Photoemission view of electron fractionalization in quasi-one dimensional metal Li0.9_{0.9}Mo6_6O17_{17}

We report Luttinger liquid line shapes better revealed by new angle resolved photoemission data taken with a much improved angle resolution on a quasi-1-dimensional metal Li$_{0.9}$Mo$_6$O$_{17}$. The new data indicate a larger spinon velocity than our previous lower resolution data indicated.Comment: submitted to SCES '0

Understanding the Mechanisms of Insecticide Resistance in Phlebotomus papatasi and Lutzoymia longipalpis Sand Flies (Diptera: Psychodidae: Phlebotominae)

The prevalence of insecticide resistance in vector species around the world is a continuous threat for any success at mitigating the spread of vector-borne diseases. With a limited arsenal of new insecticides, it is crucial for public health programs to understand the geographic range and the genetic mechanisms of resistance to best approach controlling insect vectors. Insecticide resistance is being increasingly observed in phlebotomine sand fly (Diptera: Psychodidae) populations in both the Old World and New World. Sand flies transmit the protozoans that cause leishmaniasis, a disfiguring disease that kills tens of thousands of people each year. The goal of this dissertation was to have both an applied and basic research focus towards understanding resistance in phlebotomines. I began by comparing in vivo and in vitro methods for blood-feeding two species of sand flies, Phlebotomus papatasi and Lutzomyia longipalpis, in the laboratory, both of which are important leishmaniasis vectors. I investigated the susceptibility of both species to ten different insecticides by calculating lethal concentrations that caused varying levels of mortality. Based on these results, I determined diagnostic doses and diagnostic times for both species to the same ten insecticides using an accepted, but novel, assay for sand flies. Finally, I tested for known mechanisms of insecticide resistance in four artificially resistant-selected colonies of sand flies, as well as tested for novel resistance mechanisms. Through applied research, I developed methods for efficient sand fly rearing and for determination of population resistance to insecticides, tools that have worldwide applicability. Through basic research, I determined that laboratory populations of sand flies have sufficient standing genetic variation needed to survive sublethal doses of insecticides; however, I was unable to develop artificially-selected colonies resistant to these insecticides. My research has generated information to provide new insights into the evolution of insecticide resistance in natural sand fly populations. My results support that resistance development may be possible, but evolutionary challenging, an encouraging finding that may be exploited by vector biologists and public health officials to prevent or slow the development of resistance in sand flies to insecticide

Market Your Mindful Eating Business Online

This advanced clinical practicum for a Masters in Allied Health was overseen by Dr. Susan Albers, The Mindful Eating Doctor The project focuses on the creation of materials and promotional pieces for a program the author created called, Acing College Health (ACH)

Strong One-Dimensional Characteristics of Hole-Carriers in ReS2 and ReSe2.

Each plane of layered ReS2 and ReSe2 materials has 1D chain structure, from which intriguing properties such as 1D character of the exciton states and linearly polarized photoluminescence originate. However, systematic studies on the 1D character of charge carriers have not been done yet. Here, we report on systematic and comparative studies on the energy-momentum dispersion relationships of layered transition metal dichalcogenides ReS2 and ReSe2 by angle resolved photoemission. We found that the valence band maximum or the minimum energy for holes is located at the high symmetric Z-point for both materials. However, the out-of-plane ([Formula: see text]) dispersion for ReSe2 (20 meV) is found to be much smaller than that of ReS2 (150 meV). We observe that the effective mass of the hole carriers along the direction perpendicular to the chain is about 4 times larger than that along the chain direction for both ReS2 and ReSe2. Remarkably, the experimentally measured hole effective mass is about twice heavier than that from first principles calculation for ReS2 although the in-plane anisotropy values from the experiment and calculations are comparable. These observation indicate that bulk ReS2 and ReSe2 are unique semiconducting transition metal dichalcogenides having strong one-dimensional characters

ARPES Study of X-Point Band Overlaps in LaB6_6 and SmB6_6 - Contrast to SrB6_6 and EuB6_6

In contrast to our recent finding of an X-point band gap in divalent hexaborides, we report here that angle resolved photoemission spectroscopy (ARPES) data shows that the gap is absent for trivalent LaB$_6$ and is absent or nearly so for mixed valent SmB$_6$. This finding demonstrates a nontrivial evolution of the band structure from divalent to trivalent hexaborides.Comment: submitted to SCES '0

JAMS Provides Navigation Through the Obstacle Course of Discovery

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