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Formation of microvilli

Description: Microvilli on cells frequently display a regular hexagonal packing pattern. We present here a model for how this regular pattern is established and how the microvilli are extruded from the cell. The model is based on the viscoelastic properties of the actomyosin gel in the cell cortex. 16 refs., 7 figs.
Date: January 1, 1985
Creator: Oster, G. F.; Murray, J. D. & Odell, G. M.
Partner: UNT Libraries Government Documents Department
open access

Effect of acidity on microbial processes in a forest soil

Description: The objective of this study is to obtain comprehensive baseline information on the microbial activity in a forest soil in order to begin an evaluation of the impact of pollutants resulting from energy related activities. Since most of the soils on Long Island, New York, are poorly buffered and may respond to acid precipitation more quickly, it was decided to study the effect of acidity on various microbial processes. A Riverhead sandy loam soil collected from an oak-pine forest with a pH of 4.6… more
Date: March 1, 1980
Creator: Francis, A J; Olson, D & Bernatsky, R
Partner: UNT Libraries Government Documents Department
open access

Isotope studies to determine dry deposition of sulfate to deciduous and coniferous trees: Final draft

Description: Experiments have been conducted at two locations near Oak Ridge, Tennessee, with radioactive /sup 35/S (87 day half-life) to examine the cycling behavior of sulfur in yellow poplar (Liriodendron tulipifera), red maple (Acer rubrum), and loblolly pine (Pinus taeda) trees. Some findings pertain to methods development for estimating dry deposition of sulfur to forest canopies and the magnitude of sulfur emissions from natural sources (Task II). We will determine through field studies, the internal… more
Date: January 1, 1988
Creator: Garten, C. T. Jr.
Partner: UNT Libraries Government Documents Department
open access

Functional imaging of the brain with/sup 18/F-fluorodeoxyglucose

Description: A techniques is reported by which it is possible to determine which regions of the human brain become functionally active in response to a specific stimulus. The method utilizes /sup 18/F-2-fluoro-2-deoxyglucose ((/sup 18/F)-FDG) administered as a bolus. (/sup 18/F)-FDG is used as a tracer for the exchange of glucose between plasma and brain and its phosphorylation. The subject is then scanned during administration of a physiologic stimulus by position emission tomography and the three-dimensio… more
Date: 1980~
Creator: Reivich, M.; Greenberg, J.; Alavi, A.; Hand, P.; Rintelmann, W.; Rosenquist, A. et al.
Partner: UNT Libraries Government Documents Department
open access

Biological effects of 60-Hz electric fields on small and large laboratory animals

Description: Rats and mice were exposed to 60-Hz electric fields up to 330 kV/m for durations as long as four months. No significant effects were found in the following major areas: metabolic status and growth; organ and tissue morphology; brain morphology; cardiovascular function; serum chemistry; reproduction; prenatal growth and development; teratology; bone growth; peripheral nerve function; humoral and cell-mediated immunity; susceptibility to viral infection; cell and membrane function; illness/malais… more
Date: January 1, 1981
Creator: Phillips, R.D.
Partner: UNT Libraries Government Documents Department
open access

A computational model of the cerebellum

Description: The need for realistic computational models of neural microarchitecture is growing increasingly apparent. While traditional neural networks have made inroads on understanding cognitive functions, more realism (in the form of structural and connectivity constraints) is required to explain processes such as vision or motor control. A highly detailed computational model of mammalian cerebellum has been developed. It is being compared to physiological recordings for validation purposes. The model i… more
Date: January 1, 1990
Creator: Travis, B.J.
Partner: UNT Libraries Government Documents Department
open access

Protection against UVA-induced photooxidative damage in mammalian cell lines expressing increased levels of metallothionein

