Half-BPS quotients in M-theory: ADE with a twist

We classify Freund-Rubin backgrounds of eleven-dimensional supergravity of the form AdS_4 x X^7 which are at least half BPS; equivalently, smooth quotients of the round 7-sphere by finite subgroups of SO(8) which admit an (N>3)-dimensional subspace of Killing spinors. The classification is given in terms of pairs consisting of an ADE subgroup of SU(2) and an automorphism defining its embedding in SO(8). In particular we find novel half-BPS quotients associated with the subgroups of type D_n (for n>5), E_7 and E_8 and their outer automorphisms.Comment: 16 pages; V2: notational inconsistencies addressed, final version to be published in JHE

Endovascular Management Of Extremity Arterial Trauma

Treatment of arterial traumatic injuries is usually performed with conventional revascularization techniques. However, vascular injuries can increasingly be repaired efficiently through minimally invasive procedures. We report four cases of extremity arterial trauma treated by endovascular techniques in a reference center. All patients showed satisfactory development over a 15-month follow-up. We suggest that endovascular therapy is a promising alternative to surgery for selected patients with extremity arterial trauma.715661Deguara, J., Ali, T., Modarai, B., Burnand, K.G., Upper limb ischemia: 20 years experience from a single center (2005) Vascular, 13, pp. 84-91Huynh, T.T., Pham, M., Griffin, L.W., Management of distal femoral and popliteal arterial injuries: An update (2006) Am J Surg, 192, pp. 773-778Peck, M.A., Rasmussen, T.E., Management of blunt peripheral arterial injury (2006) Perspect Vasc Surg Endovasc Ther, 18, pp. 159-173Vasdekis, S.N., Kakisis, J.D., Lazaris, A.M., Panayiotides, J.G., Angeli, A.A., Karkaletsis, K.G., Common femoral artery injury secondary to tennis ball strike (2006) J Vasc Surg, 44, pp. 1350-1352Starnes, B.W., Arthurs, Z.M., Endovascular management of vascular trauma (2006) Perspect Vasc Surg Endovasc Ther, 18, pp. 114-129Criado, E., Marston, W.A., Ligush, J., Mauro, M.A., Keagy, B.A., Endovascular repair of peripheral aneurysms, pseudoaneurysms and arteriovenous fistulas (1997) Ann Vasc Surg, 11, pp. 253-263du Toit, D.F., Strauss, D.C., Blaszczyk, M., de Villiers, R., Warren, B.L., Endovascular treatment of penetrating thoracic outlet arterial injuries (2000) Eur J Vasc Endovasc Surg, 19, pp. 489-495du Toit, D.F., Leith, J.G., Strauss, D.C., Blaszczyk, M., Odendaal, J.V., Warren, B.L., Endovascular management of traumatic cervicothoracic arteriovenous fistula (2003) Br J Surg, 90, pp. 1516-1521Kember, P.G., Wood, R.F., Gaines, P.A., Endovascular management of a non-penetrating traumatic axillary artery occlusion (1997) Eur J Vasc Endovasc Surg, 14, pp. 227-228Mattox KL, Hirshberg A. Traumatismo vascular. In: Haimovici H, editor. Cirurgia vascular. Rio de Janeiro: Di-Livros2000. p. 480-96Strauss, D.C., du Toit, D.F., Warren, B.L., Endovascular repair of occluded subclavian arteries following penetrating trauma (2001) J Endovasc Ther, 8, pp. 529-533Kuzniec, S., Traumatismos vasculares (2002) Cirurgia vascular, pp. 706-720. , Brito CJ, editor, Rio de Janeiro: Revinter;Aun, R., Leão, P.P., Tratamento dos ferimentos vasculares por métodos endovasculares (2002) Cirurgia vascular, pp. 721-727. , Brito CJ, editor, Rio de Janeiro: Revinter;Lönn, L., Delle, M., Karlström, L., Risberg, B., Should blunt arterial trauma to the extremities be treated with endovascular techniques? (2005) J Trauma, 59, pp. 1224-1227Alvarez-Tostado, J., Tulsyan, N., Butler, B., Rizzo, A., Endovascular management of acute critical ischemia secondary to blunt tibial artery injury (2006) J Vasc Surg, 44, pp. 1101-1103Johnson SF, Johnson SB, Strodel WE, Barker DE, Kearney PA. Brachial plexus injury: association with subclavian and axillary vascular trauma. J Trauma. 1991;31:1546-50. J Vasc Bras. 2008;7(1):62-

Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy

We review HB stars in a broad astrophysical context, including both variable and non-variable stars. A reassessment of the Oosterhoff dichotomy is presented, which provides unprecedented detail regarding its origin and systematics. We show that the Oosterhoff dichotomy and the distribution of globular clusters (GCs) in the HB morphology-metallicity plane both exclude, with high statistical significance, the possibility that the Galactic halo may have formed from the accretion of dwarf galaxies resembling present-day Milky Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the second-parameter problem is presented. A technique is proposed to estimate the HB types of extragalactic GCs on the basis of integrated far-UV photometry. The relationship between the absolute V magnitude of the HB at the RR Lyrae level and metallicity, as obtained on the basis of trigonometric parallax measurements for the star RR Lyrae, is also revisited, giving a distance modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are studied. Finally, the conductive opacities used in evolutionary calculations of low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and Space Scienc