bluuebunny/crossref_metadata_2025 huggingface dataset:
A 63-year-old woman presenting with a synovial sarcoma of the hand: a case report
Authors: Casal Diogo , Ribeiro Ana Isabel , Mafra Manuela , Azeda Conceição , Mavioso Carlos , Mendes Maria Manuel , Mouzinho Maria Manuel
Published: November 2012

Introduction

Synovial sarcoma is a high-grade, soft-tissue sarcoma that most frequently is located in the vicinity of joints, tendons or bursae, although it can also be found in extra-articular locations. Most patients with synovial sarcoma of the hand are young and have a poor prognosis, as these tumors are locally aggressive and are associated with a relatively high metastasis rate. According to the literature, local recurrence and/or metastatic disease is found in nearly 80% of patients. Current therapy comprises surgery, systemic and limb perfusion chemotherapy, and radiotherapy. However, the 5-year survival rate is estimated to be only around 27% to 55%. Moreover, most authors agree that synovial sarcoma is one of the most commonly misdiagnosed malignancies of soft tissues because of their slow growing pattern, benign radiographic appearance, ability to change size, and the fact that they may elicit pain similar to that caused by common trauma.

Case presentation

We describe an unusual case of a large synovial sarcoma of the hand in a 63-year-old Caucasian woman followed for 12 years by a multidisciplinary team. In addition, a literature review of the most pertinent aspects of the epidemiology, diagnosis, treatment and prognosis of these patients is presented.

Conclusion

Awareness of this rare tumor by anyone dealing with hand pathology can hasten diagnosis, and this, in turn, can potentially increase survival. Therefore, a high index of suspicion for this disease should be kept in mind, particularly when evaluating young people, as they are the most commonly affected group.
Evaluation of function predictions by PFP, ESG, and PSI-BLAST for moonlighting proteins
Authors: Khan Ishita K , Chitale Meghana , Rayon Catherine , Kihara Daisuke
Published: November 2012

Background

Advancements in function prediction algorithms are enabling large scale computational annotation for newly sequenced genomes. With the increase in the number of functionally well characterized proteins it has been observed that there are many proteins involved in more than one function. These proteins characterized as moonlighting proteins show varied functional behavior depending on the cell type, localization in the cell, oligomerization, multiple binding sites, etc. The functional diversity shown by moonlighting proteins may have significant impact on the traditional sequence based function prediction methods. Here we investigate how well diverse functions of moonlighting proteins can be predicted by some existing function prediction methods.

Results

We have analyzed the performances of three major sequence based function prediction methods, PSI-BLAST, the Protein Function Prediction (PFP), and the Extended Similarity Group (ESG) on predicting diverse functions of moonlighting proteins. In predicting discrete functions of a set of 19 experimentally identified moonlighting proteins, PFP showed overall highest recall among the three methods. Although ESG showed the highest precision, its recall was lower than PSI-BLAST. Recall by PSI-BLAST greatly improved when BLOSUM45 was used instead of BLOSUM62.

Conclusion

We have analyzed the performances of PFP, ESG, and PSI-BLAST in predicting the functional diversity of moonlighting proteins. PFP shows overall better performance in predicting diverse moonlighting functions as compared with PSI-BLAST and ESG. Recall by PSI-BLAST greatly improved when BLOSUM45 was used. This analysis indicates that considering weakly similar sequences in prediction enhances the performance of sequence based AFP methods in predicting functional diversity of moonlighting proteins. The current study will also motivate development of novel computational frameworks for automatic identification of such proteins.
Evaluation of the bioconversion of genetically modified switchgrass using simultaneous saccharification and fermentation and a consolidated bioprocessing approach
Authors: Yee Kelsey L , Rodriguez Jr Miguel , Tschaplinski Timothy J , Engle Nancy L , Martin Madhavi Z , Fu Chunxiang , Wang Zeng-Yu , Hamilton-Brehm Scott D , Mielenz Jonathan R
Published: November 2012

Background

The inherent recalcitrance of lignocellulosic biomass is one of the major economic hurdles for the production of fuels and chemicals from biomass. Additionally, lignin is recognized as having a negative impact on enzymatic hydrolysis of biomass, and as a result much interest has been placed on modifying the lignin pathway to improve bioconversion of lignocellulosic feedstocks.

Results

Down-regulation of the caffeic acid 3-O-methyltransferase (COMT) gene in the lignin pathway yielded switchgrass (Panicum virgatum) that was more susceptible to bioconversion after dilute acid pretreatment. Here we examined the response of these plant lines to milder pretreatment conditions with yeast-based simultaneous saccharification and fermentation and a consolidated bioprocessing approach using Clostridium thermocellum, Caldicellulosiruptor bescii and Caldicellulosiruptor obsidiansis. Unlike the S. cerevisiae SSF conversions, fermentations of pretreated transgenic switchgrass with C. thermocellum showed an apparent inhibition of fermentation not observed in the wild-type switchgrass. This inhibition can be eliminated by hot water extraction of the pretreated biomass, which resulted in superior conversion yield with transgenic versus wild-type switchgrass for C. thermocellum, exceeding the yeast-based SSF yield. Further fermentation evaluation of the transgenic switchgrass indicated differential inhibition for the Caldicellulosiruptor sp. strains, which could not be rectified by additional processing conditions. Gas chromatography–mass spectrometry (GC-MS) metabolite profiling was used to examine the fermentation broth to elucidate the relative abundance of lignin derived aromatic compounds. The types and abundance of fermentation-derived-lignin constituents varied between C. thermocellum and each of the Caldicellulosiruptor sp. strains.

