bluuebunny/crossref_metadata_2025 huggingface dataset:
An assessment of the Top Khuff reflectivity: Central Saudi Arabia
Authors: Aljuhani Salem Gulaiyel
Published: September 2013

The Top Khuff is a major regional seismic marker in Saudi Arabia with an apparent strong and consistent amplitude interpreted as a large impedance contrast between the Khuff carbonate and the overlying Sudair shale. However, the effective Top Khuff response is, in fact, a complex reflection of a stack of thin beds of highly contrasting impedance with significant lateral variations in reflectivity and thickness. Interference among these reflected waves disturbs the amplitude strength and effective reflection time of the Top Khuff and alters the phase and frequency bandwidth of the reflection wavelet. Variations in the Top Khuff amplitude and reflection wavelet were quantified using a Ricker wavelet and solved as an inverse problem with four model parameters: reflection coefficient, reflection time, phase, and frequency. These model parameters are interrelated, and the effective seismic response in a complex situation is a compromise among them. The fit of the Ricker wavelet with the Top Khuff amplitude revealed significant variations in these parameters and verified the Top Khuff is not a simple reflector and may not be a suitable reference horizon for seismic amplitude processing.
Magnetic modeling of iron oxide copper-gold mineralization constrained by 3D multiscale integration of petrophysical and geochemical data: Cloncurry District, Australia
Authors: Austin James R. , Schmidt Phillip W. , Foss Clive A.
Published: September 2013

Magnetite-rich iron oxide copper-gold deposits (IOCGs) are geologically and geochemically complex and present major challenges to geophysical investigation. They often sit beneath significant cover, exhibit magnetic remanence, and suffer from self-demagnetization effects. Because remanence in magnetite-bearing drill core samples is commonly overprinted by drilling, in situ natural remanent magnetization is difficult to measure accurately, and thus IOCGs cannot be modeled definitively using geophysics alone. We examined structural controls on a magnetite-rich IOCG in northwest Queensland and the relationships between structure, alteration, Fe oxides, and mineralization at core to deposit scale. Magnetite within the deposit has a multidomain structure, and thus it would commonly have an in situ magnetization parallel to the earth’s field. In contrast, pyrrhotite has a pseudosingle-domain structure and so it is the predominant carrier of stable remanence within the ore system. Geophysical lineament analyses are used to determine structural controls on mineralization, geophysical filters (e.g., analytic signal amplitude) are used to help define structural extent of the deposit, and basement geochemistry is used to map mineral footprints beneath cover. These techniques identified coincident anomalies at the intersection of north and northwest lineaments. Leapfrog™ interpolations of downhole magnetic susceptibility and Cu, Au, and Fe assay data were used to map the distribution of magnetite, copper, gold, and sulfur in 3D. The analysis revealed that Cu and Au mineralization were coupled with the magnetite net-vein architecture, but that Cu was locally enriched in the east–northeast-trending demagnetized zone. The results from this suite of geophysical, petrophysical, and geochemical techniques were integrated to constrain modeling of the Brumby IOCG. Brumby can be described as a breccia pipe sitting at the intersection of north-striking, east-dipping, and northwest-striking, southeast-dipping structures that plunges moderately to the south–southeast. The breccia pipe was overprinted by a relatively late net-vein magnetite breccia and crosscut by a later, magnetite-destructive, east–northeast-striking fault.
Inversion-based method for estimating total organic carbon and porosity and for diagnosing mineral constituents from multiple well logs in shale-gas formations
Authors: Heidari Zoya , Torres-Verdín Carlos
Published: September 2013

Reliable estimates of petrophysical and compositional properties of organic shale are critical for detecting perforation zones or candidates for hydro-fracturing jobs. Current methods for in situ formation evaluation of organic shale largely rely on qualitative responses and empirical formulas. Even core measurements can be inconsistent and inaccurate when evaluating clay minerals and other grain constituents.

We implement a recently introduced inversion-based method for organic-shale evaluation from conventional well logs. The objective is to estimate total porosity, total organic carbon (TOC), and volumetric/weight concentrations of mineral/fluid constituents. After detecting bed boundaries, the first step of the method is to perform separate inversion of individual well logs to estimate bed physical properties such as density, neutron migration length, electrical conductivity, photoelectric factor (PEF), and thorium, uranium , and potassium volumetric/weight concentrations. Next, a multilayer petrophysical model specific to organic shale is constructed with an initial guess obtained from conventional well-log interpretation or X-ray diffraction data; bed physical properties are calculated with the initial layer-by-layer values. Final estimates of organic shale petrophysical and compositional properties are obtained by progressively minimizing the difference between calculated and measured bed properties. A unique advantage of this method is the correction of shoulder-bed effects on well logs, which are prevalent in shale-gas plays. Another advantage is the explicit calculation of accurate well-log responses for specific petrophysical, mineral, fluid, and kerogen properties based on chemical formulas and volumetric concentrations of minerals/kerogen and fluid constituents.

