bluuebunny/crossref_metadata_2025 huggingface dataset:
Wavelet-based detection of singularities in acoustic impedances from surface seismic reflection data
Authors: Li Chun-Feng , Liner Christopher
Published: January 2008

Although the passage of singularity information from acoustic impedance to seismic traces is now well understood, it remains unanswered how routine seismic processing, mode conversions, and multiple reflections can affect the singularity analysis of surface seismic data. We make theoretical investigations on the transition of singularity behaviors from acoustic impedances to surface seismic data. We also perform numerical, wavelet-based singularity analysis on an elastic synthetic data set that is processed through routine seismic processing steps (such as stacking and migration) and that contains mode conversions, multiple reflections, and other wave-equation effects. Theoretically, seismic traces can be approximated as proportional to a smoothed version of the [Formula: see text] derivative of acoustic impedance,where [Formula: see text] is the vanishing moment of the seismic wavelet. This theoretical approach forms the basis of linking singularity exponents (Hölder exponents) in acoustic impedance with those computable from seismic data. By using wavelet-based multiscale analysis with complex Morlet wavelets, we can estimate singularity strengths and localities in subsurface impedance directly from surface seismic data. Our results indicate that rich singularity information in acoustic impedance variations can be preserved by surface seismic data despite data-acquisition and processing activities. We also show that high-resolution detection of singularities from real surface seismic data can be achieved with a proper choice of the scale of the mother wavelet in the wavelet transform. Singularity detection from surface seismic data thus can play a key role in stratigraphic analysis and acoustic impedance inversion.
3D forward and inverse modeling of total-field magnetic anomalies caused by a uniformly magnetized layer defined by a linear combination of 2D Gaussian functions
Authors: García-Abdeslem Juan
Published: January 2008

I develop a method for 3D forward modeling and nonlinear inversion of the total-field magnetic anomaly caused by a uniformly magnetized layer with its top and bottom surfaces represented by a linear combination of 2D Gaussian functions. The solution of the forward problem is found through both analytic and numerical methods of integration to calculate the theoretical magnetic anomaly. The magnetic anomalies computed by the present numerical method compare well with the ones calculated by using an analytic solution. To test the robustness of the algorithm, the inversion is performed with noisy synthetic data. The estimated parameters in the case of a synthetic model were found to deviate only modestly from the true parameters in the presence of noise. The algorithm is used to interpret a dipolar magnetic anomaly of high amplitude attributable to a laccolith of intermediate composition in northern Mexico.
Inverse- Q filtered migration
Authors: Wang Yanghua
Published: January 2008

An inverse-[Formula: see text] filtered migration algorithm performs seismic migration and inverse-[Formula: see text] filtering simultaneously, in which the latter compensates for the amplitudes and corrects the phase distortions resulting from the earth attenuation effect. However, the amplitudes of high-frequency components grow rapidly in the extrapolation procedure, so numerical instability is a concern when including the inverse-[Formula: see text] filter in the migration. The instability for each frequency component is independent of data and is affected only by migration models. The stabilization problem may be treated separately from the wavefield-extrapolation scheme. The proposed strategy is to construct supersedent of attenuation coefficients, based on given velocity and [Formula: see text] models, before performing wavefield extrapolation in the space-frequency domain. This stabilized algorithm for inverse-[Formula: see text] filtered migration is applicable to subsurface media with vertical and lateral variations in velocity and [Formula: see text] functions. It produces a seismic image with enhanced resolution and corrected timing, comparable to an ideal image without the earth attenuation effect.
3D underwater imaging using vector acoustic sensors
Authors: Lindwall Dennis
Published: January 2008

Marine surveys that use vector acoustic sensors may allow for 3D imaging of underwater environments with a much smaller amount of data than current 3D hydrophone surveys. Newly developed sensors make vector-acoustic-based surveys practical. This concept is demonstrated with data from a three-axis accelerometer and a collocated hydrophone in an acoustic water tank using a short-pulse source and passive scattering targets. One algorithm rectifies the vector data with scalar pressure data and another maps the vector data into a 3D volume, showing several slices of the volume images. The imaging algorithm maps the scattered energy using the direction and traveltime independently for each source-receiver pair rather than using the phase coherence methods common in exploration seismology. Imaging a more complex and realistic marine environment requires vector wavefield decomposition techniques and other theoretical developments but may allow for 3D vector-acoustic seismic surveys using logistics similar to 2D surveys that use conventional hydrophones.
Exact seismic velocities for transversely isotropic media and extended Thomsen formulas for stronger anisotropies
Authors: Berryman James G.
Published: January 2008

A different type of approximation to the exact anisotropic wave velocities as a function of incidence angle in transversely isotropic (TI) media is explored. This formulation extends Thomsen’s weak anisotropy approach to stronger deviations from isotropy without significantly affecting the equations’ simplicity. One easily recognized improvement is that the extreme value of the quasi-SV-wave speed [Formula: see text] is located at the correct incidence angle [Formula: see text] rather than always being at the position [Formula: see text]. This holds universally for Thomsen’s approximation, although [Formula: see text] actually is never correct for any TI anisotropic medium. Wave-speed magnitudes are more closely approximated for most values of the incidence angle, although there may be some exceptions depending on actual angular location of the extreme value. Furthermore, a special angle [Formula: see text] (close to theextreme point of the SV-wave speed and also needed by the new formulas) can be deduced from the same data normally used in weak anisotropy data analysis. All the main technical results are independent of the physical source of the anisotropy. Two examples illustrate the use of obtained results based on systems having vertical fractures. The first set of model fractures has axes of symmetry randomly oriented in the horizontal plane. Such a system is then isotropic in the horizontal plane and thus exhibits vertical transversely isotropic (VTI) symmetry. The second set of fractures also has its axes of symmetry in the horizontal plane, but (it is assumed) these axes are aligned so the system exhibits horizontal transverse isotropic (HTI) symmetry. Both VTI and HTI systems, as well as any other TI medium (whether because of fractures, layering, or other physical causes), are easily treated with the new phase-speed formulation.
Ground-vehicle INS/GPS vector gravimetry
Authors: Li Xiaopeng , Jekeli Christopher
Published: January 2008