Conclusions

The down-regulation of the COMT gene improves the bioconversion of switchgrass relative to the wild-type regardless of the pretreatment condition or fermentation microorganism. However, bacterial fermentations demonstrated strain-dependent sensitivity to the COMT transgenic biomass, likely due to additional soluble lignin pathway-derived constituents resulting from the COMT gene disruption. Removal of these inhibitory constituents permitted completion of fermentation by C. thermocellum, but not by the Caldicellulosiruptor sp. strains. The reason for this difference in performance is currently unknown.
An Always Correlated gene expression landscape for ovine skeletal muscle, lessons learnt from comparison with an “equivalent” bovine landscape
Authors: Sun Wei , Hudson Nicholas J , Reverter Antonio , Waardenberg Ashley J , Tellam Ross L , Vuocolo Tony , Byrne Keren , Dalrymple Brian P
Published: November 2012

Background

We have recently described a method for the construction of an informative gene expression correlation landscape for a single tissue, longissimus muscle (LM) of cattle, using a small number (less than a hundred) of diverse samples. Does this approach facilitate interspecies comparison of networks?

Findings

Using gene expression datasets from LM samples from a single postnatal time point for high and low muscling sheep, and from a developmental time course (prenatal to postnatal) for normal sheep and sheep exhibiting the Callipyge muscling phenotype gene expression correlations were calculated across subsets of the data comparable to the bovine analysis. An “Always Correlated” gene expression landscape was constructed by integrating the correlations from the subsets of data and was compared to the equivalent landscape for bovine LM muscle. Whilst at the high level apparently equivalent modules were identified in the two species, at the detailed level overlap between genes in the equivalent modules was limited and generally not significant. Indeed, only 395 genes and 18 edges were in common between the two landscapes.

Conclusions

Since it is unlikely that the equivalent muscles of two closely related species are as different as this analysis suggests, within tissue gene expression correlations appear to be very sensitive to the samples chosen for their construction, compounded by the different platforms used. Thus users need to be very cautious in interpretation of the differences. In future experiments, attention will be required to ensure equivalent experimental designs and use cross-species gene expression platform to enable the identification of true differences between different species.
Morphometrical diagnosis of the malaria vectors Anopheles cruzii, An. homunculus and An. bellator
Authors: Lorenz Camila , Marques Tatiani Cristina , Sallum Maria Anice Mureb , Suesdek Lincoln
Published: November 2012

Background

Anopheles(Kerteszia)cruziiis a primary vector ofPlasmodiumparasites in Brazil’s Atlantic Forest. Adult females ofAn. cruziiandAn. homunculus, which is a secondary malaria vector, are morphologically similar and difficult to distinguish when using external morphological characteristics only. These two species may occur syntopically withAn.bellator, which is also a potential vector ofPlasmodiumspecies and is morphologically similar toAn. cruziiandAn. homunculus. Identification of these species based on female specimens is often jeopardised by polymorphisms, overlapping morphological characteristics and damage caused to specimens during collection. Wing geometric morphometrics has been used to distinguish several insect species; however, this economical and powerful tool has not been applied toKertesziaspecies. Our objective was to assess wing geometry to distinguishAn. cruzii,An. homunculusandAn. bellator.

Methods

Specimens were collected in an area in the Serra do Mar hotspot biodiversity corridor of the Atlantic Forest biome (Cananeia municipality, State of Sao Paulo, Brazil). The right wings of females ofAn. cruzii(n= 40),An. homunculus(n= 50) andAn. bellator(n= 27) were photographed. For each individual, 18 wing landmarks were subjected to standard geometric morphometrics. Discriminant analysis of Procrustean coordinates was performed to quantify wing shape variation.

Results

Individuals clustered into three distinct groups according to species with a slight overlap between representatives ofAn. cruziiandAn. homunculus. The Mahalanobis distance betweenAn. cruziiandAn. homunculuswas consistently lower (3.50) than that betweenAn. cruziiandAn. bellator(4.58) orAn. homunculusandAn. bellator(4.32). Pairwise cross-validated reclassification showed that geometric morphometrics is an effective analytical method to distinguish betweenAn.bellator,An. cruziiandAn. homunculuswith a reliability rate varying between 78-88%. Shape analysis revealed that the wings ofAn. homunculusare narrower than those ofAn. cruziiand thatAn. bellatoris different from both of the congeneric species.

Conclusion

It is possible to distinguish among the vectorsAn. cruzii,An. homunculusandAn. bellatorbased on female wing characteristics.
Optimizing global health experiences in emergency medicine residency programs: a consensus statement from the Council of Emergency Medicine Residency Directors 2011 Academic Assembly global health specialty track
Authors: Tupesis Janis P , Babcock Christine , Char Doug , Alagappan Kumar , Hexom Braden , Kapur G Bobby
Published: November 2012

Background

An increasing number of emergency medicine (EM) residency training programs have residents interested in participating in clinical rotations in other countries. However, the policies that each individual training program applies to this process are different. To our knowledge, little has been done in the standardization of these experiences to help EM residency programs with the evaluation, administration and implementation of a successful global health clinical elective experience. The objective of this project was to assess the current status of EM global health electives at residency training programs and to establish recommendations from educators in EM on the best methodology to implement successful global health electives.