Examples are described of the successful application of the new organic-shale evaluation method in the Haynesville shale-gas formation. This formation includes complex solid compositions and thin beds where rapid depth variations of mineral/fluid constituents are commonplace. Comparison of estimates for total porosity, total water saturation, and TOC obtained with (a) commercial software for multimineral analysis, (b) our organic-shale evaluation method, and (c) core/X-ray diffraction measurements indicates a significant improvement in estimates of total porosity and water saturation yielded by our interpretation method. The estimated TOC is also in agreement with core laboratory measurements.
Pitfalls in prestack inversion of merged seismic surveys
Authors: Verma Sumit , Del Moro Yoryenys , Marfurt Kurt J.
Published: September 2013

Modern 3D seismic surveys are often of such good quality and 3D interpretation packages so user-friendly that seismic interpretation is no longer exclusively carried out by geophysicists. This ease-of-use has also been extended to more quantitative workflows, such as 3D prestack inversion, putting it in the hands of the “nonexpert” — be it geologist, engineer, or new-hire geophysicist. Indeed, given good quality input seismic data, almost any interpreter who can generate good well ties and define an accurate background model of P-impedance, S-impedance, and density can generate a quality prestack inversion. Two of the authors are new geophysicists who fell into the prestack inversion “pit.” Fortunately, they were able to recognize that something was wrong. We applied prestack inversion to gathers that were carefully reprocessed by a major service company. The problem, however, was not with the processing, but with our lack of understanding of the input legacy data that formed part of a larger “megamerge” survey. Not all of the surveys that were merged had the same offset range. In the migration step, gaps in long offsets of the older surveys were not muted. Migration noise from newer surveys was allowed to fill this space. We share our initial workflow and suspicious results. We also clarify the meaning of “fold” and “offset” for prestack-migrated gathers. In addition to presenting some QC tools useful in analyzing megamerge surveys, we show how, by limiting the offsets used in our prestack inversion, we obtain less aggressive but still useful results.
Seismic and sequence stratigraphic interpretation of the area of influence of the Magdalena submarine fan, offshore northern Colombia
Authors: Cadena Andrea F. , Slatt Roger M.
Published: September 2013

The area of influence of the Magdalena submarine fan, offshore northern Colombia, is a global frontier basin with sparse well control and only publically available 2D seismic from which to conduct exploration surveys. We have conducted a 2D seismic stratigraphic study to advance knowledge of the tectonostratigraphic evolution of this area and, furthermore, optimize exploration concepts to include stratigraphy and sedimentology to enhance such opportunities. Eight third-order seismic sequences from the early Miocene to Holocene comprise the stratigraphic record. Seismic character, thickness, and sedimentary processes vary in each sequence based on the area of deposition. Three geomorphologic areas are subject to deposition: the Tayrona depression, the undeformed central Magdalena fan and deformed wedges on either side of the fan. From oldest to youngest, sequences I to V represent bathyal paleo-environments that were deformed during the late Miocene Andean phase. Deformation of these sequences is thin skinned thrust sheets, where the main basal detachment corresponds to Oligocene shale. This deformation continued until the middle Pliocene, when sequence VI and VII were deposited on the Magdalena Fan mainly as mass transport and channel-levee deposits. Sequence VIII represents the record from early Pleistocene to the present time. From early Pliocene to present, erosion was mainly the product of submarine fan activity and bypass in areas of high slope, whereas for older deposits, erosion was caused by exposure to subaerial conditions. Superimposed on the third-order sequences are fourth-order sequences, which reveal a relative (tectonic-eustatic) sea level increase from Early Miocene to middle Late Miocene (Tortonian) time, followed by a lowstand event that extended until Holocene time. Potential reservoirs embedded within the sequences include sheet sands, channel fills, and levee-overbank. Other components of the petroleum system such as a mature source rock are still under debate.
Seismic sequence stratigraphy and sedimentary evolution of carbonate reservoirs in the Sinian Dengying Formation, Middle Sichuan Basin, Southwest China
Authors: Zhong Guangfa , Li Yalin , Liu Dingjin
Published: September 2013

The Sinian Dengying Formation in the Sichuan Basin, southwest China, mainly consisting of dolomites, is one of the most ancient gas-producing series in the world. During the past half-century, gas exploration in the formation has been largely based on the lithostratigraphic correlation, but a regional correlation scheme of time significance is usually insufficient, resulting in the difficulty of lateral correlation of strata between gas fields. Aiming to overcome the problem, we completed an interpretation of about 2500-km 2D regional seismic lines by using the seismic sequence analysis method. As a result, a sequence stratigraphic framework was successfully constructed, which consists of two sequences and five systems tracts. By integrating analysis of isopatch maps with stratal stacking patterns, we identify three depositional facies belts within the formation, which are a shallow-water platform facies belt in the eastern and southern regions, a relatively deep-water (intraplatform) basin facies belt in the northwestern region, and a northwest-dipping slope facies belt between them. During the development of sequence one in the lower of the Dengying Formation, retrogradation and aggradation dominated in the eastern and southern platform region whereas depositional condensation prevailed in the northwestern basin region. At that time, the depocenter was located on the eastern and southern platform region. However, sequence two in the upper of the Dengying Formation is dominated by the northwest-dipping sigmoid, oblique and shingled prograding packages of the platform-margin slope facies belt, indicating that the depositional center was shifted to the previous basin region in the northwest. As a result, the basin was filled gradually, and the platform-slope-basin topography was finally evolved into a northwest-dipping ramp. Our study suggests that the Late Sinian Sichuan Basin would consist of a series of shallow-water platforms separated by relatively deep-water depressions or (intraplatform) basins, which provides important clues for gas exploration.
Automated spectral recomposition with application in stratigraphic interpretation
Authors: Cai Yihua , Fomel Sergey , Zeng Hongliu
Published: September 2013

