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Visualization of Excitonic Structure in the Fenna-Matthews-OlsonPhotosynthetic Complex by Polarization-Dependent Two-DimensionalElectronic Spectroscopy

Description: Photosynthetic light-harvesting proceeds by the collection and highly efficient transfer of energy through a network of pigment-protein complexes. Inter-chromophore electronic couplings and interactions between pigments and the surrounding protein determine energy levels of excitonic states and dictate the mechanism of energy flow. The excitonic structure (orientation of excitonic transition dipoles) of pigment-protein complexes is generally deduced indirectly from x-ray crystallography in combination with predictions of transition energies and couplings in the chromophore site basis. Here, we demonstrate that coarse-grained excitonic structural information in the form of projection angles between transition dipole moments can be obtained from polarization-dependent two-dimensional electronic spectroscopy of an isotropic sample, particularly when the nonrephasing or free polarization decay signal rather than the photon echo signal is considered. The method provides an experimental link between atomic and electronic structure and accesses dynamical information with femtosecond time resolution. In an investigation of the Fenna-Matthews-Olson complex from green sulfur bacteria, energy transfer connecting two particular exciton states in the protein is isolated as being the primary contributor to a cross peak in the nonrephasing 2D spectrum at 400 fs under a specific sequence of polarized excitation pulses. The results suggest the possibility of designing experiments using combinations of tailored polarization sequencesto separate and monitor individual relaxation pathways.
Date: May 26, 2008
Creator: Department of Chemistry, The University of Chicago; Department of Biology, Department of Chemistry, Washington University; Fleming, Graham; Read, Elizabeth L.; Schlau-Cohen, Gabriela S.; Engel, Gregory S. et al.
Partner: UNT Libraries Government Documents Department

Quarterly Progress Report (April 1 to June 30, 1950)

Description: This is the second of a series of Quarterly Progress Reports. While most of the departments have summarized their work or used a form comparable to abstracts, the Chemistry Department has given both abstracts and complete reports on its work. The major part of the progress in the Reactor Science and Engineering Department is being presented simultaneously in a separate classified report. There are reports from the following departments: (1) physics department; (2) instrumentation and health physics department; (3) accelerator project; (4) chemistry department; (5) reactor science and engineering department; (6) biology department; and (7) medical department.
Date: July 1, 1950
Creator: Laboratory, Brookhaven National
Partner: UNT Libraries Government Documents Department

[Press conference naming Dr. John J. Kamerick President of North Texas State University, May 8, 1968]

Description: Photograph of members of the North Texas State University Board of Regents, administrators, and reporters at the press conference naming Dr. John J. Kamerick the new President of NTSU on May 8, 1968 in the President's Office of the Administration Building. Dr. Kamerick would serve from 1968 to 1970. Tentatively identified, from left to right: J.J. Spurlock, Vice-President of Academic Affairs; John L. Carter, Vice President of Fiscal Affairs; J.K.G. Silvey, Director, Department of Biology; John E. Tompkins, Director of Admissions (at back); Dr. John J. Kamerick (seated); unidentified (standing, behind Kamerick); E.C. Pannell, member, Board of Regents; Ben H. Wooten (North Texas State Normal College 1917) Chairmen of the Board of Regents; unidentified; A.M. Willis, Jr., member of the Board of Regents.
Date: May 8, 1968
Location Info:
Partner: UNT Libraries Special Collections

Temporary Restoration of Bull Trout Passage at Albeni Falls Dam

Description: This study was designed to monitor movements of bull trout that were provided passage above Albeni Falls Dam, Pend Oreille River. Electrofishing and angling were used to collect bull trout below the dam. Tissue samples were collected from each bull trout and sent to the U. S. Fish and Wildlife Service Abernathy Fish Technology Center Conservation Genetics Lab, Washington. The DNA extracted from tissue samples were compared to a catalog of bull trout population DNA from the Priest River drainage, Lake Pend Oreille tributaries, and the Clark Fork drainage to determine the most probable tributary of origin. A combined acoustic radio or radio tag was implanted in each fish prior to being transported and released above the dam. Bull trout relocated above the dam were able to volitionally migrate into their natal tributary, drop back downstream, or migrate upstream to the next dam. A combination of stationary radio receiving stations and tracking via aircraft, boat, and vehicle were used to monitor the movement of tagged fish to determine if the spawning tributary it selected matched the tributary assigned from the genetic analysis. Seven bull trout were captured during electrofishing surveys in 2008. Of these seven, four were tagged and relocated above the dam. Two were tagged and left below the dam as part of a study monitoring movements below the dam. One was immature and too small at the time of capture to implant a tracking tag. All four fish released above the dam passed by stationary receivers stations leading into Lake Pend Oreille and no fish dropped back below the dam. One of the radio tags was recovered in the tributary corresponding with the results of the genetic test. Another fish was located in the vicinity of its assigned tributary, which was impassable due to low water discharge at ...
Date: July 13, 2009
Creator: Paluch, Mark; Scholz, Allan; McLellan, Holly & Olson, Jason
Partner: UNT Libraries Government Documents Department