Methods

During the 2011 Council of Emergency Medicine Residency Directors (CORD) Academic Assembly, participants met to address this issue in a mediated discussion session and working group. Session participants examined data previously obtained via the CORD online listserve, discussed best practices in global health applications, evaluations and partnerships, and explored possible solutions to some of the challenges. In addition a survey was sent to CORD members prior to the 2011 Academic Assembly to evaluate the resources and processes for EM residents’ global experiences.

Results

Recommendations included creating a global health working group within the organization, optimizing a clearinghouse of elective opportunities for residents and standardizing elective application materials, site evaluations and resident assessment/feedback methods. The survey showed that 71.4% of respondents have global health partnerships and electives. However, only 36.7% of programs require pre-departure training, and only 20% have formal competency requirements for these global health electives.

Conclusions

A large number of EM training programs have global health experiences available, but these electives and the trainees may benefit from additional institutional support and formalized structure.
Murine Borrelia arthritis is highly dependent on ASC and caspase-1, but independent of NLRP3
Authors: Oosting Marije , Buffen Kathrin , Malireddi Subbarao RK , Sturm Patrick , Verschueren Ineke , Koenders Marije I , van de Veerdonk Frank L , van der Meer Jos WM , Netea Mihai G , Kanneganti Thirumala-Devi , Joosten Leo AB
Published: November 2012

Introduction

The protein platform called the NOD-like-receptor -family member (NLRP)-3 inflammasome needs to be activated to process intracellular caspase-1. Active caspase-1 is able to cleave pro-Interleukin (IL)-1β, resulting in bioactive IL-1β. IL-1β is a potent proinflammatory cytokine, and thought to play a key role in the pathogenesis of Lyme arthritis, a common manifestation of Borrelia burgdorferi infection. The precise pathways through which B. burgdorferi recognition leads to inflammasome activation and processing of IL-1β in Lyme arthritis has not been elucidated. In the present study, we investigated the contribution of several pattern recognition receptors and inflammasome components in a novel murine model of Lyme arthritis.

Methods

Lyme arthritis was elicited by live B. burgdorferi, injected intra-articularly in knee joints of mice. To identify the relevant pathway components, the model was applied to wild-type, NLRP3-/-, ASC-/-, caspase-1-/-, NOD1-/-, NOD2-/-, and RICK-/- mice. As a control, TLR2-/-, Myd88-/- and IL-1R-/- mice were used. Peritoneal macrophages and bone marrow-derived macrophages were used for in vitro cytokine production and inflammasome activation studies. Joint inflammation was analyzed in synovial specimens and whole knee joints. Mann-Whitney U tests were used to detect statistical differences.

Results

We demonstrate that ASC/caspase-1-driven IL-1β is crucial for induction of B. burgdorferi-induced murine Lyme arthritis. In addition, we show that B. burgdorferi-induced murine Lyme arthritis is less dependent on NOD1/NOD2/RICK pathways while the TLR2-MyD88 pathway is crucial.

Conclusions

Murine Lyme arthritis is strongly dependent on IL-1 production, and B. burgdorferi induces inflammasome-mediated caspase-1 activation. Next to that, murine Lyme arthritis is ASC- and caspase-1-dependent, but NLRP3, NOD1, NOD2, and RICK independent. Also, caspase-1 activation by B. burgdorferi is dependent on TLR2 and MyD88. Based on present results indicating that IL-1 is one of the major mediators in Lyme arthritis, there is a rationale to propose that neutralizing IL-1 activity may also have beneficial effects in chronic Lyme arthritis.
Response by Steve Webster to the reply by the authors
Authors: Webster Steve
Published: November 2012

My only addendum in response to the reply by Cooper and Swift is that the Al Azri et al. (1994) paper was written between the two field seasons, to comply to ASEG Conference deadlines, and only limited data could be released at that time. We hope, in the future, to publish a paper covering more data, results, and conclusions of the Oman case study.
AEROMAGNETIC AND GRAVITY STUDIES OF THE PRECAMBRIAN IN NORTHEASTERN NEW MEXICO
Authors: Andreasen G. E. , Kane M. F. , Zietz Isidore
Published: November 2012

A contour map of the Precambrian surface for a part of northeastern New Mexico has been prepared from aeromagnetic, gravity, and drill-hole data. The area extends approximately from the Colorado border south to latitude 34° N., and from the foothills of the Sangre de Cristo Mountains east to longitude 104° W.

Thirty-seven depths to Precambrian rocks were computed from aeromagnetic anomalies. Regional gravity anomalies were generally not suitable for quantitative analysis, but the gravity highs correlated with known areas of basement highs, providing a basis for contouring in areas of meager depth control. Drill-hole data provided 61 depths to basement in and near the survey area. The contouring along the east edge of the Sangre de Cristo Mountains was guided by exposures of Precambrian rocks.

