bluuebunny/crossref_metadata_2025 huggingface dataset:
Prostate Cancer Screening with Prostate-Specific Antigen in Hemodialysis Patients
Authors: Horinaga Minoru , Kitamura Koji , Saito Shiro , Ukimura Osamu , Nakanoma Takashi , Okihara Koji , Kitagawa Motonobu , Nakanishi Hiroyuki , Miki Tsuneharu
Published: May 2007

Background/Aims: The diagnostic validity of prostate-specific antigen (PSA) among men receiving hemodialysis (HD) has not been well defined. The aim of this study was to evaluate PSA levels in HD men and to compare them with those of non-uremic controls. Methods: PSA levels were measured in 620 HD men (40–89 years old, mean age 62.4 years). In patients with PSA >4.1 ng/ml, prostate biopsies were performed. Cancer-free men were defined as having PSA ranging between 0 and 4.0 ng/ml, or PSA >4.1 ng/ml but with a pathologically negative biopsy. The resulting data was compared with that for 3,636 non-uremic controls (55–59- (n = 468), 60–69- (n = 2,220), and 70–79-year-old men (n = 948)). Results: Of 45 HD men with PSA >4.1 ng/ml, 22 consented to undergo a biopsy. Ten were positive and 12 were negative. The mean PSA of cancer-free HD men of 50–59 (n = 159), 60–69 (n = 214), 70–79 (n = 116), and 80–89 (n = 30) were 1.0, 1.0, 1.3, and 2.1 ng/ml, respectively. Cancer-free HD men demonstrated significantly lower PSA compared to controls. Conclusions: HD men had lower PSA levels than those of controls.
Effect of Patient Position on Pain Experienced during Prostate Biopsy
Authors: Bruyère Franck , Faivre d’Arcier Benjamin , Haringanji Deo C. , Boutin Jean-Michel , Haillot Olivier , Lanson Yves
Published: May 2007

Objectives: To compare pain during prostate biopsy performed in two different positions. Methods: We carried out a prospective, randomized study to compare the pain experienced during biopsy in two different positions: lithotomy (group 1) and lateral (group 2). Pain was evaluated using a visual analog scale (VAS). Results: 70 patients were randomized to the two positions for biopsy. The median number of samples taken was the same for both groups (n = 10). The median VAS rating after biopsy was 30 in group 1 and 45 in group 2. 96.6% of the men in group 1 were prepared to undergo a repeat examination according to the same modalities, against only 86.7% in group 2. Only 14.3% of the men in group 1 would have preferred more analgesic against 37.1% in group 2. Pain after biopsy was less in group 1. The men with prostate adenocarcinoma tolerated biopsies better than the others. Conclusion: Our results suggest that the lithotomy position induced less pain and less post-biopsy hematuria than did the lateral position during prostate biopsy. Men with prostate adenocarcinoma tolerated the procedures better.
Area in the Rat Brain Producing Rhythmical Slow Activity after Chemical Stimulation
Authors: Mehl Lewis E. , Head James S.
Published: May 2007

Serotonin, carbamylcholine, norephinephrine, and various control substances were implanted stereotaxically into various areas of the rat brain, and the effects of the compounds in altering the hippocampal rhythmical slow activity(RSA) were noted. Both carbamylcholine and serotonin implanted into the tip of the diagonal bands of Broca were observed to produce a regular rhythm of 7 Hz in both dorsal and ventral hippocampal recording sites. Carbamylcholine implanted into the medial parolfactory area consistently elicited RSA only in the ventral hippocampus recording area, while carbamylcholine implanted into the lower limb of the diagonal bands elicited the rhythm only in dorsal hippocampal recording sites. In rats in which the rhythm was elicited by serotonin, no effect was seen upon further implantation of carbamylcholine, whereas the converse was not true. These results are interpreted as suggesting a serotonergic influence upon hippocampal RSA separate from the usual cholinergic system which seemed to be inhibitory in nature.
No Specific Thalamic Influence on Cell Composition, Sugar or Electrolytes of Peripheral Blood
Authors: Hernesniemi J. , Laitinen L.
Published: May 2007

Cellular components, blood sugar, and serum electrolyte concentrations of chloride, sodium and potassium were analyzed serially in 20 patients who underwent either stereotactic thalamotomy, frontal internal capsulotomy or subcaudate tractotomy. No significant changes were seen during the interventions either after electrical stimulation or coagulation of the target area, but 3 h after the operation the neutrophile granulocyte count was significantly raised. This reaction reached a peak by the morning of the first postoperative day. Other cellular elements, blood sugar, and serum electrolytes remained unchanged. We believe that the leukocytosis is not a specific effect of the thalamic lesions, but a nonspecific stress reaction, similar to that seen after air encephalography.
A Therapeutic Approach and Objective Test in the Treatment of Tremor
Authors: Siegfried J. , Thomann R.M.
Published: May 2007

Medical treatment of tremor is deceptive. The biochemical disturbance causing its appearance is not known, so that no specific treatment can be applied. Many substances have been proposed for their antitremulant properties, but clinical results must be interpreted with caution as tremor is a labile symptom which is under many influences. The authors have analysed the clinical effect of an interesting antitremulant drug and have reported an original method for measuring tremor.
RF Lesion Generation
Authors: Burton Charles V.
Published: May 2007

