Reconciling discordant morphological and molecular phylogenies remains a problem in modern systematics. By examining conflicting DNA-hybridization and morphological phylogenies of sand dollars, I show that morphological criteria may be used to help evaluate the reliability of molecular phylogenies where they differ from morphological trees. All available criteria for assessing the reliability o...

The Chip Firing Game (CFG) is a discrete dynamical model used in physics, computer science and economics. It is known that the set of configurations reachable from an initial configuration (this set is called the configuration space) can be ordered as a lattice. We first present a structural result about this model, which allows us to introduce some useful tools for describing those lattices. T...

Free-spawning marine invertebrates that live near shore or in estuaries may experience reduced fertilization success during low-salinity events. Although several studies have documented reproductive failure at reduced salinity in estuarine animals, few have looked at whether developmental failure is due to a failure of fertilization or to a failure of fertilized eggs to cleave. In this study, w...

Recent work on a diverse array of echinoderm species has demonstrated, as is true in amphibians, that thyroid hormone (TH) accelerates development to metamorphosis. Interestingly, the feeding larvae of several species of sea urchins seem to obtain TH through their diet of planktonic algae (exogenous source), whereas nonfeeding larvae of the sand dollar Peronella japonica produce TH themselves (...

We present a novel approach for a virtual granular material interactive manipulation with force feedback. A user can interactively change a height-field model of sand by dragging objects inside. The virtual sand behaves like real sand moving to the sides and falling back, filling holes and irregularities on the surface. The dragging object position is controlled by a haptic device that provides...

The aim of this paper was to verify hydrological and hydrochemical changes in the Iquiparí Lagoon water column, during three months, as related to an artificial sand bar opening. A drastic reduction in water volume occurred 28 hours after the sand bar opening, exposing the bottom sediment. This was densely colonized by submerged aquatic plants, which were dominant in the ecosystem metabolism, s...

Since the first NCK-Days 20 years ago, a significant body of large-scale laboratory experiments on wave-driven sand transport has been conducted in oscillatory flow tunnels and large wave flumes. The experiments have yielded measures of net sand transport rates for a wide range of flow and sand conditions and have provided insights that have informed the development of practical predictors for ...

This paper describes an experimental investigation into the pore structure of cement mortar using mercury porosimeter. Ordinary Portland cement, manufactured sand, and natural sand were used. The porosity of the manufactured sand mortar is higher than that of natural sand at the same mix proportion; on the contrary, the probable pore size and threshold radius of manufactured sand mortar are fin...

Catches of mosquitoes and sand flies in CO, traps baited with three different lures and an unbaited control were compared. The lures examined were carbon dioxide, carbon dioxide plus l-octen-3-ol, and carbon dioxide plus human hair in ethanol. Studies using a 4 x 4 Latin square design, with 3 sets of 4 consecutive trap nights, were conducted between August 6 and September 10, 2007. The study si...

Barchans are crescent-shaped sand dunes forming in aride regions with unidirectional wind and limited sand supply. We report analytical and numerical results for dune shapes under different environmental conditions as obtained from the so-called ‘minimal model’ of aeolian sand dunes. The profiles of longitudinal vertical slices (i.e. along the wind direction) are analyzed as a function of wind ...