bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling the impacts of biomass burning on air quality in and around Mexico City
Authors: Lei W. , Li G. , Molina L. T.
Published: March 2013

Abstract. The local and regional impacts of open fires and trash burning on ground-level ozone (O3) and fine carbonaceous aerosols in the Mexico City Metropolitan Area (MCMA) and surrounding region during two high fire periods in March 2006 have been evaluated using WRF-CHEM model. The model captured reasonably well the measurement-derived magnitude and temporal variation of the biomass burning organic aerosol (BBOA), and the simulated impacts of open fires on organic aerosol (OA) were consistent with many observation-based estimates. We did not detect significant effects of open fires and trash burning on surface O3 concentrations in the MCMA and surrounding region. In contrast, they had important influences on OA and elemental carbon (EC), increasing primary OA (POA) by ~60%, secondary OA (SOA) by ~22%, total OA (TOA = POA + SOA) by ~33%, and EC by ~22%, on both the local (urban) and regional scales. Although the emissions of trash burning are substantially lower than those from open fires, trash burning made slightly smaller but comparable contributions to OA as open fires did, and exerted an even higher influence on EC. Of the ~22% enhancement in SOA concentrations (equivalent to a ~15% increase in TOA) simulated, about two third was attributed to the open fires and one-third to the trash burning. On the annual basis and taking the biofuel use emissions into consideration, we estimated that open fires, trash burning and biofuel use together contributed about 60% to the loading of POA, 30% to SOA, and 25% to EC in both the MCMA and its surrounding region, of which the open fires and trash burning contributed about 35% to POA, 18% to SOA, and 15% to EC. The estimates of biomass burning impacts in this study may contain considerable uncertainties due to the uncertainties in their emission estimates in magnitude, temporal and spatial distribution, extrapolations and the nature of spot comparison. More observation and modeling studies are needed to accurately assess the impacts of biomass burning on tropospheric chemistry, regional and global air quality, and climate change.
Long term measurements of aerosol optical properties at a primary forest site in Amazonia
Authors: Rizzo L. V. , Artaxo P. , Müller T. , Wiedensohler A. , Paixão M. , Cirino G. G. , Arana A. , Swietlicki E. , Roldin P. , Fors E. O. , Wiedemann K. T. , Leal L. S. M. , Kulmala M.
Published: March 2013

Abstract. A long term experiment was conducted in a primary forest area in Amazonia, with continuous in-situ measurements of aerosol optical properties between February 2008 and April 2011, comprising, to our knowledge, the longest database ever in the Amazon Basin. Two major classes of aerosol particles, with significantly different optical properties were identified: coarse mode predominant biogenic aerosols in the wet season (January–June), naturally released by the forest metabolism, and fine mode dominated biomass burning aerosols in the dry season (July–December), transported from regional fires. Dry particle median scattering coefficients at the wavelength of 550 nm increased from 6.3 Mm−1 to 22 Mm−1, whereas absorption at 637 nm increased from 0.5 Mm−1 to 2.8 Mm−1 from wet to dry season. Most of the scattering in the dry season was attributed to the predominance of fine mode (PM2) particles (40–80% of PM10 mass), while the enhanced absorption coefficients are attributed to the presence of light absorbing aerosols from biomass burning. As both scattering and absorption increased in the dry season, the single scattering albedo (SSA) did not show a significant seasonal variability, in average 0.86 ± 0.08 at 637 nm for dry aerosols. Measured particle optical properties were used to estimate the aerosol forcing efficiency at the top of the atmosphere. Results indicate that in this primary forest site the radiative balance was dominated by the cloud cover, particularly in the wet season. Due to the high cloud fractions, the aerosol forcing efficiency absolute values were below −3.5 W m−2 in 70% of the wet season days and in 46% of the dry season days. Besides the seasonal variation, the influence of out-of-Basin aerosol sources was observed occasionally. Periods of influence of the Manaus urban plume were detected, characterized by a consistent increase on particle scattering (factor 2.5) and absorption coefficients (factor 5). Episodes of biomass burning and mineral dust particles advected from Africa were observed between January and April, characterized by enhanced concentrations of crustal elements (Al, Si, Ti, Fe) and potassium in the fine mode. During these episodes, median particle absorption coefficients increased by a factor of 2, whereas median SSA values decreased by 7%, in comparison to wet season conditions.
Airborne high spectral resolution lidar observation of pollution aerosol during EUCAARI-LONGREX
Authors: Groß S. , Esselborn M. , Abicht F. , Wirth M. , Fix A. , Minikin A.
Published: March 2013

Abstract. Airborne high spectral resolution lidar observations over Europe during the EUCAARI-LONGREX field experiment in May 2008 are analysed with respect to the optical properties of continental pollution aerosol. Continental pollution aerosol is characterized by its depolarisation and lidar ratio. Over all, the measurements of the lidar ratio and the particle linear depolarization ratio of pollution aerosols provide a narrow range of values. Therefore, this data set allows for a distinct characterization of the aerosol type "pollution aerosol" and thus is valuable both to distinguish continental pollution aerosol from other aerosol types and to determine mixtures with other types of aerosols.
Technical Note: A simple method for air–sea gas exchange measurements in mesocosms and its application in carbon budgeting
Authors: Czerny J. , Schulz K. G. , Ludwig A. , Riebesell U.
Published: March 2013

