bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimation of feed intake by cattle using controlled-release capsules containing n-alkanes or chromium sesquioxide
Authors: FERREIRA L. M. M. , OLIVÁN M. , RODRIGUES M. A. M. , OSORO K. , DOVE H. , DIAS-DA-SILVA A.
Published: October 2004

An experiment was carried out to evaluate the utilization of the n-alkane technique and the chromium sesquioxide (Cr2O3)/acid insoluble ash (AIA) procedure to estimate feed intake of meadow hay by two breeds of cattle. The animals were housed in individual pens, and offered known amounts of meadow hay as the sole diet component. One group of 4 Barrosã cows (average weight, 457±24 kg) and another group of 4 Holstein–Friesian cows (average weight, 635±148 kg) were dosed with intra-ruminal controlled-release capsules (CRC) that contained alkane markers or Cr2O3 in separate capsules. During intake estimation, meadow hay and faeces were sampled twice daily. There was no significant effect of grab sampling time on the meadow hay intake estimation, due to the fact that no differences were observed in the faecal marker concentrations.

The mean real intakes, measured as the difference between the dry weight of feed offered each day and the dry weight of daily feed refusal, were 5·64 and 7·76 kg DM/day for Barrosã and Holstein–Friesian cows, respectively. For Barrosã cows the mean estimated intakes when using the CRC release rates documented by the manufacturer (MRR) were 5·66, 6·59 and 6·90 kg DM/day, using the Cr2O3/AIA procedure, C31[ratio ]C32 and C33[ratio ]C32 n-alkane pairs, respectively. For Holstein–Friesian cows the same markers gave values of 7·72, 8·51 and 8·95 kg DM/day, respectively. Mean daily intake estimation was improved when the release rate calculated as the reduction rate in CRCs payload performed in a additional experiment (CRR), was used. The differences from the real intake values, obtained using C31[ratio ]C32 and C33[ratio ]C32 alkane pairs, decreased from 950 and 1260 g/day to 140 and 420 g/day, respectively, for Barrosã cows and from 750 and 1190 g/day to 290 and 90 g/day for Holstein–Friesian cows. The intake estimation using the Cr2O3/AIA procedure was not affected by correcting the CRC release rate, because the release rates of both MRR and the CRR were similar.

The results indicate that controlled-release capsules provide a uniform marker release in cattle, but also suggest that to obtain accurate estimates of intake, it is better to measure release rates within the context of particular experiments.
Marsalis and Baraka: an essay in comparative cultural discourse
Authors: BROWN LEE B.
Published: October 2004

In 1963, Amiri Imamu Baraka, a.k.a. LeRoi Jones, launched an Afrocentrist attack on the American white establishment that has been sustained, with variations, for forty years. He made a powerful case that the white commodity industry had systematically exploited and then debased authentic African-American music. In the meantime, a new kind of Afrocentrism has appeared, associated with the meteoric rise of Wynton Marsalis at New York's Lincoln Center. With the help of rhetoric similar to Baraka's, Marsalis has showcased and expanded the kind of black jazz he regards as authentic. However, the two men represent overlapping but also divergent points of view on the cultural politics of African-American music. This study compares these perspectives in detail, suggesting that behind the revealing differences between the two, both suffer from a formally similar outmoded essentialism.
Fixing a hole in the scale: suppressed notes in the Beatles' songs
Authors: WAGNER NAPHTALI
Published: October 2004

A suppressed note is one that is consistently left out of the collection of pitch classes (different musical notes) in a musical piece and later appears with considerable emphasis. The Beatles frequently use the technique of suppressed notes, due to their tendency to compose pentatonic melodies, which leave ‘holes’ in the diatonic scale. These holes are usually filled in later in the song, when the pentatonicism is broken. The suppressed note then attracts special attention, both because it is a new note that the melody had previously avoided and because it appears at a peak moment, which is shaped by other parameters as well (e.g. as a melodic peak in a metrically accented position) and is connected to a textual turning point. The paper peeks at the Beatles' repertoire through the keyhole of the suppressed note.
Beyond the ‘high fidelity’ stereotype: defining the (contemporary) record collector
Authors: SHUKER ROY
Published: October 2004

The popular image of record collectors is of obsessive males, whose ‘train spotting’ passion for collecting is often a substitute for ‘real’ social relationships. This image can draw on some support from academic discussions of collectors and collecting, but it represents only a partial account of record collectors. This paper draws on interviews with sixty-seven self-identified record collectors to show how they demonstrate a complex mix of characteristics: a love of music; obsessive-compulsive behaviour, accumulation and completism, selectivity and discrimination; and self-education and scholarship. As a social practice, record collecting presents itself as a core component of individual social identity and a central part of the life cycle.
Infrastructure for the Celestial Jukebox
Authors: BURKART PATRICK , McCOURT TOM
Published: October 2004

The vision of a dynamic and intelligent Celestial Jukebox, in which any cultural artifact is available to dedicated appliances or home computers via wired or wireless channels, animates many predictions for the future of media delivery. The chief proponents of this vision are transnational media firms selling hardware, software and content. Despite a prolonged downturn in the global economy for media and software, the technical and legal design of the Celestial Jukebox nears completion. We examine the development and implications of the Jukebox as it is manifested in several online music services available to US consumers (which we term Music Service Providers, or MSPs), in which the ‘Big Five’ record companies (Universal, Sony, Warner, BMG and EMI) provide content and/or hold equity stakes. First, we identify and describe the Celestial Jukebox's key technical components – Customer Relationship Management (‘eCRM’ or ‘CRM’) and Digital Rights Management (‘DRM’) software – and their intermeshing characteristics. We then discuss the implementation of CRM/DRM in MSPs and list the primary stakeholders in the leading MSP systems. We conclude with a discussion of the MSPs' role in advancing what Vincent Mosco terms a ‘pay-per’ society, in which cultural goods are purchased on a transitory, rather than permanent, basis.
DYSMETABOLIC SYNDROME, PLACENTA-MEDIATED DISEASE AND FUTURE RISK OF CARDIOVASCULAR DISEASE
Authors: RAY JOEL G
Published: October 2004