Description: Metallothionein (MT) is an endogenous low molecular weight protein that is inducible in a variety of eukaryotic cells and has the ability to selectivity bind heavy metal ions such as zinc and the cadmium. Although the exact physiological role of MT is still not understood, there is strong evidence that MT is involved in providing cellular resistance against the damaging effects of heavy metals and in the regulation of intracellular zinc and copper. Recently, it has been demonstrated that MT can… more
Date: January 1, 1990
Creator: Dudek, E.J. (Argonne National Lab., IL (USA) Illinois Inst. of Tech., Chicago, IL (USA). Dept. of Biology); Peak, J.G.; Peak, M.J. (Argonne National Lab., IL (USA)) & Roth, R.M. (Illinois Inst. of Tech., Chicago, IL (USA). Dept. of Biology)
Partner: UNT Libraries Government Documents Department
open access

Mapping of functional activity in brain with /sup 18/F-fluoro-deoxyglucose

Description: A model has been designed based on the assumptions of a steady state for glucose consumption, a first-order equilibration of the free /sup 14/C-DG pool in the tissue with the plasma level, and relative rates of phosphorylation of /sup 14/C-DG and glucose determined by their kinetic constants for hexokinase reaction. Using an operational equation based on this model, the metabolic rates of glucose are calculated in various regions of brain (utilizing brain slices and autoradiography). /sup 14/C … more
Date: January 1, 1981
Creator: Alavi, A.; Reivich, M.; Greenberg, J. & Wolf, A.
Partner: UNT Libraries Government Documents Department
open access

Mechanism of histamine release from human basophils

Description: The theory of histamine release of Dembo, Goldstein, Sobotka, and Lichtenstein is able to explain a variety of kinetic experiments in a self consistent and quantitative way. The principal elements of the theory are: the histamine content of basophils is divided into a large number of discrete and independent quanta; release of the contents of a quanta is a stochastic event; a certain fraction of the quanta in a population of basophils is nonreleasable; the probability per unit time, P/sub R/, o… more
Date: January 1, 1978
Creator: Dembo, M. & Goldstein, B.
Partner: UNT Libraries Government Documents Department
open access

Pulmonary macrophages: Phenomena associated with the particle overload'' condition

Description: Numerous lines of evidence support the generalization that alveolar macrophage (AM)-mediated particle clearance, or the transport of particle-containing AM from the alveoli out of the lung via the mucociliary apparatus, is a prominent mechanism that determines the pulmonary retention characteristics of relatively insoluble particles. Studies have also shown that the alveolar deposition of excessive burdens of particles with even low intrinsic cytotoxicity can result in impairments of the AM-med… more
Date: January 1, 1993
Creator: Lehnert, B. E.; Sebring, R. J. (Los Alamos National Lab., NM (United States)) & Oberdoerster, G. (Rochester Univ., NY (United States))
Partner: UNT Libraries Government Documents Department
open access

Protein kinase and phosphatase activities of thylakoid membranes

Description: Dephosphorylation of the 25 and 27 kDa light-harvesting Chl a/b proteins (LHCII) of the thylakoid membranes is catalyzed by a phosphatase which differs from previously reported thylakoid-bound phosphatases in having an alkaline pH optimum (9.0) and a requirement for Mg/sup 2 +/ ions. Dephosphorylation of the 8.3 kDa psb H gene product requires a Mg/sup 2 +/ ion concentration more than 200 fold higher than that for dephosphorylation of LHC II. The 8.3 kDa and 27 kDa proteins appear to be phospho… more
Date: January 1, 1987
Creator: Michel, H.; Shaw, E.K. & Bennett, J.
Partner: UNT Libraries Government Documents Department
open access

Amphetamine margin in sports. [Effects on performance of highly trained athletes]

Description: The amphetamines can enhance athletic performance. That much seems clear from the literature, some of which is reviewed here. Increases in endurance have been demonstrated in both man and rat. Smith and Beecher, 20 years ago, showed improvement of running, swimming, and weight throwing in highly trained athletes. Laboratory analogues of such performance have also been used and similar enhancement demonstrated. The amount of change induced by the amphetamines is usually small, of the order of a … more
Date: January 1, 1980
Creator: Laties, V. G. & Weiss, B.
Partner: UNT Libraries Government Documents Department
open access

