bluuebunny/crossref_metadata_2025 huggingface dataset:
A domain decomposition method for a two‐phase transport model of polymer electrolyte fuel cell containing micro‐porous layer
Authors: Sun Pengtao
Published: May 2012

In this paper, a nonlinear Dirichlet–Robin iteration‐by‐subdomain domain decomposition method is studied for a multidimensional, multiphysics, and multiphase model of polymer electrolyte fuel cell (PEFC) containing micro‐porous layer (MPL). Across the interface of gas diffusion layer and MPL in PEFC, it is well known that the capillary pressure is continuous, whereas liquid saturation is discontinuous, by which the liquid‐water removal in the porous electrodes can be significantly enhanced. We design a type of non‐overlapping domain decomposition method to deal with water transport in such multi‐layer diffusion media, where Kirchhoff transformation and its inverse techniques are employed to conquer the discontinuous and degenerate water diffusivity in the coexisting single‐phase and two‐phase regions. In addition, the conservation equations of mass, momentum, charge, and hydrogen and oxygen transport are also solved by the combined finite element–upwind finite volume method (FEM/FVM) to overcome the dominated convection effect in gas channels. Numerical simulations demonstrate that the presented techniques are effective in obtaining a fast and convergent nonlinear iteration for such a 3D PEFC model within around 50 steps, in contrast with the oscillatory and nonconvergent iteration conducted by standard FEM/FVM. A series of numerical convergence tests are also carried out to verify the efficiency and accuracy of the present numerical techniques. Copyright © 2012 John Wiley & Sons, Ltd.
Enriched space–time finite element method: a new paradigm for multiscaling from elastodynamics to molecular dynamics
Authors: Yang Ye , Chirputkar Shardool , Alpert David N. , Eason Thomas , Spottswood Stephen , Qian Dong
Published: May 2012

The main objective of this paper is to present an enriched version of the space–time FEM method to incorporate multiple temporal scale features with a focus on dynamics problems. The method is established by integrating the basic framework of the space–time discontinuous Galerkin method with the extended finite element method. Two versions of the method have been developed: one at the continuum scale (elastodynamics) and the other focuses on the dynamics at the molecular level. After an initial outline of the formulation, we explore the incorporation of different types of enrichments based on the length scale of interest. The effects of both continuous and discontinuous enrichments are demonstrated through numerical examples involving wave propagations and dynamic fracture in harmonic lattice. The robustness of the method is evaluated in terms of convergence and the ability to capture the fine scale features. It is shown that the enriched space–time FEM leads to an improvement in the convergence properties over the traditional space–time FEM for problems with multiple temporal features. It is also highly effective in integrating atomistic with continuum representations with a coupled framework. Copyright © 2012 John Wiley & Sons, Ltd.
A fast method for solving microstructural problems defined by digital images: a space Lippmann–Schwinger scheme
Authors: Yvonnet Julien
Published: May 2012

A fast numerical method is proposed to solve thermomechanical problems over periodic microstructures whose geometries are provided by experimental techniques, such as X‐ray microtomography images. In such configuration, the phase properties are defined over regular grids of voxels. To overcome the limitations of calculations on such fine models, an iterative scheme is proposed, avoiding the construction and storage of finite element matrices. Equilibrium equations are written in the form of a Lippmann–Schwinger integral equation, which can be solved iteratively. Unlike previous algorithms based on the Fourier transform, the present scheme strictly operates in the real‐space domain and removes the numerical Fourier and inverse Fourier transforms at each iteration. For this purpose, the linear operator related to the Lippmann–Schwinger equation is constructed numerically by means of transformation tensors in the real‐space domain. The convergence and accuracy of the method are evaluated through examples in both steady‐state thermics and linear elasticity problems. Computational times are found to scale linearly with the number of degrees of freedom, and parallel computations can be carried out straightforwardly. The method is also illustrated on many examples involving complex microstructures, including a problem defined by a microtomography image. Copyright © 2012 John Wiley & Sons, Ltd.
Toll‐like receptor‐4 agonist inhibits motility and invasion of hepatoblastoma HepG2 cells in vitro
Authors: Hsiao Chih‐Cheng , Kao Ying‐Hsien , Huang Shun‐Chen , Chuang Jiin‐Haur
Published: May 2012

Background

Expression of toll‐like receptor‐4 (TLR4) on tumor cells is known to mediate innate immune responses that influence tumor cell growth and migration. This study aimed to characterize TLR4 expression and elucidate its functional significance in human hepatoblastoma (HB) cells.

Procedure

Immunohistochemistry (IHC) was used to determine TLR4 expression level and its distribution pattern in HB liver tissues. Transcripts of tumor necrosis factor (TNF)‐α, interleukin (IL)‐8, matrix metalloproteinase (MMP)‐2, MMP‐13, tissue inhibitor of metalloproteinases (TIMP)‐1, and TIMP‐2 in HB HepG2 cells with lipopolysacharide (LPS) treatment were measured by quantitative PCR. Soluble cytokines and peptides in conditioned media were measured by ELISA. MMP‐2 activity was determined by using gelatin zymography. Cell motility and invasiveness was determined using wound healing migration and Matrigel invasion assays, respectively.