Abstract. Mesocosms as large experimental units provide the opportunity to perform elemental mass balance calculations, e.g. to derive net biological turnover rates. However, the system is in most cases not closed at the water surface and gases exchange with the atmosphere. Previous attempts to budget carbon pools in mesocosms relied on educated guesses concerning the exchange of CO2 with the atmosphere. Here, we present a simple method for precise determination of air–sea gas exchange in mesocosms using N2O as a deliberate tracer. Beside the application for carbon budgeting, transfer velocities can be used to calculate exchange rates of any gas of known concentration, e.g. to calculate aquatic production rates of climate relevant trace gases. Using an arctic KOSMOS (Kiel Off Shore Mesocosms for future Ocean Simulation) experiment as an exemplary dataset, it is shown that the presented method improves accuracy of carbon budget estimates substantially. Methodology of manipulation, measurement, data processing and conversion to CO2 fluxes are explained. A theoretical discussion of prerequisites for precise gas exchange measurements provides a guideline for the applicability of the method under various experimental conditions.
Surface undulations of Antarctic ice streams tightly controlled by bedrock topography
Authors: De Rydt J. , Gudmundsson G. H. , Corr H. F. J. , Christoffersen P.
Published: March 2013

Abstract. Full Stokes flow-line models predict that fast-flowing ice streams transmit information about their bedrock topography most efficiently to the surface for basal undulations with length scales between 1 and 20 times the mean ice thickness. This typical behaviour is independent of the precise values of the flow law and sliding law exponents, and should be universally observable. However, no experimental evidence for this important theoretical prediction has been obtained so far, hence ignoring an important test for the physical validity of current-day ice flow models. In our work we use recently acquired airborne radar data for the Rutford Ice Stream and Evans Ice Stream, and we show that the surface response of fast-flowing ice is highly sensitive to bedrock irregularities with wavelengths of several ice thicknesses. The sensitivity depends on the slip ratio, i.e. the ratio between mean basal sliding velocity and mean deformational velocity. We find that higher values of the slip ratio generally lead to a more efficient transfer, whereas the transfer is significantly dampened for ice that attains most of its surface velocity by creep. Our findings underline the importance of bedrock topography for ice stream dynamics on spatial scales up to 20 times the mean ice thickness. Our results also suggest that local variations in the flow regime and surface topography at this spatial scale cannot be explained by variations in basal slipperiness.
Performance Analysis of a Helical Savonius Rotor with Shaft at 45° Twist Angle Using CFD
Authors: Gupta Rajat , Deb Bachu , Misra R. D.
Published: March 2013

Helical Savonius rotor is considered to be superior to conventional Savonius rotor in terms of higher power coefficient (Cp) and better starting characteristic. However studies related to helical Savonius rotors is few. In view of this, in this paper, the performance of a helical Savonius rotor with shaft at 45° bucket twist angle for one complete cycle of rotation was analyzed using Computational Fluid Dynamics. A two-bucket helical Savonius rotor with shaft was designed using GAMBIT, having a height of 60 cm and diameter of 17 cm with 45° bucket twist angle. A three dimensional Computational Fluid Dynamics analysis using Fluent package was done to predict the performance of the rotor. Standard k-? turbulence model with second order upwind discretization scheme and standard wall condition was used. Grid independence test was also conducted to have the best meshing accuracy. Power coefficients (Cp) of the rotor at different tip speed ratios were evaluated for rotor angle variation from 0° to 180°. Cp at each rotor angle increased with increase of tip speed ratio up to an optimum tip speed ratio, but then decreased even if tip speed ratio was further increased. Moreover, the effect of rotor angle on Cp in a complete cycle of rotation was analyzed. Cp was found to be positive at all rotor angles, and higher values of Cp were obtained at rotor angles namely 45°, 90°, 225° and 270°, which would contribute maximum power production by the rotor. In addition to these, flow physics of the rotor was studied using tangential velocity plots w.r.t. rotor angle and path lines across the rotor. It was found that at 45°, 90° and 135° rotor angles, maximum concentration of the path lines near the tip of the blades in the upstream and downstream side of the rotor had occurred, which would be responsible for generation of maximum power coefficient in its clockwise rotation.
Quand mon personnage préféré consomme : Usages et représentations des médicaments et des drogues dans la websérie Skins
Authors: Thoër Christine , Lévy Joseph Josy
Published: March 2013

Dans les styles de vie des adolescents et des jeunes adultes, le visionnement de films, de téléséries et de webséries occupe une place importante. Ces productions présentent des personnages et des scénarios qui mettent en scène les différentes problématiques auxquelles ces populations peuvent être confrontées telles que la consommation de drogues et de médicaments. Afin de cerner les modèles proposés, deux saisons de la websérieSkins, produite en Grande-Bretagne et qui remporte un grand succès international, ont été analysées à partir d’une étude de contenu faisant appel à une méthodologie mixte, quantitative et qualitative. Les analyses indiquent que la question des drogues et des médicaments occupe une place importante, le cannabis restant la drogue la plus représentée et utilisée tant par les personnages masculins que féminins. Elle est suivie par l’ecstasy. Si les drogues dures sont peu représentées, le recours aux médicaments à des fins non médicales est bien illustré, en particulier par les antidépresseurs et les traitements pour les troubles de l’érection. La websérie met en scène les étapes d’accès aux substances, leur préparation, leur consommation et même leur revente alors que ces thématiques étaient traitées de façon périphérique dans les productions télévisuelles des années 1990. Les modalités des états de conscience, de la défonce légère aux effets plus extrêmes et dangereux, sont abordées dansSkins. Cela met en évidence la variété des contextes et les fonctions collectives et individuelles de la consommation. Ces substances ne font généralement pas l’objet d’une évaluation négative dans les scénarios qui insistent plutôt sur leur banalisation et sur leur intégration dans le quotidien des jeunes, et ce, sans grands risques pour l’état de santé. Il resterait à cerner le processus de réception de cette série dans les différents contextes nationaux et à voir dans quelle mesure ces contenus influencent les normes et les pratiques de consommation des substances et des médicaments chez les adolescents.
Les volutes de la peinture : l’opium au défi des images
Authors: Chantoury-Lacombe Florence
Published: March 2013

