Molecular phylogenetics of the Metazoan clade Lophotrochozoa

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2003DNA sequencing and phylogenetic analyses were conducted to investigate evolutionary relationships between taxa within the metazoan clade Lophotrochozoa. Chapter 1 presents an introduction to phylogenetics of the Metazoa and the clade Lophotrochozoa. Chapter 2 analyzes higher level relationships between the major groups within the phylum Mollusca using sequences of the nuclear ribosomal large-subunit RNA gene (LSD rDNA). Results presented provide the first molecular evidence for a close relationship between the Scaphopoda and Cephalopoda. Phylogenetic trees with this topology were found to have likelihood scores significantly better than those for phylogenies constrained to fit the Diasoma hypothesis grouping Scaphopoda and Bivalvia as sister taxa. Chapter 3 utilizes LSU rDNA sequences to analyze relationships between diverse phyla within the clade Lophotrochozoa. LSU rDNA sequences were found to provide greater resolution than has been provided by previous analyses of the nuclear small-subunit ribosomal RNA gene (SSU rDNA). Analysis ofLSU rDNA sequences recovered the monophyly of several phyla, such as Mollusca and Anelida, whose members are found to be paraphyletic using SSU rDNA sequences alone. Results also suggest that the clade Platyzoa, including rotifers and platyhelminthes, may have arisen within the Lophotrochozoa, rather than as a sister group to lophotrochozoans. Chapter 4 investigates the Hox gene complement of the bryozoan Bugula turrita. Six Hox genes were recovered, including an ortholog of the posterior class gene Post2, which is a synapomorphy for the Lophotrochozoa. The identification of a Post2 ortholog provides evidence of a close relationship between the Bryozoa and other lophotrochozoan phyla.This work was supported by a grant from the National Science Foundation, DEB-0075618 "Genomic approaches to metazoan evolution; lophotrochozoans and Hox genes" to Kenneth Halanych. Bryozoan Hox research was supported by a Doctoral dissertation Improvement Grant from the National Science Foundation, DEB-OI04984 "Phylogenetic inference from bryozoan Hox genes" to Kenneth Halanych and Yale Passamaneck. Additional support was provided by the Woods Hole Oceanographic Institution Education Office

SOME ULTRASTRUCTURAL EFFECTS OF INSULIN, HYDROCORTISONE, AND PROLACTIN ON MAMMARY GLAND EXPLANTS

The effects of insulin, hydrocortisone, and prolactin on the morphology of explants from midpregnant mouse mammary glands were studied. Insulin promotes the formation of daughter cells within the alveolar epithelium which are ultrastructurally indistinguishable from the parent cells. The addition of hydrocortisone to the medium containing insulin brings the daughter cells to a new, intermediate level of ultrastructural development by effecting an extensive increase of the rough endoplasmic reticulum (RER) throughout the cytoplasm and an increase in the lateral paranuclear Golgi apparatus. When prolactin is added to the insulin-hydrocortisone medium, the daughter cells complete their ultrastructural differentiation. There is a translocation of the RER, Golgi apparatus, and nucleus and the appearance of secretory protein granules within the cytoplasm. There is excellent correlation between the ultrastructural appearance of the alveoli and their capacity to synthesize casein

Electrical Tuning of Single Nitrogen-Vacancy Center Optical Transitions Enhanced by Photoinduced Fields

We demonstrate precise control over the zero-phonon optical transition energies of individual nitrogen-vacancy (NV) centers in diamond by applying multiaxis electric fields, via the dc Stark effect. The Stark shifts display surprising asymmetries that we attribute to an enhancement and rectification of the local electric field by photoionized charge traps in the diamond. Using this effect, we tune the excited-state orbitals of strained NV centers to degeneracy and vary the resulting degenerate optical transition frequency by >10 GHz, a scale comparable to the inhomogeneous frequency distribution. This technique will facilitate the integration of NV-center spins within photonic networks.Comment: 10 pages, 6 figure

Managing the Cost of Federally Sponsored Research at Educational Institutions

In an era of weak economic ·growth, budget deficits and government spending reductions, limited government resources must be utilized in a manner that maximizes the public welfare. One major use of such resources in recent years has been to fund research and other activities at universities. To shed light on this important area, this article examines current practice in government contracting with educational institutions, reviews recent governmental efforts to control contract costs and investigates ramifications for the affected educational institutions

Changes in Gaming and Gaming Participants in the United States

Public interest and acceptance of casino gaming as a recreational activity has resulted in a proliferation of gaming locations. The spread of gaming locations and the acceptance of gaming as a legitimate leisure activity may be explained from a marketing perspective through diffusion theory. Gaming could see continued revenue growth and participation or, like lotteries, it could face saturation and even decline. To avoid the potential problems associated with maturation, gaming operators may need to review the experiences of state lotteries which have faced and dealt with the problems of maturation and saturation

Current Trends in Illegal Reentry Cases

As the Immigration and Naturalization Service (INS) begins removing more and more aliens, a growing number are reentering illegally after their removal. Many of those reentering do not realize that by doing so they are committing a crime. The case law in this area is quite complex and fraught with constitutional considerations. This article provides an overview of the crime of illegal reentry under Immigration and Nationality Act (INA) § 276

Morphic and principal-ideal group rings

We observe that the class of left and right artinian left and right morphic rings agrees with the class of artinian principal ideal rings. For $R$ an artinian principal ideal ring and $G$ a group, we characterize when $RG$ is a principal ideal ring; for finite groups $G$, this characterizes when $RG$ is a left and right morphic ring. This extends work of Passman, Sehgal and Fisher in the case when $R$ is a field, and work of Chen, Li, and Zhou on morphic group rings.Comment: 21 page

"Charged" Particle's Tunneling from Rotating Black Holes

The behavior of a scalar field theory near the event horizon in a rotating black hole background can be effectively described by a two dimensional field theory in a gauge field background. Based on this fact, we proposal that the quantum tunneling from rotating black hole can be treated as "charged" particle' s tunneling process in its effectively two dimensional metric. Using this viewpoint and considering the corresponding "gauge charge" conservation, we calculate the non-thermal tunneling rate of Kerr black hole and Myers-Perry black hole, and results are consistent with Parikh-Wilczek's original result for spherically symmetric black holes. Especially for Myers-Perry black hole which has multi-rotation parameters, our calculation fills in the gap existing in the literature applying Parikh-Wilczek's tunneling method to various types black holes. Our derivation further illuminates the essential role of effective gauge symmetry in Hawking radiation from rotating black holes.Comment: 15 pages, no figure; any comments are welcome

An Arctic Alaskan Kelp Bed

Reports the discovery of a kelp bed near Point Barrow and describes its composition, both red and brown algae and associated fauna: a few polychaetous annelids, arthropods and six fishes, one, Enophrys diceraus new to arctic waters and kelp beds are rare in arctic Alaska waters limited in species and in number of individuals. The general poverty of marine algae is thought due to the prevalence of sediments north of Alaska and to silting effects by sea ice in winter