Results

TLR4 IHC staining demonstrated that TLR4 overexpression in HB liver tissues dramatically vanished after chemotherapy. In vitro study using an HB cell line, HepG2, showed that TLR4 agonist, LPS, significantly decreased transcripts of IL‐8 and TNF‐α, but did not affect MMP‐13 mRNA level. By contrast, LPS only down‐regulated IL‐8 production and MMP‐2 gelatinolytic activity. The latter might be in part due to the increased levels of MMP‐2/TIMP‐2 complex in conditioned media, thus leading to the decreased motility and invasiveness of HepG2 cells.

Conclusions

HB cells overexpress TLR4, whereas TLR4 agonistic treatment inhibits migration and invasion of HB HepG2 cells. These findings suggest that TLR4 signaling pathway is a potential therapeutic target for control of HB tumor progression. Pediatr Blood Cancer 2013;60:248–253. © 2012 Wiley Periodicals, Inc.
Current issues and controversies in the classification of pediatric hepatocellular tumors
Authors: López‐Terrada Dolores , Zimmermann Arthur
Published: May 2012

Systematic histopathologic examination of hepatoblastoma specimens from patients enrolled in therapeutic protocols has allowed the identification of clinically relevant histologic subtypes that are being incorporated into risk stratification systems. Genetic and molecular studies have documented recurrent chromosomal abnormalities and aberrant activation of developmental, and oncogenic signaling pathways in hepatoblastoma. Molecular profiling has also identified molecular subclasses and gene signatures that could be used to stratify hepatoblastoma patients. Future international collaboration is needed to develop consensus pathology classifications, and to progressively incorporate genetic and molecular biomarkers into therapeutic pediatric liver tumors protocols. Pediatr Blood Cancer 2012; 59: 780–784. © 2012 Wiley Periodicals, Inc.
Socioeconomic disparities in the quality of life in children with cancer or brain tumors: the mediating role of family factors
Authors: Litzelman Kristin , Barker Emily , Catrine Kristine , Puccetti Diane , Possin Peggy , Witt Whitney P.
Published: May 2012

Objective

This study aimed to determine if and to what extent (i) socioeconomic disparities exist in the health‐related quality of life (QOL) of children with cancer or brain tumors and healthy children; and (ii) family functioning and burden mediate the relationship between socioeconomic status and children's QOL.

Methods

In this cross‐sectional study, parents of children ages 2–18 with (n = 71) and without (n = 135) cancer or brain tumors completed in‐person interviewer‐assisted surveys assessing sociodemographics (including income and parental education), child QOL (measure: PedsQL), family functioning (measure: Family Adaptability and Cohesion Evaluation Scale IV) and burden (measure: Impact on the Family Scale). For children with cancer, clinical characteristics were captured through medical record abstraction. Multiple linear regression was used to determine the relationship between income and child QOL; the interaction between group status and income was assessed. Staged multivariate regression models were used to assess the role of family factors in this relationship among children with cancer.

Results

In multivariate analyses, the effect of income differed by cancer status; lower income was associated with worse QOL in children with cancer but not among healthy children. Among children with cancer, this relationship was significantly attenuated by family burden.

Conclusions

Significant socioeconomic disparities exist in the QOL of children with cancer. Family factors partially explain the relationship between low income and poor QOL outcomes among these children. Lower‐income families may have fewer resources to cope with their child's cancer. Increased support, monitoring, and referrals to reduce burden for these families may lead to improved QOL in children with cancer. Copyright © 2012 John Wiley & Sons, Ltd.
Deposition and Characterisation of Plasma Polymerised Allyl Methacrylate Based Coatings
Authors: Kakaroglou Alexandros , Scheltjens Gill , Nisol Bernard , De Graeve Iris , Van Assche Guy , Van Mele Bruno , Willem Rudolph , Biesemans Monique , Reniers François , Terryn Herman
Published: May 2012

Allyl methacrylate (AMA) was deposited on aluminium using atmospheric dielectric barrier discharge plasma. AMA posseses two CC bonds which have very different reactivities and the efficiency of the plasma on polymerising the two different kinds of double bonds was evaluated. The Fourier transform infrared spectra and the nuclear magnetic resonance spectra of the plasma coatings were compared with those of conventionally synthesised poly(AMA). The influence of the monomer feed on the ester, the vinyl and the allyl functionalities of the coatings were investigated. Plasma coatings showed lower concentration of non‐reacted allyl groups than conventional poly(AMA) suggesting a more cross‐linked network. Pull‐off adhesion tests were performed after the deposition of the a topcoat to evaluate the potential use of the AMA based coatings as adhesion promoter.