Tara, a 24 year-old woman of Sri Lankan ancestry, was diagnosed with borderline chronic hypertension just 4 months before her first pregnancy. While she experienced a healthy childhood and normal pubertal development, by age 22 years her body mass index (BMI) was 29 kg/m2. The first pregnancy was complicated by chronic hypertension and superimposed preeclampsia (PET), necessitating Caesarian delivery at 33 weeks gestation. In her third pregnancy she was diagnosed with gestational diabetes mellitus (DM), and delivered a 4100 g macrosomic infant boy by Caesarian section. By age 42 years, Tara was started on oral medications for Type 2 DM and hypertriglyceridaemia; 9 years later she suffered a small lacunar stroke, leaving her with moderate left-sided weakness of the arm and leg. Her own mother had experienced “high blood sugars” during pregnancy, was overweight, and died at age 54 years from the complications of high blood pressure.
OBSTETRIC CHOLESTASIS
Authors: KENYON ANNA P , SHENNAN ANDREW
Published: October 2004

Obstetric cholestasis (OC) is defined as pruritus of onset in pregnancy in association with abnormal liver function in the absence of any other identifiable liver pathology which resolves on delivery. It may be associated with adverse obstetric outcome and significant maternal morbidity. The significance of the disease has only recently been appreciated, and our understanding of its pathophysiology is in its infancy. This article will describe our current knowledge of the disease and critically review the interventions proposed to improve obstetric outcome and maternal morbidity.
ANTIPHOSPHOLIPID SYNDROME IN PREGNANCY: ONSET TO OUTCOME
Authors: STONE SOPHIA , POSTON LUCILLA
Published: October 2004

Antiphospholipid antibodies (aPLs) are a diverse group of autoantibodies with specificity for phospholipid surfaces. Antiphospholipid antibodies may be found in individuals with a clinical history of thrombotic events or in women suffering severe pregnancy complications typically involving fetal compromise or demise. The association is known as the antiphospholipid syndrome (APS).
Willensfreiheit, Verantwortlichkeit und Neurowissenschaft
Authors: Walter Henrik
Published: October 2004

Zusammenfassung. In dieser Arbeit wird das Problem von Willensfreiheit und Verantwortlichkeit und die Rolle der Neurowissenschaften bei seiner Lösung diskutiert. Dabei wird sich zeigen, dass die Frage, ob es Willensfreiheit gibt, natürlich davon abhängt, was genau man darunter versteht. Das Ergebnis dieser Untersuchung lautet: Willensfreiheit in einem traditionellen Sinne gibt es nicht, kann es nicht geben. Sie ist unvereinbar mit einem physikalischen Determinismus und auch der Indeterminismus rettet sie nicht. Dieses Problem kann als endgültig gelöst angesehen werden und bedeutet, dass wir bestimmte intuitive Vorstellungen von uns selbst aufgeben müssen. Eine mit dem Determinismus verträgliche Auffassung, die Willensfreiheit als natürliche Autonomie versteht, d.h. als eine psychologische Kompetenz des Handelns mit relativer Unabhängigkeit von bestimmten äußeren und inneren Einflussfaktoren (personale Freiheit, Selbstbestimmung), ist dagegen möglich und mit allem, was uns die Neurowissenschaft lehrt, verträglich. Entgegen herkömmlichen kompatibilistischen Thesen wird jedoch die These vertreten, dass dies auch Folgen für unser Verständnis von moralischer Verantwortlichkeit hat und es auch in diesem Bereich zu einer Revision unseres Selbstverständnisses kommen muss.
Laptops in der Schule - ein Weg zur Überwindung des Digital Divide zwischen Jungen und Mädchen?
Authors: Schaumburg Heike
Published: October 2004

Zusammenfassung. Forschungsergebnisse zur Computernutzung von Mädchen und Jungen bestätigen immer wieder das Vorliegen einer ‘digitalen‘ Kluft zwischen den Geschlechtern. In diesem Artikel werden Ergebnisse eines Modellversuchs dargestellt, bei dem durch den Einsatz von Laptops in der Schule unter anderem die Computer- und Internetkompetenz von Mädchen verbessert werden sollte. Es zeigte sich, dass die Schülerinnen des Projekts signifikant bessere Ergebnisse hinsichtlich Computer- und Internetwissen aufwiesen als Schülerinnen einer Kontrollgruppe ohne Laptop-Einsatz. Ihre computer- und internetbezogene Selbstwirksamkeit lag jedoch nicht höher als die der Kontrollgruppe. Im letzten Teil des Artikels werden Schlussfolgerungen für die Gestaltung von Maßnahmen zur Förderung der Computer- und Internetkompetenz von Mädchen abgeleitet.
An improved stress map for Italy and surrounding regions (central Mediterranean)
Authors: Montone Paola , Mariucci M. Teresa , Pondrelli Silvia , Amato Alessandro
Published: October 2004