For geophysical purposes, gravity is measured in many ways, from static-point observations, using a gravimeter, to mean-value determinations from gravimeter and gravity gradiometer data collected by airplanes, ships, and satellites. We tested estimates of vertical and horizontal components of the gravity vector by combining Global Positioning System (GPS) data with a Honeywell H764G inertial navigation system (INS) on a land vehicle traversing highways in southwestern Montana. The estimation methods were based on techniques applied successfully to airborne INS/GPS data. In addition, we used wavelet denoising and wavenumber correlation procedures to enhance the estimates. Analyses of multiple traverses along the roads verified levels of repeatability as good as [Formula: see text] (all numerical accuracy values refer to standard deviations) in the vertical gravity-disturbance component. Control data, interpolated onto each road segment from an available database of gravity values, had an accuracy better than [Formula: see text]. Compared with this interpolated control, our vertical gravity estimates compare as well as [Formula: see text]. Resolution of the estimated vertical component is about [Formula: see text], based on [Formula: see text] data smoothing and a vehicle averaging about [Formula: see text]. Large scale-factor errors exist in the horizontal gravity estimates. Removing those on the basis of extensive deflection-of-the-vertical (DOV) control yields repeatability in the horizontal components of [Formula: see text] and agreement with the control at [Formula: see text]. Our tests confirm that a land-vehicle INS/GPS system is capable of along-track gravity mapping with precision and resolution that have used in local geophysical modeling (e.g., continental rifts) as well as in mineral exploration.
Investigation of core data reliability to support time-lapse interpretation in Campos Basin, Brazil
Authors: Grochau Marcos Hexsel , Gurevich Boris
Published: January 2008

Quantitative interpretation of time-lapse seismic data requires knowledge of saturation and pressure effects on seismic velocities. Although the former can usually be modeled adequately using the Gassmann equation, the latter is obtained mainly by laboratory measurements, which can be affected by core damage. We investigate the magnitude of this effect on compressional-wave velocities by comparing laboratory experiments and log measurements. We use Gassmann fluid substitution to obtain low-frequency saturated velocities from dry core measurements (thus mitigating the dispersion effects) taken at reservoir pressure. The analysis is performed for an unusual densely cored well from which 43 cores were extracted over a [Formula: see text]-thick turbidite reservoir. These computed velocities show very good agreement with the sonic-log measurements. This confirms that, for this particular region, the effect of core damage on ultrasonic measurements is less than the measurement error. Consequently, stress sensitivity of elastic properties as obtained from ultrasonic measurements is adequate for quantitative interpretation of time-lapse seismic data.
Visualization of active faults using geometric attributes of 3D GPR data: An example from the Alpine Fault Zone, New Zealand
Authors: McClymont Alastair F. , Green Alan G. , Streich Rita , Horstmeyer Heinrich , Tronicke Jens , Nobes David C. , Pettinga Jarg , Campbell Jocelyn , Langridge Robert
Published: January 2008

Three-dimensional ground-penetrating radar (GPR) data are routinely acquired for diverse geologic, hydrogeologic, archeological, and civil engineering purposes. Interpretations of these data are invariably based on subjective analyses of reflection patterns. Such analyses are heavily dependent on interpreter expertise and experience. Using data acquired across gravel units overlying the Alpine Fault Zone in New Zealand, we demonstrate the utility of various geometric attributes in reducing the subjectivity of 3D GPR data analysis. We use a coherence-based technique to compute the coherency, azimuth, and dip attributes and a gray-level co-occurrence matrix (GLCM) method to compute the texture-based energy, entropy, homogeneity, and contrast attributes. A selection of the GPR attribute volumes allows us to highlightkey aspects of the fault zone and observe important features not apparent in the standard images. This selection also provides information that improves our understanding of gravel deposition and tectonic structures at the study site. A new depositional/structural model largely based on the results of our analysis of GPR attributes includes four distinct gravel units deposited in three phases and a well-defined fault trace. This fault trace coincides with a zone of stratal disruption and shearing bound on one side by upward-tilted to synclinally folded stratified gravels and on the other side by moderately dipping stratified alluvial-fan gravels that could have been affected by lateral fault drag. When used in tandem, the coherence- and texture-based attribute volumes can significantly improve the efficiency and quality of 3D GPR interpretation, especially for complex data collected across active fault zones.
High-resolution gravity study of the Gray Fossil Site
Authors: Whitelaw J. L. , Mickus K. , Whitelaw M. J. , Nave J.
Published: January 2008

