bluuebunny/crossref_metadata_2025 huggingface dataset:
In the Midst of Death We Are in Life . . . Biopolitics and Beginning Again in Rwanda
Authors: Mcnamee Eugene
Published: November 2007

This article, using a framework of analysis based on Foucauldian ideas of `biopolitics' and Agamben's `completion' of that notion, together with the more focused theorizations of Mahmood Mamdani, re-visits two basic questions of the Rwandan genocide which have not been satisfactorily resolved by purely materialist analyses of the roots, dynamics and consequences of the genocide. The first is that of why so many civilians participated in the massacres, or to put the question in strong terms, `how could even the most extreme forms of indoctrination or duress have produced such an outpouring of murder by civilians against civilians?' The second relates to the acknowledged failure by the international community to prevent or stop the genocide, and might be phrased `how could so many stand idly by when so little could have prevented such untold suffering?' The effort is to examine the plausibility and value of linking together on a conceptual (biopolitical) level the `internal' questions of why a genocide in Rwanda and why in that way, with the `external' questions of why non-intervention followed by intervention in the form that it eventually arrived, using in particular Agamben's theory of the relationship between sovereignty and `bare life'.
Utilitarianism and the Painful Orient
Authors: Haldar Piyel
Published: November 2007

The impact of Utilitarian thought on legal and quasi-legal institutions is immense. Its language pervades at the level of agendas, goals, invectives and proscriptions. Yet, little attention is paid to the manner in which Utilitarianism addresses the question of fidelity. The history of Western institutional statecraft is simultaneously a history of the profound fidelity of subjects to institutions. Does Utilitarianism have a discernible theory of subjectivity? This article takes the case of the introduction of Utilitarian reforms in British India in order to illustrate that the question of subjective attachment most useful to modern rational thinking arises in the modes of thought that such progressive thinking sought to exclude. In the case of British India, Utilitarian reforms (driven by temperate pleasures) were forced to rely upon Oriental tropes of politics that were considered illicit, despotic, and excessive. Such a case study alerts us to the manner in which all forms of Utilitarianism remain linked to arcane modes of address.
The Demon Drink and the Demonized Woman: Socio-Sexual Stereotypes and Responsibility Attribution in Rape Trials Involving Intoxicants
Authors: Finch Emily , Munro Vanessa E.
Published: November 2007

Previous studies have illustrated the existence of a double standard in the attribution of responsibility in contested sexual consent scenarios whereby intoxicated defendants tend to be held less responsible for subsequent sexual events than their sober counterparts while intoxicated complainants tend to be held more responsible. This study examined the extent to which the means by which the complainants' intoxication was secured would influence this process.1 Mock jurors, having been exposed to a trial reconstruction in which intoxicated sexual consent was at issue, deliberated towards a unanimous, or failing that, majority verdict on whether rape had occurred. Across the trial scenarios, the only variables related to the type of intoxicant ingested and the means of its administration. In a context in which the Sexual Offences Act 2003 purports to restrict reliance in the jury room on questionable stereotypes about socio-sexual behaviour, this article considers the extent to which participants' views about responsibility for intoxication shaped their conclusions on the occurrence of, and liability for, rape. It also examines the ways in which the social acceptability of some intoxicants (alcohol) and the social unacceptability of others (Rohypnol) supported the construction of `drug-assisted rape' as distinguishable from more mundane instances of intoxicated sex.
Differential expression of Toll-like receptor 2 (TLR2) and responses to TLR2 ligands between human and murine vascular endothelial cells
Authors: Shuang Chen  , Wong Michelle H. , Schulte Danica J. , Arditi Moshe , Michelsen Kathrin S.
Published: November 2007

Toll-like receptors (TLRs) initiate and maintain host defenses and inflammation, and directly contribute to diseases such as atherosclerosis. It is not completely understood in what cell types proatherogenic TLR-induced signaling arises and, particularly, there is uncertainty regarding the potential functional role of TLR2 in endothelial cells (ECs). We determined TLR2 and TLR4 gene expression in four different human and two different murine primary ECs using gene array analysis, RT-PCR, and flow cytometry and confirmed these data by functional studies by stimulating ECs with the corresponding TLR ligands. TLR4 was expressed in all human and murine ECs and these cells responded to stimulation with LPS. Faint expression of TLR2 was observed in human ECs, whereas murine ECs express considerable amounts of TLR2 mRNA. Human ECs failed to respond to TLR2 ligands while murine ECs responded to TLR2 ligands. Furthermore, in murine ECs, TLR2 was located on the cell surface while in human ECs, TLR2 was sequestered in intracellular compartments. After IFN-γ or IL-1β stimulation, TLR2 translocated to the cell surface of human ECs. In conclusion, TLR2 is expressed intracellularly in human ECs and, therefore, TLR2 ligands are inaccessible to the receptor. Murine ECs express membrane TLR2 and respond to TLR2 ligands, but human ECs normally will not respond unless they are first primed with inflammatory stimulation, which appears to trigger translocation of TLR2 to the cell surface.
Characterising Nanotechnology Research in China
Authors: Liu Li , Zhang Jingjing
Published: November 2007