Although the technique of RF lesion generation is a well-established medical technique, most professionals using it do not understand the basic principles of electronics by which the phenomenon occurs. A review of this with special attention to the ‘indifferent’ or ‘dispersive’ electrode would lead to better practice and less adverse effects, such as patient skin burns.
Percutaneous Radiofrequency Lumbar Rhizolysis (Rhizotomy)
Authors: McCulloch J.A.
Published: May 2007

Low-back pain may arise from degenerative changes in the posterior joints of the lumbar spine. These joints are innervated by a branch of the posterior primary ramus, which follows an anatomically constant course. Pain impulses from these joints can be interrupted by coagulating the nerve with a radiofrequency wave, the probe having been placed in the area of the nerve percutaneously. Percutaneous lumbar rhizolysis was carried out under local anaesthesia on an outpatient basis in 82 patients, most of whom had multiple level rhizolysis. Rhizolysis was successful in 67% of patients with mechanical low-back pain without evidence of disc herniation and nerve-root compression or psychogenic pain, who had not previously undergone an operation for relief of the pain.
Percutaneous Cervical Cordotomy
Authors: Tasker Ronald R.
Published: May 2007

Cordotomy should be reserved for patients with intractable pain resistant to conservative treatment that is not of a dysaesthetic type. The high cervical percutaneous technique permits exploitation of the principles of stereotactic surgery, especially physiological localization of the lesion site. The induction by 100 Hz stimulation of a warm or cool tingling in some portion of the contralateral half of the body without muscle tetanization ensures location within the spinothalamic tract while attention to the somatotopographic organization of the responses permits a certain degree of tailoring of the extent of analgesia to the patient’s needs. During 264 consecutive procedures the spinothalamic tract was successfully located in 99% with a 0.3% incidence of significant persistent paresis.
Premature Ovarian Failure
Authors: Goswami Deepti , Conway Gerard S.
Published: May 2007

The diagnosis of premature ovarian failure is based on the finding of amenorrhoea before age 40 associated with follicle-stimulating hormone levels in the menopausal range. Screening for associated autoimmune disorders and karyotyping, particularly in early onset disease, constitute part of the diagnostic work up. There is no role for ovarian biopsy or ultrasound in making the diagnosis. Management essentially involves hormone replacement and infertility treatment, the most successful being assisted conception with donated oocytes. Embryo cryopreservation, ovarian tissue or oocyte cryopreservation and in vitro maturation of oocytes hold promise in cases where ovarian failure is foreseeable as in women undergoing cancer treatments.
A Placebo-Controlled Double-Blind Randomized Study of Venlafaxine in the Treatment of Depression in Dementia
Authors: de Vasconcelos Cunha Ulisses Gabriel , Lopes Rocha Fábio , Ávila de Melo Rodrigo , Alves Valle Estevão , de Souza Neto José Júlio , Mendes Brega Rodrigo , Magalhães Scoralick Francisca , Araújo Silva Silvana , Martins de Oliveira Flaviana , da Costa Júnior Antônio Luciano , Xavier Faria Alves Viviane , Sakurai Emília
Published: May 2007

Background/Aims: To evaluate the efficacy and safety of venlafaxine in the treatment of major depression in dementia. Methods: Thirty-one outpatients who had dementia and major depression participated in this randomized, double-blind, placebo-controlled, 6-week, flexible dose clinical trial. The screening measures were Cornell Scale for depression in dementia, DSM-IV for depression and dementia and Mini-Mental State Examination. The outcome measures were response rate, Montgomery-Åsberg Depression Rating scale and Clinical Global Impressions. Results: The percentage of patients defined as Montgomery-Åsberg Depression Rating scale responders was approximately the same in the placebo and in the venlafaxine groups. Clinical Global Impressions showed no significant difference between the groups. The reasons for dropouts show borderline significance between the two groups. There was no statistically significant difference in the incidence of adverse events between the venlafaxine and placebo-treated groups. Conclusions: Our data do not support the hypothesis that venlafaxine improves mood in elderly demented patients.
Voter Turnout in Africa's Multiparty Regimes
Authors: Kuenzi Michelle , Lambright Gina M. S.
Published: May 2007

Many people consider voting the most important form of political participation in a democracy. To this point, no aggregate-level, cross-national studies have been done on the factors that affect voter turnout in Africa. This article seeks to fill the gap in the literature by examining the factors that influence voter turnout in sub-Saharan Africa's multiparty regimes that have had two consecutive elections since the democratic transitions in the 1990s. Many of the central findings of the research on voter turnout in other regions reappear in the examination of voter turnout in Africa. The authors find that two institutional variables—type of electoral formula and concurrency of presidential and legislative elections— have significant effects on electoral turnout. Media exposure has a significant positive relationship with voter turnout. The number of elections a polity has had also appears to affect levels of voter turnout.
Religious—Nationalist Mobilization and State Penetration
Authors: Haklai Oded
Published: May 2007