A principal feature of the contour map is the Sierre Grande Arch, a basement highland that trends southwest across the area to the northwest part of Guadalupe County. Major depressions are outlined west of Vegas Junction, northeast of Santa Rosa, and north and northeast of Las Vegas. The largest of these, the Las Vegas basin, occupies more than 1,000 square miles and may be more than 10,000 ft deep
“Full-waveform static corrections using blind channel identification,” Robbert van Vossen and Jeannot Trampert, GEOPHYSICS, 72, no. 4, U55–U66.
Authors: van Vossen Robbert , Trampert Jeannot
Published: November 2012

Figure 15 appeared distorted. We apologize for any inconvenience caused by this error.
This issue of GEOPHYSICS
Authors: Wapenaar Kees
Published: November 2012

In this article, the Editor of Geophysics provides an overview of all technical articles in this issue of the journal.
This issue of Geophysics
Authors: Grechka Vladimir
Published: November 2012

In this article the Editor of Geophysics provides an overview of all technical articles in this issue of the journal.
16th Annual 3D Seismic Symposium
Authors: Purcell Mary Sue
Published: November 2012

The 16th Annual 3D Seismic Symposium, jointly sponsored by the Rocky Mountain Association of Geologists and the Denver Geophysical Society, will be held 16 March 2010 at the Marriott City Center in Denver, USA. This year's theme “Uplifting the Rockies” has attracted 13 presentations that focus on both Rockies case histories and the latest North American shale plays. The subject matter covers the “hottest” projects available, and the role of 3D data's role in those projects.
Full wave-equation methods for complex imaging challenges
Authors: Williamson Paul , Wang Bin , Bevc Dmitri , Jones Ian
Published: November 2012

Despite being at the end of a long and full Annual Meeting week, the workshop “Full wave-equation methods for complex imaging challenges,” held 30 October 2009, drew an audience which filled the large meeting room. They were rewarded with a full day of presentations which mostly focused on emerging techniques for velocity model estimation rather than imaging itself: the consensus seemed to be that it is indeed there that the true imaging challenges lie. Nonetheless, significant contributions on the imaging side also demonstrated continuing progress in improving the quality and efficiency of imaging, and in interpreting the results.
Reviews
Authors: Bartel David C. , McCormack Michael D. , Fitzroy Ronald Green
Published: November 2012

Applications of Seismic Anisotropy in the Oil and Gas Industry (OTEIII), V. Grechka, ISBN 978-90-73781-68-9, EAGE Publications, 2009, 171 pp., €77 (non-members), €55 (EAGE members). Edge and Tip Diffractions: Theory and Applications in Seismic Prospecting, Geophysical Monograph Series No. 14, Kamill Klem-Musatov, Arkady Aizenberg, Jan Pajchel, and Hans B. Helle, ISBN 978-1-56080-149-8, SEG, 2008, 210 pp., US $119.00 (nonmembers), $79.00 (SEG members). The Misadventures of Interpreter Sam, Donald A. Herron, ISBN 978-1-56080-156-6, SEG, 2009, 97 pp., US $45 (non-members), $29 (SEG members).
Honors and Awards citations
Authors: Duncan Peter M.
Published: November 2012

One of the most important functions of a professional society is honoring those who have made significant contributions to the profession and to science. This function is implicit in SEG's constitutional objective “to promote the science of geophysics, especially as it relates to exploration and research, to foster the common scientific interests of geophysicists, and to maintain a high professional standard among its members.”
Scholarships — a global program
Authors: Young Brian K.
Published: November 2012

The SEG Foundation has been in the business of growing exceptional geophysicists for more than 50 years. Since the very first SEG scholarship was awarded in 1956, our scholarship program has provided more than US $6 million to thousands of the best geoscience students in the world. It's no wonder that ours is recognized as the most prestigious scholarship program for aspiring geophysicists. This year, the legacy grows with an additional $424,150 in scholarships to 118 students worldwide.
SEG Constitution and Bylaws: The case for change
Authors: Reilly Joseph M.
Published: November 2012

The purpose of this article is to familiarize the membership with an important effort underway to modernize our governing documents in order to better align them with current regulatory requirements, and to improve the organizational structure and overall effectiveness of the SEG leadership and Business Office.
Memorial
Authors: Mosegaard Klaus
Published: November 2012

Memorials for: Albert Tarantola 1949–2009
Announcements
Authors: Liu Gary , Todd Terry
Published: November 2012

This article provides news of recently past or upcoming SEG activities.
The case for governance reform: A personal perspective
Authors: Cheng Arthur
Published: November 2012

If you have been reading recent issues of TLE and visiting the SEG Web site, you are probably aware of the upcoming proposal to change the way SEG operates. And you are probably wondering why, why now, and how? I had the same questions when I first heard about this more than three years ago and, because I am on the current Executive Committee and previously have served as a Council member, I thought that I would share my thoughts, and what I have found out.
Preserving our heritage
Authors: Clark Dean
Published: November 2012

Thanks primarily to the efforts of Bob Wyckoff, chairman of SEG's Historical Preservation Committee, exhibits of vintage geophysical equipment and photographs have recently been installed at the University of Oklahoma and Oklahoma State University. In addition, thanks in large measure to the efforts of Guy Flanagan, SEG Gravity/Magnetics Committee, and Bill Gafford, chairman of the Museum Committee of the Geophysical Society of Houston, many items of gravity and magnetic instrumentation that were part of the Robert Iverson collection are now on display in Fugro's Houston offices.
Foundation News
Authors: Blythe Natalie
Published: November 2012