La représentation de l’opium dans les arts visuels occidentaux semble bien assujettie au signifiant flottant dupharmakonde Platon dont le sens peut facilement s’inverser et devenir remède bénéfique ou poison maléfique. De remède universel avec la thériaque, la polypharmacie à base d’opium qui fonctionnera jusqu’au XVIIIe siècle, en passant par les sirops contre la toux pour les enfants, la valeur médicinale de l’opium fera d’abord l’enjeu des représentations visuelles pour, par la suite, verser dans un univers onirique ou l’opium devient une médication du spleen. De l’exotisme à l’érotisme, les rêves opiacés des fumeurs renvoient à un Orient fantasmé que les artistes auront plaisir à figurer. De la conception d’un empoisonnement exquis au remède pernicieux, le motif de l’opium dans la peinture marque une fascination pour cette drogue et fournit des prétextes aux artistes pour élaborer des dispositifs formels savants en vue d’impliquer le spectateur et de suggérer les expériences sensorielles du fumeur.

Notre contribution porte sur les images et les motifs figuratifs privilégiés par les artistes pour représenter l’opium, les fumeurs et les fumeries d’opium. Il s’agit d’interroger les thèmes traités, entre autres, les lieux du monde de l’opium, mais aussi l’atmosphère de rêverie, de langueur, que la représentation du fumeur, arrimé à sa pipe, expose, tel un voyageur dans un paradis illicite. À travers divers médiums graphiques et picturaux, provenant tant de l’histoire de la médecine que de l’illustration populaire, en passant par les oeuvres orientalistes du XIXe siècle, notre analyse tente de comprendre les stratégies figuratives mises en place par les artistes afin de mieux saisir les enjeux socioculturels attachés à l’opium.
Translating Mad Cow Disease: A Case Study of Subtitling for a Television News Magazine
Authors: Kang Ji-Hae
Published: March 2013

This paper explores how discourse is reframed in audiovisual translation in a well-known South Korean television news magazine, PD Swuchep [PD Notebook]. The episode under consideration raised serious questions regarding the safety of US beef and the conduct of South Korean officials responsible for negotiating imported beef in the Korea-US Free Trade Agreement talks. The program, which contained sound bites of interviews in English subtitled in Korean, created uproar in the South Korean society and played a significant role in touching off many months of massive street rallies against the government for its alleged sloppy handling of the beef import negotiation talks. Based on the view that subtitling for television news is a practice of “entextualization,” the study argues that (1) different degrees of discursive transformations in the target text cumulatively work to support and exaggerate the risk of the transmission of mad cow disease as a result of eating American beef; and (2) the discursive transformation is reinforced by institutionally defined roles and procedures for target text production. The findings suggest that one of the main criteria for the selection of target text expressions may be the narrative relevance of the political slant of the translation to the story of the program. Furthermore, the narrative of the target text may not necessarily be consensually co-constructed by participants. On the contrary, it is often a product of conflict-ridden processes that are characterized by tensions and differences in power relationships among people in different roles in the media institution.
Quality Standards or Censorship? Language Control Policies in Cable TV Subtitles in Brazil
Authors: Alfaro de Carvalho Carolina
Published: March 2013

This study seeks to understand the origins and reasons behind the grammar and style guidelines elaborated by Brazilian broadcasters and video producers and applied to the translated subtitles of cable television shows. The language of the translation is often controlled, and coarse or scatological vocabulary tends to be curbed or avoided, among other restrictions. Brazil was under a military regime from 1964 to 1985, when the media was subjected to strict censorship. Could it be that this heritage still casts a shadow over current policies applied to audiovisual translation (AVT)? To approach this issue, this study outlines the history of censorship applied to content and language during the Brazilian military regime, describes the evolution of the AVT industry in the context of cable television in Brazil, and finally conveys first-hand insights and experiences on language control by quality control professionals. The ultimate goal is to bring these rulemaking processes to light, in an attempt to help improve the dialogue between end clients and service providers, for the benefit of the viewers.
Art et vie : de l’expression à l’action
Authors: Mbuyamba Lupwishi
Published: March 2013

Le phénomène de l’art est apparu en même temps que l’homme prenait conscience de sa
présence dans un environnement qui l’interpellait : d’abord, par des manifestations figurées
dans les peintures rupestres que de nombreuses cavernes disséminées à travers l’Afrique
révèlent et, plus tard, dans des oeuvres de grande ampleur dont on peut suivre verticalement
le parcours historique.

Dans l’Antiquité comme au Moyen Âge, au temps de la formation des grands empires,
on est subjugué par des réalisations impressionnantes dans tous les domaines de l’art,
malgré les mutations subies au travers des itinéraires imposés par la traite négrière, les
cultures coloniales et, aujourd’hui, par la campagne pour un art volontariste de la
revendication, de l’authenticité et de la renaissance.