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Practical Amine Functionalization of Multi‐Walled Carbon Nanotubes for Effective Interfacial Bonding
Authors: Chen Zhiqiang , Dai Xiujuan J. , Lamb Peter R. , de Celis Leal David R. , Fox Bronwyn L. , Chen Ying , du Plessis Johan , Field Matthew , Wang Xungai
Published: May 2012

Improved methods of functionalizing the surfaces of multi‐walled carbon nanotubes (MWCNTs) have been investigated. It is shown that a level of primary amines of 2.3%, higher than previously reported for any nitrogen‐containing gas plasma treatment, can be achieved using a mixture of N2 and H2, which is preferable to using NH3. Even higher levels (3.5%) of primary amines can be achieved by coating the MWCNTs with a thin layer of plasma polymerized heptylamine. In both cases, the highest levels were achieved using a combined continuous plus pulsed plasma mode which was superior to either continuous wave or pulsed wave alone. The integrity of the MWCNT structure is maintained by the plasma treatments, and the functionalized surface improves the dispersion of the MWCNTs and their interfacial bonding with epoxy, giving superior nanoindentation performance of the composites.

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Grain and grain boundary effects in Ca2+ doped BiFeO3 multiferroic ceramics
Authors: Tirupathi Patri , Chandra Amreesh
Published: May 2012

The present work reports the analysis of temperature‐dependent electrical and conductivity studies on Ca2+ doped BiFeO3 multiferroic ceramics in the temperature range of 300–600 K. The effect of Ca2+ doping on the impedance and modulus behavior of BiFeO3 lattice is discussed. The observed changes as a function of increasing Ca2+ concentration have been explained using the change in crystal unit cell. It is also shown that the microstructure changes significantly as a function of Ca2+ concentration. The grain and grain boundary effects in determining the impedance behavior is also reported in the paper.
Spatial coherence of a polariton condensate in 1D acoustic lattice
Authors: Tsyplyatyev O. , Whittaker D. M.
Published: May 2012

Several mechanisms are discussed which could determine the spatial coherence of a polariton condensate confined to a one dimensional wire. The mechanisms considered are polariton–polariton interactions, disorder scattering and non‐equilibrium occupation of finite momentum modes. For each case, the shape of the resulting spatial coherence function g(1)(x) is analysed. The results are compared with the experimental data on a polariton condensate in an acoustic lattice from E. A. Cerda‐Mendez et al. [Phys. Rev. Lett. 105, 116402 (2010)]. It is concluded that the shape of g(1)(x) can only be explained by non‐equilibrium effects, and that ∼10 modes are occupied in the experimental system.
Hepatitis E virus: neutralizing sites, diagnosis, and protective immunity
Authors: Zhang Jun , Li Shao‐Wei , Wu Ting , Zhao Qinjian , Ng Mun‐Hon , Xia Ning‐Shao
Published: May 2012

There have been increased attentions on HEV and its associated diseases in recent years as a result of an increased number of reports on autochthonous patients from many developed countries. Vaccine development and better disease management are expected from protective immunity with increased knowledge on the pathogenesis and virology of HEV. This review summarizes the current understanding of the HEV virology, the key neutralization sites (epitopes) on the surface of the viral capsid, the host humoral immune responses for HEV infection, and the protective immunity conferred by natural infection and vaccination. Recombinant VLPs were prepared to mimic the protective and neutralizing epitopes on the virion surface, thus being capable of eliciting protective immunity when injected to nonhuman primates or human volunteers during preclinical tests and clinical trials. Four markers—viral RNA, anti‐HEV IgM, anti‐HEV IgG, and low avidity of anti‐HEV IgG—are important in the diagnosis of HEV infection, particularly for patients presenting with acute hepatitis symptoms. This toolbox of genomic and immunological assays is valuable in furthering our understanding of the time course of HEV infection and the subsequent hepatitis during preclinical and clinical development of an efficacious vaccine. Two vaccine candidates had shown good tolerability, high immunogenicity, and high efficacy against symptomatic and/or asymptomatic HEV infection. One of them has been licensed in China recently. However, many issues need to be resolved before new technological progresses can benefit the people who need them most. Copyright © 2012 John Wiley & Sons, Ltd.
A theory of spatial system archetypes
Authors: BenDor Todd K. , Kaza Nikhil
Published: May 2012

Historic reference behavior and archetypes of system structure are key tools for creating rigorous system dynamics (SD) models. Modelers often delineate causal relationships by employing common archetypes of dynamic system structure, which produce behaviors such as growth and decline, oscillation, and complex combinations thereof. We extend archetypes to spatial‐dynamic models, focusing on structural archetypes that exhibit changing spatial patterns in two‐dimensional landscapes. Although many fields employ spatial modeling techniques, analogy‐based, causally focused system archetypes remain confined to non‐spatial SD models. We draw on spatial analysis literature to explore the influence of space on dynamic relationships and archetypes, including methods for articulating “space” and expressing feedback. We offer simple examples of spatial system archetypes and explore network structures for spatially extending SD models. By doing this, we argue for spatial modeling techniques that parallel the learn‐by‐analogy environment that archetypes have promoted in aspatial SD research. Copyright © 2012 System Dynamics Society.
SDRP: a secure distributed revocation protocol for vehicular environments
Authors: Chaib Noureddine , Lagraa Nasreddine , Yagoubi Mohamed Bachir , Lakas Abderrahmane
Published: May 2012