Inspiring the future generation of geophysicists. SEG and the SEG Foundation are committed to transforming today's geoscience students into outstanding geophysical professionals through our unique suite of student programs. SEG and the SEG Foundation realized early on that developing student leaders is critical business for the geophysical profession. Today's students are the next generation of practicing geophysicists and to help them achieve their best, SEG and the SEG Foundation provide students with the “tools” necessary to transition from a student in the geosciences to a working, professional geophysicist.
SEAM Update
Authors: Oristaglio Michael
Published: November 2012

The SEAM Phase II consortium has settled on three geologic models for the first set of land seismic simulations to be tendered for competitive bids later this year. The model closest to a complete digital representation contains petroleum reservoirs based on the Eagle Ford and Woodford shale-gas plays in Texas. This SEAM “unconventional model” covers an area 10 × 10 km in lateral extent and 3.75 km in depth; in its current working form, which is being used for quality control and benchmark simulations, the model has been discretized into cubic cells with sides 6.25 m in length, for a 3D grid of size 1601 × 1601 × 601.
Foundation News
Authors: Blythe Natalie
Published: November 2012

For five years now, the Jackson School of Geosciences at the University of Texas at Austin has provided a first-class, unique marine field camp experience. The field course was designed by lead instructor and research scientist Sean Gulick, who got the idea for the field course after Mead Allison, school associate director and senior research scientist, arrived at the Jackson school with equipment. Gulick, who was already working with the Jackson School's existing equipment, realized that the department now had enough equipment to start teaching students through hands-on experience. “The best way to teach is to get out in the field, process, and interpret,” Gulick said.
President's Page
Authors: Hardage Bob A.
Published: November 2012

Because of the timing of the 2011 and 2012 annual meetings, I have been fortunate to serve a longer term (14 months) than have many SEG presidents. As I near the end of my presidential term, I wish to comment on a few highlights of the past several months.
GEOPHYSICS BRIGHT SPOTS
Authors: Sun Yonghe
Published: November 2012

The September–October issue of Geophysics is here. We are in for a treat with a special section on ‘Seismic Methods in Mineral Exploration and Mine Planning.’ The following are a few brief samples of the September–October issue. I invite you to browse through the entire issue for the latest developments in exploration geophysics.
Multifocusing-based multiple attenuation
Authors: Berkovitch Alex , Deev Kostya , Landa Evgeny
Published: November 2012

It is widely considered that, in regions with significant geologic complexity, methods which work directly in the depth domain are superior to methods which operate on prestack time data. So, for example, velocity analysis using depth migration and residual moveout became standard in the industry. The most common depth-velocity analysis attempts to flatten common-image-migrated gathers for main reflectors by measuring depth errors as a function of the offset. At the same time, the fact that most depth-domain algorithms are valid only for correct or nearly correct velocity models should not be underestimated. If this assumption is violated, they can lose their convergence properties or produce wrong results.
Improving seismic velocity estimation for 2D poststack time migration of regional seismic data using kriging with an external drift
Authors: Duchesne Mathieu J. , Claprood Maxime , Gloaguen Erwan
Published: November 2012

Geostatistics is extensively used to construct reservoir models from the integration of seismic and well data, invert seismic data, and less frequently for seismic processing (Michelena and Gringarten 2009). Seismic interpretations made in time can also be converted in depth by estimating velocities within each layer using geostatistical methods (Hwang and McCorkindale, 1994).
Onboard data quality control and processing for ocean-bottom nodes
Authors: Ronen Shuki , Kandilarov Alex , Massacand Christophe , Mattocks Bruce , Paillet Jimmy , Roger Guillaume , Rokkan Arne
Published: November 2012

When we use streamers or ocean-bottom cables, we have the data in real time. When we use autonomous ocean-bottom nodes, we have the data only when we retrieve them. With 100 days endurance, we may be shooting blind for three months without knowing if we are recording good data, or not. This may cause anxiety for some people.
SEG launches new journal on interpretation
Authors: Bakamjian Ted
Published: November 2012

Imagine a multidisciplinary journal devoted to telling the stories of the subsurface, visualizing and quantifying its geologic history and current structures and properties. Imagine no more. Welcome to Interpretation, a peer-reviewed journal to be published quarterly by SEG beginning in 2013. “Interpreters are a large and diverse community underserved by available communication channels,” said SEG President Bob Hardage, a member of the journal's editorial board. “This publication will change that dynamic by helping scientists across disciplines share their experiences and improve the quality of each other's work.”
Near-surface resistivity for hydrocarbon detection
Authors: Warren Roy K.
Published: November 2012

