Consolidation of Geologic Studies of Geopressured-Geothermal Resources in Texas

Two major structural styles are identified in the Wilcox growth-fault trend of the Texas Gulf Coast. The style in central and southeast Texas is characterized by continuous, closely spaced growth faults that have little associated rollover despite moderate expansion of section and that show little flattening of the fault plane with depth. Where the growth-fault trend crosses the Houston Diapir Province, growth faults are localized by preexisting salt pillows; however, the piercement salt domes formed after the main phase of faulting, so the salt tectonics "overprints" the growth faults. In South Texas (south of Live Oak County), a narrow band of growth faults having high expansion and moderate rollover lies over and downdip of a ridge of deformed, overpressured shale and lies updip of a deep Tertiary-filled basin formed by withdrawal of overpressured shale. Significant antithetic faulting is associated with this band of growth faults. Also in South Texas, the lower Wilcox Lobo trend is deformed by highly listric normal faults beneath an unconformity that is probably related to Laramide tectonic activity. Wilcox sandstone reservoirs are predominantly of high-constructive deltaic (distributary-channel and delta-front) origin. This, together with close spacing of faults and characteristically low permeabilities, limits the size of geopressured reservoirs. The largest reservoirs may be in interfault areas or in salt- or shale-withdrawal basins.Bureau of Economic Geolog

Electroantennogram responses of male Sphinx perelegans hawkmoths to floral and ‘green-leaf volatiles’

Electroantennograms (EAGs) from field-collected male Sphinx perelegans hawkmoths were recorded in response to 10 individual floral scent compounds identified from Clarkia breweri (Onagraceae), 21 additional volatiles characteristic of other night-blooming flowers, and eight ‘green leaf’ volatiles. Measurable EAG responses were elicited to all compounds tested, but the most effective antennal stimulants were benzyl acetate, linalool, methyl salicylate and trans-2-hexenal. Mean, pooled EAGs to oxygenated terpenoids, aromatic esters and fatty acid derivatives were larger in magnitude than those in response to aromatic aldehydes/alcohols, monoterpenes and nitrogen-bearing compounds. The rank order of male S. perelegans' EAGs did not differ significantly from that of previously recorded responses of male Hyles lineata to the same scent compounds, and EAG magnitudes were generally larger for S. perelegans than for H. lineata. Both hawkmoth species are shown to have broad olfactory receptivities and could potentially respond to a wide array of plant volatiles as floral attractants.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42717/1/10667_2004_Article_158733.pd

The need for structured thoracic robotic training: the perspective of an American Association for Thoracic Surgery surgical robotic fellow

Since the initial experiences with robotic platforms in thoracic surgery (1), the number of procedures performed with this technique have continued to increase (2). Not only have newer trainees demonstrated interest in the field, but former open and VATS surgeons have also become aware of the advantages that the robotic platform provides (1,3). However, although some authors have implemented robotic thoracic surgery safely (4,5) others still consider it inefficient, citing the increased operative time (related to the learning curve), the initial instrument cost, and the lack of appropriate directed training (3)

The Luminosity Function and Mass Function in the Galactic Bulge

We present deep photometry obtained with the Hubble Space Telescope (HST) in a field in Baade's Window in the Galactic bulge. We derive a luminosity function down to I ~ 24.3, or V ~ 27.5, corresponding to M ~ 0.3 Msun. The luminosity function from the turnoff down to this level appears remarkably similar to that observed in the solar neighborhood. We derive a mass function using both an empirical local mass-luminosity relation and a mass-luminosity relation from recent stellar model calculations, allowing for the presence of binaries and photometric errors. The mass function has a power law form with dN/dM proportional to M^{-2.2} for M >~ 0.7 Msun. However, we find strong evidence for a break in the mass function slope around 0.5-0.7 Msun, with a significantly shallower slope at lower masses. The value of the slope for the low masses depends on the assumed binary fraction and the accuracy of our completeness correction. This mass function should directly reflect the initial mass function.Comment: 26 pages, 9 figures, to be published in the Astronomical Journa