Analyzing seismic attributes in the frequency domain is helpful for reservoir characterization. To analyze the reservoir interval of interest in detail, it is important to capture the seismic response at each frequency subset. Spectral recomposition can be used to extract significant components from the seismic spectrum. We propose a separable nonlinear least-squares algorithm for spectral recomposition, which estimates linear and nonlinear parts automatically in separate steps. Our approach is applied to estimate fundamental signal parameters, peak frequencies, and amplitudes, with which the seismic spectrum can be reconstructed. Automated spectral recomposition helps us visualize frequency-dependent geologic features on cross sections and time slices by extracting significant frequency components. Spectral recomposition can also indicate how frequency contents attenuate with time.
Using the image grand tour to visualize fluvial deltaic architectural elements in south Texas, USA
Authors: Wallet Bradley C.
Published: September 2013

Spectral decomposition can produce dozens of attributes for a single data set, far exceeding the ability for direct visualization. Some solutions have been proposed. The state-of-the-art approach is via the use of principal component analysis. However, this approach has significant inherent weaknesses, such as a lack of inclusion of spatial information and a tendency to inflate noise. Previous work has shown the ability of the image grand tour to construct lower-dimensional views of spectral information resulting in multiple images showing distinct architectural components. I propose a novel workflow for constructing color images to display multiple structures simultaneously. These images are constructed in a way that makes them complementary, leading to rich color images that are useful for interpretation. I demonstrate the value of this workflow though application to a land survey over Tertiary channels from south Texas.
Whither seismic stratigraphy?
Authors: Hart Bruce S.
Published: September 2013

Here, I provide an historical summary of seismic stratigraphy and suggest some potential avenues for future collaborative work between sedimentary geologists and geophysicists. Stratigraphic interpretations based on reflection geometry- or shape-based approaches have been used to reconstruct depositional histories and to make qualitative and (sometimes) quantitative predictions of rock physical properties since at least the mid-1970s. This is the seismic stratigraphy that is usually practiced by geology-focused interpreters. First applied to 2D seismic data, interest in seismic stratigraphy was reinvigorated by the development of seismic geomorphology on 3D volumes. This type of reflection geometry/shape-based interpretation strategy is a fairly mature science that includes seismic sequence analysis, seismic facies analysis, reflection character analysis, and seismic geomorphology. Rock property predictions based on seismic stratigraphic interpretations usually are qualitative, and reflection geometries commonly may permit more than one interpretation. Two geophysics-based approaches, practiced for nearly the same length of time as seismic stratigraphy, have yet to gain widespread adoption by geologic interpreters even though they have much potential application. The first is the use of seismic attributes for “feature detection,” i.e., helping interpreters to identify stratigraphic bodies that are not readily detected in conventional amplitude displays. The second involves rock property (lithology, porosity, etc.) predictions from various inversion methods or seismic attribute analyses. Stratigraphers can help quality check the results and learn about relationships between depositional features and lithologic properties of interest. Stratigraphers also can contribute to a better seismic analysis by helping to define the effects of “stratigraphy” (e.g., laminations, porosity, bedding) on rock properties and seismic responses. These and other seismic-related pursuits would benefit from enhanced collaboration between sedimentary geologists and geophysicists.
Nonlinear Dynamic Analysis of a Full-Scale Unreinforced Adobe Model
Authors: Tarque Nicola , Camata Guido , Spacone Enrico , Varum Humberto , Blondet Marcial
Published: September 2013

This paper describes the results of a numerical study of a full-scale adobe building model tested on a shaking table. Material properties of adobe masonry were calibrated to represent the wall in-plane seismic behavior, based on a prior numerical analysis of an adobe wall carried out by the authors. The inelastic part of the constitutive model was represented by a softening curve in tension and by a hardening/softening behavior in compression; thus, the fracture energy is a key issue in the modeling process. A finite element model that relies on a homogenous continuum approach was developed in Abaqus/Explicit software. The damage evolution in the numerical simulation represented fairly well the experimental crack pattern, for in-plane and out-of-plane seismic effects. Overall, the calibrated material properties and the explicit solution scheme proved to be appropriate for simulating the seismic behavior and predicting capacity of unreinforced adobe structures subjected to seismic loading.
The Emilia Earthquake: Seismic Performance of Precast Reinforced Concrete Buildings
Authors: Magliulo Gennaro , Ercolino Marianna , Petrone Crescenzo , Coppola Orsola , Manfredi Gaetano
Published: September 2013

