Supplementary Studies on the Systematics of the Genus Perdita (Hymenoptera, Andrenidae) Part ll

This is the second part of a study (1971) that is supplementary to my revision of the genus Perdita (1954, 1956, 1958, 1960, 1962, 1964, 1968). Herein are treated some 57 species, of which 44 are described as new and the synonymy of three species is given. New keys are provided for the subgenera Macroteropsis, Epimacrotera, Cockerellula, and the Octomaculata Group and Sphaeralceae Group of the subgenus Perdita. The key to Macroteropsis is new for the females of that group, that for Epimacrotera is a revision of the key in Part III (1958). The key to Cockerellula is also a revision and those for Octomaculata and Sphaeralcea groups are supplementary

A Revisional Study of the Bees of the Genus Perdita F. Smith, With Special Reference to the Fauna of the Pacific Coast (Hymenoptera, Apoidea) Part V

In parts III and IV of this revision the species of the typical subgenus of Perdita belonging in the zonalis, halictoides, and octomaculata groups have been treated. This study is now extended to include the species belonging in that section of Perdita which may be called the ventralis group. In order to facilitate the study of these bees a key to the groups treated in Part III and subsequent parts is here offered. This key may afford some help in classifying the more typical members of the groups, but because of the multiplicity and extreme diversity of these insects, I make no claim for its infallibility

A Revisional Study of the Bees of the Genus Perdita F. Smith, With Special Reference to the Fauna of the Pacific Coast (Hymenoptera, Apoidea) Part I

The genus Perdita forms one of the most interesting groups of bees of the North American fauna, and is one to which the author has devoted much attention during the last twenty-five years. The privilege of examining specimens of Perdita belonging to the United States National Museum, the American Museum of Natural History, the California Academy of Sciences, the University of California, and the University of Kansas is gratefully acknowledged, as well as the help of many individuals, who during this time have placed their specimens at the author\u27s disposal. Special mention should be made of J. C. Bridwell, J. Chester Bradley, Herman A. Scullen, E. Gorton Linsley, Charles D. Michener, George F. Knowlton, Richard M. Bohart, George E. Bohart, and Paul D. Hurd, Jr., all of whom have contributed many specimens and have discovered at least one particular species that in many cases would have otherwise remained unknown

Supplementary Studies on the Systematics of the Genus Perdita (Hymenoptera, Andrenidae)

Since or during the completion of my work on the monographic revision of the genus Perdita, published in seven parts (University of California Publications in Entomology 9:345-432, 11:247-350; 14:303-410, 17:1-156, 28:1-124, 28:125-388, 49: 1-196), much new material has accumulated or has been submitted for study and identification. As a result, I have found it necessary to present this supplementary study, and it is expected that other parts may follow, as the topic is far from exhaustion. In this part some 64 species are treated, of which 32 are thought to be new, and renewed study has revealed new synonymy involving four species and seven names. This contribution to the advancement of science, like several of the last parts of my revisional study, has been supported by financial aid from National Science Foundation Grant No. GB-5611 and GB-2014

Africa, Animals & Artistes

Join me for an interactive session where literacy truly goes global. This presentation features Gail\u27s latest children\u27s book, Nyangusi Brought a Monkey to Church, an escapade with a mission team in Tanzania. Experience energy using music, storytelling, words that rhyme, art that inspires, and creativity that sparks the imagination of all ages

A Revisional Study of the Bees of the Genus Perdita F. Smith, With Special Reference to the Fauna of the Pacific Coast (Hymenoptera, Apoidea) Part III

In the two preceding parts of this revision those species of Perdita have been treated that belong to the subgenera Xerophasma, Pseudomacrotera, Macrotera, Cockerellula, Macroteropsis, Macroterella, Heteroperdita, Glossoperdita, Hesperoperdita, Epimacrotera, Cockerellia, Procockerellia, Pentaperdita, Xeromacrotera, Callomacrotera, Hexaperdita, Perditella, Alloperdita, and Pygoperdita. The many species now remaining will be referred to the typical subgenus, although divided into numerous groups. In Part III the systematics of those sections of the typical subgenus designated as the zonalis and halictoides groups will be considered, together with supplemental information on the subgenera treated in Part I and II

Comparing periodic-orbit theory to perturbation theory in the asymmetric infinite square well

An infinite square well with a discontinuous step is one of the simplest systems to exhibit non-Newtonian ray-splitting periodic orbits in the semiclassical limit. This system is analyzed using both time-independent perturbation theory (PT) and periodic-orbit theory and the approximate formulas for the energy eigenvalues derived from these two approaches are compared. The periodic orbits of the system can be divided into classes according to how many times they reflect from the potential step. Different classes of orbits contribute to different orders of PT. The dominant term in the second-order PT correction is due to non-Newtonian orbits that reflect from the step exactly once. In the limit in which PT converges the periodic-orbit theory results agree with those of PT, but outside of this limit the periodic-orbit theory gives much more accurate results for energies above the potential step.Comment: 22 pages, 2 figures, 2 tables, submitted to Physical Review

Probing modified gravity with magnetically levitated resonators

We present an experimental procedure, based on Meissner effect levitation of neodymium ferromagnets, as a method of measuring the gravitational interactions between milligram masses. The scheme consists of two superconducting lead traps, with a magnet levitating in each trap. The levitating magnets behave as harmonic oscillators and, by carefully driving the motion of one magnet on resonance with the other, we find that it should easily be possible to measure the gravitational field produced by a 4 mg sphere, with the gravitational attraction from masses as small as 30 μg predicted to be measurable within a realistic measurement time frame. We apply this acceleration sensitivity to one concrete example and show the abilities of testing models of modified Newtonian dynamics

Testing Dissipative Collapse Models with a Levitated Micromagnet

We present experimental tests of dissipative extensions of spontaneous wave function collapse models based on a levitated micromagnet with ultralow dissipation. The spherical micromagnet, with radius $R=27$ $\mu$m, is levitated by Meissner effect in a lead trap at $4.2$ K and its motion is detected by a SQUID. We perform accurate ringdown measurements on the vertical translational mode with frequency $57$ Hz, and infer the residual damping at vanishing pressure $\gamma/2\pi<9$ $\mu$Hz. From this upper limit we derive improved bounds on the dissipative versions of the CSL (continuous spontaneous localization) and the DP (Di\'{o}si-Penrose) models with proper choices of the reference mass. In particular, dissipative models give rise to an intrinsic damping of an isolated system with the effect parameterized by a temperature constant; the dissipative CSL model with temperatures below 1 nK is ruled out, while the dissipative DP model is excluded for temperatures below $10^{-13}$ K. Furthermore, we present the first bounds on dissipative effects in a more recent model, which relates the wave function collapse to fluctuations of a generalized complex-valued spacetime metric.Comment: 10 pages, 7 figure