We present an updated present‐day stress data compilation for the Italian region and discuss it with respect to the geodynamic setting and the seismicity of the area. We collected and analyzed 190 new stress data from borehole breakouts, seismicity, and active faults and checked in detail the previous compilation [Montone et al., 1999]. Our improved data set consists of 542 data, 362 of which with a reliable quality for stress maps. The Italian region is well sampled, allowing the computation of constrained smoothed stress maps; for surrounding regions we added the World Stress Map 2003 release data. These maps depict the active stress conditions and, in the areas where the data are sparse, contribute to understand the relationship between active stress, past tectonic setting, and the seismicity of the study region. The new data are particularly representative along the northern Apennine front, from the Po Plain to offshore the Adriatic, and along the southern Tyrrhenian Sea, north of Sicily, where they point out a compressive tectonic regime. In the Alps both compressive and transcurrent regimes are observed. Our data also confirm that the whole Apenninic belt and the Calabrian arc are extending. Along the central Adriatic coast, changes from one stress regime to another are shown by abrupt variations in the minimum horizontal stress directions. Other gentler stress rotations, as, for instance, from the southern Apennines to the Calabrian arc or along the northern Apennines, follow the curvature of the arcs and are not associated to a stress regime variation.
Stratospheric influences on the tropospheric seasonal cycles of nitrous oxide and chlorofluorocarbons
Authors: Nevison C. D. , Kinnison D. E. , Weiss R. F.
Published: October 2004

The stratospheric influence on the tropospheric seasonal cycles of N2O, CFC‐11 (CCl3F), CFC‐12 (CCl2F2) and CFC‐113 (CCl2FCClF2) is investigated using observations from the AGAGE global trace gas monitoring network and the results of the Whole Atmosphere Community Climate Model (WACCM). WACCM provides the basis for a number of predictions about the relative amplitudes of N2O and CFC seasonal cycles and about the relative magnitude and phasing of seasonal cycles in the northern and southern hemispheres. These predictions are generally consistent with observations, suggesting that the stratosphere exerts a coherent influence on the tropospheric seasonal cycles of trace gases whose primary sinks are in the stratosphere. This stratospheric influence may complicate efforts to validate estimated source distributions of N2O, an important greenhouse gas, in atmospheric transport model studies.
Power law probability distributions of multiscale auroral dynamics from ground‐based TV observations
Authors: Kozelov B. V. , Uritsky V. M. , Klimas A. J.
Published: October 2004

Some of the most significant observational indications of self‐organized critical (SOC) behavior in the magnetosphere are the scale‐free statistical distributions of nighttime auroral emission regions as depicted by the Ultraviolet Imager (UVI) onboard the POLAR spacecraft [Uritsky et al., 2002]. Here, we report the results from a similar study of ground‐based optical observations. Individual active auroral regions have been detected and analyzed using a spatiotemporal technique and statistical methods appropriate for quantifying critical behavior in SOC models. Probability distributions of the lifetime, maximum and integrated size, maximum power, and integrated energy output for auroral emission regions are shown to follow power law relations over wide ranges of scales. The power‐law exponents that we obtained are consistent with the UVI image exponents, extending the range of observed scale‐free auroral SOC dynamics by several orders of magnitude to smaller spatial and temporal scales.
The impact of tropical convection and cirrus on upper tropospheric humidity: A Lagrangian analysis of satellite measurements
Authors: Soden Brian J.
Published: October 2004

Geostationary satellite observations are used in conjunction with an objective pattern‐tracking algorithm to describe the Lagrangian evolution of convection, clouds and water vapor in the tropical upper troposphere. This analysis reveals that larger convective events within a Lagrangian air mass are associated with larger and longer‐lived cirrus anvil shields. Convective systems which generate larger cirrus shields are, in turn, associated with higher downstream humidity levels following the anvil's dissipation. In the absence of cirrus, the clear‐sky upper troposphere is shown to dry at a rate consistent with radiatively‐driven subsidence. The presence of cirrus anvils following a convective event is shown to reduce the rate of drying and for large anvils can even change its sign. Analysis of the Lagrangian tendencies suggests that this moistening effect is not attributable to the evaporation of cirrus condensate, but instead results from the same dynamical mechanisms responsible for the formation and maintenance of the cirrus anvil.
Assimilation of the 2000–2001 CO MOPITT retrievals with optimized surface emissions
Authors: Yudin V. A. , Pétron G. , Lamarque J.‐F. , Khattatov B. V. , Hess P. G. , Lyjak L. V. , Gille J. C. , Edwards D. P. , Deeter M. N. , Emmons L. K.
Published: October 2004

The multi‐year retrievals of carbon monoxide (CO) by the MOPITT (Measurements Of Pollution In The Troposphere) instrument onboard the NASA Terra satellite provide an opportunity for the first time to study quantitatively the transport and sources of pollution in the mid‐troposphere. This paper presents the assimilation of the Phase I (March 3, 2000–May 6, 2001) MOPITT retrievals with optimized CO emissions constrained by monthly MOPITT CO data. The observed‐minus‐forecast (OmF) CO distributions illustrate improvement of this data analysis compared with the assimilation that employs climatological surface fluxes.
Pursuit-evasion predator-prey waves in two spatial dimensions
Authors: Biktashev V. N. , Brindley J. , Holden A. V. , Tsyganov M. A.
Published: October 2004

We consider a spatially distributed population dynamics model with excitable predator-prey kinetics, where species propagate in space due to their taxis with respect to each other’s gradient in addition to, or instead of, their diffusive spread. Earlier, we have described new phenomena in this model in one spatial dimension, not found in analogous systems without taxis: reflecting and self-splitting waves. Here we identify new phenomena in two spatial dimensions: unusual patterns of meander of spirals, partial reflection of waves, swelling wave tips, attachment of free wave ends to wave backs, and as a result, a novel mechanism of self-supporting complicated spatiotemporal activity, unknown in reaction-diffusion population models.
A numerical study of cryogenic fluid injection and mixing under supercritical conditions
Authors: Zong Nan , Meng Hua , Hsieh Shih-Yang , Yang Vigor
Published: October 2004