Fisheries Habitat Evaluation on Tributaries of the Coeur d`Alene Indian Reservation : Annual Report [1991].

Description: The purpose of this study was to conduct physical and biological surveys of streams located on the Coeur d'Alene Indian Reservation. Surveys were designed to collect information on improving spawning habitat, rearing habitat, and access to spawning tributaries for bull trout and cutthroat trout and to evaluate the existing fish stocks. The objectives of the second year of the study were to: (1) Develop a stream ranking system to select the five streams of primary fisheries potential; (2) Conduct physical field surveys; (3) Determine population dynamics; (4) Determine growth rates of existing trout species; (5) Determine macroinvertebrate densities and diversities; and (6) Determine baseline angler utilization. The Missouri method of evaluating stream reaches was modified and utilized to rank the ten tributaries (as determined by Graves et al. 1990) associated with reservation lands. The method incorporated such data as stream bank and bed stability, condition of riparian vegetation, land use, degree of urbanization, passage barriers, water quality, flow and temperature regimes, as well as the overall habitat suitability for all life history stages of cutthroat and bull trout. This data was then combined with relative abundance data, growth rates and invertebrate densities to choose five streams, which offer the best potential habitat, for further study. Relative abundance estimates resulted in the capture of 6,138 fish from June, August, and October, 1991. A total of 427 cutthroat trout were collected from all sampled tributaries. Relative abundance of cutthroat trout for all tributaries was 6.7%. Fighting Creek had the highest abundance of cutthroat trout at 93.1%, followed by Evans Creeks at 30.8%, Lake Creek at 12.1%, Hell's Gulch at 11.1%, Alder Creek at 3.3%, Benewah Creek at 2.1% and Plummer/Little Plummer creeks at 5%. Population estimates were conducted in Benewah, Alder, Evans and Lake creeks. Estimates were: 23.5 {+-} 2.3 fish/l,922.6 m2 ...
Date: February 1, 1993
Creator: Woodward-Lillengreen, Kelly L.; Johnson, D. Chad & Scholz, Allan T.
Partner: UNT Libraries Government Documents Department

Cetaceans, Sea Turtles and Seabirds in the Northern Gulf of Mexico: Distribution, Abundance and Habitat Associations, Volume 2: Technical Report

Description: The main purpose of this report covers three years of research on the distribution and number of whales, dolphins, sea turtles, and sea birds in the Gulf of Mexico. Volume two contains the technical report, going into the details and findings of the research.
Date: January 2000
Creator: Davis, Randall W.; Evans, William E. & Würsig, Bernd
Partner: UNT Libraries Government Documents Department

Plant training grant: DE-FG02-94ER20162. Final technical report

Description: The aim of this training grant was to educate students of Plant Science in the disciplines of Biochemistry and Chemistry, in addition to the more traditional courses in Plant Biology. Annual retreats were held which involved a day-long meeting and included lectures from Penn faculty as well as famous national and international scientists. Programs for two of these retreats are included. In addition to lecture courses, students performed research within the Departments of Biology, Chemistry, and Biochemistry and Biophysics; a publications list is given.
Date: February 1, 2003
Creator: Cashmore, Anthony R.
Partner: UNT Libraries Government Documents Department

The Characteristics of Morphology and Apoptosis in the Closure of the Ductus Arteriosi in Emu