Horizontalement, on peut s’arrêter sur le phénomène de l’art et pénétrer dans les
cavernes de la création. On y découvrira la contradiction fondamentale qui existe entre le
monde de l’oeuvre en elle-même et celui des acteurs des différentes sphères de la
vie.

L’oeuvre d’art, résistant aux tentatives d’apprivoisement, suivra toujours le sens
de son destin, tendue qu’elle est vers l’envol, pour s’échapper, insaisissable même par son
géniteur, se libérer du carcan et de la prison de la contingence « corruptrice » et
rejoindre le domaine du sacré dont elle émane. Tel est le sens qu’on peut donner à la
présence de l’art dans la vie.
Liturgies africaines et vie
Authors: Kabasele Lumbala François
Published: March 2013

En Afrique noire, la vie est le sacré par excellence ; aussi, demeure-t-elle la préoccupation principale de toutes les cérémonies religieuses, déjà dans les traditions, et jusqu’aujourd’hui dans les religions africaines nouvelles : les rituels regorgent d’évocations et de supplications pour la vie ; les lieux de culte sont décorés aux couleurs de la vie (la trilogie « blanc-noir-rouge ») ; les symboles déployés dans le culte au sein de ces civilisations de l’oralité sont ceux de la fécondité, du triomphe sur la mort, de communion et cohésion sociale : les bananiers, la chaux, les arbres de vie ou arbres aux ancêtres, le feu, etc. Enfin, la manière même de célébrer est des plus vivantes : les assemblées grouillent de monde, la prédication est jalonnée de cris d’acclamation et élaborée avec l’apport de toute l’assemblée, le tambour rythme la prière en réveillant efficacement tous les dormeurs et en mettant debout toute l’assemblée pour la danse qui remet le corps à l’unisson avec l’Esprit et tout le groupe ! Oui, la vie « explose » dans les célébrations africaines.
D’un Dieu tout-puissant à un Dieu partenaire qui s’offre au monde
Authors: Olivier Lydwine
Published: March 2013

L’article s’intéresse à la façon dont la théologie processuelle permet de réfléchir à la représentation de Dieu. En effet, le récit de Gn 2 pose la question du présupposé que tout un chacun porte sur Dieu. Loin d’être une réponse toute faite, une et certaine, la théologie processuelle propose de partir à la rencontre d’un Dieu qui s’offre et qui offre un monde en devenir à l’humain. Pour mieux cerner la pertinence d’une analyse processuelle de ce récit, l’article s’intéresse à certaines questions clefs de la théologie qui la sous-tend. Celles-ci portent sur le libre arbitre de l’humain, l’omniscience et la toute-puissance de Dieu, la question du pôle primordial de Dieu comme pôle transcendant, et celle de son pôle conséquent comme signe de son immanence. L’article montre que le récit est une proposition offerte au lecteur de construire sa propre représentation de Dieu, non dans un postulat figé, mais dans un mouvement à-venir, toujours en train de se créer.
Thermoelectric Properties of Li-Doped CuO
Authors: Yoshida Naoki , Naito Tomoyuki , Fujishiro Hiroyuki
Published: March 2013

Thermoelectric properties of CuO doped with alkali metal ions (Li+, Na+, K+) were investigated at temperatures up to 1273 K. Among the doped alkali metal ions, Li+ ion was the most effective to enhance the thermoelectric properties. The maximum dimensionless thermoelectric figure of merit Z
T and power factor P were, respectively, 3.2×10-2 and 1.6×10-4 W K-2 m-1 at 1246 K for the 3.0%-Li-doped CuO. The enhancement of the thermoelectric properties of the CuO system was discussed.
High Birefringence of the YVO4Crystal in the Terahertz Frequency Range
Authors: Tsai Tsong-Ru , Wang Jia-Hao , Chiang Hai-Pang
Published: March 2013

The optical constants of YVO4crystal in the frequency range of 0.2 to 1.0 THz were determined using terahertz time-domain spectroscopy. The extraordinary-ray refractive indices varied from 4.05 to 4.07 and the ordinary-ray refractive indices were approximately 3.07. We found that YVO4crystal had a large and nearly constant birefringence of ∼0.985. In addition, the power absorptions for YVO4were less than 7 cm-1. Our results indicated that YVO4crystal has a potential for applications in the THz frequency range.
Influence of Light Intensification by Subsurface Cracks on KH2PO4Crystal's Laser Induced Damage Threshold
Authors: Chen Mingjun , Li Mingquan , An Chenhui , Zhou Lian , Cheng Jian , Xiao Yong , Jiang Wei
Published: March 2013

The subsurface damage introduced by single point diamond turning (SPDT) is an important precursor that decrease the laser induced damage threshold (LIDT) of KH2PO4(KDP) crystal. In this paper, based on the Fourier model theory, the modulation property of subsurface crack is analyzed. Research results indicate that light intensification by subsurface crack is an important mechanism of KDP failure. When the feed speed increases under the certain cutting depth, the subsurface damage depth and LIDT have the inverse changing trend. Namely that the intention of obtaining smaller damage depth by choosing suitable cutting parameters, will be also beneficial to improve the surface LIDT of KDP crystal. The combination of feed and cutting depth decides the damage depth together under the given spindle speed and tool geometry. The small feed is beneficial for improving the LIDT when cutting depth is large, while the situation is opposite when cutting depth is small.
Experimental Demonstration and Numerical Analysis of Microampere Gray Zone Width with Enhanced Operating Margin in Shunted Quasi-One Junction Superconducting Quantum Interference Device Comparators
Authors: Miyajima Shigeyuki , Ortlepp Thomas , Toepfer Hannes , Bozbey Ali , Fujimaki Akira
Published: March 2013