The evolution of a cryogenic fluid jet initially at a subcritical temperature and injected into a supercritical environment, in which both the pressure and temperature exceed the thermodynamic critical state, has been investigated numerically. The model accommodates full conservation laws and real-fluid thermodynamics and transport phenomena. All of the thermophysical properties are determined directly from fundamental thermodynamics theories, along with the use of the corresponding state principles. Turbulence closure is achieved using a large-eddy-simulation technique. As a specific example, the dynamics of a nitrogen fluid jet is studied systematically over a broad range of ambient pressure. Owing to the differences of fluid states and flow conditions between the jet and surroundings, a string of strong density-gradient regimes is generated around the jet surface and exerts a stabilizing effect on the flow development. The surface layer acts like a solid wall that transfers the turbulent kinetic energy from its axial to radial component. The spatial growth rate of the surface instability wave increases with increasing pressure. The frequency of the most unstable mode exhibits a weak pressure dependence at high pressures. It, however, decreases significantly in the near-critical regime due to the enhanced effect of density stratification and increased mixing-layer momentum thickness. The result agrees well with the linear stability analysis. The jet dynamics is largely dictated by the local thermodynamic state through its influence on the fluid thermophysical properties. When the fluid temperature transits across the inflection point on an isobaric density-temperature curve, the resultant rapid property variations may qualitatively modify the jet behavior compared with its counterpart at low pressures. An increase in the ambient pressure results in an earlier transition of the jet into the self-similar regime.
Conditions for static bubbles in viscoplastic fluids
Authors: Dubash Neville , Frigaard Ian
Published: October 2004

We consider the slow motion of a gas bubble in a cylindrical column filled with a viscoplastic fluid, modeled here as a Herschel–Bulkley fluid. Because of the yield stress of the fluid, it is possible that a bubble will remain trapped in the fluid indefinitely. We adapt Prager’s two variational principles to our problem. From these variational principles we develop two general stopping conditions, i.e., for a given bubble we can calculate a critical Bingham number above which the bubble will not move. The first condition is derived by bounding the velocity field and the second condition by bounding the stress field. We illustrate these conditions by considering specific bubble shapes, e.g., axisymmetric bubbles. We also develop a condition for bubble motion.
Electrokinetic aspects of turbulent drag reduction in surfactant solutions
Authors: Fichman M. , Hetsroni G.
Published: October 2004

Electrokinetic mechanism of drag reduction of turbulent flow of surfactant solutions is proposed. The surfactant micelles with surface charge attract ions of the solvent or counterions, forming an electric double layer. The ions in the layer are “frozen” in a strongly bonded structure, which reduces the local flow around micelle. The local flow is the strain of small turbulent scale fluctuation. Numerical example indicates that electrokinetic mechanism supplies a reasonable explanation of the drag reduction in surfactant solutions. The proposed model is only the preliminary one, which points on the electrokinetics as an additional mechanism which contributes to the hydrodynamics of surfactant solutions.
Grad’s equations and hydrodynamics for weakly inelastic granular flows
Authors: Bisi M. , Spiga G. , Toscani G.
Published: October 2004

We introduce and discuss Grad’s moment equations for dilute granular systems of hard spheres with dissipative collisions and variable coefficient of restitution, under the assumption of weak inelasticity. An important by-product is that in this way we obtain the hydrodynamic description of a system of nearly elastic particles by a direct procedure from the Boltzmann equation, without resorting to any homogeneous cooling state assumption. Several crucial results of the pertinent literature are recovered in the present physical context in which deviation from elastic scattering is of the same order as the Knudsen number. In particular, the correlation function plays a fundamental role in the decay of the temperature, and the latter is described asymptotically, in space homogeneous conditions, by a corrected Haff’s law.
A Bhatnagar–Gross–Krook-type approach for chemically reacting gas mixtures
Authors: Groppi Maria , Spiga Giampiero
Published: October 2004

A recently proposed consistent approach for elastically scattering gas mixtures, of the type introduced by Bhatnagar, Gross, and Krook (BGK), has been extended to deal with a four species gas undergoing reversible bimolecular chemical reactions. The single BGK collision operator introduced for each species must take into account also transfer of mass and of energy of chemical bond. Suitable auxiliary fields have then to be introduced not only for temperatures and velocities, but also for densities, in order to fulfill correctly balance equations for mass, momentum, and total energy. The exact collision equilibrium, satisfying the mass action law of chemistry, is also recovered, and the proper choice of collision frequencies is discussed. Preliminary numerical results for the relaxation problem in space-homogeneous conditions are reported and briefly commented on.
Buoyant mixing of miscible fluids in tilted tubes
Authors: Séon T. , Hulin J.-P. , Salin D. , Perrin B. , Hinch E. J.
Published: October 2004

Buoyant mixing of two fluids in tubes is studied experimentally as a function of the tilt angle θ from vertical, the density contrast and the common viscosity μ. At high contrasts and low θ, longitudinal mixing is macroscopically diffusive, with a diffusivity D increasing strongly with θ and μ. At lower contrasts and higher θ, a counterflow of the two fluids with little transverse mixing sets in. The transition occurs at an angle increasing with density contrast and decreasing with μ. These results are discussed in terms of the dependence of transerse mixing on θ and an analogy with the Boycott effect.
The timing of eukaryotic evolution: Does a relaxed molecular clock reconcile proteins and fossils?
Authors: Douzery Emmanuel J. P. , Snell Elizabeth A. , Bapteste Eric , Delsuc Frédéric , Philippe Hervé
Published: October 2004