Nanotechnology drew considerable R&D and research policy attention during the last decade from both developed and emerging developing countries. Nanotechnology is an emerging field where scientists and engineers manipulate matter at the molecular level to create new materials with favourable physical and chemical properties; it is widely acknowledged as a revolutionary technology that will bring path-breaking benefits and profound transformation to human life. Among these developing countries, China has recently emerged as one of the leaders in nanotechnology research. What characterises China's nanotechnology research? Is it different than the nanotechnology research in developed countries? What are the main players and determining factors behind China's fast growth in nanotechnology research? These are the research questions that this article intends to answer.
Globalisation and the Adoption of ICTs in Nigerian SMEs
Authors: Lal Kaushalesh
Published: November 2007

The study aims at investigating the factors that affected the degree of adoption of new technologies in Nigerian SMEs. New technologies are by and large dominated by ICTs. Data for the analysis come from sixty-seven SMEs located in Aba, Ibadan, Lagos and Nnewi. One of the major factors inhibiting ICT diffusion and intensive utilisation is poor physical infrastructure represented by adequate and uninterrupted electricity supply and communication connectivity infrastructure. Findings of multivariate analysis suggest that firm-level variables such as financial capacity and technological absorptive capacity influenced the intensity of the adoption of ICTs. The results also suggest that globalisation of the Nigerian economy also influenced the adoption of new technologies. The study concludes that SMEs need institutional support in terms of human resource development for the augmentation of their competitiveness in the domestic as well as international markets.
Perfectionism and the Five-Factor Model of Personality
Authors: Rice Kenneth G. , Ashby Jeffrey S. , Slaney Robert B.
Published: November 2007

In this study of the discriminant, convergent, and incremental validity of the Almost Perfect Scale—Revised (APS-R), university students completed the APS-R, additional measures of perfectionism, the NEO Five-Factor Inventory—Form S, and measures of self-esteem and depression. The results revealed expected significant, but not completely overlapping, associations between the APS-R Discrepancy subscale scores and the Five-Factor Model of Personality (FFM) dimension of Neuroticism, and between the APS-R High Standards and Order subscales and the FFM dimension of Conscientiousness. The incremental validity of APS-R scores over FFM dimensions was supported in analyses of self-esteem but not depression. The implications of these findings for further psychometric and clinical studies of perfectionism and facets of FFM dimensions are discussed.
Reliability and Validity of Two Self-Report Measures of Psychopathy
Authors: Falkenbach Diana , Poythress Norman , Falki Marielle , Manchak Sarah
Published: November 2007

The present study assessed the psychometric properties and construct validity of two self-report measures of psychopathy in a male-college sample: the Levenson Psychopathy scales (LPS; Levenson, Kiehl, & Fitzpatrick, 1995) and the Psychopathic Personality Inventory (PPI; Lilienfeld & Andrews, 1996). Both the LPS and the PPI demonstrated good internal consistency, although selected items from the PPI correlated weakly with their respective factor scores, suggesting the need for further investigation of the factors' item content. The PPI showed stronger validity than the LPS in terms of convergent and discriminant validity of its factor scores and factor associations with two criterion variables, aggression, and anxiety. Overall, the current study provides greater support for the use of the PPI over the LPS in studies investigating psychopathic traits in nonclinical and nonforensic samples.
Validity of Factors of the Psychopathy Checklist—Revised in Female Prisoners
Authors: Kennealy Patrick J. , Hicks Brian M. , Patrick Christopher J.
Published: November 2007

The validity of the Psychopathy Checklist—Revised (PCL-R) has been examined extensively in men, but its validity for women remains understudied. Specifically, the correlates of the general construct of psychopathy and its components as assessed by PCL-R total, factor, and facet scores have yet to be examined in depth. Based on previous research conducted with male o fenders, a large female inmate sample was used to examine the patterns of relations between total, factor, and facet scores on the PCL-R and various criterion variables. These variables include ratings of psychopathy based on Cleckley's criteria, symptoms of antisocial personality disorder, and measures of substance use and abuse, criminal behavior, institutional misconduct, interpersonal aggression, normal range personality, intellectual functioning, and social background variables. Results were highly consistent with past findings in male samples and provide further evidence for the construct validity of the PCL-R two-factor and four-facet models across genders.
Knowledge, innovation and re-inventing technical assistance for development
Authors: Wilson Gordon
Published: November 2007