The Gray Fossil Site, Washington County, Tennessee, has produced a remarkable Mio-Pliocene fauna and flora with no known correlative in the Appalachian region. After its discovery in 2000, a series of auger holes were drilled by the Tennessee Department of Transportation (TDOT) to determine the areal extent of the site. Drilling indicated that the fossils occurred in fill material within a paleokarst basin, but the distribution of boreholes does not permit details of sinkhole topography, and therefore its formation and fill history, to be adequately resolved. To better image the sinkhole basin, a high-resolution gravity survey, which included 1104 gravity measurement stations, was conducted. These data were used to create complete Bouguer and residual gravity anomaly maps and a 3D density model via inversionmethods. The residual gravity anomaly map compares favorably with 29 TDOT auger holes drilled to basement, but contains significantly more detail. The residual gravity anomaly map reveals the presence of seven separate sinkholes. However, 3D inverse modeling constrained by drill-hole depths and density data indicates that there are 11 separate sinkholes formed within the Knox Group carbonates. These sinkholes, which range between 20 and [Formula: see text] in depth, are aligned along northwest and northeast trending linear features that correlate to structural features formed during the Appalachian orogenies. It is possible that the overall sinkhole basin formed as the result of partial coalescence of multiple sinkhole structures controlled by a joint system and that the sinkholes then acted as a natural trap for the Gray Fossil Site fauna and flora.
Nitric Oxide Isoenzymes Regulate Lipopolysaccharide-Enhanced Insulin Transport across the Blood-Brain Barrier
Authors: Banks William A. , Dohgu Shinya , Lynch Jessica L. , Fleegal-DeMotta Melissa A. , Erickson Michelle A. , Nakaoke Ryota , Vo Than Q.
Published: January 2008

Insulin transported across the blood-brain barrier (BBB) has many effects within the central nervous system. Insulin transport is not static but altered by obesity and inflammation. Lipopolysaccharide (LPS), derived from the cell walls of Gram-negative bacteria, enhances insulin transport across the BBB but also releases nitric oxide (NO), which opposes LPS-enhanced insulin transport. Here we determined the role of NO synthase (NOS) in mediating the effects of LPS on insulin BBB transport. The activity of all three NOS isoenzymes was stimulated in vivo by LPS. Endothelial NOS and inducible NOS together mediated the LPS-enhanced transport of insulin, whereas neuronal NOS (nNOS) opposed LPS-enhanced insulin transport. This dual pattern of NOS action was found in most brain regions with the exception of the striatum, which did not respond to LPS, and the parietal cortex, hippocampus, and pons medulla, which did not respond to nNOS inhibition. In vitro studies of a brain endothelial cell (BEC) monolayer BBB model showed that LPS did not directly affect insulin transport, whereas NO inhibited insulin transport. This suggests that the stimulatory effect of LPS and NOS on insulin transport is mediated through cells of the neurovascular unit other than BECs. Protein and mRNA levels of the isoenzymes indicated that the effects of LPS are mainly posttranslational. In conclusion, LPS affects insulin transport across the BBB by modulating NOS isoenzyme activity. NO released by endothelial NOS and inducible NOS acts indirectly to stimulate insulin transport, whereas NO released by nNOS acts directly on BECs to inhibit insulin transport.
A Metabolomic Perspective of Melatonin Metabolism in the Mouse
Authors: Ma Xiaochao , Chen Chi , Krausz Kristopher W. , Idle Jeffrey R. , Gonzalez Frank J.
Published: January 2008

Metabolism of melatonin (MEL) in mouse was evaluated through a metabolomic analysis of urine samples from control and MEL-treated mice. Besides identifying seven known MEL metabolites (6-hydroxymelatonin glucuronide, 6-hydroxymelatonin sulfate, N-acetylserotonin glucuronide, N-acetylserotonin sulfate, 6-hydroxymelatonin, 2-oxomelatonin, 3-hydroxymelatonin), principal components analysis of urinary metabolomes also uncovered seven new MEL metabolites, including MEL glucuronide, cyclic MEL, cyclic N-acetylserotonin glucuronide, cyclic 6-hydroxymelatonin; 5-hydroxyindole-3-acetaldehyde, di-hydroxymelatonin and its glucuronide conjugate. However, N1-acetyl-N2-formyl-5-methoxy-kynuramine and N1-acetyl-5-methoxy-kynuramine, known as MEL antioxidant products, were not detected in mouse urine. Metabolite profiling of MEL further indicated that 6-hydroxymelatonin glucuronide was the most abundant MEL metabolite in mouse urine, which comprised 75, 65, and 88% of the total MEL metabolites in CBA, C57/BL6, and 129Sv mice, respectively. Chemical identity of 6-hydroxymelatonin glucuronide was confirmed by deconjugation reactions using β-glucuronidase and sulfatase. Compared with wild-type and CYP1A2-humanized mice, Cyp1a2-null mice yielded much less 6-hydroxymelatonin glucuronide (∼10%) but more N-acetylserotonin glucuronide (∼195%) and MEL glucuronide (∼220%) in urine. In summary, MEL metabolism in mouse was recharacterized by using a metabolomic approach, and the MEL metabolic map was extended to include seven known and seven novel pathways. This study also confirmed that 6-hydroxymelatonin glucuronide was the major MEL metabolite in the mouse, and suggested that there was no interspecies difference between humans and mice with regard to CYP1A2-mediated metabolism of MEL, but a significant difference in phase II conjugation, yielding 6-hydroxymelatonin glucuronide in the mouse and 6-hydroxymelatonin sulfate in humans.
Parathyroid Hormone Increases Activating Transcription Factor 4 Expression and Activity in Osteoblasts: Requirement for Osteocalcin Gene Expression
Authors: Yu Shibing , Franceschi Renny T. , Luo Min , Zhang Xiaoyan , Jiang Di , Lai Yumei , Jiang Yu , Zhang Jian , Xiao Guozhi
Published: January 2008