Secure routing protocols that are based only on cryptographic techniques cannot guarantee security against all attacks. Among solutions that have been proposed to enhance the security in vehicular networks are the distributed revocation protocols, which provide vehicles with the ability to quickly detect and avoid malicious attacks. However, most of the proposed revocation protocols are vulnerable to colluding attacks conducted by malicious nodes, a situation which results in denial of service. In this work, we propose a new and robust distributed revocation protocol for vehicular ad hoc networks, called Secure Distributed Revocation Protocol (SDRP), with the main objective to exclude misbehaving nodes conducting or not a colluding attack from the routing operation in VANET. We present an evaluation analysis of SDRP on the basis of the simulation results and show that our scheme provides a high detection rate of misbehaving nodes with a low rate of false positives even in the presence of a large number of attackers. Copyright © 2012 John Wiley & Sons, Ltd.
Mapping out the integration of the components of pedagogical content knowledge (PCK): Examples from high school biology classrooms
Authors: Park Soonhye , Chen Ying‐Chih
Published: May 2012

This study explored the nature of the integration of the five components of pedagogical content knowledge (PCK): (a) Orientations toward Teaching Science, (b) Knowledge of Student Understanding, (c) Knowledge of Instructional Strategies and Representations, (d) Knowledge of Science Curriculum, and (e) Knowledge of Assessment of Science Learning. Given the topic and context specificity of PCK, this investigation was conducted in the context of the photosynthesis and heredity instruction of four teachers who were working at the same high school with the same curricular materials. Data sources included classroom observations, semi‐structured interviews, lesson plans, instructional materials, and students' work samples. Data were analyzed through three different approaches: (a) in‐depth analysis of explicit PCK, (b) enumerative approach, and (c) the constant comparative method. Data analysis indicated five salient features of the integration of the PCK components: (a) the integration of the components was idiosyncratic and topic‐specific; (b) Knowledge of Student Understanding and Knowledge of Instructional Strategies and Representations were central in the integration; (c) Knowledge of Science Curriculum and Knowledge of Assessment of Science Learning had most limited connection with other components; (d) Knowledge of Assessment of Science Learning was more often connected with Knowledge of Student Understanding and Knowledge of Instructional Strategies and Representations than with the other components; and (e) Didactic Orientations toward Teaching Science directed Knowledge of Instructional Strategies and Representations inhibiting its connection with other components. This study highlights that the quality of PCK depends on the coherence among the components as well as the strength of individual components. From a methodological perspective, this study demonstrates the possibility to make PCK more visible and accessible by using a PCK Map, a pictorial representation of the interactions of the PCK components. © 2012 Wiley Periodicals, Inc. J Res Sci Teach 49: 922–941, 2012
Polycystic ovaries at ultrasound: normal variant or silent polycystic ovary syndrome?
Authors: Catteau‐Jonard S. , Bancquart J. , Poncelet E. , Lefebvre‐Maunoury C. , Robin G. , Dewailly D.
Published: May 2012

Objective

It is not known whether polycystic ovaries (PCO) are an ovarian appearance without pathological meaning or whether they share with polycystic ovary syndrome (PCOS) the same ovarian follicle abnormality. There are few studies including strictly selected women with PCO but without other criteria of PCOS. In order to address these issues, we compared hormonal, metabolic and ultrasound parameters obtained from patients with PCO only, patients with PCOS and controls.

Methods

This was a comparative analysis including three age‐matched groups of 95 patients, who were included consecutively in a database: controls, patients with sonographic PCO but no symptoms (PCO group) and patients with PCOS. A clinical examination, fasting serum sampling and pelvic ultrasound examination were performed between cycle days 2 and 5 and results were compared between groups.

Results

The median serum anti‐Mullerian hormone (AMH) level in the PCO group was intermediate between that in controls and that in the PCOS group (33.6 pmol/L, 19.8 pmol/L and 63.3 pmol/L, respectively), the differences being significant after adjustment for follicle number (P < 0.05), while the mean androgen serum level in the PCO group was similar to that in the control group and significantly lower than that in the PCOS group (P < 0.05) (median serum testosterone levels: 0.90 nmol/L, 0.79 nmol/L and 1.39 nmol/L; median androstenedione levels: 5.25 nmol/L, 4.37 nmol/L and 6.09 nmol/L, respectively). Body mass index, waist circumference and insulin levels had no effect on these differences.

Conclusion

PCO is an abnormal condition, affected women showing no evidence of hyperandrogenism but having higher AMH serum levels compared with controls, suggesting a granulosa cell abnormality in PCO similar to that observed in PCOS. The absence of hyperandrogenism in PCO does not seem linked to the metabolic status. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
Does levator trauma ‘heal’?
Authors: Shek K. L. , Chantarasorn V. , Langer S. , Dietz H. P.
Published: May 2012

Objective

To evaluate if pregnancy‐ and delivery‐related changes to levator morphology and distensibility regress with time.

Methods

488 nulliparous pregnant women, recruited between 36 and 38 weeks' gestation, were invited for assessment at 3–6 months and again at 2–3 years postpartum. All underwent an interview and four‐dimensional translabial ultrasound examination. Hiatal morphometry and bladder neck descent (BND) were determined and compared between the two postpartum visits.