On 20 and 29 May 2012, two earthquakes of MW5.9 and MW5.8 occurred in the Emilia region of northern Italy, one of the most developed industrial centers in the country. A complete photographic report collected in the epicentral zone shows the seismic vulnerability of precast structures, the damage to which is mainly caused by connection systems. Indeed, the main recorded damage is either the loss of support of structural horizontal elements, due to the failure of friction beam-to-column and roof-to-beam connections, or the collapse of the cladding panels, due to the failure of the panel-to-structure connections. The damage can be explained by the intensity of the recorded seismic event and by the exclusion of the epicentral region from the seismic areas recognized by the Italian building code up to 2003. Simple considerations related to the recorded acceleration spectra allow motivating the extensive damage due to the loss of support.
Assessment of Seismic Building Vulnerability from Space
Authors: Geiß Christian , Taubenböck Hannes , Tyagunov Sergey , Tisch Anita , Post Joachim , Lakes Tobia
Published: September 2013

This paper quantitatively evaluates the suitability of multi-sensor remote sensing to assess the seismic vulnerability of buildings for the example city of Padang, Indonesia. Features are derived from remote sensing data to characterize the urban environment and are subsequently combined with in situ observations. Machine learning approaches are deployed in a sequential way to identify meaningful sets of features that are suitable to predict seismic vulnerability levels of buildings. When assessing the vulnerability level according to a scoring method, the overall mean absolute percentage error is 10.6%, if using a supervised support vector regression approach. When predicting EMS-98 classes, the results show an overall accuracy of 65.4% and a kappa statistic of 0.36, if using a naive Bayes learning scheme. This study shows potential for a rapid screening assessment of large areas that should be explored further in the future.
William Dampier’s “Mixt Relation”: Narrative Vs. Natural History in A New Voyage Round the World (1697)
Authors: Thell Anne M.
Published: September 2013

Published in collaboration with the Royal Society of London in 1697, William Dampier’s A New Voyage Round the World was the most popular and influential travel account of the first half of the eighteenth century. Yet despite the astonishing success of New Voyage within commercial, literary, and scientific spheres, Dampier’s style of composition became an easy target for satire. These vituperative and long-lasting critiques emphasized the awkwardness of Dampier’s method, but they also suggest the immense stakes of his project. Probing the limits of representation, Dampier was involved in a much larger process than he realized: he was transforming how knowledge, nature, and experience could and should be related in narrative. In this essay, I study the narrative problems and complexities of New Voyage, and place them in the context of the reforms in travel writing (and, more broadly, in knowledge production) that were occurring in the final decades of the seventeenth century. I view the text as a literary and scientific document that in its narrative fissures illustrates a particular moment in the history of two increasingly incompatible systems of knowing that developed in tandem in the travel genre: the static, ostensibly objective description of nature (what Dampier refers to as “Places”) and the dynamic account of individual experience (what Dampier calls “Actions”).
The Future Is Queer Stuff
Authors: Shahani Nishant
Published: September 2013

In this review, I consider recent works by José Esteban Muñoz (Cruising Utopia), Judith (Jack) Halberstam (The Queer Art of Failure), and Christopher Castiglia and Christopher Reed (If Memory Serves) as investments in the politics of queer futurity. Collectively, I analyze these works as offering both theoretical mobilizations of and departures from traditions of critical utopianism. Analyzed together, they explicitly challenge theories of queer antirelationality and implicitly insist — in the face of queer theory's ostensible death — that the future is, and still must be imagined as, queer stuff. In contrast to the recent insistence on queer antirelationality and anticommunal modes of unbelonging, these books insist on the performative and political dimensions of critical futurity. Furthermore, I show how even as the preoccupation with a certain kind of idealism (what Castiglia and Reed call “ideality politics”) is mapped onto the present and future, the pull toward the past in these texts is equally palpable, as a structure of feeling as well as a critical method, appearing in the form of retrospective returns, activist legacies, spaces of memory, aesthetic blueprints, backward failings and feelings. Despite their distinct theoretical interventions, the mobilizations of critical utopianism and idealism in all three books further the conversations about queer historiography and temporality in dynamic and compelling ways.
Fragile X mental retardation protein regulates trans-synaptic signaling inDrosophila
Authors: Friedman Samuel H. , Dani Neil , Rushton Emma , Broadie Kendal
Published: September 2013