This paper traces the evolution of Technical Assistance to Technical Co-operation alongside more recent concepts of Knowledge Management and Innovation Systems. Originally conceived as transfer from a knowledge-rich North to a knowledge-poor South, the later terminology represents a more co-operative and dialogic conception. The evolution has been driven by persistent issues concerning capacity and knowledge-in-context and by changing approaches to development practice. The paper argues, however, that a further epistemological turn is needed that conceives of co-operative learning as ‘learning with’, where difference between actors is conceived as a resource, rather than a problem, for knowledge production.
Economic reform and foreign direct investment in Latin America
Authors: Porzecanski Roberto , Gallagher Kevin P.
Published: November 2007

After almost 25 years of experimenting with the neo-liberal economic reforms collectively known as ‘Washington Consensus’ policies, Latin Americans are starting to re-assess the merits of these policies at the voting booth. Whereas one of the key policies of the ‘Washington Consensus’ package was the liberalization of investment regimes, many of the newly elected governments are beginning to scrutinize the role of foreign direct investment (FDI) in their countries. Indeed, some nations have gone as far as to nationalize foreign firms. Without endorsing or condoning the actions taken by these governments, in this paper we argue that it is quite rational and very justified for governments in the region to re-evaluate the role of FDI for their development paths. Our exhaustive review of the literature on FDI in Latin America during the reform period shows that very few nations in the region actually received significant amounts of FDI as a result of reform, and that when FDI did materialize, it often fell far short of generating the necessary linkages required to make FDI work for economic development.
What is wrong with the Global Support Facility for small-scale mining?
Authors: Hilson Gavin
Published: November 2007

The World Bank, United Nations and UK Department for International Development (DfID) have spearheaded a recent global drive to regularize artisanal and small-scale mining (ASM), and provide assistance to its predominantly impoverished participants. To date, millions of dollars have been pledged toward the design of industry-specific policies and regulations; implementation of mechanized equipment; extension; and the launch of alternative livelihood (AL) programmes aimed at diversifying local economies. Much of this funding, however, has failed to facilitate marked improvements, and in many cases, has exacerbated problems. This paper argues that a poor understanding of artisanal, mine-community dynamics and operators’ needs has, in a number of cases, led to the design and implementation of inappropriate industry support schemes and interventions. The discussion focuses upon experiences from sub-Saharan Africa, where ASM is in the most rudimentary of states.
The Beach, the gaze and film tourism
Authors: Law Lisa , Bunnell Tim , Ong Chin-Ee
Published: November 2007

Based on the book by Alex Garland, Twentieth Century Fox's movie, The Beach, proffers critical views on the effects of traveller tourism in Thailand. Yet the movie is itself bound up with tourist practices in a variety of ways. In this article, we are concerned with how such intertwining extends beyond `film tourism', conventionally conceived. In particular, we seek to elaborate the modification of the Maya Bay set(ting) for The Beach as part a broader process whereby `tropical environments' are staged in line with the `tourist gaze'. In this way, film viewing itself may be understood as a form of tourism — a kind of tropical flânerie which both reflects and constitutes a range of tourist practices in Thailand. Yet these practices extend beyond the western film viewer or would-be tourist, and include Thai environmental activists, Japanese Di Caprio fans and researchers such as ourselves. Including these groups helps us displace normative constructions of the gaze, and situates The Beach within an interpretive field that considers networks of influence rather than unidirectional representation.
Can developing women produce primitive art?
Authors: Davis Coralynn V.
Published: November 2007

In this article, I examine the values and meanings that adhere to objects made by Maithil women at a development project in Janakpur, Nepal — objects collectors have called `Janakpur Art'. I seek to explain how and why changes in pictorial content in Janakpur Art — shifts that took place over a period of five or six years in the 1990s — occurred, and what such a change might indicate about the link between Maithil women's lives, development, and tourism. As I will demonstrate, part of the appeal for consumers of Janakpur Art has been that it is produced at a `women's development project' seeking to empower its participants. And yet, the project's very successes threaten to displace the producers (and what they produce) from their perceived qualities/identities as `traditional' and `primitive,' thereby bringing into question the authenticity of the `art' they produce. The conundrum begs this question: can developing women produce primitive art?
Media Literacy, "Thinking Television," and African American Communication
Authors: Kavoori Anandam P.
Published: November 2007

This essay is a critical, reflexive engagement with the practice, politics and pedagogy of a student centered media literacy project titled `thinking television.` Written as a theoretical diagnostic, the essay examines the project's value-providing a new vocabulary for democratic communication-and drawbacks, the restrictive nature of narrative possibilities around race in the student projects.
The Color of Fear
Authors: Weems Mary E.
Published: November 2007

This auto/ethnographic performance text is my critical response to Lee Mun Wah's documentary The Color of Fear. The film records one focus group's weekend long journey to face their fears regarding racism and sexism. To create the piece, I watched the film with a group of students and noted lines of dialogue I wanted to include in my response. I share it in the hope that it will inspire more people to begin to face their own fears around issues of race and gender.
Harnessing the UN System Into a Common Approach On Communication for Development
Authors: Servaes Jan
Published: November 2007