The use of nucleotide and amino acid sequences allows improved understanding of the timing of evolutionary events of life on earth. Molecular estimates of divergence times are, however, controversial and are generally much more ancient than suggested by the fossil record. The limited number of genes and species explored and pervasive variations in evolutionary rates are the most likely sources of such discrepancies. Here we compared concatenated amino acid sequences of 129 proteins from 36 eukaryotes to determine the divergence times of several major clades, including animals, fungi, plants, and various protists. Due to significant variations in their evolutionary rates, and to handle the uncertainty of the fossil record, we used a Bayesian relaxed molecular clock simultaneously calibrated by six paleontological constraints. We show that, according to 95% credibility intervals, the eukaryotic kingdoms diversified 950–1,259 million years ago (Mya), animals diverged from choanoflagellates 761–957 Mya, and the debated age of the split between protostomes and deuterostomes occurred 642–761 Mya. The divergence times appeared to be robust with respect to prior assumptions and paleontological calibrations. Interestingly, these relaxed clock time estimates are much more recent than those obtained under the assumption of a global molecular clock, yet bilaterian diversification appears to be ≈100 million years more ancient than the Cambrian boundary.
Glutamate and acetylcholine corelease at developing synapses
Authors: Li W.-C. , Soffe S. R. , Roberts Alan
Published: October 2004

Most neurons release a single fast-acting low-molecular-weight transmitter at synapses to activate and open postsynaptic ion channels. We challenge this principle with evidence for corelease of the two major excitatory transmitters, glutamate and acetylcholine (ACh), from single identified neurons in the developing frog tadpole spinal cord. Whole-cell patch electrodes were used to record from single spinal neurons. When action potentials and inhibition were blocked, spontaneous miniature excitatory postsynaptic currents (mEPSCs) were recorded. These were fully blocked only by joint application of glutamate [α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) and
N
-methyl-D-aspartate receptor (NMDAR)] and nicotinic ACh receptor (nAChR) antagonists. Fast nAChR and slow NMDAR mEPSCs were isolated pharmacologically. We then show that some mEPSCs have both the fast nAChR rise and slow NMDAR decay and conclude that some individual synaptic vesicles corelease glutamate and ACh. Whole-cell recordings from pairs of neurons were then used to identify the spinal interneurons coreleasing the two excitatory transmitters. One anatomical class of interneuron with descending axons was found to excite other spinal neurons by activating nAChR, AMPAR, and NMDAR simultaneously at its synapses. Although Jonas, Bischofberger, and Sandkuhler [Jonas, P., Bischofberger, J. & Sandkuhler, J. (1998)
Science
281, 419-424] showed that the inhibitory transmitters GABA and glycine can be coreleased at spinal synapses, the
Xenopus
tadpole provides a case where the two main CNS excitatory transmitters are released from single vesicles, and where the presynaptic neuron coreleasing two transmitters has been identified.
Fourier transform ion cyclotron resonance MS reveals the presence of a water molecule in an enzyme transition-state analogue complex
Authors: Borchers Christoph H. , Marquez Victor E. , Schroeder Gottfried K. , Short Steven A. , Snider Mark J. , Speir J. Paul , Wolfenden Richard
Published: October 2004

The structures of several powerful inhibitors of hydrolytic enzymes resemble that of the altered substrate in the transition state, except that a hydrogen atom replaces one substituent (typically the leaving group). To test the hypothesis that a water molecule might be present in the gap resulting from this replacement, we examined a transition-state analogue complex formed by
Escherichia coli
cytidine deaminase by Fourier transform ion cyclotron resonance MS in electrospray mode. Upon nebularization from aqueous solution under conditions (pH 5.6) where the enzyme is active, cytidine deaminase remains dimeric in the vapor phase. In the presence of inhibitor, the enzyme's exact mass can be used to infer the presence at each active site of zinc, 5-fluoro-3,4-dihydrouridine, and a single water molecule.
Cellular integrins function as entry receptors for human cytomegalovirus via a highly conserved disintegrin-like domain
Authors: Feire Adam L. , Koss Heidi , Compton Teresa
Published: October 2004

Human cytomegalovirus (HCMV) is capable of manifesting disease in nearly every organ system in immunocompromised patients. This broad pathogenic tropism correlates with the ability of the virus to infect all tested vertebrate cell types
in vitro
, a characteristic that has made receptor identification extremely difficult. During virus entry, HCMV induces cellular morphological changes and signaling cascades consistent with engagement of cellular integrins; however, HCMV structural proteins do not possess the widely used RGD integrin-binding motif. We identified an integrin-binding disintegrin-like domain within HCMV envelope glycoprotein B, a protein required for virus entry and fusion throughout the
Herpesviridae
. Accepted receptor criteria are met through the use of function-blocking integrin Abs, β1 integrin knockout mouse fibroblasts, and glycoprotein B disintegrin-like peptides, all of which support a critical role for α2β1, α6β1, and αVβ3 integrins as HCMV entry receptors and signaling mediators acting during the penetration stage of the entry pathway. Strikingly, the glycoprotein B disintegrin-like domain is conserved in many human and animal herpesviruses, suggesting that integrins may support entry across this medically important virus family.
Book Reviews
Authors: Stridbeck Hans , Nakstad Per Hj , Johansson Kerstin , Ringertz Hans , Dullerud Reidar , Jonsson Kjell , Ekberg Olle , Skaane Per
Published: October 2004

Imaging of the Pancreas - Cystic and Rare Tumors. Edited by C. Procacci and A. J. Megibow. Springer-Verlag 2003. ISBN 3-540-42742-2. Price: EUR 139.95

Emergency Radiology. Rules and Tools. Edited by Jane Young. Remedica 2003. ISBN 1-901346-28-5. Price: EUR 40.