A new method called the “grid resistivity system” (GRS) is described which measures relative changes in subsurface resistivity using the low-frequency harmonics (either 50 or 60 Hz) generated by electric power lines. The electromagnetic waves emanate from the power grid, and some of this energy interacts with the air-Earth interface to be absorbed by the Earth. The lowest frequency penetrates to the greatest depth. The power from the grid causes current to flow in the rocks and soil. The Earth material with higher conductivity offers a path for the current to follow. The method can help locate geophysical signatures associated with the geochemical response of hydrocarbon chimney leakage. Data collection is fast and low cost. Processing results in cross sections of resistivity. Interpretation focuses on the identification of the larger conductors related to clay alteration caused by chimney leakage from a reservoir.
A column on the history and culture of geophysics and science in general
Authors: Liner Christopher L.
Published: November 2012

As this is written in early July 2012, I have been around the world a couple of times delivering the SEG Distinguished Instructor Short Course (DISC) titled Seismic Dispersion: A Somewhat Practical Guide to Frequency-dependent Phenomena. The year 2012 also marks exactly 20 years since my first Seismos column appeared in the pages of The Leading Edge. I have found sadly little time of late to write Seismos columns, what with the effort of writing the DISC book in 2010–2011, preparing slides in late 2011 and early 2012 and the actual travel this year to give the course. It is late in the year for a first column of 2012, but here it is.
2012 Honors and awards citations
Authors: Thomsen Leon
Published: November 2012

One of the most important functions of a professional society is honoring those who have made significant contributions to the profession and to science. This function is implicit in SEG's stated objective “to promote the science of geophysics, especially as it relates to exploration and research, to foster the common scientific interests of geophysicists, and to maintain a high professional standard among its members.” Moreover, the founders of SEG underscored this importance though explicit references in our founding documents. Our profession has many components: the science of exploration geophysics; the education of geophysicists, other professionals, and the general public; collaboration with professionals in related fields; and application of geophysical knowledge to economically find and develop natural resources, characterize the near surface, and mitigate Earth hazards. The 2012 Honors and Awards Program recognizes superior achievement in all of these areas. The distinguished recipients of this year's awards are role models for excellence in our profession, and the Society proud to honor their contributions.
Foundation News
Authors: Pangman Peter
Published: November 2012

CGGVeritas is a well-respected name in the geophysical community. Less well known is its position in the top tier of SEG Foundation “sustaining investors,” with support of more than US $250,000 per year. Unlike other companies, CGGVeritas has chosen to distribute its ongoing support across several programs: Student Membership Dues (2008), Distinguished Lecture (2009), Geoscientists Without Borders (2011) and University Excellence (2012). We have asked Jean-Georges Malcor, CGGVeritas CEO since mid-2010, to share his thinking on SEG and the SEG Foundation with us.
Introduction to this special section: Passive seismic and microseimic—Part 1
Authors: Goodway Bill
Published: November 2012

The increase in the United States' production of unconventional gas from about 5% in 1995 to around 60% in 2009 is because of hydraulic fracture stimulation of horizontal wells, an advance in engineering technology equivalent to the introduction of 3D and 4D in reflection seismic (Figure 1). However, the process of inducing failure by raising fluid pressure in the reservoir is hardly a new technological breakthrough. The first well-documented account of this is probably of a technique employed by the Romans in 77 CE to undermine and instantly remove vast quantities of mountainside to extract gold from the buried mother lode at Las Médulas in northwest Spain.
Tracking microseismic signals from the reservoir to surface
Authors: Maxwell S.C. , Raymer D. , Williams M. , Primiero P.
Published: November 2012

Since the launch of commercial microseismic mapping of hydraulic fracturing in the Barnett Shale in 2000, microseismic has become the de facto geophysical technique to characterize stimulated fracture networks in unconventional reservoirs. Effective stimulation of these resources through hydraulic stimulations along multiple intervals of horizontal wells is critical to economic production from tight and shale oil and gas resources. The inherent low permeability of these formations necessitates creation of permeable flow paths between the reservoir and wellbore through injection of high-pressure fluids. Microseismic observations over the last decade have led to a paradigm shift in our concept and engineering models of hydraulic fractures from simple, planar fractures to complex fracture networks controlled by the stress state and the existence of pre-existing fractures. Injected fluids in rock tend to follow the “path of least resistance” that minimizes the work done, preferentially growing into pre-existing fractures and lower stress intervals. Microseismic is the only technology that can image these fracture networks and has led to the incredible expansion of microseismic monitoring. Over the past decade, a vast microseismic database has been collected covering all North American shale oil and gas fields, in addition to key international fields. The microseismic results have demonstrated the significant variability in hydraulic fracturing responses on all scales: across a field, along the horizontal length of a well, and even between perforations of a single frac stage.
Observations and implications from simultaneous recording of microseismic surface and borehole data
Authors: Diller David E. , Gardner Stephen P.
Published: November 2012

Simultaneously recording microseismic surface and borehole data (hereinafter referred to as co-recorded data) offers some unique challenges. In many cases, timing differences between the surface and borehole data sets cannot be accurately resolved, which greatly limits the usefulness of the experiment. Velocity models that are derived from sonic well logs and calibrated for each seismic data type are typically incompatible, and cannot be used for simultaneous focusing of the events. However, despite the acquisition and processing challenges, co-recorded surface and borehole data also offer some unique benefits. The inherent sensitivity of borehole data allows us to routinely determine when the reported events from the processed surface data include “false positives” (reported events that actually do not exist), and provides an opportunity to improve our surface data-processing algorithms and workflows to reduce false positives. The inherent horizontal accuracy of surface data allows us to determine when the event azimuths from borehole data are inaccurate, and provides an opportunity to improve the accuracy of our borehole data-processing algorithms. The difficulty in resolving the velocities is actually a benefit, because it allows us to constrain the velocities, and constrain anisotropy, to produce more accurate location results. Simultaneous recording of surface and borehole data may offer some of the benefits of using multiple observation wells.
High-quality surface microseismic data illuminates fracture treatments: A case study in the Montney
Authors: Birkelo Bradley , Cieslik Konrad , Witten Ben , Montgomery Summer , Artman Brad , Miller David , Norton Mark
Published: November 2012