Expansion of the Genomic Encyclopedia of Bacteria and Archaea

Description: To date the vast majority of bacterial and archaeal genomes sequenced are of rather limited phylogenetic diversity as they were chosen based on their physiology and/ or medical importance. The Genomic Encyclopedia of Bacteria and Archaea (GEBA) project (Wu et al. 2009) is aimed to systematically filling the gaps of the tree of life with phylogenetically diverse reference genomes. However more than 99percent of microorganisms elude current culturing attempts, severely limiting the ability to rec… more
Date: March 20, 2011
Creator: Rinke, Christian; Sczyrba, Alex; Malfatti, Stephanie; Lee, Janye; Cheng, Jan-Fang; Stepanauskas, Ramunas et al.
Partner: UNT Libraries Government Documents Department
open access

Subcellular localization of proteins in the anaerobic sulfate reducer Desulfovibrio vulgaris via SNAP-tag labeling and photoconversion

Description: Systems Biology studies the temporal and spatial 3D distribution of macromolecular complexes with the aim that such knowledge will allow more accurate modeling of biological function and will allow mathematical prediction of cellular behavior. However, in order to accomplish accurate modeling precise knowledge of spatial 3D organization and distribution inside cells is necessary. And while a number of macromolecular complexes may be identified by its 3D structure and molecular characteristics a… more
Date: June 1, 2010
Creator: Gorur, A.; Leung, C. M.; Jorgens, D.; Tauscher, A.; Remis, J. P.; Ball, D. A. et al.
Partner: UNT Libraries Government Documents Department
open access

2010 IRON-SULFUR ENZYMES GORDON RESEARCH CONFERENCE, JUNE 6-11, 2010

Description: Iron-sulfur (FeS) centers are essential for biology and inspirational in chemistry. These protein cofactors are broadly defined as active sites in which Fe is coordinated by S-donor ligands, often in combination with extra non-protein components, for example, additional metal atoms such as Mo and Ni, and soft ligands such as CN{sup -} and CO. Iron-sulfur centers are inherently air sensitive: they are found in essentially all organisms and it is possible that they were integral components of the… more
Date: June 11, 2010
Creator: Gray, Nancy Ryan
Partner: UNT Libraries Government Documents Department
open access

Pulmonary macrophages: Phenomena associated with the particle ``overload`` condition

Description: Numerous lines of evidence support the generalization that alveolar macrophage (AM)-mediated particle clearance, or the transport of particle-containing AM from the alveoli out of the lung via the mucociliary apparatus, is a prominent mechanism that determines the pulmonary retention characteristics of relatively insoluble particles. Studies have also shown that the alveolar deposition of excessive burdens of particles with even low intrinsic cytotoxicity can result in impairments of the AM-med… more
Date: May 1, 1993
Creator: Lehnert, B. E.; Sebring, R. J. & Oberdoerster, G.
Partner: UNT Libraries Government Documents Department
open access

2004 Structural, Function and Evolutionary Genomics

Description: This Gordon conference will cover the areas of structural, functional and evolutionary genomics. It will take a systematic approach to genomics, examining the evolution of proteins, protein functional sites, protein-protein interactions, regulatory networks, and metabolic networks. Emphasis will be placed on what we can learn from comparative genomics and entire genomes and proteomes.
Date: March 23, 2005
Creator: Gray, Douglas L. Brutlag Nancy Ryan
Partner: UNT Libraries Government Documents Department
open access

Measuring dopamine release in the human brain with PET

Description: The dopamine system is involved in the regulation of brain regions that subserve motor, cognitive and motivational behaviors. Disruptions of dopamine (DA) function have ben implicated in neurological and psychiatric illnesses including substance abuse as well as on some of the deficits associated with aging of the human brain. This has made the DA system an important topic in research in the neurosciences and neuroimaging as well as an important molecular target for drug development. Positron E… more
Date: December 1, 1995
Creator: Volkow, N. D.; Fowler, J. S.; Logan, J. & Wang, G. J.
Partner: UNT Libraries Government Documents Department
open access

