Non-Gaussian curvature distribution of actin-propelled biomimetric colloid trajectories

We analyze the motion of colloids propelled by a comet-like tail of polymerizing actin filaments. The curvature of the particle trajectories deviates strongly from a Gaussian distribution, implying that the underlying microscopic processes are fluctuating in a non-independent manner. Trajectories for beads of different size all showed the same non-Gaussian behavior, while the mean curvature decreased weakly with size. A stochastic simulation that includes nucleation, force-dependent dissociation, growth, and capping of filaments, shows that the non-Gaussian curvature distribution can be explained by a positive feedback mechanism in which attached chains under higher tension are more likely to sna

Diphoton production in gluon fusion at small transverse momentum

We discuss the production of photon pairs in gluon-gluon scattering in the context of the position-space resummation formalism at small transverse momentum. We derive the remaining unknown coefficients that arise at $O(\alpha_S)$, as well as the remaining $O(\alpha_S^2)$ coefficient that occurs in the Sudakov factor. We comment on the impact of these coefficients on the normalization and shape of the resummed transverse momentum distribution of photon pairs, which comprise an important background to Higgs boson production at the LHC.Comment: 11 pages, 3 figures; minor changes, additional referenc

A comprehensive study of shower to shower fluctuations

By means of Monte Carlo simulations of extensive air showers (EAS), we have performed a comprehensive study of the shower to shower fluctuations affecting the longitudinal and lateral development of EAS. We split the fluctuations into physical fluctuations and those induced by the thinning procedure customarily applied to simulate showers at EeV energies and above. We study the influence of thinning on the calculation of the shower to shower fluctuations in the simulations. For thinning levels larger than 10^(-5) - 10^(-6), the determination of the shower to shower fluctuations is hampered by the artificial fluctuations induced by the thinning procedure. However, we show that shower to shower fluctuations can still be approximately estimated, and we provide expressions to calculate them. The influence of fluctuations of the depth of first interaction on the determination of shower to shower fluctuations is also addressed.Comment: 17 pages, 15 figure

Simulation of Beam-Beam Effects and Tevatron Experience

Effects of electromagnetic interactions of colliding bunches in the Tevatron had a variety of manifestations in beam dynamics presenting vast opportunities for development of simulation models and tools. In this paper the computer code for simulation of weak-strong beam-beam effects in hadron colliders is described. We report the collider operational experience relevant to beam-beam interactions, explain major effects limiting the collider performance and compare results of observations and measurements with simulations.Comment: 23 pages, 17 figure

Exile Vol. XI No. 1

FICTION By the Fire of the Chief by Peggy Schmidt 9-17 From the Diary of a Vanishing Man by Ed Brunner 19-29 Dialogue by Ken Booth 35-37 POETRY Johnny Joe by Bill West 6-7 Caterpillar by Barb Bergantz 17 Poem by Bonnie McCarthy 29 The Queen by Hugh Wilder 31 The Clown by Barb Bergantz 32 Poem by Gretchen Schenck 33 Treatise on Cosmology by P. M. Grout 37 Stimulus by Susan Sherwood 37 Depot by Susan Sherwood 39 GRAPHICS Pen and Ink by Dave Goodwin 7 Pen and Ink by Ramona Gibbs 8 Pen and Ink by Tod Riddell 18 Charcoal by Dave Goodwin 30 Woodcut by Parker Waite III 34 Woodcut by Lela Giles 3

Diagnostic Nodes of Patient Selection for Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy Among Colorectal Cancer Patients: A Swiss National Multicenter Survey.

The management of patients with colorectal cancer (CRC) with peritoneal metastases is challenging, and the roles of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are unclear and debated among experts. The experts of the Swiss Peritoneal Cancer Group were contacted and agreed to participate in this analysis. Experts from 9 centers in Switzerland provided their decision algorithms for CRS/HIPEC for patients with or at high risk for peritoneal metastases from CRC. Their responses were converted into decision trees on the basis of objective consensus methodology. The decision trees were used as a basis to identify consensus and discrepancies. The final treatment algorithms included a total of 5 decision criteria (age, Peritoneal Cancer Index [PCI], extraperitoneal metastases, Peritoneal Surface Disease Severity Score, and various risk factors [RF]) and 2 treatment options (HIPEC, yes or no). HIPEC was never recommended for patients without peritoneal metastases in the absence of RF for peritoneal metastases. For patients with a PCI ≤15 without organ metastases, all centers recommended CRS/HIPEC. There was also a consensus not to perform CRS/HIPEC in elderly patients (80 years and older), those with a PCI >20, and those with unresectable metastases. For patients with a PCI = 16 to 20, there was no consensus. Multiple decision criteria relevant to all participating centers were identified. Because patient selection for CRS/HIPEC remains difficult, uniform criteria for the term "high risk" for peritoneal metastases and systemic metastases are helpful. Future trials and guidelines should take these criteria into account