A mechanochemical model for normal and abnormal dermal wound repair

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The Antibiotic Revolution

In 1928, Alexander Fleming discovered Penicillin, which revolutionized the way infections were treated. This discovery was revolutionary because it impacted the scientific field, the medical field, the pharmaceutical industry, and all of humanity. Alexander Fleming’s discovery of Penicillin sparked the development of antibiotics, which has continued to save people’s lives since the revolution. Thomas Kuhn would qualify the discovery of Penicillin by Alexander Fleming as a revolution because it led to a paradigm shift. Prior to the discovery of Penicillin, patients died from trivial injuries and infections. Fleming’s discovery of Penicillin is revolutionary because it changed the worldview of the way doctors treat patients with infectious diseases; and as a result of the antibiotic revolution, individuals are not vulnerable to death by bacterial diseases

Charmless Hadronic B Decays at BABAR

We present preliminary results of several searches for rare charmless hadronic decays of the B meson using data collected by the BABAR detector at the Stanford Linear Accelerator Center's PEP-II storage ring. We search for the decays h^+h^-, h^+h^-h^+, h^+h^-pi^0, X^0h^+, and X^0 K_S^0, where h = pi or K, and X^0 = eta^prime or omega. In a sample of 8.8 million B-anti-B decays we measure the branching fractions: BF(B^0 --> pi^+pi^-) = (9.3^{+2.6}_{-2.3}^{+1.2}_{-1.4}) x 10^{-6}, BF(B^0 --> K^+pi^-) = (12.5^{+3.0}_{-2.6}^{+1.3}_{-1.7}) x 10^{-6}, BF(B^0 --> rho^-pi^+) = (49 +/- 13^{+6}_{-5}) x 10^{-6}$, and BF(B^+ --> eta^prime K^+) = (62 +/- 18 +/- 8) x 10^{-6}$. We calculate upper limits for the modes without a significant signal.Comment: 6 pages, 2 postscript figues, submitted to Proceedings of DPF200

How Neighbours Communicate: The Role of Language in Border Relations

This paper reports on a study of the linguistic situation in the border region where Norway meets Russia in the north. The aim of the study was to investigate language use when contact is revitalised after a long period with closed borders. The Norwegian and Russian languages are very different in vocabulary and structure, which makes communication difficult. How are the two languages affected by extended contact and migration across the border? The study was carried out by the author and Marit Bjerkeng through interviews, a questionnaire and observation of the linguistic situations in two Norwegian communities. The results show an ongoing development where the neighbouring language is increasingly noticeable, and there is a clear link between attitudes, identity and language use. The role of public policy seems to play an important role for the developing linguistic situation, as the Barents region as a political concept introduced in the 1990s has led to cross-border contact within various fields and also inspired local language policy, contributing to cultural pride and changing attitudes

Increased Response Variability and Attentional Lapses After Chronic Cocaine Self-Administration

In humans, cocaine use has long been associated with poor attentional control and decreased efficiency in goal-oriented behavior. Animal models of these stereotypic drug effects, however, have thus far failed to produce quantifiable data sets in part because of a lack of species differences and analysis techniques. Recent work (Hervey et al. 2006) has successfully quantified attentional lapses in disorders such as ADHD through the analysis of response time variations in simple tasks, but this analysis has yet to be applied to the drug abuse scenario. To determine the effects of chronic cocaine administration on response time variability, 14 rhesus macaque monkeys (8 cocaine administering and 6 performance-matched controls) were subjected to a 50 trial simple attention task. This task was performed W-F prior to cocaine self-administration sessions in the test group. Treatment groups were compared to both each other and to baseline task sessions recorded prior to beginning the administration paradigm. In addition to typical measures of variability, an ex-Gaussian response time analysis was performed to quantify the contribution of attentional lapses to overall variability. The cocaine-administering group had a significantly higher response time standard deviation than their pre-administration sessions (p<0.05). No difference was observed between pre- and post-administration sessions for the control group. When ex-Gaussian methods were applied to the response time datasets, no differences were observed between groups in the normal mean (mu), suggesting that the variability increase in the cocaine group was due to an increased skew in the right tail of the response time distribution. Indeed, the cocaine group showed a significant increase in the value of tau(exponential value representing the distribution tail magnitude) post-administration versus tau pre-administration (p<0.05). These data suggest that cocaine administration leads to increased behavioral variability in simple response time tasks, and that this variability increase is primarily due to the prevalence of abnormally long responses. Similar results have been demonstrated in clinical disorders such as ADHD, suggesting both the relevance of the primate model in studies of attentional processing and the possible similarity in affected brain regions or transmitter systems

Dimensional reduction of dual topological theories

We describe the reduction from four to two dimensions of the SU(2) Donaldson-Witten theory and the dual twisted Seiberg-Witten theory, i.e. the Abelian topological field theory corresponding to the Seiberg--Witten monopole equations.Comment: LateX, 6 page

Assessing the performance of the Random Phase Approximation for exchange and superexchange coupling constants in magnetic crystalline solids

The Random Phase Approximation (RPA) for total energies has previously been shown to provide a qualitatively correct description of static correlation in molecular systems, where density functional theory (DFT) with local functionals are bound to fail. This immediately poses the question of whether the RPA is also able to capture the correct physics of strongly correlated solids such as Mott insulators. Due to strong electron localization, magnetic interactions in such systems are dominated by superexchange, which in the simplest picture can be regarded as the analogue of static correlation for molecules. In the present work we investigate the performance of the RPA for evaluating both superexchange and direct exchange interactions in the magnetic solids NiO, MnO, Na3Cu2SbO6, Sr2CuO3, Sr2CuTeO6, and a monolayer of CrI3, which are chosen to represent a broad variety of magnetic interactions. It is found that the RPA can accurately correct the large errors introduced by Hartree-Fock - independent of the input orbitals used for the perturbative expansion. However, in most cases, accuracies similar to RPA can be obtained with DFT+U, which is significantly simpler from a computational point of view.Comment: 9 page