In the UN system, conflicts and contradictions seldom concern the Millennium Development Goals (MDGs) as such, but rather the means of achieving them. These differences of opinion about priorities, and about how much and to whom development aid or assistance should be directed, could be explained by analysing the ontological, epistemological and methodological assumptions underpinning the general perspectives in the communication for development (C4D) field. Theoretical changes in the perspective on development communication (modernization, dependency, multiplicity) have also reached the level of policy-makers. As a result, different methodologies and terminologies have evolved, which often make it difficult for agencies, even though they share a common commitment to the overall goals of development communication, to identify common ground, arrive at a full understanding of each other's objectives, or to cooperate effectively in operational projects. Consequently, it is difficult for development organizations in general and UN agencies in particular to reach a common approach and strategy.
A Brave New World for International News? Exploring the Determinants of the Coverage of Foreign News on US Websites
Authors: Wu H. Denis
Published: November 2007

/ This study content analyzed international news published on two of the most visited websites in the US, cnn.com and www.nytimes.com. The influences of trade, existence of news agencies, national traits and cultural and geographic proximity on these two news websites were examined. The international news from the online version was analyzed and compared with the print and broadcast versions. The study found that trade volume and existence of news agencies are two leading predictors of international news coverage in both online and traditional media. Yet, the influence of news agencies on the websites seems greater than on the traditional media. Also, press freedom was found irrelevant to international coverage in the US media.
National Influences in Foreign News
Authors: Novais Rui Alexandre
Published: November 2007

/ This article examines the impact of national influences and national interests upon foreign news coverage. To this end, it examines the newspaper reporting on the 12 November 1991 `Dili Massacre', a case study neglected by academic research and press coverage analysis. This work introduces the distinction between intra-media and extra-media influences while looking at nuanced dimensions regarding the source of national influences on the basis of differences between the press and government agendas as well as the level of critique within the coverage. In considering all these variables, this study proposes an elaborated analysis and assessment of foreign news that runs counter to previous findings in the literature, notably Lee and Yang's study on national interest in foreign news.
SERpredict: Detection of tissue- or tumor-specific isoforms generated through exonization of transposable elements
Authors: Mersch Britta , Sela Noa , Ast Gil , Suhai Sándor , Hotz-Wagenblatt Agnes
Published: November 2007

Background

Transposed elements (TEs) are known to affect transcriptomes, because either new exons are generated from intronic transposed elements (this is called exonization), or the element inserts into the exon, leading to a new transcript. Several examples in the literature show that isoforms generated by an exonization are specific to a certain tissue (for example the heart muscle) or inflict a disease. Thus, exonizations can have negative effects for the transcriptome of an organism.

Results

As we aimed at detecting other tissue- or tumor-specific isoforms in human and mouse genomes which were generated through exonization of a transposed element, we designed the automated analysis pipeline SERpredict (SER = S pecific E xonized R etroelement) making use of Bayesian Statistics. With this pipeline, we found several genes in which a transposed element formed a tissue- or tumor-specific isoform.

Conclusion

Our results show that SERpredict produces relevant results, demonstrating the importance of transposed elements in shaping both the human and the mouse transcriptomes. The effect of transposed elements on the human transcriptome is several times higher than the effect on the mouse transcriptome, due to the contribution of the primate-specific Alu elements.
Critical views on postpartum care expressed by new mothers
Authors: Rudman Ann , Waldenström Ulla
Published: November 2007

Background

Women's evaluation of hospital postpartum care has consistently been more negative than their assessment of other types of maternity care. The need to further explore what is wrong with postpartum care, in order to stimulate changes and improvements, has been stressed. The principal aim of this study was to describe women's negative experiences of hospital postpartum care, expressed in their own words. Characteristics of the women who spontaneously gave negative comments about postpartum care were compared with those who did not.

Methods

Data were taken from a population-based prospective longitudinal study of 2783 Swedish-speaking women surveyed at three time points: in early pregnancy, at two months, and at one year postpartum. At the end of the two follow-up questionnaires, women were asked to add any comment they wished. Content analysis of their statements was performed.

Results

Altogether 150 women gave negative comments about postpartum care, and this sample was largely representative of the total population-based cohort. The women gave a diverse and detailed description of their experiences, for instance about lack of opportunity to rest and recover, difficulty in getting individualised information and breastfeeding support, and appropriate symptom management. The different statements were summarised in six categories: organisation and environment, staff attitudes and behaviour, breastfeeding support, information, the role of the father and attention to the mother.

