All-Orders Quadratic-Logarithmic Behavior for Amplitudes.

We classify origin limits of maximally helicity violating multigluon scattering amplitudes in planar N=4 super-Yang-Mills theory, where a large number of cross ratios approach zero, with the help of cluster algebras. By analyzing existing perturbative data and bootstrapping new data, we provide evidence that the amplitudes become the exponential of a quadratic polynomial in the large logarithms. With additional input from the thermodynamic Bethe ansatz at strong coupling, we conjecture exact expressions for amplitudes with up to eight gluons in all origin limits. Our expressions are governed by the tilted cusp anomalous dimension evaluated at various values of the tilt angle.

Cluster Algebras for Feynman Integrals.

We initiate the study of cluster algebras in Feynman integrals in dimensional regularization. We provide evidence that four-point Feynman integrals with one off-shell leg are described by a C_{2} cluster algebra, and we find cluster adjacency relations that restrict the allowed function space. By embedding C_{2} inside the A_{3} cluster algebra, we identify these adjacencies with the extended Steinmann relations for six-particle massless scattering. The cluster algebra connection we find restricts the functions space for vector boson or Higgs plus jet amplitudes and for form factors recently considered in N=4 super Yang-Mills. We explain general procedures for studying relationships between alphabets of generalized polylogarithmic functions and cluster algebras and use them to provide various identifications of one-loop alphabets with cluster algebras. In particular, we show how one can obtain one-loop alphabets for five-particle scattering from a recently discussed dual conformal eight-particle alphabet related to the G(4,8) cluster algebra.

Origin of the Six-Gluon Amplitude in Planar N=4 Supersymmetric Yang-Mills Theory.

We study the maximally-helicity-violating six-gluon scattering amplitude in planar N=4 super-Yang-Mills theory at finite coupling when all three cross ratios are small. It exhibits a double logarithmic scaling in the cross ratios, controlled by a handful of "anomalous dimensions" that are functions of the coupling constant alone. Inspired by known seven-loop results at weak coupling and the integrability-based pentagon operator product expansion, we present conjectures for the all-order resummation of these anomalous dimensions. At strong coupling, our predictions agree perfectly with the string theory analysis. Intriguingly, the simplest of these anomalous dimensions coincides with one describing the lightlike limit of the octagon, namely, the four-point function of large-charge Bogomol'nyi-Prasad-Sommerfield (BPS) operators.

Volar Metacarpophalangeal Dislocation of Fingers: Review of the Literature.

Isolated volar metacarpophalangeal dislocations of fingers are extremely rare. There are few cases published in English and French literature. In this article, we aim to review the literature and present a case of isolated open volar dislocation of a finger. We treated this dislocation first by a dorsal approach alone and later, after recurrence, using a combined dorsal and volar approach. This report emphasizes the pathology of such injuries, clarifies the mechanisms, and outlines the treatment options of the dislocations. Close reduction can be achieved and maintained if done early. It must be attempted first for all cases. In irreducible or reducible but unstable dislocations, we recommend surgical restoration. During an open reduction, the major torn or avulsed soft tissue joint stabilizers must be repaired. A combined dorsal and volar approach, starting dorsally, is useful.

Spontaneous rupture of a type IVA choledochal cyst in a young adult during radiological imaging.

A case of a 24-year-old male with jaundice and epigastric pain is reported. The patient underwent a thorough clinical, laboratory, and imaging investigation. Computerized tomography revealed a 9 cm mult 10 cm choledochal cyst. Magnetic resonance imaging and magnetic cholangiopancreatography were performed, during which he developed an "acute abdomen", with radiological evidence of biliary peritoneal leak. Urgent surgery revealed rupture of the distended malformed common bile duct. A peritoneal drain was instilled and a more definitive surgical procedure was accordingly scheduled. Hepatobiliary scintigraphy following surgery verified these findings, as well as confirmed the adequacy of the urgent surgery. A combination of radiological and nuclear medicine techniques substantially contributes to the diagnosis of choledochal cyst rupture and the adequacy of surgical intervention.