Long-range electron transfer in structurally engineered pentaammineruthenium (histidine-62) cytochrome c

In many biological processes, long-range electron transfer (ET) plays a key role. When the three-dimensional structures of proteins are accurately known, use of modified proteins and protein-protein complexes provides an experimental approach to study ET rates between two metal centers. For Ru(His)- modified proteins, the introduction of histidine residues at any desired surface location by site-directed mutagenesis opens the way for systematic investigations of ET pathways

Enhanced detection method for corneal protein identification using shotgun proteomics

<p>Abstract</p> <p>Background</p> <p>The cornea is a specialized transparent connective tissue responsible for the majority of light refraction and image focus for the retina. There are three main layers of the cornea: the epithelium that is exposed and acts as a protective barrier for the eye, the center stroma consisting of parallel collagen fibrils that refract light, and the endothelium that is responsible for hydration of the cornea from the aqueous humor. Normal cornea is an immunologically privileged tissue devoid of blood vessels, but injury can produce a loss of these conditions causing invasion of other processes that degrade the homeostatic properties resulting in a decrease in the amount of light refracted onto the retina. Determining a measure and drift of phenotypic cornea state from normal to an injured or diseased state requires knowledge of the existing protein signature within the tissue. In the study of corneal proteins, proteomics procedures have typically involved the pulverization of the entire cornea prior to analysis. Separation of the epithelium and endothelium from the core stroma and performing separate shotgun proteomics using liquid chromatography/mass spectrometry results in identification of many more proteins than previously employed methods using complete pulverized cornea.</p> <p>Results</p> <p>Rabbit corneas were purchased, the epithelium and endothelium regions were removed, proteins processed and separately analyzed using liquid chromatography/mass spectrometry. Proteins identified from separate layers were compared against results from complete corneal samples. Protein digests were separated using a six hour liquid chromatographic gradient and ion-trap mass spectrometry used for detection of eluted peptide fractions. The SEQUEST database search results were filtered to allow only proteins with match probabilities of equal or better than 10^-3and peptides with a probability of 10^-2or less with at least two unique peptides isolated within the run along with default Xcorr values. These parameters resulted in the identification of over 350 proteins, including over 225 new proteins not previously detected in the cornea by mass spectrometry. In addition, corneal layer separation resulted in identification of nearly every protein that was identified in the complete cornea assay. The epithelium and endothelium each revealed many unique proteomes specific to each layer. In the endothelium, the protein olfactomedin-like 3 was identified for the first time in the cornea by this analysis. Olfactomedin-3 is a neuronal expressed protein also known as optimedin that stimulates formation of cell adherent and cell-cell tight junctions and its expression modulates cytoskeleton organization and cell migration. However, the function of this protein in rabbit corneal endothelium is currently unknown.</p> <p>Conclusion</p> <p>This manuscript presents a description of a more comprehensive proteomic profile for mammalian cornea compared to past methods. The use of simple dissection procedures of the tissue and the application of long chromatographic gradients, many more proteins can be identified.</p

Total Variation Regularization of Geodetically and Geologically Constrained Block Models for the Western United States

Geodetic observations of interseismic deformation in the Western United States provide con- straints on microplate rotations, earthquake cycle processes, and slip partitioning across the Pacific–North America Plate boundary. These measurements may be interpreted using block models, in which the upper crust is divided into microplates bounded by faults that accumulate strain in a first-order approximation of earthquake cycle processes. The number and geometry of microplates are typically defined with boundaries representing a limited subset of the large number of potentially seismogenic faults. An alternative approach is to include a large number of potentially active faults bounding a dense array of microplates, and then algorithmically estimate the boundaries at which strain is localized. This approach is possible through the application of a total variation regularization (TVR) optimization algorithm, which simultaneously minimizes the L2 norm of data residuals and the L1 norm of the variation in the differential block motions. Applied to 3-D spherical block models, the TVR algorithm can be used to reduce the total variation between estimated rotation vectors, effectively grouping microplates that rotate together as larger blocks, and localizing fault slip on the boundaries of these larger block clusters. Here we develop a block model comprised of 137 microplates derived from published fault maps, and apply the TVR algorithm to identify the kinematically most important faults in the western United States. This approach reveals that of the 137 microplates considered, only 30 unique blocks are required to approximate deformation in the western United States at a residual level of \u3c2 mm yr−1

Braggoriton--Excitation in Photonic Crystal Infiltrated with Polarizable Medium

Light propagation in a photonic crystal infiltrated with polarizable molecules is considered. We demonstrate that the interplay between the spatial dispersion caused by Bragg diffraction and polaritonic frequency dispersion gives rise to novel propagating excitations, or braggoritons, with intragap frequencies. We derive the braggoriton dispersion relation and show that it is governed by two parameters, namely, the strength of light-matter interaction and detuning between the Bragg frequency and that of the infiltrated molecules. We also study defect-induced states when the photonic band gap is divided into two subgaps by the braggoritonic branches and find that each defect creates two intragap localized states inside each subgap.Comment: LaTeX, 8 pages, 5 figure

Differences in Heart Disease Risk Perception and Actual Cardiac Risk in Men vs. Women