Conclusion

The findings of this study underline the need to further discuss and specify the aims of postpartum care. The challenge of providing high-quality follow-up after childbirth is discussed in the light of a development characterised by a continuous reduction in the length of hospital stay, in combination with increasing public demands for information and individualised care.
Comparison of Evoked vs. Spontaneous Tics in a Patient with Trigeminal Neuralgia (Tic Doloureux)
Authors: Borsook David , Moulton Eric A , Pendse Gautam , Morris Susie , Cole Sadie H , Aiello-Lammens Matthew , Scrivani Steven , Becerra Lino R
Published: November 2007

A 53-year old woman with tic doloureaux, affecting her right maxillary division of the trigeminal nerve (V2), could elicit shooting pains by slightly tapping her teeth when off medication. The pains, which she normally rated as > 6/10 on a visual analog scale (VAS), were electric shock-like in nature. She had no other spontaneous or ongoing background pain affecting the region. Based on her ability to elicit these tics, functional magnetic resonance imaging (fMRI) was performed while she produced brief shocks every 2 minutes on cue (evoked pain) over a 20 min period. In addition, she had 1–2 spontaneous shocks manifested between these evoked pains over the course of functional image acquisition. Increased fMRI activation for both evoked and spontaneous tics was observed throughout cortical and subcortical structures commonly observed in experimental pain studies with healthy subjects; including the primary somatosensory cortex, insula, anterior cingulate, and thalamus. Spontaneous tics produced more decrease in signals in a number of regions including the posterior cingulate cortex and amygdala, suggesting that regions known to be involved in expectation/anticipation may have been activated for the evoked, but not spontaneous, tics. In this patient there were large increases in activation observed in the frontal regions, including the anterior cingulate cortex and the basal ganglia. Spontaneous tics showed increased activation in classic aversion circuitry that may contribute to increased levels of anxiety. We believe that this is the first report of functional imaging of brain changes in tic-doloureaux.
Multiple treatment comparisons in epilepsy monotherapy trials
Authors: Tudur Smith Catrin , Marson Anthony G , Chadwick David W , Williamson Paula R
Published: November 2007

Background

The choice of antiepileptic drug for an individual should be based upon the highest quality evidence regarding potential benefits and harms of the available treatments. Systematic reviews and meta-analysis of randomised controlled trials should be a major source of evidence supporting this decision making process. We summarise all available individual patient data evidence from randomised controlled trials that compared at least two out of eight antiepileptic drugs given as monotherapy.

Methods

Multiple treatment comparisons from epilepsy monotherapy trials were synthesized in a single stratified Cox regression model adjusted for treatment by epilepsy type interactions and making use of direct and indirect evidence. Primary outcomes were time to treatment failure and time to 12 month remission from seizures. A secondary outcome was time to first seizure.

Results

Individual patient data for 6418 patients from 20 randomised trials comparing eight antiepileptic drugs were synthesized. For partial onset seizures (4628 (72%) patients), lamotrigine, carbamazepine and oxcarbazepine provide the best combination of seizure control and treatment failure. Lamotrigine is clinically superior to all other drugs for treatment failure but estimates suggest a disadvantage compared to carbamazepine for time to 12 month remission [Hazard Ratio (95% Confidence Interval) = 0.87(0.73 to 1.04)] and time to first seizure [1.29(1.13 to 1.48)]. Phenobarbitone may delay time to first seizure [0.77(0.61 to 0.96)] but at the expense of increased treatment failure [1.60(1.22 to 2.10)]. For generalized onset tonic clonic seizures (1790 (28%) patients) estimates suggest valproate or phenytoin may provide the best combination of seizure control and treatment failure but some uncertainty remains about the relative effectiveness of other drugs.

Conclusion

For patients with partial onset seizures, results favour carbamazepine, oxcarbazepine and lamotrigine. For generalized onset tonic clonic seizures, results favour valproate and phenytoin.
Mycophenolate sodium treatment in patients with primary Sjögren syndrome: a pilot trial
Authors: Willeke Peter , Schlüter Bernhard , Becker Heidemarie , Schotte Heiko , Domschke Wolfram , Gaubitz Markus
Published: November 2007

The aim of this study was to evaluate the efficacy and safety of mycophenolate sodium (MPS) in patients with primary Sjögren syndrome (pSS) refractory to other immunosuppressive agents. Eleven patients with pSS were treated with MPS up to 1,440 mg daily for an observation period of 6 months in this single-center, open-label pilot trial. At baseline, after 3 months, and after 6 months, we examined the clinical status, including glandular function tests, as well as different laboratory parameters associated with pSS. In addition, subjective parameters were determined on the basis of different questionnaires. Treatment with MPS was well tolerated in 8 of 11 patients. Due to vertigo or gastrointestinal discomfort, two patients did not complete the trial. One patient developed pneumonia 2 weeks after treatment and was withdrawn. In the remaining patients, MPS treatment resulted in subjective improvement of ocular dryness on a visual analogue scale and a reduced demand for artificial tear supplementations. However, no significant alterations of objective parameters for dryness of eyes and mouth were observed, although a substantial improvement of glandular functions occurred in two patients with short disease duration. In addition, treatment with MPS resulted in significant reduction of hypergammaglobulinemia and rheumatoid factors as well as an increase of complement levels and white blood cells. MPS promises to be an additional therapeutic option for patients with pSS, at least in those with shorter disease duration. Further investigations about the efficacy and safety of MPS in pSS have to be performed in larger numbers of patients.
Challenges for modeling and interpreting the complex biology of severe injury and inflammation
Authors: Lowry Stephen F , Calvano Steve E
Published: November 2007