When will public agencies act in violation of the rules set by the state in a strong state? This article demonstrates that when an organized religious— nationalist force manages to penetrate the state apparatus, it can cause the state to lose some enforcement capacity vis-à-vis the penetrating force. The activists, in turn, can use the infiltrated arms of the state to realize their preferences, even if the pursuant practices contradict state laws. These conclusions are based on research conducted on Jewish settlements constructed unlawfully in the West Bank. The establishment of these settlements necessitated some collaboration from state agencies. Settler activism that included penetration into important arms of the bureaucracy is identified as an important facilitator of unauthorized settlements. The lessons drawn from the case are generalizable and can apply to other types of societal mobilization.
Small States and Skill Specificity
Authors: Culpepper Pepper D.
Published: May 2007

The varieties of capitalism literature has put skill systems at the center of comparative politics. Yet its claims about skill specificity are driven by two large coordinated economies, Germany and Japan. This article examines political change of skills in two small coordinated economies. Switzerland has expanded its general skills orientation, whereas Austria retains a highly specific skills system. The cause of this divergence is the different interests of small and large employers: Small employers are more cost sensitive than are large employers, which leads them to oppose the introduction of more general education. The study also shows that the primary measure of skill specificity used in quantitative work—vocational training share—is unreliable. It fails to distinguish between secondary and tertiary vocational training, which have opposite effects on skill specificity. The article develops and justifies an alternative measure—tertiary vocational training—that better predicts the skills clusters observed in advanced capitalism.
Shared Site Intergenerational Programs: A Case Study
Authors: Jarrott Shannon E. , Bruno Kelly
Published: May 2007

Shared site intergenerational programs (SSIP) unite disparate age groups in quasi-kin relationships and meet the care needs of multiple generations of families. SSIPs can effectively support development through intergenerational relationships. However, many programs prove unsustainable. The authors conducted a case study of an established SSIP serving frail older adults and preschool-aged children using surveys and interviews from parents, family caregivers, and older adult clients with dementia. Benefits included appreciation for diversity, formation of close intergenerational relationships, and enhanced client self-esteem. Challenges related to developmental differences and need for greater communication with families. SSIPs can benefit individuals, families, and human services organizations.
Why Older Adults Seek Employment: Differing Motivations Among Subgroups
Authors: Loi Jasmin Lui Ping , Shultz Kenneth S.
Published: May 2007

Differences among four subgroups of older adults seeking employment—midlife career changers aged 40 to 55, displaced workers aged 56 to 61, younger retirees aged 62 to 69, and older retirees aged 70 or older—were examined. The underlying assumption was that different subgroups of older adults have different motivations for seeking employment. To test this assumption, a 71-item survey measuring subgroups of older adults, their motivation to work, the extent to which they wanted to engage in work, and their need for satisfaction and achievement through work was administered at several public agencies in inland southern California. One hundred one older adults volunteered to participate in the study. The results of a one-way multivariate analysis of variance showed that older adults in the different subgroups could be differentiated by factors addressing the income and benefits associated with work and the scheduling needs of job seekers. The authors conclude with a discussion of the implications of the results for organizations and needs for future research.
From an Editorial Board Member
Authors: Brownstein Henry H.
Published: May 2007

Researchers, policy makers, and practitioners have indicated support for the notion that social science research should inform policy and practice. Although expressions such as “data-driven policy” have become commonplace, there is no consensus about how research can and should contribute. In this article, two ways for criminal justice research to contribute to policy and practice are discussed. Criminologists can be providers of findings from their research that can be used to help policy makers and practitioners make informed decisions. Or they can be advocates for positions they espouse based on their substantial knowledge and experience as scientists. The former is more consistent with their training and socialization as social scientists. However, in this article, it is argued that for social scientists in general and for criminologists in particular to be effective, they need to be able to compete and collaborate in a political process that includes others making contrary claims.
`Not in Our Name'? On Responsibility and Its Disavowal
Authors: Veitch Scott
Published: May 2007

Taking as a starting point the banner that came to prominence with the protests against the invasion of Iraq, this article explores the ways in which legal institutions and categories organize the responsibility, and irresponsibility, of its citizens. It does so by providing a variety of perspectives of the relation between state and citizen, and by paying particular attention to how the categorization of responsibility in legal, economic and political terms manages issues of responsibility and its disavowal.
The Future of Narrative
Authors: Hendry Petra Munro
Published: May 2007

This article raises questions about the basic assumptions of narrative research regarding representation, research relationships and the very construct of narrative as a method and a form of research. The author suggests the need to rethink the very understanding of narrative as research because this reduces stories to objects thereby reifying a positivist view of knowledge. An alternative view of narrative as outside of research is explored that rethinks research not as a scientific act but as a spiritual act, one that honors the sacredness of our stories and humanity.
Confronting the Frugal Editors: The Revue de Paris' Madame Bovary
Authors: Naddaff Ramona
Published: May 2007