Relationships between histone phosphorylation and cell proliferation

Description: From studies with various Peromyscus cell lines, correlations were made which led to the proposal that H2A phosphorylation is most active in constitutive heterochromatin. Recent studies on the two H2A variants found in these cells have revealed that the high level of H2A phosphorylation associated with heterochromatin is not the result of an increase in H2A phosphorylation rate or an increase in the number of phosphorylation sites, but rather, is due to an increase in the proportion of one of t… more
Date: January 1, 1980
Creator: Gurley, L. R.; D'Anna, J. A.; Halleck, M. S.; Barham, S. S.; Walters, R. A.; Jett, J. H. et al.
Partner: UNT Libraries Government Documents Department
open access

Neuromagnetic source reconstruction

Description: In neuromagnetic source reconstruction, a functional map of neural activity is constructed from noninvasive magnetoencephalographic (MEG) measurements. The overall reconstruction problem is under-determined, so some form of source modeling must be applied. We review the two main classes of reconstruction techniques-parametric current dipole models and nonparametric distributed source reconstructions. Current dipole reconstructions use a physically plausible source model, but are limited to case… more
Date: December 31, 1994
Creator: Lewis, P. S.; Mosher, J. C. & Leahy, R. M.
Partner: UNT Libraries Government Documents Department
open access

GAMMA RADIATION INTERACTS WITH MELANIN TO ALTER ITS OXIDATION-REDUCTION POTENTIAL AND RESULTS IN ELECTRIC CURRENT PRODUCTION

Description: The presence of melanin pigments in organisms is implicated in radioprotection and in some cases, enhanced growth in the presence of high levels of ionizing radiation. An understanding of this phenomenon will be useful in the design of radioprotective materials. However, the protective mechanism of microbial melanin in ionizing radiation fields has not yet been elucidated. Here we demonstrate through the electrochemical techniques of chronoamperometry, chronopotentiometry and cyclic voltammetry… more
Date: May 17, 2011
Creator: Turick, C.; Ekechukwu, A. & Milliken, C.
Partner: UNT Libraries Government Documents Department
open access

Low Dose Radiation Response Curves, Networks and Pathways in Human Lymphoblastoid Cells Exposed from 1 to 10 cGy of Acute Gamma Radiation

Description: We investigated the low dose dependency of the transcriptional response of human cells to characterize the shape and biological functions associated with the dose response curve and to identify common and conserved functions of low dose expressed genes across cells and tissues. Human lymphoblastoid (HL) cells from two unrelated individuals were exposed to graded doses of radiation spanning the range of 1-10 cGy were analyzed by transcriptome profiling, qPCR and bioinformatics, in comparison to … more
Date: April 18, 2011
Creator: Wyrobek, A. J.; Manohar, C. F.; Nelson, D. O.; Furtado, M. R.; Bhattacharya, M. S.; Marchetti, F. et al.
Partner: UNT Libraries Government Documents Department
open access

Biosynthesis of the Cyclotide Kalata B1 using a Protein Splicing Unit

Description: Cyclotides are a newly emerging family of large backbone cyclic polypeptides ({approx}30 residues long) characterized by a disulfide-stabilized core (3 disulfide bonds) with an unusual knotted structure. In contrast to other cyclic polypeptides, cyclotides have a well-defined three-dimensional structure. Therefore, despite their small size, they can be considered miniproteins. The unique cyclic-backbone topology and knotted arrangement of 3 disulfide bonds endow cyclotides with exceptional stab… more
Date: August 13, 2005
Creator: Kimura, R H; Tran, A T & Camarero, J A
Partner: UNT Libraries Government Documents Department
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