Fragile X syndrome (FXS), the most common inherited determinant of intellectual disability and autism spectrum disorders, is caused by loss of the fragile X mental retardation 1 (FMR1) gene product (FMRP), an mRNA-binding translational repressor. A number of conserved FMRP targets have been identified in the well-characterized Drosophila FXS disease model, but FMRP is highly pleiotropic in function and the full spectrum of FMRP targets has yet to be revealed. In this study, screens for upregulated neural proteins in Drosophila fmr1 (dfmr1) null mutants reveal strong elevation of two synaptic heparan sulfate proteoglycans (HSPGs): GPI-anchored glypican Dally-like protein (Dlp) and transmembrane Syndecan (Sdc). Our recent work has shown that Dlp and Sdc act as co-receptors regulating extracellular ligands upstream of intracellular signal transduction in multiple trans-synaptic pathways that drive synaptogenesis. Consistently, dfmr1 null synapses exhibit altered WNT signaling, with changes in both Wingless (Wg) ligand abundance and downstream Frizzled-2 (Fz2) receptor C-terminal nuclear import. Similarly, a parallel anterograde signaling ligand, Jelly belly (Jeb), and downstream ERK phosphorylation (dpERK) are depressed at dfmr1 null synapses. In contrast, the retrograde BMP ligand Glass bottom boat (Gbb) and downstream signaling via phosphorylation of the transcription factor MAD (pMAD) seem not to be affected. To determine whether HSPG upregulation is causative for synaptogenic defects, HSPGs were genetically reduced to control levels in the dfmr1 null background. HSPG correction restored both (1) Wg and Jeb trans-synaptic signaling, and (2) synaptic architecture and transmission strength back to wild-type levels. Taken together, these data suggest that FMRP negatively regulates HSPG co-receptors controlling trans-synaptic signaling during synaptogenesis, and that loss of this regulation causes synaptic structure and function defects characterizing the FXS disease state.
An insert-based enzymatic cell culture system to rapidly and reversibly induce hypoxia: investigations of hypoxia-induced cell damage, protein expression and phosphorylation in neuronal IMR-32 cells
Authors: Huang Ying , Zitta Karina , Bein Berthold , Steinfath Markus , Albrecht Martin
Published: September 2013

Ischemia-reperfusion injury and tissue hypoxia are of high clinical relevance because they are associated with various pathophysiological conditions such as myocardial infarction and stroke. Nevertheless, the underlying mechanisms causing cell damage are still not fully understood, which is at least partially due to the lack of cell culture systems for the induction of rapid and transient hypoxic conditions. The aim of the study was to establish a model that is suitable for the investigation of cellular and molecular effects associated with transient and long-term hypoxia and to gain insights into hypoxia-mediated mechanisms employing a neuronal culture system. A semipermeable membrane insert system in combination with the hypoxia-inducing enzymes glucose oxidase and catalase was employed to rapidly and reversibly generate hypoxic conditions in the culture medium. Hydrogen peroxide assays, glucose measurements and western blotting were performed to validate the system and to evaluate the effects of the generated hypoxia on neuronal IMR-32 cells. Using the insert-based two-enzyme model, hypoxic conditions were rapidly induced in the culture medium. Glucose concentrations gradually decreased, whereas levels of hydrogen peroxide were not altered. Moreover, a rapid and reversible (on-off) generation of hypoxia could be performed by the addition and subsequent removal of the enzyme-containing inserts. Employing neuronal IMR-32 cells, we showed that 3 hours of hypoxia led to morphological signs of cellular damage and significantly increased levels of lactate dehydrogenase (a biochemical marker of cell damage). Hypoxic conditions also increased the amounts of cellular procaspase-3 and catalase as well as phosphorylation of the pro-survival kinase Akt, but not Erk1/2 or STAT5. In summary, we present a novel framework for investigating hypoxia-mediated mechanisms at the cellular level. We claim that the model, the first of its kind, enables researches to rapidly and reversibly induce hypoxic conditions in vitro without unwanted interference of the hypoxia-inducing agent on the cultured cells. The system could help to further unravel hypoxia-associated mechanisms that are clinically relevant in various tissues and organs.
Chemicals-Inspired Biomaterials: Developing Biomaterials Inspired by Material Science Based on POSS
Authors: Tanaka Kazuo , Chujo Yoshiki
Published: September 2013

The concept of “chemicals-inspired biomaterials” and several examples are demonstrated in this review. The idea and background for the design of chemicals-inspired biomaterials which are constructed based on the chemistry and characteristics in material science are explained. As an example, we show several chemicals-inspired materials utilizing polyhedral oligomeric silsesquioxane (POSS) as a building block to apply the material functions of the POSS chemicals for fabricating a series of biomaterials having superior properties. Initially, the filler effects of POSS are explained. Because of the robust silica cube, POSS derivatives can show significant effect as a filler reinforcing the thermal and mechanical properties of conventional plastics simply by mixing. Based on these results, we designed rigid chelators for the complexation with gadolinium ions as an MRI contrast agent. It is demonstrated that the enhancement of the rigidity is a valid strategy for the improvement of the sensitivity. Next, we assembled the functional molecules into the POSS-core dendrimer. We observed from the dendrimer complexes that photon upconversion can be accomplished via an optical process which should be suppressed in electroluminescence devices. The last topic concerns the selective encapsulation by the POSS-core dendrimer for biomolecules. From the study of POSS-based ionic liquids, it was found that the strength of the hydrogen bonds with the ion pair moiety was significantly increased by tethering to POSS. Based on this enhancement, we accomplished selective encapsulation with the POSS-core dendrimer. The results and the prominent properties of the chemicals-inspired biomaterials are shown in this review.
Asymmetric Aldol Reaction on Water Using an Organocatalyst Tethered on a Thermoresponsive Block Copolymer
Authors: Suzuki Noriyuki , Inoue Takahiro , Asada Takumi , Akebi Ryuji , Kobayashi Go , Rikukawa Masahiro , Masuyama Yoshiro , Ogasawara Masamichi , Takahashi Tamotsu , Thang San H
Published: September 2013