In “Confronting the Frugal Editors,” I argue that the Revue de Paris ' 1856 editorial censorship of Madame Bovary complicates understandings of the identities and boundaries of author and editor; writing, editing and censorship; and, finally, of repressive and productive censorship in nineteenth-century France. Drawing on legal and literary history, on the history of the book, as well as on archival research of Flaubert's original handwritten manuscripts, I examine how Flaubert's editors were not “censors” in a strict and limiting sense. As “editorial censors,” they unwittingly enabled Flaubert — who engaged in the specific practice of writing by suppression — to refine and rewrite crucial passages in the novel. As such, the editorial censorship of Madame Bovary neither silenced nor censored the author. It opened up a space for Flaubert to (re)view and (re)write his manuscript from the otherwise alienating demands of professional editors and of literary censorship laws of the time. Law, Culture and the Humanities 2007; 3: 266—292
AlzPharm: integration of neurodegeneration data using RDF
Authors: Lam Hugo YK , Marenco Luis , Clark Tim , Gao Yong , Kinoshita June , Shepherd Gordon , Miller Perry , Wu Elizabeth , Wong Gwendolyn T , Liu Nian , Crasto Chiquito , Morse Thomas , Stephens Susie , Cheung Kei-Hoi
Published: May 2007

Background

Neuroscientists often need to access a wide range of data sets distributed over the Internet. These data sets, however, are typically neither integrated nor interoperable, resulting in a barrier to answering complex neuroscience research questions. Domain ontologies can enable the querying heterogeneous data sets, but they are not sufficient for neuroscience since the data of interest commonly span multiple research domains. To this end, e-Neuroscience seeks to provide an integrated platform for neuroscientists to discover new knowledge through seamless integration of the very diverse types of neuroscience data. Here we present a Semantic Web approach to building this e-Neuroscience framework by using the Resource Description Framework (RDF) and its vocabulary description language, RDF Schema (RDFS), as a standard data model to facilitate both representation and integration of the data.

Results

We have constructed a pilot ontology for BrainPharm (a subset of SenseLab) using RDFS and then converted a subset of the BrainPharm data into RDF according to the ontological structure. We have also integrated the converted BrainPharm data with existing RDF hypothesis and publication data from a pilot version of SWAN (Semantic Web Applications in Neuromedicine). Our implementation uses the RDF Data Model in Oracle Database 10g release 2 for data integration, query, and inference, while our Web interface allows users to query the data and retrieve the results in a convenient fashion.

Conclusion

Accessing and integrating biomedical data which cuts across multiple disciplines will be increasingly indispensable and beneficial to neuroscience researchers. The Semantic Web approach we undertook has demonstrated a promising way to semantically integrate data sets created independently. It also shows how advanced queries and inferences can be performed over the integrated data, which are hard to achieve using traditional data integration approaches. Our pilot results suggest that our Semantic Web approach is suitable for realizing e-Neuroscience and generic enough to be applied in other biomedical fields.
Receptor binding specificity of recent human H3N2 influenza viruses
Authors: Kumari Kshama , Gulati Shelly , Smith David F , Gulati Upma , Cummings Richard D , Air Gillian M
Published: May 2007

Background

Human influenza viruses are known to bind to sialic acid linked α2-6 to galactose, but the binding specificity beyond that linkage has not been systematically examined. H3N2 human influenza isolates lost binding to chicken red cells in the 1990s but viruses isolated since 2003 have re-acquired the ability to agglutinate chicken erythrocytes. We have investigated specificity of binding, changes in hemagglutinin sequence of the recent viruses and the role of sialic acid in productive infection.

Results

Viruses that agglutinate, or do not agglutinate, chicken red cells show identical binding to a Glycan Array of 264 oligosaccharides, binding exclusively to a subset of α2-6-sialylsaccharides. We identified an amino acid change in hemagglutinin that seemed to correlate with chicken red cell binding but when tested by mutagenesis there was no effect. Recombinant hemagglutinins expressed on Sf-9 cells bound chicken red cells but the released recombinant baculoviruses agglutinated only human red cells. Similarly, an isolate that does not agglutinate chicken red cells show hemadsorption of chicken red cells to infected MDCK cells. We suggest that binding of chicken red cells to cell surface hemagglutinin but not to virions is due to a more favorable hemagglutinin density on the cell surface. We investigated whether a virus specific for α2-6 sialyloligosaccharides shows differential entry into cells that have varying proportions of α2-6 and α2-3 sialic acids, including human A549 and HeLa cells with high levels of α2-6 sialic acid, and CHO cells that have only α2-3 sialic acid. We found that the virus enters all cell types tested and synthesizes viral nucleoprotein, localized in the nucleus, and hemagglutinin, transported to the cell surface, but infectious progeny viruses were released only from MDCK cells.

Conclusion

Agglutination of chicken red cells does not correlate with altered binding to any oligosaccharide on the Glycan Array, and may result from increased avidity due to density of hemagglutinin and not increased affinity. Absence of α2-6 sialic acid does not protect a cell from influenza infection and the presence of high levels of α2-6-sialic acids on a cell surface does not guarantee productive replication of a virus with α2-6 receptor specificity.
Sensitivity analysis of seismic reflectivity to partial gas saturation
Authors: Gomez Carmen T. , Tatham Robert H.
Published: May 2007