Human injury is associated with inflammatory responses that are modulated by the acute and chronic activity of endogenous factors and exogenous interventions. A characteristic feature of chronic, severe inflammatory states is the diminished signal output variability of many organ systems, including innate immune responsiveness and endogenous neural and endocrine-mediated functions. The attenuation of signal/response variability and integration of feedback capacity may contribute to systemic and tissue-specific deterioration of function. Some well-intentioned therapies directed toward support of systemic and tissue functions may actually promote the loss of system(s) adaptability and contribute to adverse outcomes in severely stressed patients. In vivo and in silico models of stress, injury, and infection have yet to fully define the influences of ongoing stressful stimulae as well as genetic variation and epigenetic factors in the context of an evolving inflammatory state. Experimental and human models incorporating variable, antecedent stress(es) and altered neuroendocrine rhythms might approximate the altered adaptability in immune and organ function responses. Such models may also provide insights into the salient mechanisms of risk and outcome more precisely than do the constrained study conditions of current animal or human models of systemic inflammation.
Basin model inversion using information theory and seismic data
Authors: Lee Jejung , Sayyed-Ahmad Abdallah , Sheen Dong-Hoon
Published: November 2007

We present a new approach to basin-model inversion in which uncertain parameters in a basin model are estimated using information theory and seismic data. We derive a probability function from information theory to quantify uncertainties in the estimated parameters in basin modeling. The derivation requires two constraints: a normalization and a misfit constraint. The misfit constraint uses seismic information by minimizing the difference between calculated seismograms from a basin simulator and observed seismograms. The information-theory approach emphasizes the relative difference between the so-called expected and calculated minima of the misfit function. The synthetic-model application shows that the greater the difference between the expected and calculated minima of the misfit function, the larger the uncertainty in parameter estimation. Uncertainty analysis provides secondary information on how accurately the inversion process is performed in basin modeling.
Interval velocity estimation via NMO-based differential semblance
Authors: Li Jintan , Symes William W.
Published: November 2007

The differential semblance method of velocity analysis flattens image gathers automatically by updating interval velocity to minimize the mean square difference of neighboring traces. We detail an implementation using hyperbolic normal moveout correction as the imaging method. The algorithm is fully automatic, accommodates arbitrary acquisition geometry, and outputs 1D, 2D, or 3D interval velocity models. This variant of differential semblance velocity analysis is effective within the limits of its imaging methodology: mild lateral heterogeneity and data dominated by primary events. Coherent noise events such as multiple reflections tend to degrade the quality of the velocity model estimated by differential semblance. We show how to combine differential semblance velocity analysis with dip filtering to suppress multiple reflections and thus improve considerably the accuracy of the velocity estimate. We illustrate this possibility using multiple-rich data from a 2D marine survey.
Generalization of Gassmann equations for porous media saturated with a solid material
Authors: Ciz Radim , Shapiro Serge A.
Published: November 2007

Gassmann equations predict effective elastic properties of an isotropic homogeneous bulk rock frame filled with a fluid. This theory has been generalized for an anisotropic porous frame by Brown and Korringa’s equations. Here, we develop a new model for effective elastic properties of porous rocks — a generalization of Brown and Korringa’s and Gassmann equations for a solid infill of the pore space. We derive the elastic tensor of a solid-saturated porous rock considering small deformations of the rock skeleton and the pore infill material upon loading them with the confining and pore-space stresses. In the case of isotropic material, the solution reduces to two generalized Gassmann equations for the bulk and shear moduli. The applicability of the new model is tested by independent numerical simulations performed on the microscale by finite-difference and finite-element methods. The results show very good agreement between the new theory and the numerical simulations. The generalized Gass-mann model introduces a new heuristic parameter, characterizing the elastic properties of average deformation of the pore-filling solid material. In many cases, these elastic moduli can be substituted by the elastic parameters of the infill grain material. They can also represent a proper viscoelastic model of the pore-filling material. Knowledge of the effective elastic properties for such a situation is required, for example, when predicting seismic velocities in some heavy oil reservoirs, where a highly viscous material fills the pores. The classical Gassmann fluid substitution is inapplicable for a configuration in which the fluid behaves as a quasi-solid.
Seismoelectric imaging of the vadose zone of a sand aquifer
Authors: Dupuis J. Christian , Butler Karl E. , Kepic Anton W.
Published: November 2007