We evaluated the relationship between the gray zone width and the operating margin for comparators composed of quasi-one-junction superconducting quantum interference devices (QOSs) with shunt resistors, which are often used as high-speed readout circuits in multiple superconductor detector systems. The gray zone width is a good measure of current sensitivity of a single-bit comparator. We numerically analyzed the gray zone width of a QOS comparator and determined the circuit parameters. The gray zone width obtained from the experiments concurred with the results of the numerical analysis and was 2–3 µA at 4.2 K in a QOS comparator composed of three Nb/AlOx/Nb junctions with critical currents of less than 90 µA. The experimentally obtained operating margin for the bias current provided to the comparator was ±15% at the bias current of around 140 µA. These results show that QOS comparators are promising for readout circuits operating up to tens of GHz and imply that gray zone width is the thermal noise in the resistors at 4.2 K.
Conduction-Type Control of Carbon Nanotube Field-Effect Transistors by Ti and Pd Overlayer
Authors: Ishii Satoshi , Tamaoki Masato , Kishimoto Shigeru , Mizutani Takashi
Published: March 2013

The conduction-type of carbon nanotube field-effect transistors (CNTFETs) was controlled by depositing metal overlayers with different work functions (Ti and Pd) onto the side surfaces of the CNT channel of the ambipolar CNTFETs. The devices with the Ti overlayer showed n-type conduction. On the other hand, the devices with the Pd overlayer showed p-type conduction. The phenomena were explained by the suppression of carrier injection from the drain contact by the energy barrier formed at the CNT-overlayer source-side contact.
Discovery of Biologically Active Oncologic and Immunologic Small Molecule Therapies using Zebrafish: Overview and Example of Modulation of T Cell Activation
Authors: Trede Nikolaus S. , Heaton William , Ridges Suzanne , Sofla Hossein , Cusick Matthew , Bearss David , Jones David , Fujinami Robert S.
Published: March 2013

Zebrafish models continue to gain popularity as in vivo models for drug discovery. Described in this overview are advantages and challenges of zebrafish drug screening, as well as a novel in vivo screen for immunomodulatory compounds using transgenic, T cell reporting zebrafish larvae designed for discovery of compounds targeting T cell leukemia. This assay system allows rapid screening of large numbers of compounds while avoiding the pitfalls of assays based on cell cultures, which lack biologic context and are afflicted by genomic instability. The rationale for this approach is based on similarities of immature normal T cells and developmentally arrested, malignant lymphoblasts in mammalian species. The screening algorithm has been used to identify a nontoxic compound with activity in both acute leukemia models and models of multiple sclerosis, demonstrating the utility of this screening procedure. Curr. Protoc. Pharmacol. 60:14.24.1‐14.24.13. © 2013 by John Wiley & Sons, Inc.
Metabolic engineering of 2‐pentanone synthesis in Escherichia coli
Authors: Lan Ethan I. , Dekishima Yasumasa , Chuang Derrick S. , Liao James C.
Published: March 2013

Expanding the chemical diversity of microbial fermentation products enables green production of fuel, chemicals, and pharmaceuticals. In recent years, coenzyme A (CoA) dependent chain elongation, resembling the reversed β‐oxidation pathway, has attracted interest for its use in producing higher alcohols, fatty acids, and polyhydroxyalkanoate. To expand the chemical diversity of this pathway, we metabolically engineered Escherichia coli to produce 2‐pentanone, which is not a natural fermentation product of E. coli. We describe the first demonstration of 2‐pentanone synthesis in E. coli by coupling the CoA‐dependent chain elongation with the acetone production pathway. By bioprospecting for enzymes capable of efficient hydrolysis of 3‐keto‐hexanoyl‐CoA, production of 2‐pentanone increased 20 fold, reaching a titer of 240 mg/L. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3167–3175, 2013
Role of Bruton's tyrosine kinase in myeloma cell migration and induction of bone disease
Authors: Bam Rakesh , Ling Wen , Khan Sharmin , Pennisi Angela , Venkateshaiah Sathisha Upparahalli , Li Xin , van Rhee Frits , Usmani Saad , Barlogie Bart , Shaughnessy John , Epstein Joshua , Yaccoby Shmuel
Published: March 2013