PTH is an important peptide hormone regulator of calcium homeostasis and osteoblast function. However, its mechanism of action in osteoblasts is poorly understood. Our previous study demonstrated that PTH activates mouse osteocalcin (Ocn) gene 2 promoter through the osteoblast-specific element 1 site, a recently identified activating transcription factor-4 (ATF4) -binding element. In the present study, we examined effects of PTH on ATF4 expression and activity as well as the requirement for ATF4 in the regulation of Ocn by PTH. Results show that PTH elevated levels of ATF4 mRNA and protein in a dose- and time-dependent manner. This PTH regulation requires transcriptional activity but not de novo protein synthesis. PTH also increased binding of nuclear extracts to osteoblast-specific element 1 DNA. PTH stimulated ATF4-dependent transcriptional activity mainly through protein kinase A with a lesser requirement for protein kinase C and MAPK/ERK pathways. Lastly, PTH stimulation of Ocn expression was lost by small interfering RNA down-regulation of ATF4 in MC-4 cells and Atf4−/− bone marrow stromal cells. Collectively, these studies for the first time demonstrate that PTH increases ATF4 expression and activity and that ATF4 is required for PTH induction of Ocn expression in osteoblasts.
Thyroid Hormone Activates Adenosine 5′-Monophosphate-Activated Protein Kinase via Intracellular Calcium Mobilization and Activation of Calcium/Calmodulin-Dependent Protein Kinase Kinase-β
Authors: Yamauchi Masako , Kambe Fukushi , Cao Xia , Lu Xiuli , Kozaki Yasuko , Oiso Yutaka , Seo Hisao
Published: January 2008

AMP-activated protein kinase (AMPK) is a key regulator of glucose and fatty acid homeostasis. In muscle cells, AMPK stimulates mitochondrial fatty acid oxidation and ATP production. The thyroid hormone T3 increases cellular oxygen consumption and is considered to be a major regulator of mitochondrial activities. In this study, we examined the possible involvement of AMPK in the stimulatory action of T3 on mitochondria. Treatment of C2C12 myoblasts with T3 rapidly led to phosphorylation of AMPK. Acetyl-coenzyme A carboxylase, a direct target of AMPK, was also phosphorylated after T3 treatment. Similar results were obtained with 3T3-L1, FRTL-5, and HeLa cells. Stable expression of T3 receptor (TR)-α or TRβ in Neuro2a cells enhanced this effect of T3, indicating the involvement of TRs. Because HeLa cells express only Ca2+/calmodulin-dependent protein kinase kinase-β (CaMKKβ), one of two known AMPK kinases, it was suggested that the effect of T3 is mediated by CaMKKβ. Indeed, experiments using a CaMKK inhibitor, STO-609, and an isoform-specific small interfering RNA demonstrated the CaMKKβ-dependent phosphorylation of AMPK. Furthermore, T3 was found to rapidly induce intracellular Ca2+ mobilization in HeLa cells, and a Ca2+ chelator, 1,2-bis(2-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid (BAPTA), suppressed T3- as well as ionomycin-dependent phosphorylation of AMPK. In addition, T3-dependent oxidation of palmitic acids was attenuated by BAPTA, STO-609, and the small interfering RNA for CaMKKβ, indicating that T3-induced activation of AMPK leads to increased fatty acid oxidation. These results demonstrate that T3 nontranscriptionally activates AMPK via intracellular Ca2+ mobilization and CaMKKβ activation, thereby stimulating mitochondrial fatty acid oxidation.
Zeb1 links epithelial-mesenchymal transition and cellular senescence
Authors: Liu Yongqing , El-Naggar Shahenda , Darling Douglas S. , Higashi Yujiro , Dean Douglas C.
Published: January 2008

Overexpression of zinc finger E-box binding homeobox transcription factor 1(Zeb1) in cancer leads to epithelial-to-mesenchymal transition (EMT) and increased metastasis. As opposed to overexpression, we show that mutation of Zeb1 in mice causes a mesenchymal-epithelial transition in gene expression characterized by ectopic expression of epithelial genes such as E-cadherin and loss of expression of mesenchymal genes such as vimentin. In contrast to rapid proliferation in cancer cells where Zeb1 is overexpressed,this mesenchymal-epithelial transition in mutant mice is associated with diminished proliferation of progenitor cells at sites of developmental defects, including the forming palate, skeleton and CNS. Zeb1dosage-dependent deregulation of epithelial and mesenchymal genes extends to mouse embryonic fibroblasts (MEFs), and mutant MEFs also display diminished replicative capacity in culture, leading to premature senescence. Replicative senescence in MEFs is classically triggered by products of the Ink4a(Cdkn2a) gene. However, this Ink4a pathway is not activated during senescence of Zeb1 mutant MEFs. Instead, there is ectopic expression of two other cell cycle inhibitory cyclin-dependent kinase inhibitors,p15Ink4b (Cdkn2b) and p21Cdkn1a (Cdkn1a). We demonstrate that this ectopic expression of p15Ink4b extends in vivo to sites of diminished progenitor cell proliferation and developmental defects in Zeb1-null mice.
KBP is essential for axonal structure, outgrowth and maintenance in zebrafish, providing insight into the cellular basis of Goldberg-Shprintzen syndrome
Authors: Lyons David A. , Naylor Stephen G. , Mercurio Sara , Dominguez Claudia , Talbot William S.
Published: January 2008