We analyze the sensitivity of seismic reflectivity to contrasts in density, seismic propagation velocities, Poisson’s ratio, and gas saturation using the complete Zoeppritz equations. Sensitivities of reflection coefficients to each bulk elastic parameter are computed as the partial derivatives of the seismic reflectivities, relative to each parameter. The sensitivity of reflectivity to gas saturation is then calculated as the full derivative of the reflectivities with respect to gas saturation, assuming both a homogeneous and a patchy distribution of gas in the pore fluids. We compute sensitivities for a sealing shale/gas-sand interface and a gas-sand/wet-sand (gas-water contact, GWC) interface. For the SH-SH reflectivity, the effect of density contrast is strongest in the 30°–50° range of incidence angles for the fluid-fluid interface and at nearer offsets for the shale/gas-sand interface. P-SV reflectivity forthe fluid-fluid interfaces is more sensitive to density contrast in the range of angles of incidence from 30° to 60°. The overall response of P-SV reflectivity to gas saturation throughout all offsets is dominated by the Poisson’s ratio of the gas sand. In the case of P-P reflectivity, the sensitivity to gas saturation increases with increasing incidence angles. The sensitivity of P-SV reflectivity to gas saturation tends to be greatest in the 20°–40° range of incidence angles. For SH-SH reflectivity, the sensitivity to gas saturation for most offsets is controlled mainly by the density contrast, and the sensitivity to density decreases with increasing offset. There is still not a generally accepted seismic reflection method to discriminate commercial gas concentrations from low gas saturation. From the sensitivity analysis, we conclude that the use of P-SV or SH-SH amplitude variation with offset (AVO), integrated with the P-P AVO, will be an essential element in understanding this problem fully.
Local seismic attributes
Authors: Fomel Sergey
Published: May 2007

Local seismic attributes measure seismic signal characteristics not instantaneously, at each signal point, and not globally, across a data window, but locally in the neighborhood of each point. I define local attributes with the help of regularized inversion and demonstrate their usefulness for measuring local frequencies of seismic signals and local similarity between different data sets. I use shaping regularization for controlling the locality and smoothness of local attributes. A multicomponent-image-registration example from a nine-component land survey illustrates practical applications of local attributes for measuring differences between registered images.
Estimation of layer parameters for linear P- and S-wave velocity functions
Authors: Stovas Alexey , Ursin Bjørn
Published: May 2007

For a horizontally layered medium with isotropic layers with constant P- and S-wave velocity gradients, it is possible to estimate the velocity functions (gradient and velocity at the top of each layer) and thickness of each layer. From large-offset PP seismic reflections, one can estimate three traveltime parameters: the zero-offset two-way traveltime, the NMO velocity, and a heterogeneity coefficient responsible for the nonhyperbolicity of the traveltime curve, using the different traveltime approximations. From large-offset (offset/depth greater than two) PS seismic reflections, one can estimate two traveltime parameters: zero-offset two-way traveltime and NMO velocity. From the estimated traveltime parameters at the top and bottom of a layer, it is possible to compute the thickness and velocity functions of the layer.
On the ambiguity of elasticity measurements in layered rocks
Authors: Grechka Vladimir , Rojas Maria Alejandra
Published: May 2007

Different boundary conditions applied to finite-size, heterogeneous rocks result in different average or apparent elastic stiffnesses. In statics, the apparent stiffness tensors that correspond to the homogeneous stress and homogeneous strain boundary conditions provide the lower and upper bounds for the true or effective stiffness tensor. It appears that similar bounds cannot be established for experiments utilizing wave propagation. We present static and dynamic computations of the apparent properties of stacks of horizontal isotropic layers. The effective stiffness tensors of such media are known to be vertically transversely isotropic (VTI) and are given by Backus theory for statics in the limit of zero thicknesses of the constituent layers. We verify the theoretical static bounds for these effective stiffnesses with the finite-element method. The existing stiffness bounds, however, do not lead to bounds for the effective Thomsen anisotropic coefficients. In particular, we show that any static measurement on rocks composed of a finite number of isotropic layers underestimates Thomsen coefficients [Formula: see text] and [Formula: see text] and is likely to overestimate [Formula: see text]. The apparent stiffnesses of a stack of layers derived from wave-propagation experiments can deviate from Backus theory and depend on details of the wave signature used to estimate them. Our numerical tests indicate that the apparent stiffnesses do not converge to their effective, Backus-predicted values when the ratio of layer thicknesses to the minimum wavelength goes to zero; however, the differences are usually insignificant for practice.
Stepped inversion of magnetic data
Authors: Tuma Soraya Lozada , Mendonça Carlos Alberto
Published: May 2007

We present a three-step magnetic inversion procedure in which invariant quantities with respect to source parameters are inverted sequentially to give (1) shape cross section, (2) magnetization intensity, and (3) magnetization direction for a 2D (elongated) magnetic source. The quantity first inverted (called here the shape function) is obtained from the ratio of the gradient intensity of the total-field anomaly to the intensity of the anomalous vector field. For homogenous sources, the shape function is invariant with source magnetization and allows reconstruction of the source geometry by attributing an arbitrary magnetization to trial solutions. Once determined, the source shape is fixed and magnetization intensity is estimated by fitting the total gradient of the total-field anomaly (equivalent to the amplitude of the analytic signal of magnetic anomaly). Finally, the source shape and magnetization intensity are fixed and the magnetization direction is determined by fitting the magnetic anomaly. As suggested by numerical modeling and real data application, stepped inversion allows checking whether causative sources are homogeneous. This is possible because the shape function from inhomogeneous sources can be fitted by homogeneous models, but a model obtained in this way fits neither the total gradient of the magnetic anomaly nor the magnetic anomaly itself. Such a criterion seems effective in recognizing strongly inhomogeneous sources. Stepped inversion is tested with numerical experiments, and is used to model a magnetic anomaly from intrusive basic rocks from the Paraná Basin, Brazil.
Feasibility study for 2D frequency-dependent electromagnetic sensing through casing
Authors: Pardo David , Torres-Verdín Carlos , Demkowicz Leszek F.
Published: May 2007