l-Proline moieties, which serve as organocatalysts, were tethered on block copolymers that consisted of thermoresponsive poly(N-isopropylacrylamide) and PEG-grafted polyacrylate blocks. The copolymer dissolved in water at temperatures below the LCST (25 °C), whereas they formed micelles at temperatures above the LCST (50 °C). Aldol reactions between an arylaldehyde and a ketone were conducted in this aqueous solution. The aldol products were obtained in high yield with high diastereo- and enantioselectivity (96% ee). The catalyst solution could be reused up to three times.
Review of postoperative CT and ultrasound for endovascular aneurysm repair using Talent stent graft: Can we simplify the surveillance protocol and reduce the number of CT scans?
Authors: Nyheim Thomas , Staxrud Lars Erik , Rosen L , Slagsvold Carl Erik , Sandbæk Gunnar , Jørgensen Jørgen J
Published: September 2013

Background

Simplifying a postoperative surveillance protocol for endovascular aneurysm repair (EVAR) requires quality control comparing computerized tomography (CT) and ultrasound (US) results of abdominal aortic aneurysm (AAA) diameter measurements and endoleaks.

Purpose

To test if US is comparable to CT, then assess a simplified follow-up with our conventional surveillance to assess patient safety.

Material and Methods

During 2001-2006, data on 56 patients treated with Talent stent graft were prospectively registered. Median follow-up was 41.5 months (range, 2-94 months), with CT, US, and plain film abdomen X-rays (PFA) at 1, 6, and 12 months, then yearly. Bland-Altman plot was used to assess the agreement between CT and US measuring the AAA diameters and mixed model by the time effect to assess the difference in diameter over time. Sensitivity and specificity for detection of endoleaks by US, with CT as ‘gold standard’ were calculated. A simplified surveillance protocol with US/PFA at 6 and 8 weeks, CT/US/PFA at 1 year, and yearly US/PFA thereafter, was evaluated. CT was carried out when poor visibility, endoleak detected, AAA diameter increase (≥5 mm) on US or migration (≥10 mm) on PFA. This regime was compared with our conventional follow-up protocol.

Results

Diameter measurements on US appear comparable to CT with 91% specificity and 85% sensitivity for endoleaks detected by US. Using the simplified surveillance protocol no endoleaks, migrations, or endotension requiring treatment were overlooked. The simplified protocol generated 53 selective CT scans, avoiding approximately 144 CT scans. If further simplified by omitting the 1-year CT scan, one type II endoleak would be missed with a 1-year delay, eliminating a further 45 CT scans.

Conclusion

US appears comparable to CT in the follow-up of Talent stent grafts in our institution. The proposed simplified surveillance protocol seems safe and can lead to a significant reduction in the number of CT scans.
Ultrasound-guided percutaneous laser and ethanol ablation of rabbit VX2 liver tumors
Authors: Zou Xiaojuan , Liu Qing , Zhou Xiaodong , He Guangbin , Yu Ming , Han Zenghui , Meng Xin , Su Haili
Published: September 2013

Background

Only a small percentage of patients with hepatocellular carcinoma (HCC) may benefit out of surgical resection. Thus, lots of these patients are in need of local control, such as percutaneous ethanol injection (PEI), percutaneous laser ablation (PLA), or radiofrequency thermal ablation (RF).

Purpose

To investigate the effects of ultrasound-guided PLA combined with PEI on rabbit VX2 liver tumors, using conventional gray-scale ultrasonography (US), color/power Doppler (CD/PD)US, contrast-enhanced (CE) US, and histologic examination.

Material and Methods

VX2 tumors were implanted in the livers of 80 rabbits. Fourteen days after implantation, animals were randomly separated into four groups of 20 rabbits. Treatment of the four groups was with: (i) PLA; (ii) PEI; (iii) combined therapy of PLA immediately followed by PEI; and (iv) combined therapy of PEI immediately followed by PLA. Conventional gray-scale US, CD US, PD US, and CE US were performed before and after ablation. The effects on ablated areas were assessed by histologic examination.

Results

Conventional gray-scale US showed a clear boundary around the ablated area in groups 1, 3, and 4. An isoechoic treated region with an irregular boundary was seen in group 2. On CE US, coagulated areas demonstrated a perfusion defect. Both conventional gray-scale US and CE US showed that the ablated volume in group 4 was larger than that in groups 1, 2, and 3. CD US and PD US demonstrated residual tumor in the periphery of ablated areas in groups 1 and 2, but not in groups 3 and 4. CE US demonstrated no residual tumor in group 4, unlike in groups 1, 2, and 3. Examination of treated tumors demonstrated necrosis in the ablated zones and increasing surrounding fibrous bands in the four treatment groups. Residual viable tissue in group 4 was less than that in groups 1, 2, and 3.