Monitoring hydraulic fracture stimulations from the surface is a technique that, in the past, met with mixed success. One reason for this experience is that the measurement has often been treated as if it were only a minor variant of the reflection surveys our industry is most familiar with. While reflection seismic sources are designed to generate primarily P-waves, fracturing rocks emit both P- and S-waves with the much larger proportion of energy as S-waves. To capture the information content in the microseismic wavefield, surveys must be designed to record, and processing strategies designed to use, the full vector wavefield energy emitted by the fracture process. To record the full vector wavefield requires the use of appropriate sensors capable of recording low frequencies and three components.
Quality assessment of microseismic event locations and traveltime picks using a multiplet analysis
Authors: Kocon Ken , van der Baan Mirko
Published: November 2012

The proliferation of hydraulic fracturing (frac) stimulation and other enhanced oil recovery techniques in unconventional plays has spurred interest in microseismic monitoring. Changes in stress in the subsurface produced by hydrocarbon production may induce brittle failure events. Many enhanced oil recovery techniques such as hydraulic frac stimulation or cyclic steam stimulation involve injecting large volumes of fluid at high pressure into a reservoir. Microseismic events, hereafter events, may illuminate the reach and effectiveness of enhanced recovery techniques within a reservoir. When array configuration is favorable, advanced analysis of microseismic data may provide additional information. For instance, seismic moment tensor inversion (Eaton and Forouhideh, 2010) may estimate the failure mode of an event. The aforementioned failure modes may include fracture-opening, shear, or fracture-closing events. Knowledge of the failure modes allows a detailed analysis of the effects of changing parameters such as steam injection temperature or well spacing.
Potential use of resonance frequencies in microseismic interpretation
Authors: Tary J. B. , van der Baan M.
Published: November 2012

Continuous passive recordings of microseismic experiments can be used to detect and trace the modifications in frequency content during hydraulic fracturing or heavy-oil steam injection. We analyze the performance of four different time-frequency representations, namely the short-time Fourier transform, the S-transform, the continuous wavelet transform, and the autoregressive method, on a real microseismic data set of intermediate quality. We show that time-frequency transforms provide an efficient tool to highlight time-varying resonance frequencies occurring during reservoir fracturing. Four distinct resonance frequencies at ∼17, ∼35, ∼51, and 60 Hz are observed during two experiments using the same experimental setup.
Geomechanical modeling of rock fracturing and associated microseismicity
Authors: Chorney Drew , Jain Piyush , Grob Melanie , van der Baan Mirko
Published: November 2012

Microseismic monitoring is increasingly being used to assess in real time the effectiveness of hydraulic fracture treatments. Operators are interested in three key questions. (1) Where are the microseismic events occurring (what is the size of the microseismic cloud)? (2) What is the failure mechanism (are fractures opening, closing, or shearing)? (3) Why is failure occurring in specific locations but not others (why are fractures not always symmetric with respect to the injection well and what is the geomechanical behavior of the reservoir)? In particular, the last question is difficult to answer from the recorded seismicity alone because the geomechanical behavior depends on the in-situ stress field, the local rock properties (lithologies), and any existing areas of weakness including faults, fractures and joints (Grob and Van der Baan, 2011). Geomechanical modeling can thus play a key role in better understanding both brittle and ductile deformation inside a reservoir because of hydraulic fracturing and the resulting microseismicity.
3D joint inversion of geophysical data with Gramian constraints: A case study from the Carrapateena IOCG deposit, South Australia
Authors: Zhdanov Michael S. , Gribenko Alexander V. , Wilson Glenn A. , Funk Charles
Published: November 2012

Explorers are moving to increase the “discovery space” by exploring under cover and to greater depths, e.g., subsalt and sub-basalt exploration for oil and gas, and beneath transported cover for minerals. With this shift, there becomes an increased reliance on geophysical methods to delineate resources with no recognized geological or geochemical expressions. Different geophysical fields provide information about different physical properties of the Earth. Multiple geophysical surveys spanning gravity, magnetic, electromagnetic, and seismic methods are often interpreted to infer geology from models of different physical properties. In many cases, the various geophysical data are complementary, making it natural to consider a formal mathematical framework for their joint inversion to a shared Earth model. There are different approaches to joint inversion. The simplest case of joint inversion is where the physical properties are identical between different geophysical methods (e.g., Jupp and Vozoff, 1975). In other cases, joint inversion may infer theoretical, empirical, or statistical correlations between different physical properties (e.g., Hoversten et al., 2003, 2006). In cases where the physical properties are not correlated but, nevertheless, can be assumed to share a similar structure, joint inversions have been formulated as a minimization of the cross-gradients between different physical properties (e.g., Haber and Oldenburg, 1997; Gallardo and Meju, 2003, 2004). The latter has now been widely adopted by joint inversion practitioners as the de facto standard (e.g., Colombo and De Stefano, 2007; Hu et al., 2009; Jegen et al., 2009; De Stefano et al., 2011).
Reviews
Authors: Green William R.
Published: November 2012

