Complex wave patterns in an effective reaction–diffusion model for chemical reactions in microemulsions

An effective medium theory is employed to derive a simple qualitative model of a pattern forming chemical reaction in a microemulsion. This spatially heterogeneous system is composed of water nanodroplets randomly distributed in oil. While some steps of the reaction are performed only inside the droplets, the transport through the extended medium occurs by diffusion of intermediate chemical reactants as well as by collisions of the droplets. We start to model the system with heterogeneous reaction–diffusion equations and then derive an equivalent effective spatially homogeneous reaction–diffusion model by using earlier results on homogenization in heterogeneous reaction–diffusion systems [ S. Alonso, M. Bär, and R. Kapral, J. Chem. Phys. 134, 214102 (2009)]. We study the linear stability of the spatially homogeneous state in the resulting effective model and obtain a phase diagram of pattern formation, that is qualitatively similar to earlier experimental results for the Belousov–Zhabotinsky reaction in an aerosol OT (AOT)-water-in-oil microemulsion [ V. K. Vanag and I. R. Epstein, Phys. Rev. Lett. 87, 228301 (2001)]. Moreover, we reproduce many patterns that have been observed in experiments with the Belousov–Zhabotinsky reaction in an AOT oil-in-water microemulsion by direct numerical simulations.Peer ReviewedPostprint (published version

Calculations of Neutralino-Stop Coannihilation in the CMSSM

We present detailed calculations of the neutralino-stop coannihilation channels that have the largest impact on the relic neutralino density in the constrained minimal supersymmetric extension of the Standard Model (CMSSM), in which scalar masses m_0, gaugino masses m_1/2 and the trilinear soft supersymmetry-breaking parameters A_0 are each assumed to be universal at some input grand unification scale. The most important stop-stop* and stop-stop annihilation channels are also calculated, as well as stop-slepton coannihilation channels. We illustrate the importance of these new coannihilation calculations when A_0 is relatively large. While they do not increase the range of m_1/2 and hence neutralino mass allowed by cosmology, these coannihilation channels do open up new `tails' of parameter space extending to larger values of m_0.Comment: 45 pages, 7 figure

Runway 9-27 Rehabilitation with FDR Treatment

In this session we discuss the rehabilitation of Runway 9-27, which over its lifetime had been piecemealed and overlaid multiple times, resulting in a non-homogenous structure with pavement failures much sooner than the most recent 20-year design life expectancy. Testing showed that many of the distresses were full-depth, and total reconstruction was necessary. Because of its cost-effectiveness, we chose FDR. The project was extremely successful and is now being considered at other airports around the state

Solar Terrestrial Relations Observatory (STEREO) Mission and Concept of Operations

The Solar Terrestrial Relations Observatory (STEREO) is a new NASA mission designed to increase the understanding of the origin and consequences of coronal mass ejections (CMEs). The mission will consist of two identical spacecraft at approximately lAU from the Sun: one drifting ahead of the Earth and one behind. Simultaneous image pairs will be obtained by the spacecraft at gradually increasing angular separations over the course of the 2-year mission. The spacecraft launch date is scheduled for 2003. The concept of operations for this mission consists of independent and decoupled instrument and spacecraft bus operations. The Science Operations Teams will generate the instrument commands to accomplish the science objectives, and the STEREO Mission Operations Team (MOT) will support the spacecraft bus. All spacecraft servicing, including commanding and science data recovery, will occur during a daily ground track with the Deep Space Network. All science data will be flowed in near real-time to the Science Operations Center via the Internet. During the normal operations phase of the mission, each track will run autonomously with a small MOT to conduct planning and assessment tasks. The spacecraft and ground system will be highly autonomous, making this mission ideal for lights out operations

Re-Evaluation of the Elastic Scattering of Supersymmetric Dark Matter

We examine the cross sections for the elastic scattering of neutralinos $\chi$ on nucleons $p,n$, as functions of $m_\chi$ in the constrained minimal supersymmetric standard model. We find narrow bands of possible values of the cross section, that are considerably lower than some previous estimates. The constrained model is based on the minimal supergravity-inspired framework for the MSSM, with universal scalar and gaugino masses $m_0, m_{1/2}$, and $\mu$ and the MSSM Higgs masses treated as dependent parameters. We explore systematically the region of the $(m_{1/2}, m_0)$ plane where LEP and other accelerator constraints are respected, and the relic neutralino density lies in the range $0.1 \le \Omega_{\chi} h^2 \le 0.3$ preferred by cosmology. We update previous discussions of both the spin-independent and -dependent scattering matrix elements on protons and neutrons, using recent analyses of low-energy hadron experiments.Comment: 16 pages, latex, 14 eps figure