Myeloma cells typically grow in bone, recruit osteoclast precursors and induce their differentiation and activity in areas adjacent to tumor foci. Bruton's tyrosine kinase (BTK), of the TEC family, is expressed in hematopoietic cells and is particularly involved in B‐lymphocyte function and osteoclastogenesis. We demonstrated BTK expression in clinical myeloma plasma cells, interleukin (IL)−6– or stroma–dependent cell lines and osteoclasts. SDF‐1 induced BTK activation in myeloma cells and BTK inhibition by small hairpin RNA or the small molecule inhibitor, LFM‐A13, reduced their migration toward stromal cell‐derived factor‐1 (SDF‐1). Pretreatment with LFM‐A13 also reduced in vivo homing of myeloma cells to bone using bioluminescence imaging in the SCID‐rab model. Enforced expression of BTK in myeloma cell line enhanced cell migration toward SDF‐1 but had no effect on short‐term growth. BTK expression was correlated with cell‐surface CXCR4 expression in myeloma cells (n = 33, r = 0.81, P < 0.0001), and BTK gene and protein expression was more profound in cell‐surface CXCR4‐expressing myeloma cells. BTK was not upregulated by IL‐6 while its inhibition had no effect on IL‐6 signaling in myeloma cells. Human osteoclast precursors also expressed BTK and cell‐surface CXCR4 and migrated toward SDF‐1. LFM‐A13 suppressed migration and differentiation of osteoclast precursors as well as bone‐resorbing activity of mature osteoclasts. In primary myeloma‐bearing SCID‐rab mice, LFM‐A13 inhibited osteoclast activity, prevented myeloma‐induced bone resorption and moderately suppressed myeloma growth. These data demonstrate BTK and cell‐surface CXCR4 association in myeloma cells and that BTK plays a role in myeloma cell homing to bone and myeloma‐induced bone disease. Am. J. Hematol. 88:463–471, 2013. © 2013 Wiley Periodicals, Inc.
Chemische Tricks zur Zähmung von Silanonen und ihren schweren Homologen mit EO‐Bindungen (E=Si–Pb): von schwer fassbaren Spezies zu isolierbaren Bausteinen
Authors: Xiong Yun , Yao Shenglai , Driess Matthias
Published: March 2013

Die Reaktivität der Ketone (R2CO) ist deutlich besser untersucht als die ihrer schweren Homologen R2EO (E=Si, Ge, Sn, Pb). Die Gründe dafür sind die hohe Polarität der EO‐Bindung und die daraus folgende Neigung zur Oligomerisation. Erst kürzlich konnten große Erfolge bei der Synthese von isolierbaren Verbindungen mit EO‐Bindungen erzielt werden, darunter Donor‐stabilisierte isolierbare Silanone und das erste echte Germanon. Diese Verbindungen zeigen in ihrer Reaktivität drastische Unterschiede zu Ketonen und bilden darüber hinaus vielseitige Synthesebausteine in der Silicium‐Sauerstoff‐ und Germanium‐Sauerstoff‐Chemie. Diese und andere erstaunliche Erfolge werden im vorliegenden Kurzaufsatz beschrieben.
Chemical Tricks To Stabilize Silanones and Their Heavier Homologues with EO Bonds (E=Si–Pb): From Elusive Species to Isolable Building Blocks
Authors: Xiong Yun , Yao Shenglai , Driess Matthias
Published: March 2013

In contrast to the well‐established chemistry of ketones (R2CO), the reactivity of the elusive heavier congeners R2EO (E=Si, Ge, Sn, Pb) is far less explored because of the high polarity of the EO bonds and hence their tendency to oligomerize with no activation barrier. Very recently, great advances have been achieved in the synthesis of isolable compounds with EO bonds, including the investigation of donor‐stabilized isolable silanones and the first stable “genuine” germanone. These compounds show drastically different reactivities compared to ketones and represent versatile building blocks in silicon–oxygen and germanium–oxygen chemistry. This and other exciting achievements are described in this Minireview.
1‐Allyl‐3‐methylimidazolium halometallate ionic liquids as efficient catalysts for the glycolysis of poly(ethylene terephthalate)
Authors: Wang Qian , Lu Xingmei , Zhou Xueyuan , Zhu Minli , He Hongyan , Zhang Xiangping
Published: March 2013

Series of 1‐allyl‐3‐methylimidazolium halometallate ionic liquids (ILs) were synthesized and used to degrade poly(ethylene terephthalate) (PET) as catalysts in the solvent of ethylene glycol. One important feature of these new IL catalysts is that most of them, especially [amim][CoCl3] and [amim][ZnCl3], exhibit higher catalytic activity under mild reaction condition, compared to the traditional catalysts [e.g., Zn(Ac)2], the conventional IL catalysts (e.g., [bmim]Cl), Fe‐containing magnetic IL catalysts (e.g., [bmim][FeCl4]), and metallic acetate IL catalysts (e.g., [Deim][Zn(OAc)3]). For example, using [amim][ZnCl3] as catalyst, the conversion of PET and the selectivity of bis(hydroxyethyl) terephthalate (BHET) reach up to 100% and 80.1%, respectively, under atmospheric pressure at 175°C for only 1.25 h. Another important feature is that BHET can be easily separated from the catalyst and has a high purity. Finally, based on the experimental phenomena, in ‐situ infrared spectra, and experimental results, the possible mechanism of degradation with synthesized IL is proposed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Induction of heat shock gene expression in RAT1 primary fibroblast cells by ELF electric fields
Authors: Frisch Paul , Li Gloria C. , McLeod Kenneth , Laramee Craig B.
Published: March 2013

Recent studies have demonstrated that the Ku70 gene fragment can be placed in the anti‐sense orientation under the control of a heat‐inducible heat shock protein 70 (HSP70) promoter and activated through heat shock exposure. This results in attenuation of the Ku70 protein expression, inhibiting cellular repair processes, and sensitizing the transfected cells to exposures such as the ionizing radiation exposures used clinically. However, achieving the tissue temperatures necessary to thermally induce the HSP70 response presents significant limitations to the clinical application of this strategy. Previous findings suggest an alternative approach to inducing a heat shock response, specifically through the use of extremely low frequency (ELF) electrical field stimulation. To further pursue this approach, we investigated HSP70 responses in transfected rat primary fibroblast (RAT1) cells exposed to 10 Hz electric fields at intensities of 20–500 V/m. We confirmed that low frequency electric fields can induce HSP70 heat shock expression, with peak responses obtained at 8 h following a 2 h field exposure. However, the approximate threefold increase in expression is substantially lower than that obtained using thermal stimulation, raising questions of the clinical utility of the response. Bioelectromagnetics 34:405–413, 2013. © 2012 Wiley Periodicals, Inc.
Inhomogeneous background magnetic field in biological incubators is a potential confounder for experimental variability and reproducibility
Authors: Portelli Lucas A. , Schomay Theodore E. , Barnes Frank S.
Published: March 2013