We perform a numerical-sensitivity study of various physical phenomena of interest for borehole resistivity logging applications in steel-cased wells. Specifically, we analyze the sensitivity of through-casing measurements for detecting water invasion, shale-laminated sands, and electrical anisotropy in the formation. In addition, we study the influence of the frequency of operation on through-casing resistivity measurements. The sensitivity analysis is performed using a highly accurate and reliable numerical method based on a 2D self-adaptive, goal-oriented, high-order, finite-element method (FEM). This method can be applied to simulate all types of resistivity logging measurements, including normal/laterolog, induction, and through-casing resistivity measurements. Results quantify the effects of several physical phenomena that can be sensed through casing and that can be measured with accurate sensors. We find that water invasion and shale-laminated sands behind casing can be detected and accurately quantified at frequencies below [Formula: see text]. On the other hand, measurements are almost insensitive to electrical anisotropy behind casing, but otherwise highly sensitive to frequency variations. Our simulations indicate that a frequency in the range of [Formula: see text] is the most adequate for maximizing the sensitivity of through-casing measurements with respect to spatial variations of electrical conductivity within the formation.
Smoothing imaging condition for shot-profile migration
Authors: Guitton Antoine , Valenciano Alejandro , Bevc Dimitri , Claerbout Jon
Published: May 2007

Amplitudes in shot-profile migration can be improved if the imaging condition incorporates a division (deconvolution in the time domain) of the upgoing wavefield by the downgoing wavefield. This division can be enhanced by introducing an optimal Wiener filter which assumes that the noise present in the data has a white spectrum. This assumption requires a damping parameter, related to the signal-to-noise ratio, often chosen by trial and error. In practice, the damping parameter replaces the small values of the spectrum of the downgoing wavefield and avoids division by zero. The migration results can be quite sensitive to the damping parameter, and in most applications, the upgoing and downgoing wavefields are simply multiplied. Alternatively, the division can be made stable by filling the small values of thespectrum with an average of the neighboring points. This averaging is obtained by running a smoothing operator on the spectrum of the downgoing wavefield. This operation called the smoothing imaging condition. Our results show that where the spectrum of the downgoing wavefield is high, the imaging condition with damping and smoothing yields similar results, thus correcting for illumination effects. Where the spectrum is low, the smoothing imaging condition tends to be more robust to the noise level present in the data, thus giving better images than the imaging condition with damping. In addition, our experiments indicate that the parameterization of the smoothing imaging condition, i.e., choice of window size for the smoothing operator, is easy and repeatable from one data set to another, making it a valuable addition to our imaging toolbox.
Velocity-independent time-domain seismic imaging using local event slopes
Authors: Fomel Sergey
Published: May 2007

By estimating local event slopes in prestack seismic reflection data, it is possible to accomplish all common time-domain imaging tasks, from normal moveout to prestack time migration, without the need to estimate seismic velocities or any other attributes. Local slopes contain complete information about the reflection geometry. Once they are estimated, seismic velocities and all other moveout parameters turn into data attributes and are directly mappable from the prestack data domain into the time-migrated image domain. I develop an analytical theory, which defines the transformation from data and local slopes to the image space for different time-domain imaging operators. Computational experiments with synthetic and field data examples confirm theoretical expectations and demonstrate practical effectiveness of the proposed method.
Simultaneous measurement of hysteresis in capillary pressure and electric permittivity for multiphase flow through porous media
Authors: Plug Willem-Jan , Slob Evert , Bruining Johannes , Moreno Tirado Leticia M.
Published: May 2007

We present a tool that simultaneously measures the complex permittivity and the capillary pressure characteristics for multiphase flow. The sample holder is a parallel plate capacitor. A precision component analyzer is used to measure the impedance amplitude and phase angle as a function of frequency ([Formula: see text] to [Formula: see text]). The complex impedance of the (partially) saturated sample is directly related to the effective complex permittivity. We have conducted main drainage and main imbibition cycles for unconsolidated sand-water-gas [Formula: see text] systems at 8-bar pressure and at temperatures between [Formula: see text] and [Formula: see text]. Hysteresis in capillary pressure and electric permittivity, as a result of phase distribution, is found between drainage and imbibition for [Formula: see text] and becomes more pronounced at higher water saturations. Good agreement of the measured electric permittivity with the complex refractive index model indicates that induced polarization is not observed for [Formula: see text] and the water saturation is reasonably predicted. The experiments have been performed to study the capillary pressure behavior during [Formula: see text] sequestration.
Optimum split-step Fourier 3D depth migration: Developments and practical aspects
Authors: Zhang Jianfeng , Liu Linong
Published: May 2007

