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Monmouth, IL, United States

For over a century, the origin of eukaryotes has been a topic of intense debate among scientists. Although it has become widely accepted that organelles such as the mitochondria and chloroplasts arose via endosymbiosis, the origin of the eukaryotic nucleus remains enigmatic. Numerous models for the origin of the nucleus have been proposed over the years, many of which use endosymbiosis to explain its existence. Proposals of microbes whose ancestors may have served as either a host or a guest in various endosymbiotic scenarios abound, none of which have been able to sufficiently incorporate the cell biological as well as phylogenetic data which links these organisms to the nucleus. While it is generally agreed that eukaryotic nuclei share more features in common with archaea rather than with bacteria, different studies have identified either one or the other of the two major groups of archaea as potential ancestors, leading to somewhat of a stalemate. This paper seeks to resolve this impasse by presenting evidence that not just one, but a pair of archaea might have served as host to the bacterial ancestor of the mitochondria. This pair may have consisted of ancestors of both Ignicoccus hospitalis as well as its ectosymbiont/ectoparasite 'Nanoarchaeum equitans'. © 2012 Godde; licensee BioMed Central Ltd.

Kleinbaum E.,Purdue University | Kumar A.,Monmouth College | Pfeiffer L.N.,Princeton University | West K.W.,Princeton University | Csathy G.A.,Purdue University
Physical Review Letters | Year: 2015

In the region of the second Landau level several theories predict fractional quantum Hall states with novel topological order. We report the opening of an energy gap at the filling factor ν=3+1/3, firmly establishing the ground state as a fractional quantum Hall state. This and other odd-denominator states unexpectedly break particle-hole symmetry. Specifically, we find that the relative magnitudes of the energy gaps of the ν=3+1/3 and 3+1/5 states from the upper spin branch are reversed when compared to the ν=2+1/3 and 2+1/5 counterpart states in the lower spin branch. Our findings raise the possibility that at least one of the former states is of an unusual topological order. © 2015 American Physical Society.

Cramer K.L.,Monmouth College | Vetter R.S.,University of California at Riverside | Vetter R.S.,ISCA Technologies, Inc.
Journal of Medical Entomology | Year: 2014

The medical importance of the brown recluse spider, Loxosceles reclusa Gertsch and Mulaik, is well known, but there is a need for more accurate information about the distribution of the spider in North America. We gathered information via an Internet offer to identify spiders in Illinois and Iowa that were thought to be brown recluses. We also mined brown recluse locality information from other agencies that kept such records. In Iowa, the brown recluse is unknown from its northern counties and rare in southern counties. In Illinois, brown recluse spiders are common in the southern portion of the state and dwindle to almost nonexistence in a transition to the northern counties. Although there were a few finds in the Chicago, IL area and its suburbs, these are surmised to be human-transported specimens and not part of naturally occurring populations. Considering the great human population density and paucity of brown recluses in the Chicago area, medical personnel therein should obtain patient geographic information and be conservative when diagnosing loxoscelism in comparison with southern Illinois, where the spiders are plentiful and bites are more likely. © 2014 Entomological Society of America.

Stiles T.A.,Monmouth College
American Journal of Physics | Year: 2014

Ultrasound imaging provides an interesting and accessible example of the intersection between biology, medicine, and physics. This article provides a review of the physics and technology currently available and discusses two recent methods that have expanded the diagnostic capabilities of ultrasound imaging. We also describe two undergraduate physics laboratory exercises involving ultrasound imaging. © 2014 American Association of Physics Teachers.

Agency: NSF | Branch: Continuing grant | Program: | Phase: PHYSICAL & DYNAMIC METEOROLOGY | Award Amount: 228.50K | Year: 2012

Lightning, the massive dielectric breakdown of the atmosphere that occurs during thunderstorms, is a dramatic process that demands study and explanation. The mechanisms that cause lightning and the mechanisms by which lightning proceeds in storms are complex and still areas of active study. In fact, understanding lightning is considered one of the great-unsolved problems of atmospheric physics. This research seeks to investigate a particularly intriguing feature of lightning that was verified experimentally only recently - the production of X-rays by lightning.

To achieve this goal, an array of 10 X-Ray/lightning detectors will be built and deployed at Monmouth College and at high schools throughout western Illinois and eastern Iowa, which will accumulate lightning, X-ray, E-field and atmospheric data for long time periods. There is clear evidence that a large ground based detector array can measure X-ray spectra from natural lightning. When the resulting spectra are combined with electric field and meteorological data, significant understandings of lightning, lightning generated X-rays and the storms that produce them can be obtained.

Intellectual Merit:
The goal of this research is to measure the energy spectrum of natural lightning while recording data on electric field strength and meteorological data. The following specific and important questions will be addressed in this study.
1) What is the energy spectrum of natural lightning generated X-rays?
2) Which storms produce lightning generated X-rays, which dont, and how are they different?
3) How can the energy spectrum of lightning generated X-rays and environmental conditions be used to understand how lightning is generated?
4) How can the energy spectrum of lightning generated X-rays be used to test models of lightning formation and propagation?

Broader Impact:
By measuring the X-ray spectra while recording other data, significant contributions to understanding lightning and the storms that form lightning can be made. These data will be an important part of advancing this understanding.

The project also has broad impact through its outreach component. Undergraduate and high-school students will play an active role in both taking and analyzing data. This study will collect data for extended periods of time at many locations and provides a small undergraduate college a considerable outreach opportunity. Research experiences like this are sound pedagogy and will allow college faculty to engage students in new and creative ways.

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