This report shows that the background magnetic field in biological incubators can vary by orders of magnitude within and between incubators. These variations can be observed within the same incubator in locations that are centimeters apart from each other as well as between incubators that are identical and located in the same laboratory. Additionally, the values measured were frequently outside the range of magnitudes found naturally on the Earth's surface or ordinary habitation spaces. Exposure to such altered magnetic field environments has been experimentally shown to be sufficient to cause numerous effects in cell cultures. Examples of the effects reported span from differential generation of free radicals and heat shock proteins to differences in cellular proliferation, differentiation, and death. Although the effects are not well established and the molecular mechanism of action is currently under debate, these observations alone support the notion that the inhomogeneity of the background magnetic field in incubators is a potential confounding source of the variability and reproducibility for studies performed on cell cultures. In this regard, it is recommended that special measures be adopted to control the background magnetic fields in incubators when investigating the biological effects of exposure to magnetic fields of comparable characteristics as the ones measured in this study, or when studying small biological effects in general. Bioelectromagnetics 34:337–348, 2013. © 2012 Wiley Periodicals, Inc.
G protein‐coupled receptors engage the mammalian Hippo pathway through F‐actin
Authors: Regué Laura , Mou Fan , Avruch Joseph
Published: March 2013

The Hippo pathway, a cascade of protein kinases that inhibits the oncogenic transcriptional coactivators YAP and TAZ, was discovered in Drosophila as a major determinant of organ size in development. Known modes of regulation involve surface proteins that mediate cell‐cell contact or determine epithelial cell polarity which, in a tissue‐specific manner, use intracellular complexes containing FERM domain and actin‐binding proteins to modulate the kinase activities or directly sequester YAP. Unexpectedly, recent work demonstrates that GPCRs, especially those signaling through Galpha12/13 such as the protease activated receptor PAR1, cause potent YAP dephosphorylation and activation. This response requires active RhoA GTPase and increased assembly of filamentous (F‐)actin. Morever, cell architectures that promote F‐actin assembly per se also activate YAP by kinase‐dependent and independent mechanisms. These findings unveil the ability of GPCRs to activate the YAP oncogene through a newly recognized signaling function of the actin cytoskeleton, likely to be especially important for normal and cancerous stem cells.
Enzyme production by the mixed fungal culture with nano‐shear pretreated biomass and lignocellulose hydrolysis
Authors: Lu Jue , Weerasiri Rankothge Ranjith , Liu Yan , Wang Wei , Ji Shaowen , Lee Ilsoon
Published: March 2013

Cellulase, xylanase, and β‐glucosidase production was studied on novel nano‐shear pretreated corn stover by the mixed fungi culture. The high shear force from a modified Tayor‐Couette nano‐shear mixing reactor efficiently disintegrated corn stover, resulting in a homogeneous watery mash with particles in much reduced size. Scanning electron microscope study showed visible mini‐pores on the fiber cell wall surface, which could improve the accessibility of the pretreated corn stover to microorganisms. Mixed fungal culture of Trichoderma reesei RUT‐C30 and Aspergillus niger produced enzymes with higher cellulolytic and xylanolytic activities on corn stover pretreated with nano‐shear mixing reactor, in comparison with other pretreatment methods, including acid and ammonia fiber explosion (AFEX) pretreatment. The hydrolytic potential of the whole fermentation broth from the mixed fungi was studied, and the possibility of applying the whole cell saccharification concept was also investigated to further reduce the cost of lignocellulose hydrolysis. Biotechnol. Bioeng. 2013; 110: 2123–2130. © 2013 Wiley Periodicals, Inc.
Visualizing cellulase activity
Authors: Bubner Patricia , Plank Harald , Nidetzky Bernd
Published: March 2013

Commercial exploitation of lignocellulose for biotechnological production of fuels and commodity chemicals requires efficient—usually enzymatic—saccharification of the highly recalcitrant insoluble substrate. A key characteristic of cellulose conversion is that the actual hydrolysis of the polysaccharide chains is intrinsically entangled with physical disruption of substrate morphology and structure. This “substrate deconstruction” by cellulase activity is a slow, yet markedly dynamic process that occurs at different length scales from and above the nanometer range. Little is currently known about the role of progressive substrate deconstruction on hydrolysis efficiency. Application of advanced visualization techniques to the characterization of enzymatic degradation of different celluloses has provided important new insights, at the requisite nano‐scale resolution and down to the level of single enzyme molecules, into cellulase activity on the cellulose surface. Using true in situ imaging, dynamic features of enzyme action and substrate deconstruction were portrayed at different morphological levels of the cellulose, thus providing new suggestions and interpretations of rate‐determining factors. Here, we review the milestones achieved through visualization, the methods which significantly promoted the field, compare suitable (model) substrates, and identify limiting factors, challenges and future tasks. Biotechnol. Bioeng. 2013; 110: 1529–1549. © 2013 Wiley Periodicals, Inc.
Improved polyhydroxybutyrate production by Saccharomyces cerevisiae through the use of the phosphoketolase pathway
Authors: Kocharin Kanokarn , Siewers Verena , Nielsen Jens
Published: March 2013