Results

367 participants returned for assessment at 4.1 (interquartile range (IQR), 3.7–5.0) months and 161 returned at 2.6 (IQR, 2.0–3.1) years, allowing a groupwise comparison. There was no significant difference in hiatal area (22 vs 22 cm2, P = 0.95) or BND on Valsalva maneuver (26.3 vs 25.5 mm, P = 0.49). Pairwise comparison in women who had attended both postpartum appointments without second births (n = 77), separately for those who had a Cesarean section (n = 24) and those who had a vaginal delivery (n = 53) originally, showed no significant changes, except a reduction in BND (31.2 vs 28.3 mm, P = 0.025) in those who had delivered vaginally. Two women out of 12 diagnosed with a levator avulsion at 3–6 months showed obvious anatomical improvement on translabial ultrasound at 2–3 years.

Conclusions

We found no evidence of regression or healing of pregnancy‐ and delivery‐related changes to levator distensibility on comparing imaging data obtained at 3–6 months and 2–3 years postpartum. However, we documented anatomical improvement on translabial ultrasound at the second postpartum visit in two women diagnosed with levator avulsion at 3–6 months postpartum.
Fetal growth: a review of terms, concepts and issues relevant to obstetrics
Authors: Mayer C. , Joseph K. S.
Published: May 2012

The perinatal literature includes several potentially confusing and controversial terms and concepts related to fetal size and growth. This article discusses fetal growth from an obstetric perspective and addresses various issues including the physiologic mechanisms that determine fetal growth trajectories, known risk factors for abnormal fetal growth, diagnostic and prognostic issues related to restricted and excessive growth and temporal trends in fetal growth. Also addressed are distinctions between fetal growth ‘standards’ and fetal growth ‘references’, and between fetal growth charts based on estimated fetal weightvsthose based on birth weight. Other concepts discussed include the incidence of fetal growth restriction in pregnancy (does the frequency of fetal growth restriction increase or decrease with increasing gestation?), the obstetric implications of studies showing associations between fetal growth and adult chronic illnesses (such as coronary heart disease) and the need for customizing fetal growth standards.
Chapter 2: Medical Tests Guidance (2) Developing the Topic and Structuring Systematic Reviews of Medical Tests: Utility of PICOTS, Analytic Frameworks, Decision Trees, and Other Frameworks
Authors: Samson David , Schoelles Karen M.
Published: May 2012

Topic development and structuring a systematic review of diagnostic tests are complementary processes. The goals of a medical test review are to identify and synthesize evidence to evaluate the impacts alternative testing strategies on health outcomes and to promote informed decisionmaking. A common challenge is that the request for a review may state the claim for the test ambiguously. Due to the indirect impact of medical tests on clinical outcomes, reviewers need to identify which intermediate outcomes link a medical test to improved clinical outcomes. In this paper, we propose the use of five principles to deal with challenges: the PICOTS typology (patient population, intervention, comparator, outcomes, timing, setting), analytic frameworks, simple decision trees, other organizing frameworks and rules for when diagnostic accuracy is sufficient.
Chapter 10: Deciding Whether to Complement a Systematic Review of Medical Tests with Decision Modeling
Authors: Trikalinos Thomas A. , Kulasingam Shalini , Lawrence William F.
Published: May 2012

Limited by what is reported in the literature, most systematic reviews of medical tests focus on “test accuracy” (or better, test performance), rather than on the impact of testing on patient outcomes. The link between testing, test results and patient outcomes is typically complex: even when testing has high accuracy, there is no guarantee that physicians will act according to test results, that patients will follow their orders, or that the intervention will yield a beneficial endpoint. Therefore, test performance is typically not sufficient for assessing the usefulness of medical tests. Modeling (in the form of decision or economic analysis) is a natural framework for linking test performance data to clinical outcomes. We propose that (some) modeling should be considered to facilitate the interpretation of summary test performance measures by connecting testing and patient outcomes. We discuss a simple algorithm for helping systematic reviewers think through this possibility, and illustrate it by means of an example.
Chapter 5: Assessing Risk of Bias as a Domain of Quality in Medical Test Studies
Authors: Santaguida P. Lina , Riley Crystal M. , Matchar David B.
Published: May 2012

Assessing methodological quality is a necessary activity for any systematic review, including those evaluating the evidence for studies of medical test performance. Judging the overall quality of an individual study involves examining the size of the study, the direction and degree of findings, the relevance of the study, and the risk of bias in the form of systematic error, internal validity, and other study limitations. In this chapter of the Methods Guide for Medical Test Reviews, we focus on the evaluation of risk of bias in the form of systematic error in an individual study as a distinctly important component of quality in studies of medical test performance, specifically in the context of estimating test performance (sensitivity and specificity). We make the following recommendations to systematic reviewers: 1) When assessing study limitations that are relevant to the test under evaluation, reviewers should select validated criteria that examine the risk of systematic error, 2) categorizing the risk of bias for individual studies as “low,” “medium,” or “high” is a useful way to proceed, and 3) methods for determining an overall categorization for the study limitations should be established a priori and documented clearly.
Oxidative stress adaptation in aggressive prostate cancer may be counteracted by the reduction of glutathione reductase
Authors: Freitas Mariana , Baldeiras Inês , Proença Teresa , Alves Vera , Mota-Pinto Anabela , Sarmento-Ribeiro Ana
Published: May 2012