Differences in Heart Disease Risk Perception and Actual Cardiac Risk in Male vs. Female Cardiac Patients Amanda Dietz, Julie Borsack, Steve Martin, Kathy L. Hill, Thomas Meade, Stephen F. Crouse, FACSM, and John S. Green, FACSM Texas A&M University, College Station, TX (Sponsor: John S. Green, FACSM) PURPOSE: To describe gender differences in both risk perception and actual coronary risk in patients with coronary artery disease (CAD). METHODS: 33 females and 67 males with documented CAD completed a questionnaire designed to assess CAD risk perception. They also underwent assessments for all ACSM risk factors. Five-point Likert scale responses to the question “Compared to others of your own age and gender, how would you rate your risk of ever having a heart attack?” were used to quantify CAD risk perception. To quantify actual risk, the number of ACSM risk markers for each subject was tabulated. It should be noted that, since all of the subjects had active CAD, they were all at high risk. Tabulations and Likert scale responses were compared using Chi-square analysis or Fisher’s Exact test with significance accepted at p\u3c0.05. To further assess risk perception accuracy, Chi-square analysis with pre-determined expected cell count percentages was used. RESULTS: Likert responses for perceived risk between genders were not significantly different but showed perception inaccuracies of the entire cohort. Only 41% of the subjects perceived their risk as “higher” or “much higher” than their peers while 27% perceived their risk as lower or much lower. 32% of the subjects perceived their risk to be the same as their peers. Comparison of risk marker number between genders was significantly different (Fisher’s exact test, p = .046) with males having 33% more markers than females. Chi-square analysis using an expected cell percentage of 75% in the “higher” Likert category, 25% in the “much higher” Likert category, and fractions of 1 in the other categories revealed significance (p\u3c.0001) with only 29.8% of subject responses in the “higher” category and 11.9% in the “much higher” category. The female cohort showed similar results with test percentages of 73% in the “higher” category and 27% in the “much higher” category. Responses were significantly different (p\u3c.0001) with only 30% choosing the “higher” category and 10% choosing the “much higher” category. CONCLUSIONS: Although significant differences in actual cardiac risk exist between genders in a cohort of cardiac patients, perceived risks are not significantly different. Both genders greatly underestimate their risk

Effects of resonant tunneling in electromagnetic wave propagation through a polariton gap

We consider tunneling of electromagnetic waves through a polariton band gap of a 1-D chain of atoms. We analytically show that a defect embedded in the structure gives rise to the resonance transmission at the frequency of a local polariton state associated with the defect. Numerical Monte-Carlo simulations are used to examine properties of the electromagnetic band arising inside the polariton gap due to finite concentration of defects.Comment: 12 pages, 6 figures, RevTe

Profiles of Coronary Artery Disease Risk in Cardiac Patients: Actual versus Perceived

PURPOSE: To describe interrelations and differences between actual vs. perceived cardiac risk in a cohort of coronary artery disease (CAD) patients. METHODS: 33 females (HT: 164 cm, WT: 80kg) and 67 males (HT: 179 cm, WT: 93kg) with documented CAD completed a questionnaire designed to assess CAD risk perception. They also underwent assessments for all ACSM risk factors. Five-point Likert scale responses to the question “Compared to other persons of your own age and sex, how would you rate your risk of ever having a heart attack?” were used to quantify CAD risk perception. To quantify actual risk, the number of ACSM risk markers for each subject was tabulated. It should be noted that, since all of the subjects had active CAD, they were all at high risk. Tabulations and Likert scale responses were compared using Chi-square analysis or Fisher’s Exact test with significance accepted at p\u3c0.05. To assess risk perception accuracy, Chi-square analysis with pre-determined expected cell count percentages was used. RESULTS: When compared to diagnosis driven expected frequencies of risk perception being higher or much higher (75% and 25% respectively), patients responses were only 30% and 11% respectively (Chi-square=19696.9, p\u3c.0001). Also, as the number of actual ACSM risk markers increased for each patient, no increase in patient risk perception was found (Chi-square=40.2, p=0.29). Factors associated with accurate perception include age, resting ECG status, and number of bypass grafts. Factors that were not accurately included in risk perception include family history, waist circumference, number and type of angioplasties, smoking, having had a heart attack, number of additional structural cardiac abnormalities present, the presence of arrhythmias, elevated blood lipids and blood glucose, and elevated systolic and diastolic blood pressures. CONCLUSION: Although substantial differences in number and type of actual cardiac risk exist in a cohort of cardiac patients, individual perception of these risks is not accurate in the majority of cases

GLIMPSE: I. A SIRTF Legacy Project to Map the Inner Galaxy

GLIMPSE (Galactic Legacy Infrared Mid-Plane Survey Extraordinaire), a SIRTF Legacy Science Program, will be a fully sampled, confusion-limited infrared survey of the inner two-thirds of the Galactic disk with a pixel resolution of \~1.2" using the Infrared Array Camera (IRAC) at 3.6, 4.5, 5.8, and 8.0 microns. The survey will cover Galactic latitudes |b| <1 degree and longitudes |l|=10 to 65 degrees (both sides of the Galactic center). The survey area contains the outer ends of the Galactic bar, the Galactic molecular ring, and the inner spiral arms. The GLIMPSE team will process these data to produce a point source catalog, a point source data archive, and a set of mosaicked images. We summarize our observing strategy, give details of our data products, and summarize some of the principal science questions that will be addressed using GLIMPSE data. Up-to-date documentation, survey progress, and information on complementary datasets are available on the GLIMPSE web site: www.astro.wisc.edu/glimpse.Comment: Description of GLIMPSE, a SIRTF Legacy project (Aug 2003 PASP, in press). Paper with full res.color figures at http://www.astro.wisc.edu/glimpse/glimpsepubs.htm