Design and update of a classification system : the UCSD map of science

Global maps of science can be used as a reference system to chart career trajectories, the location of emerging research frontiers, or the expertise profiles of institutes or nations. This paper details data preparation, analysis, and layout performed when designing and subsequently updating the UCSD map of science and classification system. The original classification and map use 7.2 million papers and their references from Elsevier’s Scopus (about 15,000 source titles, 2001–2005) and Thomson Reuters’ Web of Science (WoS) Science, Social Science, Arts & Humanities Citation Indexes (about 9,000 source titles, 2001–2004)–about 16,000 unique source titles. The updated map and classification adds six years (2005–2010) of WoS data and three years (2006–2008) from Scopus to the existing category structure–increasing the number of source titles to about 25,000. To our knowledge, this is the first time that a widely used map of science was updated. A comparison of the original 5-year and the new 10-year maps and classification system show (i) an increase in the total number of journals that can be mapped by 9,409 journals (social sciences had a 80% increase, humanities a 119% increase, medical (32%) and natural science (74%)), (ii) a simplification of the map by assigning all but five highly interdisciplinary journals to exactly one discipline, (iii) a more even distribution of journals over the 554 subdisciplines and 13 disciplines when calculating the coefficient of variation, and (iv) a better reflection of journal clusters when compared with paper-level citation data. When evaluating the map with a listing of desirable features for maps of science, the updated map is shown to have higher mapping accuracy, easier understandability as fewer journals are multiply classified, and higher usability for the generation of data overlays, among others

Effects of deep sedation or general anesthesia on cardiac function in mice undergoing cardiovascular magnetic resonance

<p>Abstract</p> <p>Background</p> <p>Genetically engineered mouse models of human cardiovascular disease provide an opportunity to understand critical pathophysiological mechanisms. Cardiovascular magnetic resonance (CMR) provides precise reproducible assessment of cardiac structure and function, but, in contrast to echocardiography, requires that the animal be immobilized during image acquisition. General anesthetic regimens yield satisfactory images, but have the potential to significantly perturb cardiac function. The purpose of this study was to assess the effects of general anesthesia and a new deep sedation regimen, respectively, on cardiac function in mice as determined by CMR, and to compare them to results obtained in mildly sedated conscious mice by echocardiography.</p> <p>Results</p> <p>In 6 mildly sedated normal conscious mice assessed by echo, heart rate was 615 ± 25 min^-1(mean ± SE) and left ventricular ejection fraction (LVEF) was 0.94 ± 0.01. In the CMR studies of normal mice, heart rate was slightly lower during deep sedation with morphine/midazolam (583 ± 30 min^-1), but the difference was not statistically significant. General anesthesia with 1% inhaled isoflurane significantly depressed heart rate (468 ± 7 min^-1, p < 0.05 vs. conscious sedation). In 6 additional mice with ischemic LV failure, trends in heart rate were similar, but not statistically significant. In normal mice, deep sedation depressed LVEF (0.79 ± 0.04, p < 0.05 compared to light sedation), but to a significantly lesser extent than general anesthesia (0.60 ± 0.04, p < 0.05 vs. deep sedation).</p> <p>In mice with ischemic LV failure, ejection fraction measurements were comparable when performed during light sedation, deep sedation, and general anesthesia, respectively. Contrast-to-noise ratios were similar during deep sedation and during general anesthesia, indicating comparable image quality. Left ventricular mass measurements made by CMR during deep sedation were nearly identical to those made during general anesthesia (r²= 0.99, mean absolute difference < 4%), indicating equivalent quantitative accuracy obtained with the two methods. The imaging procedures were well-tolerated in all mice.</p> <p>Conclusion</p> <p>In mice with normal cardiac function, CMR during deep sedation causes significantly less depression of heart rate and ejection fraction than imaging during general anesthesia with isoflurane. In mice with heart failure, the sedation/anesthesia regimen had no clear impact on cardiac function. Deep sedation and general anesthesia produced CMR with comparable image quality and quantitative accuracy.</p

Hubble Space Telescope imaging of η Carinae

We present new high spatial resolution observations of the material around η Carinae obtained with the Hubble Space Telescope Wide Field/Planetary Camera. The star η Carinae is one of the most massive and luminous stars in our Galaxy, and has been episodically expelling significant quantities of gas over the last few centuries. The morphology of the bright central nebulosity (the homunculus) indicates that it is a thin shell with very well defined edges, and is clumpy on 0".2 (~10^(16)cm) scales. An extension to the northeast of the star {NN/NS using Walborn's [ApJL, 204, L17 ( 1976)] nomenclature} appears to be a stellar jet and its associated bow shock. The bow shock is notable for an intriguing series of parallel linear features across its face. The S ridge and the W arc appear to be part of a "cap" of emission located to the SW and behind the star. Together, the NE jet and the SW cap suggest that the symmetry axis for the system runs NE-SW rather than SE-NW, as previously supposed. Overall, the data indicate that the material around the star may represent an oblate shell with polar blowouts, rather than a bipolar flow