PC3 shows higher ROS production but also the highest GSH levels and Gl‐Red activity, possibly contributing to oxidative stress resistance. This is also associated with higher mitochondrial membrane potential, TAS and lower lipid peroxidation. On the other hand, we identified Gl‐Red activity reduction as a new strategy in overcoming oxidative stress resistance, by inducing H2O2 cytotoxicity. Therefore these results suggest Gl‐Red activity reduction as a new potential therapeutic approach, in prostate cancer.
Shape oscillations of an oil drop rising in water: effect of surface contamination
Authors: Abi Chebel Nicolas , Vejražka Jiří , Masbernat Olivier , Risso Frédéric
Published: May 2012

Inertial shape oscillations of heptane drops rising in water are investigated experimentally. Diameters from 0.59 to 3.52 mm are considered, corresponding to a regime where the rising motion should not affect shape oscillations for pure immiscible fluids. The interface, however, turns out to be contaminated. The drag coefficient is considerably increased compared to that of a clean drop due to the well-known Marangoni effect resulting from a gradient of surfactant concentration generated by the fluid motion along the interface. Thanks to the decomposition of the shape into spherical harmonics, the eigenfrequencies and the damping rates of oscillation modes$n= 2$, 3, 4 and 5 have been measured. Frequencies are not affected by contamination, while damping rates are increased by a considerable amount that depends neither on drop instantaneous velocity nor on diameter. This augmentation, however, depends on the mode number: it is maximum for mode two (multiplied by 2.4) and then relaxes towards the value of a clean drop as$n$increases. A previous similar investigation of a drop attached to a capillary has not revealed such an increase of the damping rates, indicating that the coupling between rising motion and surface contamination is responsible for this effect.
Blacked-out spaces: Freud, censorship and the re-territorialization of mind
Authors: GALISON PETER
Published: May 2012

Freud's analogies were legion: hydraulic pipes, military recruitment, magic writing pads. These and some three hundred others took features of the mind and bound them to far-off scenes – the id only very partially resembles an uncontrollable horse, as Freud took pains to note. But there was one relation between psychic and public act that Freud did not delimit in this way: censorship, the process that checked memories and dreams on their way to the conscious. (Freud dubbed the relation between internal and external censorship a ‘parallel’ rather than a limited analogy.) At first, Freud likened this suppression to the blacking out of texts at the Russian frontier. During the First World War, he suffered, and spoke of suffering under, Viennese postal and newspaper censorship – Freud was forced to leave his envelopes unsealed, and to recode or delete content. Over and over, he registered the power of both internal and public censorship in shared form: distortion, anticipatory deletion, softenings, even revision to hide suppression. Political censorship left its mark as the conflict reshaped his view of the psyche into a society on a war footing, with homunculus-like border guards sifting messages as they made their way – or did not – across a topography of mind.
Reduction of dietary glycaemic load modifies the expression of microRNA potentially associated with energy balance and cancer pathways in pre-menopausal women
Authors: McCann Susan E. , Liu Song , Wang Dan , Shen Jie , Hu Qiang , Hong Chi-Chen , Newman Vicky A. , Zhao Hua
Published: May 2012

Energy metabolism, insulin resistance and adiposity have been implicated in breast cancer, but dietary interventions to reduce breast cancer morbidity and mortality have had limited success. MicroRNA (miRNA) are short, non-coding RNA that participate in the control of metabolic processes through the post-transcriptional modification of RNA. We investigated the effect of a low-glycaemic load dietary intervention on miRNA expression, with subsequent bioinformatics pathway analyses to explore metabolic pathways potentially affected by the diet. Total RNA, including miRNA, was isolated from the serum of fourteen otherwise healthy pre-menopausal women with a high breast cancer risk participating in a 12-month dietary intervention designed to lower glycaemic load by at least 15 % from baseline. Genome-wide miRNA expression was conducted using Illumina BeadChips. In the intervention subjects, three differentially expressed miRNA were validated by real-time (RT)-PCR, and in the twenty control participants, four top differentially expressed miRNA were evaluated to confirm a diet effect. In post-interventionv. baseline serum, twenty miRNA were found to be differentially expressed, with twelve up-regulated and eight down-regulated. These differentially expressed miRNA were predicted to be potentially associated with energy balance and cancer pathways based on exploratory enrichment analysis. Quantitative RT-PCR validations in the controls confirmed that the observed miRNA differential expression was dietary intervention induced. Manipulation of dietary glycaemic load has the potential to modify the expression of multiple miRNA predicted to be involved in energy balance and cancer pathways. Further research is necessary to confirm the role of these miRNA in the control of energy metabolism and relationships with cancer-related processes.
Picturing a Crude Past: Primitivism, Public Art, and Corporate Oil Promotion in the United States
Authors: BARRETT ROSS
Published: May 2012

