Phoresy by Pseudoscorpions

Excerpt: Phoretic behavior involving a non-parasitic association of a larger animal by a smaller animal resulting in transportation is well-documented in some pseudoscorpions. Muchmore (1971) summarized the records of pseudoscorpion phoresy in Central and North America as presented by Beier and as published since 1948

The Biology of Pseudoscorpions. Peter Weygoldt. Cambridge, Massachusetts. Harvard University Press, 1969, viii 145 pp. $6.00.

Excerpt: This is the first comprehensive approach to the biology of pseudoscorpions. Through excellent discourse and a well-organized presentation the author aims to stimulate more interest in this diverse yet little-known group

Introduction to Zoology. T. H. Savory. New York: Philosophical Library, 1968. viii, 239 pp. $6.00.

Excerpt: This book would delight the traditional zoologist as its emphasis is on systematics and evolution. primarily based on morphology. By the author\u27s own admission he neglects areas concerning histology, embryology, physiology and genetics, while giving little time to areas he terms animal biology--symbiosis, parthenogenesis, behavior and parasitism. Dr. Savory feels the aforementioned areas warrant volumes of their own. Yet this book is titled Introduction to Zoology. Perhaps a better title would be Introduction to Zoology, Part I. Systematics and Evolution

Fighter aircraft flight control technology design requirements

The evolution of fighter aircraft flight control technology is briefly surveyed. Systems engineering, battle damage considerations for adaptive flutter suppression, in-flight simulation, and artificial intelligence are briefly discussed

Dynamics of Rotation of Super-Earths

We numerically investigate the dynamics of rotation of several close-in terrestrial exoplanet candidates. In our model, the rotation of the planet is disturbed by the torque of the central star due to the asymmetric equilibrium figure of the planet. We model the shape of the planet by a Jeans spheroid. We use surfaces of section and spectral analysis to explore numerically the rotation phase space of the systems adopting different sets of parameters and initial conditions close to the main spin-orbit resonant states. One of the parameters, the orbital eccentricity, is critically discussed here within the domain of validity of orbital circularization timescales given by tidal models. We show that, depending on some parameters of the system like the radius and mass of the planet, eccentricity etc, the rotation can be strongly perturbed and a chaotic layer around the synchronous state may occupy a significant region of the phase space. 55 Cnc e is an example.Comment: In Press. Celestial Mechanics and Dynamical Astronomy. 30 pages, 9 figure

Buckling of a growing tissue and the emergence of two-dimensional patterns

The process of biological growth and the associated generation of residual stress has previously been considered as a driving mechanism for tissue buckling and pattern selection in numerous areas of biology. Here, we develop a two-dimensional thin plate theory to simulate the growth of cultured intestinal epithelial cells on a deformable substrate, with the goal of elucidating how a tissue engineer might best recreate the regular array of invaginations (crypts of Lieberkühn) found in the wall of the mammalian intestine. We extend the standard von Kármán equations to incorporate inhomogeneity in the plate’s mechanical properties and surface stresses applied to the substrate by cell proliferation. We determine numerically the configurations of a homogeneous plate under uniform cell growth, and show how tethering to an underlying elastic foundation can be used to promote higher-order buckled configurations. We then examine the independent effects of localised softening of the substrate and spatial patterning of cellular growth, demonstrating that (within a two-dimensional framework, and contrary to the predictions of one-dimensional models) growth patterning constitutes a more viable mechanism for control of crypt distribution than does material inhomogeneity

Low level accelerometer test methods are investigated

Problems associated with testing accelerometers to an accuracy where the standard error is less than .0000001 g are centered around the elimination of uncertainties in the acceleration input to the accelerometer. By placing a test rig in free fall, the uncertainty in the earths gravity field can be eliminated

On Measurement of Helicity Parameters in Top Quark Decay

To enable an evaluation of future measurements of the helicity parameters for " t --> W b " decay in regard to " T_FS violation", this paper considers the effects of an additional pure-imaginary coupling, (i g/2 Lambda) or (i g), associated with a specific, single additional Lorentz structure, i = S, P, S + P, ... Sizable " T_FS violation" signatures can occur for low-effective mass scales (< 320 GeV), but in most cases can be more simply excluded by 10% precision measurement of the probabilities P(W_L) and P(b_L). Signatures for excluding the presence of " T_FS violation" associated with the two dynamical phase-type ambiguities are investigated.Comment: 15 pages, 1 table, 7 figures, no macro