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

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

Colletes from Colorado

p. 385-410 : ill. ; 25 cm.Includes bibliographical references

Changes in Floquet state structure at avoided crossings: delocalization and harmonic generation

Avoided crossings are common in the quasienergy spectra of strongly driven nonlinear quantum wells. In this paper we examine the sinusoidally driven particle in a square potential well to show that avoided crossings can alter the structure of Floquet states in this system. Two types of avoided crossings are identified: on type leads only to temporary changes (as a function of driving field strength) in Floquet state structure while the second type can lead to permanent delocalization of the Floquet states. Radiation spectra from these latter states show significant increase in high harmonic generation as the system passes through the avoided crossing.Comment: 8 pages with 10 figures submitted to Physical Review

Interaction and Localization of One-electron Orbitals in an Organic Molecule: Fictitious Parameter Analysis for Multi-physics Simulations

We present a new methodology to analyze complicated multi-physics simulations by introducing a fictitious parameter. Using the method, we study quantum mechanical aspects of an organic molecule in water. The simulation is variationally constructed from the ab initio molecular orbital method and the classical statistical mechanics with the fictitious parameter representing the coupling strength between solute and solvent. We obtain a number of one-electron orbital energies of the solute molecule derived from the Hartree-Fock approximation, and eigenvalue-statistical analysis developed in the study of nonintegrable systems is applied to them. Based on the results, we analyze localization properties of the electronic wavefunctions under the influence of the solvent.Comment: 4 pages, 5 figures, the revised version will appear in J. Phys. Soc. Jpn. Vol.76 (No.1

Review of epidemiologic data on the debate over smokeless tobacco's role in harm reduction

Some tobacco researchers have argued that the European Union should remove its ban on a form of low-nitrosamine smokeless tobacco referred to as Swedish 'snus'. This argument has developed in to an international debate over the use of smokeless tobacco as a measure of harm reduction for smokers. Leading authorities in the USA have firmly stated that there is no safe tobacco - a message which does not allow for any discussion of comparative tobacco risks. This commentary is intended to review the origin of the controversy over Swedish 'snus', to examine briefly the meta-analysis on cancer risks by Peter Lee and Jan Hamling (published in July in BMC Medicine) and to discuss the anticipated direction of the debate on tobacco-harm reduction in the USA. We anticipate that much of the debate will shift from the discussion of epidemiologic data to the discussion of the marketing, health communication and economics of smokeless tobacco. While the Food and Drug Administration's newly approved authority over tobacco will undoubtedly affect the smokeless products, it may not be the sole determinant of harm reduction's fate in the USA

Dynamics of quantum systems

A relation between the eigenvalues of an effective Hamilton operator and the poles of the $S$ matrix is derived which holds for isolated as well as for overlapping resonance states. The system may be a many-particle quantum system with two-body forces between the constituents or it may be a quantum billiard without any two-body forces. Avoided crossings of discrete states as well as of resonance states are traced back to the existence of branch points in the complex plane. Under certain conditions, these branch points appear as double poles of the $S$ matrix. They influence the dynamics of open as well as of closed quantum systems. The dynamics of the two-level system is studied in detail analytically as well as numerically.Comment: 21 pages 7 figure