Imaging in Paediatric Urology. Edited by W. Becker, J. Meller, H. Zappel, A. Leenen and F. Seseke. Springer-Verlag 2003. ISBN 3-540-43348-1. Price hardcover EUR 145,55.

Imaging in Stroke. Edited by M. G. Henerici. Remedica publishing limited 2003. ISBN 0-387-95454-6. 216 pages with 75 figures and 8 tables. Price: EUR 45.

Imaging of the Foot and Ankle. Techniques and Applications. By A. M. Davies, R. W. Whietehouse and J. P. R. Jenkins. Springer-Verlag 2002. Price: EUR 159.

Radiology of the Postoperative GI Tract. By B. R. Javors and E. L. Wolf. Springer-Verlag 2003. ISBN 0-387-95200-4. Price: US$ 159.

Imaging-Guided Interventional Breast Techniques. Edited by D. David Dershaw. Springer-Verlag 2003. ISBN 0-387-95454-6. 212 pages, 304 figures. Price Hardcover: EUR 139.
The value of routine MR myelography at MRI of the lumbar spine
Authors: O'Connell M. J. , Ryan M. , Powell T. , Eustace S.
Published: October 2004

Purpose: To determine whether a commercially available automated MR myelogram sequence improves the interpretation and diagnostic yield at MRI of the lumbar spine.

Material and Methods: A total of 207 consecutive patients referred for MR examination of the lumbar spine for evaluation of low back pain or spinal radicular symptoms were included for study. All patients had initial imaging with sagittal T1-W and T2-W scans, followed by axial T2-W images. Subsequently an MR myelogram was acquired in each case in coronal, sagittal and oblique planes. MR myelogram images were evaluated initially and a diagnosis was established and recorded. Subsequently, a diagnosis was established by review of conventional images of the lumbar spine in sagittal and axial planes, in conjunction with the MR myelogram. The utility of the MR myelogram in establishing the diagnosis was graded on a 4-point scale, where grade 0 indicated that it contributed no additional information and grade 3 indicated that it was essential for diagnosis. Analysis of the additional value of myelography in patients with multilevel disease was made.

Results: Primary diagnoses were disc herniation in 69 cases (33%), degenerative disc disease in 51 cases (26%), spinal stenosis in 19 cases (9%), isolated lateral recess stenosis in 5 cases (2%), or other diagnoses, including facet degeneration in 48 cases (23%). Scans were normal in 15 cases (7%). MR myelography was graded as grade 0 in 151 cases (73%), grade 1 in 44 cases (21%) and grade 2 in 12 cases (6%). In no case was MR myelography essential for diagnosis (grade 3). In patients with multilevel disease (n = 27), in 17 cases MR myelography was graded as grade 1 (63%) and in 8 cases grade 2 (30%).

Conclusion: MR myelography when employed in routine practice was of limited value, assisting in establishing a diagnosis in a minority of cases (6%). The technique was of limited additional value in patients with multilevel pathology and to a lesser extent in patients with scoliosis, where it helped to establish the level most likely to account for pathology.
Volume-rendered 3D display of MR angiograms in the diagnosis of cerebral arteriovenous malformations
Authors: Tsuchiya K. , Katase S. , Hachiya J. , Shiokawa Y.
Published: October 2004

Purpose: To determine whether application of a volume-rendered display of 3D time-of-flight (TOF) MR angiography could assist the diagnosis of cerebral arteriovenous malformations (AVMs).

Material and Methods: Volume-rendered 3D images of postcontrast 3D time-of-flight MR angiography were compared with conventional angiograms in 12 patients. The correlation between the 3D images and the operative findings was also analyzed in 5 patients.

Results: The 3D-displayed images showed all of the feeders and drainers in 10 and 9 patients, respectively. In all patients, the nidus was three-dimensionally visualized. In 3 patients with hematomas, the relationship between the hematoma and the AVM was well demonstrated. The 3D images corresponded well with the operative findings in the 5 patients.

Conclusion: This method is of help in assessing the relationship between the components of an AVM as well as that between an AVM and an associated hematoma.
MR analysis of the transverse ligament in the late stage of whiplash injury
Authors: Krakenes J. , Kaale B. R. , Nordli H. , Moen G. , Rorvik J. , Gilhus N. E.
Published: October 2004

Purpose: To analyse and classify structural changes in the transverse ligament in the late stage of whiplash injury by use of high-resolution MRI, and to evaluate the reliability of our classification.

Material and Methods: Ninety-two whiplash-injured (2–9 years previously, mean 6 years) and 30 non-injured individuals underwent proton-weighted MR imaging of the craniovertebral junction in three orthogonal planes. Structural changes in the transverse ligaments were graded twice (grades 1–3) based on increased signal, independently by 3 radiologists with a 4-month interval. Inter- and intraobserver statistics were calculated by ordinary and weighted kappa (K).