Conclusion

Combined therapy of PEI immediately followed by PLA can coagulate significantly larger volumes of tumor and reduce residual tumor.
Interventional embolization of giant thoracic tumors before surgical resection
Authors: Liu Feng-Yong , Wang Mao-Qiang , Fan Qing-Sheng , Duan Feng , Wang Zhi-Jun , Song Peng
Published: September 2013

Background

Preoperative embolization of tumors is a well-established procedure that has been successfully applied in various clinical situations. Preoperative embolization can reduce the vascularity of tumors resulting in a clearer operative field, less difficult dissection, decreased blood loss, and, in some cases, a decrease in tumor size. However, few studies have been conducted regarding the preoperative embolization of giant thoracic tumors.

Purpose

To examine the effectiveness and safety of interventional embolization of giant thoracic tumors before surgical resection.

Material and Methods

A total of 14 consecutive patients with giant thoracic tumors received angiography and the feeding arteries of the tumors were embolized using polyvinyl alcohol (PVA) particles and gelatin sponges 1 day before surgical resection. The patient records were retrospectively reviewed and data regarding diagnoses, embolization, and surgical resection were recorded.

Results

Angiography revealed the feeding arteries of the tumors to be characterized by multiple branches and thickened vessel trunks with abnormal distal branches superimposed of the tumor shadow. Embolization was successfully without complications in all patients, and all feeding vessels of each tumor were occluded. Embolization reduced the severity of bleeding during surgery and decreased the difficulty of resection of the tumor. No intraoperative or postoperative complications occurred.

Conclusion

Interventional embolization is a safe and efficient method to facilitate the surgical resection of giant thoracic tumors.
Research Note—Partial Least Squares and Models with Formatively Specified Endogenous Constructs: A Cautionary Note
Authors: Aguirre-Urreta Miguel I. , Marakas George M.
Published: September 2013

Information systems researchers have recently begun to propose models that include formatively specified constructs, and largely rely on partial least squares (PLS) to estimate the parameters of interest in those models. In this research, we focus on those cases where the formatively specified constructs are endogenous to other constructs in the research model in addition to their own manifest indicators, which are quite common in published research in the discipline, and analyze whether PLS is a valid statistical technique for estimating those models. Although there is evidence that covariance-based approaches can accurately estimate them, this is the first research that examines whether PLS can indeed do so. Through a theoretical analysis based on the inner workings of the PLS algorithm, which is later validated and extended through a series of Monte Carlo simulations, we conclude that is not the case. Specifically, estimates obtained from PLS are capturing something other than the relationship of interest when the formatively specified constructs are endogenous to others in the model. We show how our results apply more generally to a class of models, and discuss implications for future research practice.
Research Note—A Dynamic View of the Impact of Network Structure on Technology Adoption: The Case of OSS Development
Authors: Peng Gang , Dey Debabrata
Published: September 2013

We examine how network centrality and closure, two key aspects of network structure, affect technology adoption. In doing so, we consider the content of potential information flows within the network and argue that the impact of network structure on technology adoption can be better understood by separately examining its impact from two groups of alters—current and potential adopters. We contend that increased network centrality and closure among current adopters contribute positively to adoption, whereas the same among potential adopters has exactly the opposite impact. Accordingly, we propose a dynamic view where the fraction of current adopters in the network positively moderates the impact of network centrality and closure. We empirically test the theory by analyzing the adoption of software version control technology by open source software projects. Our results strongly support the theory.
Profit-Increasing Consumer Exit
Authors: Pazgal Amit , Soberman David , Thomadsen Raphael
Published: September 2013

This paper examines the phenomenon of profit-increasing consumer exit and the related phenomenon of profit-decreasing consumer entry. We demonstrate that firms can be better off in shrinking markets and worse off in growing markets, even in the absence of competitive entry or exit. Specifically, firms may benefit if a segment of consumers who are relatively indifferent about consuming any product in the category leave the market. Profits can increase for all firms even if the exiting consumers have strong preferences for only one of the products in the market. In shrinking markets, it is reasonable to assume that the people who are likely to exit the market first are people who are “least committed” to the category. In particular, people who are the least satisfied with the existing offers are the most likely to change their behavior by finding an alternative or adopting a new technology. Similarly, in growing markets, consumers who enter the market late are generally the least committed to the category. Such exiting can relax the competitive pressure between firms and lead to increased profitability. Our findings provide an explanation for profit growth that has been observed in product industries exhibiting slow and predictable declines over time, including vacuum tubes, cigarettes, and soft drinks.
Wedded Bliss or Tainted Love? Stock Market Reactions to the Introduction of Cobranded Products
Authors: Cao Zixia , Sorescu Alina
Published: September 2013