Global Environment: Water, Air, and Geochemical Cycles, 2nd edition, by E. K. Berner and R. A. Berner, ISBN 978-0-691-13678-3, 2012, Princeton University Press, 444 pp. US $85 (electronic version available).
Vitamin a supplementation, serum lipids, liver enzymes and C-reactive protein concentrations in obese women of reproductive age
Authors: Farhangi Mahdieh Abbasalizad , Keshavarz Seyyed Ali , Eshraghian Mohammadreza , Ostadrahimi Alireza , Saboor-Yaraghi Ali Akbar
Published: November 2012

Background

High-dose vitamin A influences glucose and lipid profile; however, the possible effects of moderate doses (25,000 IU/d) are conflicting. We aimed to compare the effect of vitamin A supplementation on several anthropometric and biochemical variables between obese and non-obese women.

Methods

This study was performed on 84 women among whom 56 were obese (body mass index [BMI] 30-35 kg/m2) and 28 were non-obese (BMI 18.5-24.9 kg/m2). Obese women were randomly divided into two groups: one group received 25,000 IU/d retinyl palmitate and another group received placebo. The third group was age-matched non-obese women who received 25,000 IU/d retinyl palmitate. At baseline and four months after intervention, fasting blood glucose (FBG), lipid profile, C-reactive protein (CRP) and liver enzymes were evaluated.

Results

Baseline concentrations of serum FBG and triglyceride in the obese vitamin A-treated group were significantly higher compared with the other groups (P = 0.004 and 0.007, respectively). A significant increase in serum FBG (P = 0.026), total cholesterol (TC) (P = 0.004) and low-density lipoprotein cholesterol (LDL-C) (P = 0.016) in the non-obese group and a significant decrease in serum high-density lipoprotein cholesterol (HDL-C) (P = 0.001) in the obese group was observed. Serum CRP increased significantly in the obese vitamin A-treated group (P = 0.03) and serum aspartate transaminase increased significantly in the obese and non-obese groups after vitamin A supplementation (P = 0.008 and 0.001, respectively).

Conclusions

Treatment with 25,000 IU/d vitamin A induced a mild elevation in serum lipids, CRP and liver enzymes in obese and non-obese women. Considering the other information about possible side-effects of excess vitamin A, use of vitamin A in this dose and duration should be considered with caution.
Validation of diagnostic criteria using gadoxetic acid-enhanced and diffusion-weighted MR imaging for small hepatocellular carcinoma (≤ 2.0 cm) in patients with hepatitis-induced liver cirrhosis
Authors: Park Min Jung , Kim Young Kon , Lee Mi Hee , Lee Jiyoung Hwang Won Jae
Published: November 2012

Background

Gadoxetic acid and diffusion-weighted imaging (DWI) is increasingly used for the diagnosis of hepatocellular carcinoma (HCC). It is relevant to refine the diagnostic parameters for HCC, using state-of-the-art imaging techniques.

Purpose

To validate usefulness of magnetic resonance imaging (MRI) criteria with gadoxetic acid-enhanced MRI and DWI for diagnosis of small HCC by differentiation from dysplastic nodule (DN) or regenerative nodule (RN) in cirrhotic patients with strongly suspected small HCC.

Material and Methods

One hundred and eight patients with 102 HCCs and 29 benign nodules including 21 DNs and two large RNs (≤ 2.0 cm), and 40 patients with no HCC underwent gadoxetic acid-enhanced MRI and DWI. All patients also underwent MDCT. Index MR criteria for HCC were: (i) arterial hyperenhancement and hypointensity on hepatobiliary phase (HBP) with hyperintensity on DWI; (ii) hypovascular nodule with hyperintensity on DWI; (iii) arterial hyperenhancement and hypointensity on HBP without hyperintensity on DWI; (iv) arterial hyperenhancement and either iso- or hyperintensity on HBP, with hyperintensity on DWI; and (v) hyperintensity only on DWI. According to these criteria, MRI findings for HCCs and benign nodules were independently classified by two reviewers.

Results

On multidetector-row computed tomography, 64 HCCs (62.7%) showed typical features for HCC while 13 (12.8%) were not identified. On MRI, 84 HCCs (82.4%) showed arterial hyperenhancement and hypointensity on HBP, and hyperintensity on DWI. Eight HCCs were regarded as hypovascular HCCs with hyperintensity DWI (category 2). One HCC (0.6 cm in diameter) was demonstrated only by DWI. For each observer, 101 (99.0%) and 100 HCCs (98.0%) were discernible when applying all MRI criteria for HCC, respectively. Three DNs also fit the HCC criteria, thus the specificity was 90.9% for both observers.

Conclusion

With the HCC criteria based on combined gadoxetic acid-enhanced MRI and DWI, it is possible to reliably diagnose small HCC including hypovascular HCCs.