Results: Image quality was excellent in 109 cases and slightly reduced in 13. Twenty-two out of 30 ligaments in the control group were classified as normal (73%) compared with only 32 out of 92 in the injured group (36%). Two or all 3 observers agreed in their grading in 101 out of 122 ligaments (83%). Intraobserver agreement (weighted K) was fair to good (0.33–0.73). Pair-wise interobserver agreement was fair (0.24–0.39). Reasons for divergent grading were insufficient knowledge of normal variations, low signal intensity in the peridental soft tissue obscuring the ligament and interpretation flaw.

Conclusion:Whiplash trauma can damage the transverse ligament. By use of high-resolution proton-weighted MR images such lesions can be detected and classified. The reliability of this classification still needs improvement.
Pictorial Review: Uncommon locations of hydatid cysts
Authors: Kıreşi D. A. , Karabacakoğlu A. , Ödev K. , Karaköse S.
Published: October 2004

Hydatid disease is endemic in many parts of the world. It may develop in almost any part of the body. The location is mostly hepatic (75%) and pulmonary (15%), and only 10% occur in the rest of the body. In this article, the various imaging findings of hydatid cysts in unusual localizations are reviewed, based on our experience. Findings in brain, cavernous sinus, submandibular gland, thyroid gland, heart, pleura, chest wall, retrocrural tissue, kidney, spleen, pancreas, peritoneal cavity and inguinal canal, breast, bone and soft tissue are discussed.
Quantitative and qualitative assessment of left ventricular volume with ECG-gated multislice spiral CT: value of different image reconstruction algorithms in comparison to MRI
Authors: Mahnken A. H. , Spuentrup E. , Niethammer M. , Buecker A. , Boese J. , Wildberger J. E. , Flohr T. , Sinha A. M. , Krombach G. A. , Günther R. W.
Published: October 2004

Purpose: To assess the value of different image reconstruction algorithms for assessment of the left ventricular function using retrospectively ECG-gated multislice spiral computed tomography (MSCT) of the heart.

Material and Methods: MSCT and cine magnetic resonance (MR) imaging of the heart were performed in 15 patients. For MSCT, standard and multisegmental image reconstruction with improved temporal resolution were used. Standardized multiplanar reformats in the short axis and long axis views were reconstructed from MSCT data. End-systolic (ESV) and end-diastolic volume (EDV), stroke volume (SV), ejection fraction (EF) and myocardial mass (MM) were calculated. Left ventricular wall motion was assessed qualitatively.

Results: MSCT was in acceptable agreement with MR imaging for quantification of the ventricular function. According to the Bland–Altman approach the mean differences for the left ventricular volumes (ESV, EDV, SV) ranged from −9.6 ml to 3.1 ml with standard image reconstruction and from −0.6 ml to 1.9 ml utilizing multisegmental image reconstruction with limits of agreement ranging from −26.6 ml to 12.5 ml and −15.6 ml to 15.0 ml, respectively. Applying the multisegmental image reconstruction algorithm, a significantly improved agreement with the MR data was found for EDV, SV and EF. For wall motion analysis, standard image reconstruction showed a significant difference to MR imaging with a correspondence in 83.75% of the 240 assessed segments, while multisegmental image reconstruction agreed with MR imaging in 92.5% of the segments.

Conclusion: Multisegmental image reconstruction improves the quantitative assessment of left ventricular function when compared to standard image reconstruction. Multisegmental image reconstruction allows qualitative wall motion analysis.
The most useful findings for diagnosing acute appendicitis on contrast-enhanced helical CT
Authors: Choi D. , Park H. , Lee Y. R. , Kook S.-H. , Kim S. K. , Kwag H. J. , Chung E. C.
Published: October 2004

Purpose: To evaluate the most useful findings to look for in diagnosing acute appendicitis on contrast-enhanced helical CT.

Material and Methods: Appendiceal helical CT scans with intravenous contrast administration (abdomen, 7-mm collimation; abdominopelvic junction, 5-mm collimation) of 71 patients with surgically proven acute appendicitis and 167 patients with alternative diagnoses were reviewed retrospectively. Three radiologists analyzed the following parameters: enlarged appendix (>6 mm in diameter), appendiceal wall thickening, appendiceal wall enhancement, no identification of the appendix, appendicolith(s), appendiceal intraluminal air, intramural air, extraluminal air, periappendiceal fat stranding, extraluminal fluid, phlegmon, abscess, lymphadenopathy, segmental terminal ileal wall thickening, focal cecal apical thickening, focal colonic wall thickening, and segmental colonic wall thickening. The features that best distinguished appendicitis from alternative diagnoses were selected with stepwise logistic regression analysis.

Results: Nine CT findings distinguished acute appendicitis from alternative diagnoses (P < 0.05): enlarged appendix ( R = 0.739), appendiceal wall thickening ( R = 0.525), periappendiceal fat stranding ( R = 0.414), appendiceal wall enhancement ( R = 0.404), focal cecal apical thickening ( R = 0.171), appendicolith(s) ( R = 0.157), extraluminal air ( R = 0.050), intramural air ( R = 0.043), and phlegmon ( R = 0.030). Enlarged appendix (sensitivity, 93%; specificity, 92%), appendiceal wall thickening (sensitivity, 66%; specificity, 96%), periappendiceal fat stranding (sensitivity, 87%; specificity, 74%), and appendiceal wall enhancement (sensitivity, 75%; specificity, 85%) showed the statistically most significant association with acute appendicitis.

Conclusion: On 5-mm-section contrast-enhanced helical CT examinations, enlarged appendix, appendiceal wall thickening, periappendiceal fat stranding, and appendiceal wall enhancement were the most useful findings for diagnosing acute appendicitis.
Characterization of hepatocellular carcinomas with triphasic CT and correlation with histopathologic findings
Authors: Karahan O. I. , Yikilmaz A. , Isin S. , Orhan S.
Published: October 2004

Purpose: To determine the utility of triphasic CT in the characterization of hepatocellular carcinomas (HCCs) and correlations with histopathologic findings.