We have acquired a [Formula: see text] seismoelectric section over an unconfined aquifer to demonstrate the effectiveness of interfacial signals at imaging interfaces in shallow sedimentary environments. The seismoelectric data were acquired by using a [Formula: see text] accelerated weight-drop source and a 24-channel seismoelectric recording system composed of grounded dipoles, preamplifiers, and seismographs. In the shot records, interfacial signals were remarkably clear; they arrived simultaneously at offsets as far as [Formula: see text] from the seismic source. The most prominent signal was generated at the water table at a depth of approximately [Formula: see text] and had peak amplitudes on the order of [Formula: see text]. A weaker response was generated at a shallower interface that is interpreted to be a water-retentive layer. The validity of these two laterally continuous events, and of other discontinuous events indicative of vadose-zone heterogeneity, is corroborated by the presence of reflections exhibiting similar characteristics in a ground-penetrating radar profile acquired along the same line.
Data-driven adaptive decomposition of multicomponent seabed seismic recordings: Application to shallow-water data from the North Sea
Authors: Muijs Remco , Robertsson Johan O. A. , Holliger Klaus
Published: November 2007

Exploiting the full potential of multicomponent seabed seismic recordings requires the decomposition of the recorded data into their upgoing and downgoing P- and S-wave constituents. We present a case study from the North Sea, where a novel adaptive wave-equation-based decomposition method is applied to a 2D data set shot inline with a cable-based seabed seismic acquisition system. The data were recorded in relatively shallow [Formula: see text] water, such that severe interference exists between primary reflections and water-layer multiples. Such conditions represent a challenge for many decomposition methods, because these often require a significant amount of interpretive, user-defined input. Conversely, the adaptive algorithm demonstrated in this study is fully data-driven, requiring as sole input a rough estimate of the water depth. The importance of careful mutual calibration of the sensors is demonstrated by critically assessing the properties of the derived calibration filters and the resulting estimates of the elastic properties of the seabed. To assess the effectiveness of the decomposition procedure, we compare a number of key events identified in the unprocessed data with their equivalents in the decomposed wavefields. The results of this case study show that the noninteractive decomposition method, which was demonstrated on seabed seismic data acquired in deep [Formula: see text] water, can be applied successfully in shallower conditions without further modification.
Poststack velocity analysis by separation and imaging of seismic diffractions
Authors: Fomel Sergey , Landa Evgeny , Taner M. Turhan
Published: November 2007

Small geologic features manifest themselves in seismic data in the form of diffracted waves, which are fundamentally different from seismic reflections. Using two field-data examples and one synthetic example, we demonstrate the possibility of separating seismic diffractions in the data and imaging them with optimally chosen migration velocities. Our criteria for separating reflection and diffraction events are the smoothness and continuity of local event slopes that correspond to reflection events. For optimal focusing, we develop the local varimax measure. The objectives of this work are velocity analysis implemented in the poststack domain and high-resolution imaging of small-scale heterogeneities. Our examples demonstrate the effectiveness of the proposed method for high-resolution imaging of such geologic features as faults, channels, and salt boundaries.
Stereographic imaging condition for wave-equation migration
Authors: Sava Paul
Published: November 2007

Imaging under the single-scattering approximation consists of two steps: wavefield reconstruction of source and receiver wavefields from simulated and recorded data, respectively, and imaging from the extrapolated wavefields of locations where reflectors occur. Conventionally, the imaging condition indicates the presence of reflectors when propagation times of reflections in the source and receiver wavefields match. The main drawback of a conventional crosscorrelation imaging condition is that it ignores the local spatial coherence of reflection events and relies only on their propagation time. This leads to interference between unrelated events that occur at the same time. Sources of crosstalk include seismic events corresponding to different seismic experiments, propagation paths, types of reflections (primary or multiple), or wave modes (P or S). An alternative imaging condition operates on the same extrapolated wavefields, but crosscorrelation takes place in a higher-dimension domain where seismic events are separated based on their local space-time slope. Events are matched based on two parameters (time and local slope), thus justifying the name “stereographic” for this imaging condition. Stereographic imaging attenuates wavefield crosstalk and reduces imaging artifacts compared with conventional imaging. Applications of the stereographic imaging condition include simultaneous imaging of multiple seismic experiments, multiple attenuation in the imaging condition, and attenuation of crosstalk between multiple wavefield branches or multiple wave modes.
A tutorial on complex seismic trace analysis
Authors: Barnes Arthur E.
Published: November 2007