Hubble Space Telescope Planetary Camera images of R136

The Planetary Camera of the Hubble Space Telescope has been used to obtain broad and narrowband images ofR136, the core of the massive star cluster 30 Doradus in the Large Magellanic Cloud. R136a, the brightest component ofR136, is shown to have at least 12 separate components, including the eight originally identified by speckle interferometry. Three of the 12 components are previously unidentified close companions of the speckle components. The stars within R136a are found to have luminosities and colors of normal evolved (Wolf-Rayet and blue supergiants) and zero-age main-sequence (ZAMS) massive stars. A narrowband He II filter was used to investigate the Wolf-Rayet stellar population. We find that three stars in R136a are of the Wolf-Rayet type; of the two identified from ground-based data, one is now resolved into two components. We present color-magnitude diagrams and a luminosity function of the stars within the larger region (~2 pc) defined as R136. We find that the stars in R136 are similar in color and luminosity to those of cluster members that lie outside that crowded inner region. The lower end of the color-magnitude diagram corresponds to ZAMS spectral type B3. No red supergiants have been detected within R136. The luminosity per unit area in the inner 1" (0.25 pc) of R136 is ≥ 50 times that of the center of Orion for a comparable area and seven times that of the core of NGC 3603. The luminosity per unit area of all of R136 is comparable to that of Orion but is sustained over 130 times the area. An F336W surface brightness profile is constructed for R136 based on the stellar photometry. The distribution is found to be consistent with a pure power law with l(r}ɑ r^y with y=-1.72±0.06 or with a small core with r_c 5 X 10^4 M_☉ pc^(-3). The implied upper limit on the relaxation time for the cluster is much smaller than the age of 3.5 X 10^6 yrs required by the presence of Wolf-Rayet stars. This suggests that relaxation effects have been very important in determining the observed structure of the cluster unless a large population of lower mass stars is also present

Planetary camera observations of the central parsec of M32

Analysis of V band HST Planetary Camera images of the elliptical galaxy M32 shows that its nucleus is extremely dense and remains unresolved at even the HST diffraction limit. A combined approach of image deconvolution and model fitting is used to investigate the starlight distribution into limiting radii of 0".04 (0.14 pc at 700 kpc). The logarithmic slope of the brightness profile smoothly flattens from y= -1.2 at 3.4 pc to y= -0.5 at 0.34 pc; interior to this radius the profile is equally consistent with a singular µ(r)∝ r,^(-1/2) cusp or a small nonisothermal core with r_c<0.37 pc. The isophotes maintain constant ellipticity into tlle center, and there is no evidence for a central point source, disk, dust, or any other substructures. The cusp model implies central mass densities p_0 > 3 X 10^7 M_☉ pc^(-3) at the resolution limit and is consistent with a central M_• = 3 X 10^6 M_☉ black hole; the core model implies p_0≈4 X 10^6 M_☉ pc^(-3). From the viewpoint of long-term stability, we argue that a starlight cusp surrounding a central black hole is the more plausible interpretation of the observations. A core at the implied density and size without a black hole has a relaxation time of only ~7 X 10^7 yr and a short stellar oollision timescale implying wholesale stellar merging over the age of the universe. The core would be strongly vulnerable to collapse and concomitant runaway stellar merging. Collapse may lead to formation of a massive black hole in any case if it cannot be reversed by formation of a binary from high-mass merger products. Regardless of the ultimate fate of the core, however, structural evolution of the core will always be accompanied by strong evolution of the core population-the constant isophote shape and absence of a central color gradient appear to show that such evolution has not occurred. In contrast, the high velocities around a black hole imply long relaxation and stellar collision times for the cusp population compared to the age of the universe

Boundary Conditions on Internal Three-Body Wave Functions

For a three-body system, a quantum wave function $\Psi^\ell_m$ with definite $\ell$ and $m$ quantum numbers may be expressed in terms of an internal wave function $\chi^\ell_k$ which is a function of three internal coordinates. This article provides necessary and sufficient constraints on $\chi^\ell_k$ to ensure that the external wave function $\Psi^\ell_m$ is analytic. These constraints effectively amount to boundary conditions on $\chi^\ell_k$ and its derivatives at the boundary of the internal space. Such conditions find similarities in the (planar) two-body problem where the wave function (to lowest order) has the form $r^{|m|}$ at the origin. We expect the boundary conditions to prove useful for constructing singularity free three-body basis sets for the case of nonvanishing angular momentum.Comment: 41 pages, submitted to Phys. Rev.