The metabolic pathways of the central carbon metabolism in Saccharomyces cerevisiae are well studied and consequently S. cerevisiae has been widely evaluated as a cell factory for many industrial biological products. In this study, we investigated the effect of engineering the supply of precursor, acetyl‐CoA, and cofactor, NADPH, on the biosynthesis of the bacterial biopolymer polyhydroxybutyrate (PHB), in S. cerevisiae. Supply of acetyl‐CoA was engineered by over‐expression of genes from the ethanol degradation pathway or by heterologous expression of the phophoketolase pathway from Aspergillus nidulans. Both strategies improved the production of PHB. Integration of gapN encoding NADP+‐dependent glyceraldehyde‐3‐phosphate dehydrogenase from Streptococcus mutans into the genome enabled an increased supply of NADPH resulting in a decrease in glycerol production and increased production of PHB. The strategy that resulted in the highest PHB production after 100 h was with a strain harboring the phosphoketolase pathway to supply acetyl‐CoA without the need of increased NADPH production by gapN integration. The results from this study imply that during the exponential growth on glucose, the biosynthesis of PHB in S. cerevisiae is likely to be limited by the supply of NADPH whereas supply of acetyl‐CoA as precursor plays a more important role in the improvement of PHB production during growth on ethanol. Biotechnol. Bioeng. 2013; 110: 2216–2224. © 2013 Wiley Periodicals, Inc.
Hepatic regeneration and functional recovery following partial liver resection in an experimental model of hepatic steatosis treated with omega-3 fatty acids
Authors: Marsman H A , de Graaf W , Heger M , van Golen R F , ten Kate F J W , Bennink R , van Gulik T M
Published: March 2013

Background

Omega-3 fatty acids (FAs) have been shown to reduce experimental hepatic steatosis and protect the liver from ischaemia–reperfusion injury. The aim of this study was to examine the effects of omega-3 FAs on regeneration of steatotic liver.

Methods

Steatosis was induced in rats by a 3-week methionine/choline-deficient diet, which was continued for an additional 2 weeks in conjunction with oral administration of omega-3 FAs or saline solution. Steatosis was graded histologically and quantified by proton magnetic resonance spectroscopy (1H-MRS) before and after the diet/treatment. Liver function was determined by 99mTc-labelled mebrofenin hepatobiliary scintigraphy (HBS). In separate experiments, the hepatic regenerative capacity and functional recovery of omega-3 FA-treated, saline-treated or non-steatotic (control) rats were investigated 1, 2, 3 and 5 days after partial (70 per cent) liver resection by measurement of liver weight change and hepatocyte proliferation (Ki-67) and HBS.

Results

Severe steatosis (over 66 per cent) in the saline group was reduced by omega-3 FAs to mild steatosis (less than 33 per cent), and hepatic fat content as assessed by 1H-MRS decreased 2·2-fold. 99mTc-mebrofenin uptake in the saline group was more than 50 per cent lower than in the control group, confirming the functional effects of steatosis. 99mTc-mebrofenin uptake and regenerated liver mass were significantly greater in the omega-3 group compared with the saline group on days 1 and 3. The posthepatectomy proliferation peak response was delayed until day 2 in saline-treated rats, compared with day 1 in the omega-3 and control groups.

Conclusion

Omega-3 FAs effectively reduced severe hepatic steatosis, which was associated with improved liver regeneration and functional recovery following partial hepatectomy.
A knowledge‐based web platform for collaborative physical system modeling and simulation
Authors: Yanshan Zhang , Fah Yap Fook , Singh Jasleen , Ting Lei , Lei Gao
Published: March 2013

A web platform, called Proteus (http://www.visualphysics.net/pweb), has been developed by a team in Nanyang Technological University. This platform is designed for education and academic research, and is free to use. It provides a place where students, educators, and academic researchers can easily create and share their computer models of physical systems described using Modelica, a non‐proprietary, object‐oriented, equation‐based language for physical system modeling. It comes with a web‐based, graphical modeling, and simulation tool called ProteusGWT (http://www.visualphysics.net/ProteusGWT). ProteusGWT is web‐based and uses an intuitive, graphical component‐oriented approach to the modeling of physical systems spanning multiple domains including systems containing mechanical, hydraulic, thermal, control, electrical, electronic, electric power, or process‐oriented subcomponents. It synthesizes state‐of‐the‐art web technologies (e.g., HTML5, GWT, and cloud computing), computational methods for physical systems modeling, and simulation to create a computing environment that is widely deployable and scalable. Google Web Toolkit (GWT) is a development toolkit from Google for building and optimizing complex web‐based applications. It allows developers to create and maintain complex JavaScript applications in Java language. Proteus allows anyone with a computer or browser‐enabled device to be able to use it. Hence, anyone can contribute their computer models of physical systems to this platform. As this platform grows, it could turn out to be an online interactive repository for all kinds of physical system models, for example, a student may examine complete computer models of a motorcycle, a refrigerator, a burglar alarm, or robot arm and learn about how they work. He or she could run simulations, modify the models, or create new designs and share with others. There is nothing quite like this currently on the Internet. © 2013 Wiley Periodicals, Inc. Comput Appl Eng Educ 23:23–35, 2015; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21572