We present an efficient scheme for depth extrapolation of wide-angle 3D wavefields in laterally heterogeneous media. The scheme improves the so-called optimum split-step Fourier method by introducing a frequency-independent cascaded operator with spatially varying coefficients. The developments improve the approximation of the optimum split-step Fourier cascaded operator to the exact phase-shift operator of a varying velocity in the presence of strong lateral velocity variations, and they naturally lead to frequency-dependent varying-step depth extrapolations that reduce computational cost significantly. The resulting scheme can be implemented alternatively in spatial and wavenumber domains using fast Fourier transforms (FFTs). The accuracy of the first-order approximate algorithm is similar to that of the second-order optimum split-step Fourier method in modeling wide-angle propagation through strong, laterally varying media. Similar to the optimum split-step Fourier method, the scheme is superior to methods such as the generalized screen and Fourier finite difference. We demonstrate the scheme’s accuracy by comparing it with 3D two-way finite-difference modeling. Comparisons with the 3D prestack Kirchhoff depth migration of a real 3D data set demonstrate the practical application of the proposed method.
Amplitude and phase correction of helicopter EM data
Authors: Ley-Cooper Yusen , Macnae James
Published: May 2007

We aim to develop a quantitative method for recalibration of historic helicopter electromagnetic data sets. Recent research has shown that frequency-domain helicopter electromagnetic data collected over a conductive half-space such as calm seawater can be used to correct system calibration errors. However, most historic surveys consist only of data collected over land, where the conductive half-space assumption is rarely justified. We estimate the required recalibration parameters by analyzing systematic misfits in the inversion of statistically chosen measures of historic data. Our method requires the identification, within the survey area, of a zone of conductive responses that are reasonably uniform. From this zone, a set of altitude-corrected median responses are estimated. These are inverted using geologically specifiedconstraints to obtain a best-fit layered earth model. Systematic inconsistencies between the median measured altitude and the inverted depth to surface are attributed to altitude error. Remaining frequency-dependent fitting errors are assumed to be the calibration errors. We tested the method with partial success on helicopter electromagnetic data sets collected over uniform deep sediments where seawater data were also available and two different inland surveys over multiple lithologies in one general area. At high frequencies, our method works reliably. Recalibration of low-frequency data is not possible if the area used as a reference consists of moderate or poor conductors. In this case, data amplitudes are small and are greatly affected by imperfect drift and magnetic susceptibility corrections. Historic helicopter electromagnetic data may require amplitude rescaling up to 20%–30%, with phase shifts of up to 3°.
BRAF Mutations in Papillary Thyroid Carcinomas Inhibit Genes Involved in Iodine Metabolism
Authors: Durante C. , Puxeddu E. , Ferretti E. , Morisi R. , Moretti S. , Bruno R. , Barbi F. , Avenia N. , Scipioni A. , Verrienti A. , Tosi E. , Cavaliere A. , Gulino A. , Filetti S. , Russo D.
Published: May 2007

Context: BRAF mutations are common in papillary thyroid carcinomas (PTCs). By affecting the expression of genes critically related to the development and differentiation of thyroid cancer, they may influence the prognosis of these tumors.

Objective: Our objective was to characterize the expression of thyroid-specific genes associated with BRAF mutation in PTCs.

Design/Setting and Patients: We examined the expression of key markers of thyrocyte differentiation in 56 PTCs with BRAF mutations (BRAF-mut) and 37 with wild-type BRAF (BRAF-wt). Eight samples of normal thyroid tissue were analyzed as controls. Quantitative PCR was used to measure mRNA levels for the sodium/iodide symporter (NIS), apical iodide transporter (AIT-B), thyroglobulin (Tg), thyroperoxidase (TPO), TSH receptor (TSH-R), the transcription factor PAX8, and glucose transporter type 1 (Glut1). NIS protein expression and localization was also analyzed by immunohistochemistry.

Results: mRNA levels for all thyroid-specific genes were reduced in all PTCs vs. normal thyroid tissues. NIS, AIT-B, Tg, and TPO expression was significantly lower in BRAF-mut tumors than in the BRAF-wt group. Glut-1 transcript levels were increased in all PTCs, and additional increases were noted in BRAF-mut tumors. In both tumor subsets, the NIS protein that was expressed was abnormally retained in the cytoplasm.

Conclusion: BRAF V600E mutation in PTCs is associated with reduced expression of key genes involved in iodine metabolism. This effect may alter the effectiveness of diagnostic and/or therapeutic use of radioiodine in BRAF-mut PTCs.
Nogo enhances the adhesion of olfactory ensheathing cells and inhibits their migration
Authors: Su Zhida , Cao Li , Zhu Yanling , Liu Xiujie , Huang Zhihui , Huang Aijun , He Cheng
Published: May 2007