Complex seismic trace analysis treats a seismic trace as the product of two independent and separable functions: instantaneous amplitude and cosine of the instantaneous phase. At any given time, instantaneous amplitude is the maximum value the seismic trace can attain under a constant phase rotation, and instantaneous phase is the phase angle required to rotate the trace to the maximum. Defining these two attributes in this way permits complex seismic trace analysis to be founded without reference to the complex trace. All other complex seismic trace attributes derive from amplitude and phase through differentiation, averaging, combination, or transformation. The chief derived attributes are frequency, relative amplitude change, wavelength, dip, and azimuth. At any point on a seismic trace, the instantaneous attributes describe a sinusoid that locally matches the trace. Most instantaneous attributes are improved through filtering or weighted averaging. The phase wavenumber vector provides a convenient basis for quantifying 3D seismic properties such as reflection parallelism.
On the relation between seismic interferometry and the migration resolution function
Authors: Thorbecke Jan , Wapenaar Kees
Published: November 2007

Seismic interferometry refers to the process of retrieving new seismic responses by crosscorrelating seismic observations at different receiver locations. Seismic migration is the process of forming an image of the subsurface by wavefield extrapolation. Comparing the expressions for backward propagation known from migration literature with the Green’s function representations for seismic interferometry reveals that these seemingly distinct concepts are mathematically equivalent. The frequency-domain representation for the resolution function of migration is identical to that for the Green’s function retrieved by seismic interferometry (or its square, in the case of double focusing). In practice, they differ because the involved Green’s functions in seismic interferometry are all defined in the actual medium, whereas in migration one of the Green’s functions is defined in a background medium.
Rayleigh-to-shear wave conversion at the tunnel face — From 3D-FD modeling to ahead-of-drill exploration
Authors: Bohlen Thomas , Lorang Ulrich , Rabbel Wolfgang , Müller Christof , Giese Rüdiger , Lüth Stefan , Jetschny Stefan
Published: November 2007

For safe tunnel excavation, it is important to predict lithologic and structural heterogeneities ahead of construction. Conventional tunnel seismic prediction systems utilize body waves (P- and S-waves) that are directly generated at the tunnel walls or near the cutter head of the tunnel boring machine (TBM). We propose a new prediction strategy that has been discovered by 3D elastic finite-difference (FD) modeling: Rayleigh waves arriving at the front face of the tunnel are converted into high-amplitude S-waves propagating further ahead. Reflected or backscattered S-waves are converted back into Rayleigh waves which can be recorded along the sidewalls. We name these waves RSSR waves. In our approach, the front face acts as an S-wave transceiver. One technical advantage is that both the sources and the receivers may be placed behind the cutter head of the TBM. The modeling reveals that the RSSR waves exhibit significantly higher amplitudes than the directly reflected body waves. The excavation damage zone causes dispersion of the RSSR wave leading to multimodal reflection response. For the detection of geologic interfaces ahead, RSSR waves recorded along the sidewalls are corrected for dispersion and stacked. From the arrival times, the distance to the S-S reflection point can be estimated. A recurrent application, while the tunnel approaches the interface, allows one to quantify the orientation of the reflecting interfaces as well. Our approach has been verified successfully in a field experiment at the Piora adit of the Gotthard base tunnel. The distance to the Piora fault zone estimated from stacked RSSR events agrees well with the information obtained by geologic surveying and exploratory drilling.
The fallacy of the “shallow-water problem” in marine CSEM exploration
Authors: Weiss Chester J.
Published: November 2007

The recent explosion of activity in offshore controlled-source electromagnetic (CSEM) exploration has shown, both theoretically and in practice for the time-harmonic case, that shallow-water environments (depths less than, say, [Formula: see text]) can pose a significant challenge for detection and characterization of thin resistive targets in the subsurface because the weakly attenuated atmospheric response overprints the weaker target response. As an alternative, the transient CSEM experiment is considered to explore the nature of the “airwave” signature when viewed from the perspective of CSEM time series. The signature of a thin, isolated, resistive horizon is computed by using the quasi-analytic solution for a 1D earth in response to excitation by a horizontal electric dipole antenna. That signature, clearly seen in the transient data, generally lies in the time interval between the arrivalof the airwave and the late-time seawater response.The fact that either decreasing the water depth or increasing the source-receiver offset broadens this time interval suggests a target response that is generally easier to identify in shallow water than when viewed from a frequency-domain perspective. The airwave arrival is nearly synchronous across an inline receiver array, whereas the response time of the conducting elements of the model — the sea, the sediments, and the target — increases with increasing source-receiver offset. At short offsets (less than a few kilometers), and in intermediate water depths (approximately [Formula: see text]), these signatures can overlap and be difficult to decouple. However, modeling results also show that moveout rates of the post-airwave arrival may be used to infer the presence and depth of thin resistive targets within the geologic section to depths of [Formula: see text] below [Formula: see text] of water.