Mutations in Kif1-binding protein/KIAA1279 (KBP) cause the devastating neurological disorder Goldberg-Shprintzen syndrome (GSS) in humans. The cellular function of KBP and the basis of the symptoms of GSS, however, remain unclear. Here, we report the identification and characterization of a zebrafish kbp mutant. We show that kbp is required for axonal outgrowth and maintenance. In vivo time-lapse analysis of neuronal development shows that the speed of early axonal outgrowth is reduced in both the peripheral and central nervous systems in kbp mutants. Ultrastructural studies reveal that kbp mutants have disruption to axonal microtubules during outgrowth. These results together suggest that kbp is an important regulator of the microtubule dynamics that drive the forward propulsion of axons. At later stages, we observe that many affected axons degenerate. Ultrastructural analyses at these stages demonstrate mislocalization of axonal mitochondria and a reduction in axonal number in the peripheral, central and enteric nervous systems. We propose that kbp is an important regulator of axonal development and that axonal cytoskeletal defects underlie the nervous system defects in GSS.
Letter: Silver Mediated Ester Bond Formation in the Gas Phase: Substrate Structure is Important
Authors: Khairallah George N. , Waters Tom , O'Hair Richard A.J.
Published: January 2008

The silver acetate cation CH3CO2Ag2+ reacted with allyl iodide via C–O bond coupling to produce Ag2I+ and allyl acetate, but only underwent adduct formation with methyl iodide, highlighting the importance of substrate on reactivity. DFT calculations predicted the reaction with allyl iodide to be exothermic by 0.48 eV and suggested that intermediates in the reaction benefit from multiple interactions between the allyl and iodide moieties of allyl iodide and the two silver atoms in CH3CO2Ag2+.
Copper-Induced Oligomerization of Peptides: A Model Study
Authors: Schlosser Gitta , Stefanescu Raluca , Przybylski Michael , Murariu Manuela , Hudecz Ferenc , Drochioiu Gabi
Published: January 2008

In this work, copper-binding of the tetraglycine peptide (Gly–Gly–Gly–Gly) was studied by electrospray ionization mass spectrometry. Experiments were performed under alkaline conditions, in the presence of ethanolamine (pH 10.95). We observed that the presence of copper(II) ions induces the aggregation of the peptide and the formation of copper-bound complexes with higher molecular mass is favored, such as the oligomer complexes [3M + 2Cu – 3H]+ and [4M + 3Cu – 5H]+. At 1:1 peptide–copper(II) ion ratio, the singly charged [3M + 2Cu – 3H]+ oligomer complex is the base peak in the mass spectrum. Metal ion-induced oligomerization of neurotoxic peptides is well known in the literature; however, there are very few examples in which such oligomerization was directly observed by mass spectrometry. Our results show that application of short peptides can be useful to study the mechanism of metal ion binding and metal ion-induced oligomerization of peptides.
Interactions of Nucleobases with Alkali Earth Metal Cations—Electrospray Ionization Mass Spectrometric Study
Authors: Frańska Magdalena
Published: January 2008

Interactions of nucleobases with alkali earth metal cations have been studied by electrospray ionization mass spectrometry (ESI-MS). Nucleobases containing at least one oxygen atom form stable complexes with alkali earth metal cations. This phenomenon can be explained on the grounds of the well known theory of hard and soft acids and bases. Uracil and thymine make complexes only when in their deprotonoted forms. The cations of great radii (Sr2+, Ba2+) are more prone to form complexes of stoichiometry 1:1 with uracil and thymine than the cations of small radii (Mg2+, Ca2+). On the other hand, Mg2+ forms complexes of stoichiometry 2:1 and 3:2 with uracil and thymine. Gas-phase stabilities of the 1:1 complexes are higher for the cations of small radii, in contrast to the solution stabilities. For cytosine and 9-methylhypoxantine the 1:1 complexes of their deprotonated forms are observed at higher cone voltage as a result of HCl molecule loss from the complexes containing the counter ion (Cl−). In solution, more stable complexes are formed with metal cations of low radii. Gas-phase stability of the complexes formed by deprotonated 9-methylhypoxantine increases with increasing metal cation radius.
Letter: Lanthanum-Calcium-Manganate (La0.67Ca0.33MnO3) Nanoparticle-Assisted Affinity Probes for Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Analysis of Proteins
Authors: Mandal Santi M. , De Debasis , Roy Sanat K. , Ghosh Ananta K. , Ram Shanker , Das Amit K.
Published: January 2008

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) has been used extensively for the analysis of intact proteins and for proteomics. Proteins or proteomics analyses with low molecular mass range have some limitations because of background interference from the salt or surfactant ions. Lanthanum-calcium-manganate La0.67Ca0.33MnO3 nanoparticles (LCMONPs) have been used as the matrix-assisting material after surface modification to reduce the salt or surfactant interference. The detectable mass range was tested in the range of 800–16,000 Da. The surface-modified LCMONPs have affinity with protein molecules through ionic or electrostatic interaction at pH 4.0. The nanoparticles mixed with proteins give a spectrum with a large signal-to-noise ratio for the analytes, and effectively eliminate the noise from interfering salt or surfactant ions. The results indicate that surface-modified La0.67Ca0.33MnO3 nanoparticles can be used with MALDI matrix for proteins to eliminate the excessive noise of selective surfactants or salt ions from the MALDI spectrum.
Further conventions for NMR shielding and chemical shifts (IUPAC Recommendations 2008)
Authors: Harris Robin K. , Becker Edwin D. , Cabral de Menezes Sonia M. , Granger Pierre , Hoffman Roy E. , Zilm Kurt W.
Published: January 2008

