effects of oil wealth, as well as of sudden changes in oil prices, on regime failure, political protest and civil war. He finds that oil wealth is robustly associated with more durable regimes, and significantly related to lower levels of anti-state protest and civil war. In this comment, I discuss Smith's empirical approach - especially his treatment of possible reverse causality between conflict and economic performance, his use of the Polity democracy index, and his choice of the resource dependence variable - and provide suggestions for improvement

Study of e+,e− production in elementary and nuclear collisions near the production threshold with HADES

HADES is a second generation experiment designed to study dielectron production in proton, pion, and heavy ion induced reactions at the GSI accelerator facility in Darmstadt. The physics programme of HADES is focused on in-medium properties of the light vector mesons. In this contribution we present status of the HADES experiment, demonstrate its capability to identify rare dielectron signal, show first experimental results obtained from C+C reactions at 2 A GeV and shortly discuss physics programme of up-coming experimental runs. © 2004 Elsevier B.V. All rights reserved. 53 1 49 58 Cited By :1

Impact of the Coulomb field on charged-pion spectra in few-GeV heavy-ion collisions

In nuclear collisions the incident protons generate a Coulomb field which acts on produced charged particles. The impact of these interactions on charged-pion transverse-mass and rapidity spectra, as well as on pion–pion momentum correlations is investigated in Au + Au collisions at $\sqrt{^{S}NN}$ = 2.4 GeV. We show that the low-m$_{t}$ region (m$_{t}$ < 0.2 GeV / c$^{2}$) can be well described with a Coulomb-modified Boltzmann distribution that also takes changes of the Coulomb field during the expansion of the fireball into account. The observed centrality dependence of the fitted mean Coulomb potential energy deviates strongly from a $A_{part}^{2/3}$ scaling, indicating that, next to the fireball, the non-interacting charged spectators have to be taken into account. For the most central collisions, the Coulomb modifications of the HBT source radii are found to be consistent with the potential extracted from the single-pion transverse-mass distributions. This finding suggests that the region of homogeneity obtained from two-pion correlations coincides with the region in which the pions freeze-out. Using the inferred mean-square radius of the charge distribution at freeze-out, we have deduced a baryon density, in fair agreement with values obtained from statistical hadronization model fits to the particle yields

Less Than a state, more than an international organization: The Sui generis nature of the European Union

In this paper, I show that the European Union (EU) is less than a state, but more than an international organization. Although it possesses some characteristics of both, the European Union is, I argue, a sui generis project: Although the EU wields extensive influence in some policy areas (such as competition policy or international trade regulation), its institutions’ powers are quite limited in many areas that remain firmly within the grasp of its Member States’ governments (such as security, justice, tax or redistribution policies). The European Union’s supranational elements – especially the EU laws’ supremacy over the laws of individual Member States – distinguish it, furthermore, from international organizations, such as the United Nations or the World Trade Organization. I conclude that the European Union is really a sui generis project that has not been attempted anywhere else: As such, it could be regarded as a useful case study, or perhaps even a “pilot project,” for regional integration projects elsewhere