Description: Presentation for the 2007 University Scholars Day at the University of North Texas. This presentation discusses research on characterizing the changes in tissue morphology occurring in the emu ductus arteriosus during hatching and what role apoptosis plays during the process of the ductus closure.
Date: March 29, 2007
Creator: Castilla, Lauren & Dzialowski, Edward M. (Edward Michael)
Partner: UNT Honors College

Molecular characterization of a novel heavy metal uptake transporter from higher plants and its potential for use in phytoremediation. 1998 annual progress report

Description: 'Soils and waters contaminated with high levels of heavy metals such as Cadmium, Lead and Copper are detrimental to human and environmental health. Many human disorders have been attributed to environmental contamination by heavy metals. Removal of heavy metals from highly contaminated sites is therefore a very costly but necessary process that is currently being pursued. Recent research in several laboratories indicates that uptake of heavy metals into plants via the root system may provide a cost-effective approach for decontamination of certain heavy metal-laden soils and waters. Several mechanisms have been identified, which allow detoxification in the cytosol and vacuoles of plants. However, the molecular biological mechanisms by which heavy metals are transported from soils across the plasma membrane into roots have remained largely unknown. In recent research, the laboratory has cloned a cation uptake transporter cDNA from plants. Yeast cells expressing this cDNA show enhanced uptake of calcium and cadmium. The proposed research is testing the transport of toxic and nutrient metals by the encoded protein.'
Date: June 1, 1998
Creator: Schroeder, J.I.
Partner: UNT Libraries Government Documents Department

Workshop on stems and trunks in plant form and function. Final report

Description: This document is the final report on the workshop on stems and trunks in plant form and function relating to DOE grant DE-FG06-93ER20128 which took place at Oregon State University in February 1994. The resulting book is organized into four sections and a synthesis: roles of stem architecture in plant performance, roles of stems in transport and storage of water, roles of live stem cells in plant performance, and the roles of stems in preventing or reacting to response to plant injury. The synthesis stemmed from debated and discussion by the authors and a few dozen other workshop participants. The authors cover many stem functions, although the list is not exhaustive, and the focus is on terrestrial woody tree stems, primarily of temperate and boreal zones. More research on trunks, branches and twigs is important for a baseline understanding of plant biology. In the face of anticipated human-caused changes to most environments, we need not only have a baseline understanding of whole-plant biology, but also predictive capabilities for how plants will react to perturbations.
Date: March 1, 1995
Creator: Gartner, B.L.
Partner: UNT Libraries Government Documents Department

The compact Selaginella genome identifies changes in gene content associated with the evolution of vascular plants

Description: We report the genome sequence of the nonseed vascular plant, Selaginella moellendorffii, and by comparative genomics identify genes that likely played important roles in the early evolution of vascular plants and their subsequent evolution
Date: April 28, 2011
Creator: Grigoriev, Igor V.; Banks, Jo Ann; Nishiyama, Tomoaki; Hasebe, Mitsuyasu; Bowman, John L.; Gribskov, Michael et al.
Partner: UNT Libraries Government Documents Department

Factors limiting microbial activity in volcanic tuff at Yucca Mountain

Description: Samples of tuff aseptically collected from 10 locations in the Exploratory Shaft Facility at the site of the proposed high-level nuclear waste repository at Yucca Mountain, Nevada Test Site were analyzed for microbiological populations, activities, and factors limiting microbial activity. Radiotracer assays ({sup 14}C-labeled organic substrate mineralization), direct microscopic counts, and plate counts were used. Radiolabeled substrates were glucose, acetate, and glutamate. Radiotracer experiments were carried out with and without moisture and inorganic nutrient amendments to determine factors limiting to microbial activities. Nearly all samples showed the presence of microorganisms with the potential to mineralize organic substrates. Addition of inorganic nutrients stimulated activities in a small number of samples. The presence of viable microbial communities within the tuff has implications for transport of contaminants.
Date: September 1, 1996
Creator: Kieft, T.L.; Kovacik, W.P. & Taylor, J.
Partner: UNT Libraries Government Documents Department

A Bacteriological Survey of a Freshwater Reservoir

Description: In this study organisms that can be subcultured from lake water, using a prescribed procedure, limit, to an extent, the population, or portions of the population, that can be monitored. In essence, what is taking place is that a set of conditions is set forth and a study is made of the bacteria that will grow under these prescribed conditions.
Date: January 1968
Creator: Stiles, John Clayborn
Partner: UNT Libraries