This essay examines the first monument dedicated to the US oil industry, the Drake Memorial in Titusville, Pennsylvania (1899–1901), as an influential project of corporate self-representation. Commissioned by Standard Oil, the memorial shaped a public image for the petroleum industry that addressed concerns about the sustainability and social effects of oil capitalism, and established the key terms for a promotional discourse that would circulate throughout the twentieth century. This discourse, which I call “petro-primitivism,” reimagined the ultramodern oil industry as an extension of timeless practices rooted in an imagined archaic past. By shaping a primitivist spectacle that figured oil as an eternal component of the natural world and a primordial object of “human” endeavor, I argue, the Drake Memorial encouraged audiences to take the long view on oil: to adopt an expansive perspective that reconceived oil as a timelessly abundant element, and the boom-and-bust oil industry as an age-old venture. These tropes proved useful to the industry throughout the crises of the early twentieth century, reappearing in corporate displays and filtering into the rhetoric of industry advertising and publicity. Accordingly, I examine two later projects that appropriated the themes of petro-primitivism: the Sinclair Oil exhibit at the 1933–34 World's Fair, and Sun Oil's exhibit Oil Serves America at the Franklin Institute in Philadelphia (1953–c.1962). Echoing the earlier Drake Memorial, these displays employed strategies drawn from public art and civic architecture to organize collective experiences around the image of oil. By examining these popular exhibits alongside the Drake Memorial, I aim to offer a new account of the promotional culture of the early petroleum industry that explores the intersections between the traditional arts and industry publicity and illuminates the vital role that cultural representations played in accommodating twentieth-century Americans to the dynamic structures of petro-capitalism.
Fossil, Fuel: Manifesto for the Post-oil Museum
Authors: LE MENAGER STEPHANIE
Published: May 2012

It is no secret that natural history museums strive to be archives of life, a common task grown more fraught in recent decades because of the crisis of biodiversity, the extinction of roughly 60,000 species per year. “Bio-informatics” has been a buzzword in the natural history literature of the twenty-first century, which recommends the digitization of museum collections such that global information sharing can keep scientists up to date about species loss. Some curators resent the emphasis upon information technology as the key to the continuing relevance of their collections, arguing, for instance, that “museums are the cornerstone of an object-oriented approach to the natural world.” The question of what durability means for natural history, and by extension for both “nature” and “history,” breaks around what counts as most lifelike: information or object, technology or bone. Los Angeles is a rich setting for the consideration of these questions, both because it is the world capital of the entertainment industry and because it hosts the world's largest archive of Pleistocene fossils, preserved in the asphaltum sinks that formed atop the Salt Lake Oil Field, itself the largest urban oil reserve. What petroleum means to evolving definitions of life, and thus to nature and history, has long been on display at the La Brea tar pits. What isnoton display, namely micro-organisms grown up in the region's petroleum sludge, may be the saviors of our current geologic epoch and key to the renewal of the tired natural history concept.
A Short History of Oil Cultures: Or, the Marriage of Catastrophe and Exuberance
Authors: BUELL FREDERICK
Published: May 2012

In opposition to energy historian Vaclav Smil, who argues that “timeless literature … show[s] no correlation with advances in energy consumption,” this essay makes the general claim that energy history is significantly entwined with cultural history. Energy history is in fact entwined with changing cultural conceptualizations and representations of psyche, body, society, and environment; it is correlated not just with changing material cultures, but with symbolic cultures as well. To see this, the essay argues, one must conceptualize energy history in terms of a succession of energy systems – systems that are constituted by sociocultural, economic, environmental, and technological relationships. The essay's specific argument then traces the effects on symbolic culture, especially literature, of the nineteenth – and twentieth-century shift from coal capitalism to oil–electric capitalism. It starts by looking at the features of early oil extraction culture, from Drake's 1859 oil strike in Titusville, Pennsylvania to Upton Sinclair's novelOil!, and examines how oil–electric capitalism develops and defines itself culturally against the previous era of coal capitalism. Then the essay considers how the consolidation of the oil–electric capitalist system is significantly related to the emergence of modernist culture, affecting the production of both popular culture and high art. By the end of the twentieth century, a new phase in oil–electric capitalism emerges with the expansion of the postwar petrochemical industry, the dramatic expansion of environmental crisis discourse in the 1960s and 1970s, and the return of peak-oil discourse to the mainstream in the last decade. The essay examines how the material features of oil, as well as its dominant uses as luminant, motor fuel, lubricant, and eventually petrochemical feedstock, take on cultural importance. Exemplifying both the cultural innovations and reinventions of oil capitalism from the extraction era to the consolidation era and the post-World War II period, the essay focusses throughout on the two recurring motifs, exuberance and catastrophe, as they play out in a wide range of literary texts and popular enthusiasms.
Sundownand “Liquid Modernity” in Pawhuska, Oklahoma
Authors: MUSIOL HANNA
Published: May 2012