IUPAC has published a number of recommendations regarding the reporting of nuclear magnetic resonance (NMR) data, especially chemical shifts. The most recent publication [Pure Appl. Chem.
73, 1795 (2001)] recommended that tetramethylsilane (TMS) serve as a universal reference for reporting the shifts of all nuclides, but it deferred recommendations for several aspects of this subject. This document first examines the extent to which the 1H shielding in TMS itself is subject to change by variation in temperature, concentration, and solvent. On the basis of recently published results, it has been established that the shielding of TMS in solution [along with that of sodium-3-(trimethylsilyl)propanesulfonate, DSS, often used as a reference for aqueous solutions] varies only slightly with temperature but is subject to solvent perturbations of a few tenths of a parts per million (ppm). Recommendations are given for reporting chemical shifts under most routine experimental conditions and for quantifying effects of temperature and solvent variation, including the use of magnetic susceptibility corrections and of magic-angle spinning (MAS). This document provides the first IUPAC recommendations for referencing and reporting chemical shifts in solids, based on high-resolution MAS studies. Procedures are given for relating 13C NMR chemical shifts in solids to the scales used for high-resolution studies in the liquid phase. The notation and terminology used for describing chemical shift and shielding tensors in solids is reviewed in some detail, and recommendations are given for best practice.
Performance evaluation criteria for preparation and measurement of macro- and microfabricated ion-selective electrodes (IUPAC Technical Report)
Authors: Lindner Ernö , Umezawa Yoshio
Published: January 2008

Over the last 30 years, IUPAC published several documents with the goal of achieving standardized nomenclature and methodology for potentiometric ion-selective electrodes (ISEs). The ISE vocabulary was formulated, measurement protocols were suggested, and the selectivity coefficients were compiled. However, in light of new discoveries and experimental possibilities in the field of ISEs, some of the IUPAC recommendations have become outdated. The goal of this technical report is to direct attention to ISE practices and the striking need for updated or refined IUPAC recommendations which are consistent with the state of the art of using macro- and microfabricated planar microelectrodes. Some of these ISE practices have never been addressed by IUPAC but have gained importance with the technological and theoretical developments of recent years. In spite of its recognized importance, a generally acceptable revision of the current IUPAC recommendations is far beyond the scope of this work.
Impact of scientific developments on the Chemical Weapons Convention (IUPAC Technical Report)
Authors: Balali-Mood Mahdi , Steyn Pieter S. , Sydnes Leiv K. , Trapp Ralf
Published: January 2008

This report summarizes the findings and recommendations of an international workshop that was organized jointly by IUPAC and the Organisation for the Prohibition of Chemical Weapons (OPCW), and held in Zagreb, Croatia, from 22 to 25 April 2007. It was held to assist with preparation for the Second Review Conference of the Chemical Weapons Convention (CWC), which will commence in April 2008. The CWC has been in force since 29 April 1997, and today 182 States have joined the Convention. The CWC aims at the total prohibition of all chemical weapons (CW) and the destruction of all CW stockpiles and production facilities by 2007. Extensions have been agreed upon and, for some CW stockpiles, the deadline is now 2012. This disarmament is subject to strict international verification by the OPCW. The CWC also prohibits the development, production, acquisition, stockpiling, and retention of CW and requires national implementation measures, including legislation, together with the international verification of chemical industry facilities. Furthermore, the CWC aims to strengthen States Parties' capacities in the field of protection against CW, and encourages international cooperation in the peaceful application of chemistry. The CWC requires that reviews of the operation of the Convention are carried out at five-year intervals and specifies that such reviews "shall take into account any relevant scientific and technological developments", so as to ensure the continued effectiveness of the treaty and of its verification and implementation systems. This report has been prepared to assist the parties of the CWC with that review.
High-Grade Mucoepidermoid Carcinoma of the Mandibular Salivary Gland in a Lion (Panthera leo)
Authors: Dorso L. , Risi E. , Triau S. , Labrut S. , Nguyen F. , Guigand L. , Wyers M. , Abadie J.
Published: January 2008

A 13–year-old neutered male lion was presented with a primary neoplasm arising from the left mandibular salivary gland associated with metastases to regional lymph nodes, thoracic viscera (lungs, heart, esophagus, and diaphragm), and kidney. Histologic and immunohistochemical investigations led to a diagnosis of a high-grade mucoepidermoid carcinoma of the mandibular salivary gland. In this case report, we point out the importance of the immunohistochemical characterization for differential diagnosis between various types of carcinomas of the salivary gland.
Toxicity of the Lichen Secondary Metabolite (+)-Usnic Acid in Domestic Sheep
Authors: Dailey R. N. , Montgomery D. L. , Ingram J. T. , Siemion R. , Vasquez M. , Raisbeck M. F.
Published: January 2008

Toxicity following ingestion of the vagrant, foliose lichen Xanthoparmelia chlorochroa was identified as the putative etiology in the death of an estimated 400–500 elk on the Red Rim-Daley Wildlife Habitat Management Area in Wyoming during the winter of 2004. A single, unsubstantiated report in 1939 attributed toxicity of X. chlorochroa in cattle and sheep to usnic acid, a common lichen secondary metabolite. To test the hypothesis that usnic acid is the proximate cause of death in animals poisoned by lichen, domestic sheep were dosed PO with (+)-usnic acid. Clinical signs in symptomatic ewes included lethargy, anorexia, and signs indicative of abdominal discomfort. Serum creatine kinase, aspartate aminotransferase, and lactate dehydrogenase activities were considerably elevated in symptomatic sheep. Similarly, only symptomatic ewes exhibited appreciable postmortem lesions consisting of severe degenerative appendicular skeletal myopathy. The median toxic dose (ED50) of (+)-usnic acid in domestic sheep was estimated to be between 485 and 647 mg/kg/day for 7 days.
Correlation of Pituitary Histomorphometry with Adrenocorticotrophic Hormone Response to Domperidone Administration in the Diagnosis of Equine Pituitary Pars Intermedia Dysfunction
Authors: Miller M. A. , Pardo I. D. , Jackson L. P. , Moore G. E. , Sojka J. E.
Published: January 2008