Material and Methods: Thirty patients with hepatocellular carcinomas were included in the study and triphasic CT examinations were performed. The CT protocol included hepatic arterial, portal venous and late phases. A histopathologic examination was carried out in all but 3 patients, and the diagnosis and degrees of differentiation were determined.

Results: Hepatocellular carcinomas were hyperattenuated in 17 (57%) and hypoattenuated in 13 (43%) of the 30 patients in arterial phase images. The lesions were hypoattenuated in 26 (87%) and hyperattenuated in 4 (13%) patients in portal venous phase images. These hyperattenuated tumors were well-differentiated in the histopathologic examinations (P ≤ 0.05). Portal vein invasion was seen in 50% of the patients and this relationship was significant in patients whose lesions was greater than 10 cm (P < 0.05). Capsule formation, abnormal internal vessels and necrosis were detected in 57%, 53% and 40% of the patients, respectively.

Conclusion: Triphasic CT can aid in the histopathologic differentiation of HCCs, in addition to their characterization. Hyperattenuation in PVP images was found to be associated with well-differentiated HCCs and portal vein invasion was more frequent in tumors larger than 10 cm.
Stability of acetabular axis after total hip arthroplasty, repeatability using CT and a semiautomated program for volume fusion
Authors: Olivecrona H. , Olivecrona L. , Weidenhielm L. , Noz M. E. , Maguire G. Q. , Zeleznik M. P. , Svensson L. , Jonson T.
Published: October 2004

Purpose: To validate a CT method for detecting changes in acetabular cup orientation after THA

Material and Methods: 26 CT examinations were obtained from a pelvic model with an uncemented acetabular cup. The model position was altered between acquisitions, but the cup axis angle vis-à-visthe pelvis was maintained. Data sets were combined into 37 pairs, each containing a unique positioning error. The pelvi in different examinations were fused, creating transformed volumes. Landmarks corresponding to the cup before and after fusion were placed interactively by two independent examiners. The orientation of the acetabular axis was calculated for each volume and compared across volumes.

Results: Before fusion the mean angle error between the acetabular axes was 4.17° (SD ± 1.95°). After fusion the mean angle error was 0.36° (SD ± 0.17). The 95% repeatability limits were below 0.7°. There was no significant interobserver difference. Analysis of the cup landmarking pattern by condition numbers and individual landmark errors showed stability.

Conclusion: Non-invasive fusion of CT volumes and a stable landmarking pattern for the acetabular cup outperforms routine plain radiography in detecting changes in the orientation of the acetabular axis over time. The method delivers both visual and numerical output and could be used in clinical practice.
Are Oxidized LDL/β2‐glycoprotein I Complexes Pathogenic Antigens in Autoimmune‐mediated Atherosclerosis?
Authors: Matsuura Eiji , Lopez Luis R.
Published: October 2004

The oxidative modification of low‐density lipoprotein (LDL) in the intima of
arteries contributes to the initiation and progression of atherosclerotic lesions.
We have previously reported that oxidized LDL (oxLDL) interacts with
an endogenous plasma protein, β2‐glycoprotein I (β2GPI), to form
complexes and that the interaction is mediated by oxLDL specific ligands. We have also
demonstrated the presence of oxLDL/β2GPI complexes in the blood stream
of patients with systemic inflammatory and autoimmune diseases. These findings
implicate that oxLDL/β2GPI complexes are possible atherogenic autoantigens.
Autoantibodies to oxLDL/β2GPI complexes have been associated with arterial
thrombosis. Further, circulating IgG immune complexes containing oxLDL and
2GPI were also detected in patients with systemic lupus erythematosus (SLE)
and/or antiphospholipid syndrome (APS). Although many unanswered questions
remain about the exact pathogenic mechanism(s) involved, oxLDL/β2GPI
complexes may be described as metabolic products relevant in atherogenesis and as
significant participants in autoimmune‐mediated atherosclerosis.
Cloning and Sequencing of Protein Kinase cDNA from Harbor Seal (Phoca vitulina) Lymphocytes
Authors: Neale Jennifer C. C. , Kenny Thomas P. , Gershwin M. Eric
Published: October 2004

Protein kinases (PKs) play critical roles in signal transduction and
activation of lymphocytes. The identification of PK genes provides a tool for
understanding mechanisms of immunotoxic xenobiotics. As part of a larger study
investigating persistent organic pollutants in the harbor seal and their possible
immunomodulatory actions, we sequenced harbor seal cDNA fragments encoding
PKs. The procedure, using degenerate primers based on conserved motifs of
human protein tyrosine kinases (PTKs), successfully amplified nine phocid PK gene
fragments with high homology to human and rodent orthologs. We identified eight
PTKs and one dual (serine/threonine and tyrosine) kinase. Among these were
several PKs important in early signaling events through the B‐ and T‐cell receptors
(FYN, LYN, ITK and SYK) and a MAP kinase involved in downstream signal
transduction. V‐FGR, RET and DDR2 were also expressed. Sequential activation
of protein kinases ultimately induces gene transcription leading to the proliferation
and differentiation of lymphocytes critical to adaptive immunity. PKs are potential
targets of bioactive xenobiotics, including persistent organic pollutants of the marine
environment; characterization of these molecules in the harbor seal provides
a foundation for further research illuminating mechanisms of action of contaminants
speculated to contribute to large‐scale
die‐offs of marine mammals via immunosuppression.