The early twentieth-century oil boom radically transformed the Osage reservation in Oklahoma, and in the early 1920s the Osages became the world's richest community because of their collective sharing of profits from mineral resources. In 1934, John Joseph Mathews, an Osage American tribal historian, publishedSundown, his only work of fiction, a peculiarBildungsromanabout the life of Chal Windzer in the aftermath of oil discovery on the Osage reservation. I argue that Mathews's use of the novel of formation is a particularly important literary and intellectual intervention. First, at a time when the significance of material resources to the American economy and American national imaginary was growing, Mathews uses the generic convention of progress to narrate oil's social “formation,” alongside the tale of Chal's dissolution, his failure, that is, of the very development which the novel's genre implies. Second, Mathews's literary representation of the oil boom as the Great Frenzy – a period of widespread violence and cultural chaos – complicates traditional accounts of capitalist economic development, which define late-stage capitalism and its financial deregulation and IT boom as an era of radical cultural “fluidity” (Bauman, Sennett). By drawing attention to the material and social fluidity of oil culture and the force with which it affected the Osages,Sundownpoints to a specific Osage American colonial, and thus always already transnational, history of (petro)modernity. The character of modernity, Mathews shows us, is inextricably tied to the conditions under which human and natural resources are extracted and allowed to become “social.” The destabilization of reservation culture derives equally from oil discovery itself, and the technological transformations within the energy industry, from the colonialist conditions that impose capitalism upon the Osages, and from the very collectivist modes of wealth distribution that the Osages adopted in order to resist colonial exploitation. Thus Mathews's novel reveals an alternative genealogy of the destabilization of cultural forms to the one that begins with post-Bretton Woods global financial deregulation, the collapse of state institutions in the global North, and the late twentieth-century emergence of new communication technologies. For the Osages in the 1920s and for the characters inSundown, crude oil and colonial exploitation, as well as, paradoxically, anticapitalist legal provisions of the Allotment Act's collectivizing of it, make reservation culture “liquid” and “uncertain” precisely at the time of America's entering into the presumably “solid” econo-political phase of development.
Crude Aesthetics: The Politics of Oil Documentaries
Authors: SZEMAN IMRE
Published: May 2012

How does the problem of oil appear in documentary film? I provide an answer to this question by examining the narrative and aesthetic choices through which the problem of oil is framed in three recent “feature” documentaries: Basil Gelpke and Ray McCormack's A Crude Awakening (2006), Joe Berlinger’s Crude: The Real Price of Oil (2009), and Shannon Walsh's H2Oil (2009). My aim is to understand not only the specific politics enacted through the formal and aesthetic choices made in each film, but to map out what these documentaries tell us about the social life of oil today, and the capacity for films such as these to meaningfully intervene in the looming consequences of our dependence on oil. The essay proceeds in three parts. First, by offering readings of the discursive, narrative and aesthetic strategies of these documentaries, I draw out the ways in which each comes to understand the problem of oil. In the second part, I identify the key insights that these films offer regarding the specific social contradictions and political blockages that emerge from their attempt to name and understand oil. Finally, I conclude with an exploration of the insights these films provide for addressing the antinomies that define and separate the anticapitalist and environmental movements.
Institutional Development and Colonial Heritage within Brazil
Authors: NARITOMI JOANA , SOARES RODRIGO R. , ASSUNÇÃO JULIANO J.
Published: May 2012

This article analyzes the determinants of local institutions in Brazil. We show that institutional quality and distribution of land are partly inherited from the colonial histories experienced by different areas of the country. The sugar cane boom—characterized by an oligarchic society—is associated with more land inequality. The gold boom—characterized by a heavily inefficient presence of the Portuguese state—is associated with worse governance and access to justice. We do not find similar effects for a postcolonial boom (coffee). We also find that the colonial episodes are correlated with lower provision of public goods.
Associations of current and remitted major depressive disorder with brain atrophy: the AGES–Reykjavik Study
Authors: Geerlings M. I. , Sigurdsson S. , Eiriksdottir G. , Garcia M. E. , Harris T. B. , Sigurdsson T. , Gudnason V. , Launer L. J.
Published: May 2012

Background

To examine whether lifetime DSM-IV diagnosis of major depressive disorder (MDD), including age at onset and number of episodes, is associated with brain atrophy in older persons without dementia.

Method

Within the population-based Age, Gene/Environment Susceptibility (AGES)–Reykjavik Study, 4354 persons (mean age 76 ± 5 years, 58% women) without dementia had a 1.5-T brain magnetic resonance imaging (MRI) scan. Automated brain segmentation total and regional brain volumes were calculated. History of MDD, including age at onset and number of episodes, and MDD in the past 2 weeks was diagnosed according to DSM-IV criteria using the Mini-International Neuropsychiatric Interview (MINI).

Results

Of the total sample, 4.5% reported a lifetime history of MDD; 1.5% had a current diagnosis of MDD (including 75% with a prior history of depression) and 3.0% had a past but no current diagnosis (remission). After adjusting for multiple covariates, compared to participants never depressed, those with current MDD (irrespective of past) had more global brain atrophy [B = –1.25%, 95% confidence interval (CI) −2.05 to −0.44], including more gray- and white-matter atrophy in most lobes, and also more atrophy of the hippocampus and thalamus. Participants with current, first-onset MDD also had more brain atrophy (B = –1.62%, 95% CI −3.30 to 0.05) whereas those remitted did not (B = 0.06%, 95% CI −0.54 to 0.66).

Conclusions

In older persons without dementia, current MDD, irrespective of prior history, but not remitted MDD was associated with widespread gray- and white-matter brain atrophy. Prospective studies should examine whether MDD is a consequence of, or contributes to, brain volume loss and development of dementia.