Functional evaluation of the pars intermedia (PI) is required for the early diagnosis of equine pituitary PI dysfunction (PPID), yet most assays target the hypothalamic-pituitary-adrenal axis, which regulates the pars anterior. In contrast, the PI is regulated by dopaminergic tone from hypothalamic neurons. Loss of dopaminergic inhibition is hypothesized to cause the PI hypertrophy and hyperplasia that result in the clinical manifestations of PPID. Domperidone, a dopamine receptor antagonist, should exacerbate the loss of dopaminergic inhibition in horses with PPID and increase the release of endogenous adrenocorticotrophic hormone (eACTH) by PI melanotrophs. To test this, plasma eACTH concentration was determined in horses with or without clinical signs of PPID at 0, 4, and 8 hours after oral administration of 3.3 mg domperidone/kg. Pituitary glands were evaluated postmortem by histologic grading and morphometry. In the 33 horses, median age, plasma ACTH concentration 8 hours after domperidone, and PI area in median sagittal sections were associated with histologic grade as follows: pituitary grade 1 (normal), n = 3, 7.5 years, 20.0 pg/ml, 0.16 cm2; grade 2 (focal hypertrophy or hyperplasia), n = 9, 14.5 years, 27.1 pg/ml, 0.27 cm2; grade 3 (diffuse adenomatous hyperplasia), n = 5, 21.0 years, 64.4 pg/ml, 0.48 cm2; grade 4 (microadenomas), n = 12, 23.3 years, 128.0 pg/ml, 0.87 cm2; grade 5 (adenoma), n = 4, 24.9 years, 720.5 pg/ml, 2.1 cm2. Results suggest that horses with pituitary histologic grade ≥3 respond to domperidone with increased plasma ACTH concentration.
Melanosis of the Urinary Bladder in a Cow
Authors: Russo V. , Borzacchiello G. , Brun R. , D'Ischia M. , Napolitano A. , Paciello O. , Panzella L. , Roperto F. , Urraro C. , Roperto S.
Published: January 2008

Melanosis of the urinary bladder is a very rare condition characterized by an abnormal black or brownish-black pigmentation of the organ. The pigmentary disorder can involve both the urothelial cell layers and/or the submucosa. The biologic potential of the melanosis of urinary bladder remains unknown because only a few cases have been reported in medical literature. So far melanosis of the urinary bladder is not known to occur in cattle. Here we describe the first case of melanosis of the urinary bladder in an inbred red-spotted, 7-year-old cow. Light, ultrastructural, and immunohistochemic investigations demonstrated melanin pigment in the submucosa and lamina propria but not the urothelium of the bladder. In addition, biochemical characterization of the pigment-laden cells demonstrated that the pigment of this disorder consisted mainly of eumelanin, thus corroborating the morphologic studies. Finally, virologic examination revealed the presence of bovine papillomavirus type 2.
A Clonal Outbreak of Acute Fatal Hemorrhagic Pneumonia in Intensively Housed (Shelter) Dogs Caused by Streptococcus equi subsp. zooepidemicus
Authors: Pesavento P. A. , Hurley K. F. , Bannasch M. J. , Artiushin S. , Timoney J. F.
Published: January 2008

An outbreak of acute, fatal, hemorrhagic pneumonia was observed in more than 1,000 mixed breed dogs in a single animal shelter. The Department of Anatomic Pathology at the University of California at Davis School of Veterinary Medicine performed necropsies on dogs that were found moribund in acute respiratory distress or found dead with evidence of nasal bleeding. All dogs had hemothorax and an acute, fibrinosuppurative pneumonia. Large numbers of gram-positive cocci were observed within the lungs of all dogs and within septic thromboemboli of remote organs in about 50% of cases. Bacterial cultures from the dogs and their environment revealed widespread beta-hemolytic Streptococus equi subspecies zooepidemicus (Lancefield Group C). Extensive diagnostic testing failed to reveal the consistent presence of copathogens in individual cases. The clinical, epidemiologic, molecular biologic, and pathologic data indicate that a single clone of S. zooepidemicus was the cause of an acutely fatal respiratory infection in these dogs.
Esophageal Duplication Cyst in a Dog
Authors: Gabor L. J. , Walshaw R.
Published: January 2008

A cranial cervical mass was surgically removed from a dog. On histologic examination, the mass was consistent with an esophageal duplication cyst, a condition rare in humans and not reported in the dog.
Transthyretin Amyloidosis and Two Other Aging-Related Amyloidoses in an Aged Vervet Monkey
Authors: Nakamura S. , Okabayashi S. , Ageyama N. , Koie H. , Sankai T. , Ono F. , Fujimoto K. , Terao K.
Published: January 2008

An aged male vervet monkey showed severe cardiac arrhythmia for more than 3 years. A multifocal amyloid consisting of transthyretin was deposited in all areas of the heart wall, especially in the extracellular stroma among muscle fibers and external tunica of arterioles. Moreover, the amyloid was deposited in the stroma and arterioles of other systemic organs except the liver and spleen. These characteristics are consistent with senile systemic amyloidosis in humans. A second amyloid consisting of amyloid β protein was in senile plaques and cerebral amyloid angiopathy in the cerebral cortex. A third amyloid consisting of islet amyloid polypeptide was deposited in islets of the pancreas. Apolipoprotein E and amyloid P component colocalized with the 3 amyloids. Thus, 3 different aging-related amyloids were found in an aged vervet monkey. In particular, to our knowledge, this is the first report on spontaneous transthyretin amyloidosis in animals.
Experimental Transmission of US Scrapie Agent by Nasal, Peritoneal, and Conjunctival Routes to Genetically Susceptible Sheep
Authors: Hamir A. N. , Kunkle R. A. , Richt J. A. , Miller J. M. , Greenlee J. J.
Published: January 2008

