Streamwise vortex structure in plane mixing layers

The development of three-dimensional motions in a plane mixing layer was investigated experimentally. It is shown that superimposed on the primary, spanwise vortex structure there is a secondary, steamwise vortex structure. Three aspects of this secondary structure were studied. First, the spanwise vortex instability that generates the secondary structure was characterized by measurements of the critical Reynolds number and the spanwise wavelength at several flow conditions. While the critical Reynolds number was found to depend on the velocity ratio, density ratio and initial shear-layer-profile shape, the mean normalized wavelength is independent of these parameters. Secondly, flow visualization in water was used to obtain cross-sectional views of the secondary structure associated with the streamwise counter-rotating vortices. A model is proposed in which those vortices are part of a single vortex line winding back and forth between the high-speed side of a primary vortex and the low-speed side of the following one. Finally, the effect of the secondary structure on the spanwise concentration field was measured in a helium-nitrogen mixing layer. The spatial organization of the secondary structure produces a well-defined spanwise entrainment pattern in which fluid from each stream is preferentially entrained at different spanwise locations. These measurements show that the spanwise scale of the secondary structure increases with downstream distance

Access to diagnosis and treatment of Chagas disease/infection in endemic and non-endemic countries in the XXI century.

In this article, Médicos Sin Fronteras (MSF) Spain faces the challenge of selecting, piecing together, and conveying in the clearest possible way, the main lessons learnt over the course of the last seven years in the world of medical care for Chagas disease. More than two thousand children under the age of 14 have been treated; the majority of whom come from rural Latin American areas with difficult access. It is based on these lessons learnt, through mistakes and successes, that MSF advocates that medical care for patients with Chagas disease be a reality, in a manner which is inclusive (not exclusive), integrated (with medical, psychological, social, and educational components), and in which the patient is actively followed. This must be a multi-disease approach with permanent quality controls in place based on primary health care (PHC). Rapid diagnostic tests and new medications should be available, as well as therapeutic plans and patient management (including side effects) with standardised flows for medical care for patients within PHC in relation to secondary and tertiary level, inclusive of epidemiological surveillance systems

Interference pattern in the collision of structures in the BEC dark matter model: comparison with fluids

In order to explore nonlinear effects on the distribution of matter during collisions within the Bose-Einstein condensate (BEC) dark matter model driven by the Schr\"odinger-Poisson system of equations, we study the head-on collision of structures and focus on the interference pattern formation in the density of matter during the collision process. We explore the possibility that the collision of two structures of fluid matter modeled with an ideal gas equation of state also forms interference patterns and found a negative result. Given that a fluid is the most common flavor of dark matter models, we conclude that one fingerprint of the BEC dark matter model is the pattern formation in the density during a collision of structures.Comment: 7 pages, 22 eps figure

J D Bernal: philosophy, politics and the science of science

This paper is an examination of the philosophical and political legacy of John Desmond Bernal. It addresses the evidence of an emerging consensus on Bernal based on the recent biography of Bernal by Andrew Brown and the reviews it has received. It takes issue with this view of Bernal, which tends to be admiring of his scientific contribution, bemused by his sexuality, condescending to his philosophy and hostile to his politics. This article is a critical defence of his philosophical and political position

J D Bernal: philosophy, politics and the science of science

This paper is an examination of the philosophical and political legacy of John Desmond Bernal. It addresses the evidence of an emerging consensus on Bernal based on the recent biography of Bernal by Andrew Brown and the reviews it has received. It takes issue with this view of Bernal, which tends to be admiring of his scientific contribution, bemused by his sexuality, condescending to his philosophy and hostile to his politics. This article is a critical defence of his philosophical and political position

The Jahn-Teller active fluoroperovskites ACrF3A\mathrm{CrF_3} A=Na+,K+A=\mathrm{Na^+},\mathrm{K^+}: thermo- and magneto optical correlations as function of the AA-site

