Xantusia henshawi

Number of Pages: 2Integrative BiologyGeological Science

Anolis sericeus

Number of Pages: 2Integrative BiologyGeological Science

Planar Ultrametric Rounding for Image Segmentation

We study the problem of hierarchical clustering on planar graphs. We formulate this in terms of an LP relaxation of ultrametric rounding. To solve this LP efficiently we introduce a dual cutting plane scheme that uses minimum cost perfect matching as a subroutine in order to efficiently explore the space of planar partitions. We apply our algorithm to the problem of hierarchical image segmentation

Power-law intensity distribution in γ\gamma-decay cascades -- Nuclear Structure as a Scale-Free Random Network

By modeling the transition paths of the nuclear $\gamma$-decay cascade using a scale-free random network, we uncover a universal power-law distribution of $\gamma$-ray intensity $\rho_I(I) \propto I^{-2}$, with $I$ the $\gamma$-ray intensity of each transition. This property is consistently observed for all datasets with a sufficient number of $\gamma$-ray intensity entries in the National Nuclear Data Center database, regardless of the reaction type or nuclei involved. In addition, we perform numerical simulations which support the model's predictions of level population density

A Melanic Pieris Rapae from Michigan (Lepidoptera: Pierdae)

The Arthur J. Yates collection of Michigan Lepidoptera, recently donated to Michigan State University (see Fischer, 1967), contained a striking melanic male cabbage butterfly [Pieris rapae (Linnaeus)] (Figs. 1, 2) now incorporated into the MSU series. Yates collected the specimen on 29 May 1934 in Roseville, Macomb County, near the western shore of Lake St. Clair in southeastern Michigan. An examination of the androconia and genitalia, using the characters described by Chang (1963), assured proper identification of the specimen. Although we have found no record of a similar rapae taken in North America, there are some named European forms of various species of Pieris that resemble our specimen

Predicting Success, Preventing Failure: An Investigation of the California High School Exit Exam

Examines early indicators that identify fourth-grade students in San Diego who are at risk of failing the California High School Exit Exam, discusses implications for when and how to intervene to address those factors, and makes policy recommendations

Shape fluctuations and elastic properties of two-component bilayer membranes

The elastic properties of two-component bilayer membranes are studied using a coarse grain model for amphiphilic molecules. The two species of amphiphiles considered here differ only in their length. Molecular Dynamics simulations are performed in order to analyze the shape fluctuations of the two-component bilayer membranes and to determine their bending rigidity. Both the bending rigidity and its inverse are found to be nonmonotonic functions of the mole fraction $x_{\rm B}$ of the shorter B-amphiphiles and, thus, do not satisfy a simple lever rule. The intrinsic area of the bilayer also exhibits a nonmonotonic dependence on $x_{\rm B}$ and a maximum close to $x_{\rm B} \simeq 1/2$.Comment: To appear on Europhysics Letter