Scrapie is a naturally occurring fatal neurodegenerative disease of sheep and goats. This study documents incubation periods, pathologic findings, and distribution of abnormal prion proteins (PrPSc) by immunohistochemistry in tissues of genetically susceptible sheep inoculated with US sheep scrapie agent. Four-month-old Suffolk lambs (QQ at codon 171) were inoculated by 1 of 3 different routes (nasal, peritoneal, and conjunctival) with an inoculum (No. 13–7) consisting of a pool of scrapie-affected sheep brains. Except for 3 sheep, all inoculated animals were euthanized when advanced clinical signs of scrapie were observed between 19 and 46 months postinoculation (MPI). Spongiform lesions in the brains and labeling of PrPSc in central nervous system and lymphoid tissues were present in these sheep. One intranasally inoculated sheep euthanized at 12 MPI had presence of PrPSc that was confined to the pharyngeal tonsil. These results indicate that the upper respiratory tract, specifically the pharyngeal tonsil, may serve as a portal of entry for prion protein in scrapie-infected environments.
Choriocarcinoma with Metastasis in a Rabbit (Oryctolagus cuniculi)
Authors: Kaufmann-Bart M. , Fischer I.
Published: January 2008

A 3-year-old female rabbit ( Oryctolagus cuniculi) presented with apathy and indisposition for 2–3 days. Palpation revealed a mass in the caudal abdomen, namely, in the wall of the uterus. Ovariohysterectomy was performed, and the tissues were submitted for histopathologic examination. The mass consisted of 3 different (trophoblastic, syncytiotrophoblastic, and cytotrophoblastic) neoplastic cell types originating from the uterus. Immunohistochemistry was positive for cytokeratin in all 3 neoplastic cell types, and the syncytiotrophoblasts were positive also for human chorionic gonadotropin. Together these features allow the diagnosis choriocarcinoma. This report documents the first case of a spontaneous choriocarcinoma in a rabbit.
Spinal Arthropathy Associated with Ochrobactrum anthropi in Free-ranging Cane Toads (Chaunus [Bufo] marinus) in Australia
Authors: Shilton C. M. , Brown G. P. , Benedict S. , Shine R.
Published: January 2008

Inflammatory or degenerative pathology involving the vertebral bodies and/or ventral intervertebral joints has been described in numerous species, both captive and free ranging, including mammals, birds, and snakes, although never in amphibians. We described 15 cases of a newly recognized spinal arthropathy in adult cane toads ( Chaunus [Bufo] marinus), an invasive species in Australia. Grossly appreciable lesions consisted primarily of ventral proliferation of bone and cartilage that resulted in ankylosis. Histologic examination of the entire vertebral columns of the 15 affected toads revealed 13 toads to have lesions at multiple intervertebral sites, totalling 41 intervertebral joints with lesions. Most lesions involved bone and cartilage proliferation that resulted in fusion of the joint, with (n = 15) or without (n = 9) associated pyogranulomatous inflammation. In the remaining 17 affected joints, histologic lesions were characterized by degeneration of articular cartilage without joint fusion. In addition, in one of these joints, there was also hemorrhage and pyogranulomatous inflammation. Bacterial culture of affected joints in 9 toads and grossly normal joints in 4 control toads resulted in isolation of Ochrobactrum anthropi in 7 affected toads but in none of the controls ( P < .01). We proposed an interaction between degenerative and bacterial etiologies in the pathogenesis of this condition. Invasive toads may be predisposed to this condition because of their large size; increased rates of movement; and, possibly, immunosuppression resulting from inhabiting a novel environment.
Cutaneous Papillomatosis and Carcinomatosis in the Western Barred Bandicoot (Perameles bougainville)
Authors: Woolford L. , O'Hara A. J. , Bennett M. D. , Slaven M. , Swan R. , Friend J. A. , Ducki A. , Sims C. , Hill S. , Nicholls P. K. , Warren K. S.
Published: January 2008

A progressive wart-like syndrome in both captive and wild populations of the Western barred bandicoot (WBB) is hindering conservation efforts to prevent the extinction of this endangered marsupial. In this study, 42 WBBs exhibiting the papillomatosis and carcinomatosis syndrome were examined. The disease was characterized by multicentric proliferative lesions involving cutaneous and mucosal surfaces, which were seen clinically to increase in size with time. Grossly and histologically the smaller skin lesions resembled papillomas, whereas the larger lesions were most commonly observed to be squamous cell carcinomas. Large amphophilic intranuclear inclusion bodies were observed in hyperplastic conjunctival lesions of 8 WBBs under light microscopy. Conjunctival lesions from 2 WBBs examined using transmission electron microscopy contained a crystalline array of spherical electrondense particles of 45-nm diameter, within the nucleus of conjunctival epithelial cells, consistent with a papillomavirus or polyomavirus. Conjunctival samples from 3 bandicoots that contained intranuclear inclusion bodies also demonstrated a positive immunohistochemical reaction after indirect immunohis-tochemistry for papillomavirus structural antigens. Ultrastructural and/or immunohistochemical evidence of an etiologic agent was not identified in the nonconjunctival lesions examined. Here we describe the gross, histopathologic, ultrastructural, and immunohistochemical findings of a papillomatosis and carcinomatosis syndrome recently identified in the WBB.