The migration of olfactory ensheathing cells (OECs) is essential for pioneering the olfactory nerve pathway during development and for promoting axonal regeneration when implanted into the injured central nervous system (CNS). In the present study, recombinant Nogo-66 enhanced the adhesion of OECs and inhibited their migration. Using immunocytochemistry and western blot, we showed that the Nogo-66 receptor (NgR) was expressed on OECs. When NgR was released from the cell surface with phosphatidylinositol-specific phospholipase C or neutralized by NgR antibody, the effect of Nogo-66 on OEC adhesion and migration was markedly attenuated. Nogo-66 was found to promote the formation of focal adhesion in OECs and inhibited their membrane protrusion through the activation of RhoA. Furthermore, the co-culture migration assay demonstrated that OEC motility was significantly restricted by Nogo-A expressed on Cos7 cell membranes or oligodendrocytes. Moreover, treatment with anti-NgR antibody facilitated migration of implanted OECs in a spinal cord hemisection injury model. Taken together, we demonstrate, for the first time, that Nogo, a myelin-associated inhibitor of axon regeneration in the CNS, enhances the adhesion and inhibits the migration of OECs via NgR regulation of RhoA.
NRAGE associates with the anti-apoptotic factor Che-1 and regulates its degradation to induce cell death
Authors: Di Certo Maria Grazia , Corbi Nicoletta , Bruno Tiziana , Iezzi Simona , De Nicola Francesca , Desantis Agata , Ciotti Maria Teresa , Mattei Elisabetta , Floridi Aristide , Fanciulli Maurizio , Passananti Claudio
Published: May 2007

Neurotrophin receptor-interacting MAGE homolog (NRAGE) has been recently identified as a cell-death inducer, involved in molecular events driving cells through apoptotic networks during neuronal development. Recently, we have focused on the functional role of Che-1, also known as apoptosis-antagonizing transcription factor (AATF), a protein involved in cell cycle control and gene transcription. Increasing evidence suggests that Che-1 is involved in apoptotic signalling in neural tissues. In cortical neurons Che-1 exhibits an anti-apoptotic activity, protecting cells from neuronal damage induced by amyloid β-peptide.

Here, we report that Che-1 interacts with NRAGE and that an EGFP-NRAGE fusion protein inhibits nuclear localization of Che-1, by sequestering it within the cytoplasmic compartment. Furthermore, NRAGE overexpression downregulates endogenous Che-1 by targeting it for proteasome-dependent degradation. Finally, we propose that Che-1 is a functional antagonist of NRAGE, because its overexpression completely reverts NRAGE-induced cell-death.
Promotional Effect of Potassium Salt in Low-temperature Formate and Methanol Synthesis from CO/CO2/H2 on Copper Catalyst
Authors: Zhao Tian-Sheng , Yoneyama Yoshiharu , Fujimoto Kaoru , Yamane Noriyuki , Fujimoto Kenichiro , Tsubaki Noritatsu
Published: May 2007

Alkyl formates can be formed from CO2-containing syngas with C1–C4 alkyl alcohol solvents in the presence of potassium carbonate, which changed to potassium formate as catalyst. The formates can be in situ hydrogenolysized further to produce methanol effectively over manganese oxide or magnesia-supported copper catalysts. These homogeneous and heterogeneous catalysts constitute a novel system for methanol synthesis from CO/CO2/H2 even at 443 K.
Synthesis and Characterization of Aromatic Block Copolyamides by Condensative Chain Polymerization
Authors: Ohshimizu Kaoru , Shibasaki Yuji , Komura Motonori , Nakajima Ken , Ueda Mitsuru
Published: May 2007

Aromatic block copolyamides with well-controlled molecular weights (MWs) and narrow polydispersities (PDIs) were successfully prepared by the condensative chain polymerization of 3-[4-(N-octylamino)benzoyl]benzoxazoline-2-thione (1) and 3-[4-(N-1,1,1,2,2,3,3,4,4,5,5,6,6-tridecafluorooctylamino)benzoyl]benzoxazoline-2-thione (2). The formation of the block copolymers was confirmed by GPC, DSC, and NMR analyses. The thin film formed on mica was analyzed using atomic force microscopy (AFM), and the results indicated the existence of phase segregation.
Rhodium-catalyzed Reactions of Cyclobutanones with Alcohols and Amines Forming Esters and Amides
Authors: Matsuda Takanori , Shigeno Masanori , Maruyama Yohei , Murakami Masahiro
Published: May 2007

Cyclobutanones react with alcohols in the presence of rhodium(I)–phosphine catalysts to give esters in good yields through an addition/ring-opening process. Amides are formed by a similar reaction with amines.
Evaluation of the fluorescent treponemal antibody absorption test for detection of antibodies (immunoglobulins G and M) to Treponema pallidum in serologic diagnosis of syphilis
Authors: Aktas Gulseren , Young Hugh , Moyes Alex , Badur Selim
Published: May 2007

We compared the fluorescent treponemal antibody-absorption (FTA-ABS) (immunoglobulin (Ig)G + IgM) assay with the (micro-) Treponema pallidum haemagglutination assay (TPHA), the T. pallidum particle agglutination assay (TPPA), the Murex syphilis ICE (ICE) enzyme-linked immunosorbent assay (ELISA), the Diesse Enzywell TP (TP) (ELISA) using 122 serum samples and the Western blot (WB) assay using 42 serum samples whose results were inharmonious with other tests. Additionally, the Captia syphilis-M (IgM) (ELISA) were performed. All sera had already been examined by the rapid plasma reagin (RPR) card test, a non-treponemal test and the TPHA, a treponemal test using routine screening tests. Agreements of the FTA-ABS with the TPHA test, the TPPA test, the ICE test and the TP test were 97.5%, 95.9%, 98.3% and 98.3%, respectively. The results suggest that the FTA-ABS test is a useful confirmatory test, but can be inadequate as a confirmatory test for serologic diagnosis of syphilis by giving equivocal and false-negative results even rarely.