Constraints from Accelerator Experiments on the Elastic Scattering of CMSSM Dark Matter

We explore the allowed ranges of cross sections for the elastic scattering of neutralinos \chi on nucleons in the constrained minimal supersymmetric extension of the Standard Model (CMSSM), in which scalar and gaugino masses are each assumed to be universal at some input grand unification scale. We extend previous calculations to larger \tan \beta and investigate the limits imposed by the recent LEP lower limit on the mass of the Higgs boson and by b \to s \gamma, and those suggested by g_\mu - 2. The Higgs limit and b \to s \gamma provide upper limits on the cross section, particularly at small and large \tan \beta, respectively, and the value of g_\mu - 2 suggests a lower limit on the cross section for \mu > 0. The spin-independent nucleon cross section is restricted to the range 6 \times 10^{-8} pb > \sigma_{SI} > 2 \times 10^{-10} pb for \mu > 0, and the spin-dependent nucleon cross section to the range 10^{-5} pb > \sigma_{SD} > 2 \times 10^{-7} pb. Lower values are allowed if \mu <0.Comment: 15 pages, latex, 18 eps figure

Capital shocks and bank growth -- 1973 to 1991

Bank capital ; Banks and banking

Tissue Resident Macrophages Drive Fibrosis During Pancreas Inflammatory Injury and Pancreatic Ductal Adenocarcinoma

The immune system, and especially macrophages, are central in responding to infections, as well as providing a wide array of functions in other pathologies, especially in responding to inflammation. It is established that macrophages will accumulate within tissues during inflammation, many times secreting cytokines and chemokines central to the inflammatory response. This is particularly true during pancreatitis, or inflammation of the pancreas, where it has been shown that macrophages and monocytes accumulate in the pancreas to have various roles in further promoting inflammation. It is not well established, however, whether there are divergent roles for the distinct macrophage subsets that exist within the pancreas. Recent lineage tracing studies have shown macrophages are not only derived from circulating monocytes, but that precursors during embryonic development give rise to tissue-resident macrophage (TRM) populations. We therefore set out to investigate whether TRMs display divergent phenotypes from monocyte-derived macrophages (MDMs) during pancreatitis, and how this might shape our understanding of macrophage biology, and possible therapeutic strategies, during inflammation, as well as during pancreatic ductal adenocarcinoma (PDAC). Here, we show a significant portion of macrophages that accumulated during pancreatitis and pancreatic cancer were expanded from TRMs. We further established that pancreas TRMs have a distinct extracellular matrix remodeling and growth factor signaling phenotype, that was critical for maintaining tissue homeostasis during inflammation. Loss of TRMs led to exacerbation of severe pancreatitis and animal death, due to impaired acinar cell survival and recovery. In pancreatitis, TRMs elicited protective effects by triggering the accumulation and activation of fibroblasts, namely through PDGF-PDGFR signaling, which was necessary for initiating fibrosis as a wound healing response. The same TRM-driven fibrosis, however, drove pancreas cancer pathogenesis and progression. Together, these findings indicate that TRMs play divergent roles in the pathogenesis of pancreatitis and cancer through regulation of stromagenesis

The Crisis in Creativity Research Stems From Too Little Fragmentation, Not Too Much

Glăveanu is right that there is a crisis in creativity research, but his prescription would make things worse, not better. It is the attempt to build grand, domain-transcending, all-encompassing theories that has crippled creativity research and led to a field in which it is the norm for research results to contradict each other. Creativity is more like expertise (where every domain has its own definition and understanding of what constitutes expertise) than intelligence (where g reigns, albeit not without critics). The skills, traits, and motivations that lead to creative performance in physics, poetry, and painting are not fungible: one’s intrinsic motivation to write poetry cannot be transmuted into a love of painting, one’s openness to experience in art does not make one more open to new ideas in physics, and one’s physics-related divergent-thinking skill will not lead to more creative poems. Intrinsic motivation, openness to experience, and divergent thinking may promote creativity in many (but probably not all) domains, but they are different in each domain, as will be their effects. Treating them as domain-general skills or attributes invites confusion. We need more fragmentation, in the sense of more domain-specific theories, if we want to make progress in understanding [email protected] University Lawrenceville, USA1220020