Isolated and non-isolated dwarfs in terms of modified Newtonian dynamics

Within the framework of modified Newtonian dynamics (MOND) we investigate the kinematics of two dwarf spiral galaxies belonging to very different environments, namely KK 246 in the Local Void and Holmberg II in the M81 group. A mass model of the rotation curve of KK 246 is presented for the first time, and we show that its observed kinematics are consistent with MOND. We re-derive the outer rotation curve of Holmberg II, by modelling its HI data cube, and find that its inclination should be closer to face-on than previously derived. This implies that Holmberg II has a higher rotation velocity in its outer parts, which, although not very precisely constrained, is consistent with the MOND prediction.Comment: Accepted in A&A as a Research Note. 6 pages, 3 figure

Isolated and non-isolated dark matter halos and the NFW profile

We compare the conclusions reached using the coarse-graining technique employed by Henriksen (2004) for a one degree of freedom (per particle) collisionless system, to those presented in a paper by Binney (2004) based on an exact one degree of freedom model. We find agreement in detail but in addition we show that the isolated 1D system is self-similar and therefore unrelaxed. Fine graining of this system recovers much less prominent wave-like structure than in a spherically symmetric isotropic 3D system. The rate of central flattening is also reduced in the 1D system. We take this to be evidence that relaxation of collisionless systems proceeds ultimately by way of short wavelength Landau damping. N-body systems, both real and simulated, can be trapped in an incompletely relaxed state because of a break in the cascade of energy to small scales. This may be due to the rapid dissipation of the small scale oscillations in an isolated system, to the existence of conserved quantities such as angular momentum, or to the failure in simulations to resolve sub-Jeans length scales. Such a partially relaxed state appears to be the NFW state, and is to be expected especially in young systems. The NFW core is shown to be isolated. In non-isolated systems continuing coarse-grained relaxation should be towards a density core in solid body rotation.Comment: 14 pages, MNRAS, submitted 21 June 200

Isolated Gonococcal Extensor Tenosynovitis

Neisseria gonorrhoeae is a mucosal infection that has the propensity to disseminate, causing symptoms that commonly include arthralgias, skin lesions, fevers, chills, dysuria, genital discharge, septic arthritis, and/or tenosynovitis. Typically, gonococcal tenosynovitis affects the flexor sheath and is associated with arthralgias, skin lesions, or both. To the best of our knowledge, there has not been a documented case of isolated gonococcal extensor tenosynovitis. We report the case of a 16-year-old boy with isolated left upper-extremity gonococcal extensor tenosynovitis who was successfully treated with surgical debridement and antibiotic therapy