Chromium (II) fluoroperovskites $A\mathrm{CrF_3}(A\mathrm{=Na^+,K^+})$ are strongly correlated Jahn-Teller active materials at low temperatures. In this paper, we examine the role that the $A$-site ion plays in this family of fluoroperovskites using both experimental methods (XRD, optical absorption spectroscopy and magnetic fields) and DFT simulations. Temperature-dependent optical absorption experiments show that the spin-allowed transitions $E_2$ and $E_3$ only merge completely for $A$= Na at 2 K. Field-dependent optical absorption measurements at 2 K show that the oscillating strength of the spin-allowed transitions in $\mathrm{NaCrF_3}$ increases with increasing applied field. Direct magneto-structural correlations which suppress the spin-flip transitions are observed for ${\rm KCrF_3}$ below its Ne\'el temperature. In ${\rm NaCrF_3}$ the spin-flip transitions vanish abruptly below 9 K revealing magneto-optical correlations not linked to crystal structure changes. This suggests that as the long range ordering is reduced local JT effects in the individual ${\rm CrF_6^{4-}}$ octahedra take control of the observed behavior. Our results show clear deviation from the pattern found for the isoelectronic $A_x{\rm MnF}_{3+x}$ system. The size of the $A$-site cation is shown to be central in dictating the physical properties and phase transitions in $A{\rm CrF}_3$, opening up the possibility of varying the composition to create novel states of matter with tuneable properties

Scalar Field Dark Matter: head-on interaction between two structures

In this manuscript we track the evolution of a system consisting of two self-gravitating virialized objects made of a scalar field in the newtonian limit. The Schr\"odinger-Poisson system contains a potential with self-interaction of the Gross-Pitaevskii type for Bose Condensates. Our results indicate that solitonic behavior is allowed in the scalar field dark matter model when the total energy of the system is positive, that is, the two blobs pass through each other as should happen for solitons; on the other hand, there is a true collision of the two blobs when the total energy is negative.Comment: 8 revtex pages, 11 eps figures. v2 matches the published version. v2=v1+ref+minor_change

Resolution characteristics of holographic particle image velocimetry

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76221/1/AIAA-1992-9-516.pd

Signals of CP Violation Beyond the MSSM in Higgs and Flavor Physics

We study an extension of the Higgs sector of the Minimal Supersymmetric Standard Model (MSSM), considering the effects of new degrees of freedom at the TeV scale, and allowing for sources of CP violation beyond the MSSM (BMSSM). We analyze the impact of the BMSSM sources of CP violation on the Higgs collider phenomenology and on low energy flavor and CP violating observables. We identify distinct Higgs collider signatures that cannot be realized, either in the case without CP violating phases or in the CP violating MSSM, and investigate the prospects to probe them at the Tevatron and the LHC. The most striking benchmark scenario has three neutral Higgs bosons that all decay dominantly into W boson pairs and that are well within the reach of the 7 TeV LHC run. On the other hand, we also present scenarios with three Higgs bosons that have masses M_Hi > 150 GeV and decay dominantly into b bbar. Such scenarios are much more challenging to probe and can even lie completely outside the reach of the 7 TeV LHC run. We explore complementary scenarios with standard MSSM Higgs signals that allow to accommodate a sizable B_s mixing phase as indicated by D0, as well as the excess in B_s --> mu+ mu- candidates recently reported by CDF. We find that, in contrast to the MSSM, a minimal flavor violating soft sector is sufficient to generate significant corrections to CP violating observables in meson mixing, compatible with EDM constraints. In particular, a sizable B_s mixing phase, S_psiphi < 0.4, can be achieved for specific regions of parameter space. Such a large B_s mixing phase would unambiguously imply a sizable suppression of S_psiKs with respect to the SM prediction and a BR(B_s --> mu+ mu-) close to the 95% C.L. upper bound reported by CDF.Comment: 58 pages, 15 figures, 2 tables, v2 matches published versio

Complete genome sequence of a Pseudomonas putida clinical isolate, strain H8234

We report the complete genome sequence of Pseudomonas putida strain H8234, which was isolated from a hospital patient presenting with bacteremia. This strain has a single chromosome (6,870,827 bp) that contains 6,305 open reading frames. The strain is not a pathogen but exhibits multidrug resistance associated with 40 genomic islands