We examine whether cobranding—the practice of using two established brand names on the same product—increases the market value of parent firms. Using data from the consumer packaged goods industry, we document that the average stock market reaction to the announcement of cobranded new products is approximately +1.0%. We hypothesize that this reaction is significantly higher than it would have been if these same products were single branded, and we find evidence consistent with this hypothesis. We also examine the determinants of this stock market reaction. We find that the consistency between the two brand images, the innovativeness of the product, and the exclusivity of the cobranding relationship significantly increase the market reaction to cobranding announcements. Our findings provide important managerial guidelines for enhancing firm value through cobranding partnerships.
Comparative Law in the House of Lords and Supreme Court
Authors: Stanton Keith
Published: September 2013

This paper surveys the use made of comparative law by the House of Lords and Supreme Court in tort cases decided in the period 1990–2013. Consideration is given to the use of materials from both common law and civil law jurisdictions. The research finds that these courts make a great deal of use of comparative common law (albeit from a limited number of jurisdictions) and that these materials have played a part in a variety of ways in developing the law. In contrast, use of materials from civil law jurisdictions has been at a much lower level and appears to have declined in recent years. The enthusiasm for using civil law sources that certain judges showed in the past has not been continued in more recent years.
The Problem of Regulation in EU Fisheries
Authors: Wakefield Jill
Published: September 2013

The European Union's common fisheries policy is undergoing reform but the essential problem, in that those exploiting the resource bear no responsibility for its sustainable maintenance, is not addressed. The proposals devised by the Commission for reform are expressly predicated on the tragedy of the commons. The Commission subscribes to the concept of property as regulation and proposes to address the problems of overfishing and overcapacity through an ecosystem-based approach with a ban on discards, the adoption of multiannual plans and the introduction of a target to restore stocks, together with a system of transferable fishing concessions for appropriators to engender a greater sense of responsibility. However, the inability of complex fisheries regulation to redress degradation suggests its utility may be coming to an end and that the Commission should look to market-based solutions and impose the cost of marine fisheries depletion on those permitted to extract from the resource.
Water Rights and Environmental Damage: An Enquiry into Stewardship in the Context of Abstraction Licensing Reform in England and Wales
Authors: McGillivray Donald
Published: September 2013

The intersection of private rights and public responsibilities lies at the heart of both environmental and property law. This article considers this intersection in the context of debates about property ownership and notions of environmental stewardship. These form the background to considering shifts in water rights law in England and Wales and the extent to which they can be said to exhibit or exemplify a shift towards stewardship. Section 27 of the Water Act 2003 is analysed as this authorises revocation or variation of an abstraction licence without compensation in order to protect waters or aquatic flora and fauna from ‘serious damage’. Because regulatory abstraction licensing is a modern overlay on the common law, but one which has protected many existing abstractors from restrictions on their rights, section 27 might be regarded as strongly indicative of a stewardship shift in water rights. However, I argue that greater attention needs to be paid to the wider context within which this provision operates before it can be deployed as an unambiguous pro-stewardship example. I suggest that a range of related regulatory, economic and interpretive factors are likely to lead, in practice, to limited direct legal intrusion on private water rights. The case of section 27 serves as a ‘bottom up’ example of a need for circumspection about whether any specific formal, doctrinal reform is likely to exemplify, or support, a shift towards stewardship in water or property law, and draws out some of the complex relations between public and private interests that characterise stewardship.
Visualization and simulation of the human heart based on ECG
Authors: Sochocka Anna , Kawa Tomasz , Płaneta Roman
Published: September 2013

The aim of this study was to develop a three-dimensional (3D) animation of the heart that can show its components and function using electrocardiography. Another aim of the study was to increase knowledge on computer graphics and animation as well as to create a useful educational tool that, through play, will also teach. Because the heart is one of the most important organs and a very complex one, the authors decided to create a 3D model. This article presents the current state of knowledge in the use of computer-generated models of the human heart as a learning aid and for creating simulation. The authors describe the tools used to implement the program and sources that were used for modeling the heart. The result is presented in the form of descriptions and screenshots on how to use the program. At the end of the article, a description is placed of further developments that will be applied to the program.
A serious game – a new training addressing particularly prospective memory in the elderly
Authors: Laskowska Ilona , Zając-Lamparska Ludmiła , Wiłkość Monika , Malicki Michał , Szałkowska Agnieszka , Jurgielewicz Anna , Lewandowski Paweł , Węgrzyn Paweł , Roterman-Konieczna Irena , Izdebski Paweł
Published: September 2013

A training in the form of a computer game that aims at improving five cognitive functions in the elderly has been developed: visuospatial memory, attention, memory for prose, working memory and prospective memory. It was devised as a collaboration among the Department of Cognitive Psychology in Warsaw, Department of Individual Differences Psychology in Bydgoszcz, Faculty of Physics, Astronomy and Applied Computer Science – Game Academy in Cracow, and Department of Human Psychology and Department of Psychiatry of Ludwik Rydygier Collegium Medicum in Bydgoszcz. This software is an example of the so-called serious games. To the best of our knowledge it is the first one to focus particularly on prospective memory. This is the first report concerning the present training, which is currently being elaborated. The next step in its development will be testing its validity.