bluuebunny/crossref_metadata_2025 huggingface dataset:
Control of Hepatitis B Virus Replication by Innate Response of Heparg Cells
Authors: Lucifora Julie , Durantel David , Testoni Barbara , Hantz Olivier , Levrero Massimo , Zoulim Fabien
Published: August 2009

Hepatitis B virus (HBV) is currently viewed as a stealth virus that does not elicit innate immunity

in vivo

. This assumption has not yet been challenged

in vitro

because of the lack of a relevant cell culture system. The HepaRG cell line, which is physiologically closer to differentiated hepatocytes and permissive to HBV infection, has opened new perspectives in this respect.HBV baculoviruses were used to initiate an HBV replication in both HepG2 and HepaRG cells. To monitor HBV replication, the synthesis of encapsidated DNA, and secretion of hepatitis B surface antigen (HBsAg), was respectively analyzed by southern blot and enzyme-linked immunosorbent assay. The induction of a type I interferon (IFN) response was monitored by targeted quantitative reverse transcription polymerase chain reaction (qRT-PCR), low-density arrays, and functional assays. The invalidation of type I IFN response was obtained by either antibody neutralization or RNA interference. We demonstrate that HBV elicits a strong and specific innate antiviral response that results in a noncytopathic clearance of HBV DNA in HepaRG cells. Challenge experiment showed that transduction with Bac-HBV-WT, but not with control baculoviruses, leads to this antiviral response in HepaRG cells, whereas no antiviral response is observed in HepG2 cells. Cellular gene expression analyses showed that IFN-β and other IFN-stimulated genes were up-regulated in HepG2 and HepaRG cells, but not in cells transduced by control baculoviruses. Interestingly, a rescue of viral replication was observed when IFN-β action was neutralized by antibodies or RNA interference of type I IFN receptor.

Conclusion:

Our data suggest that a strong HBV replication is able to elicit a type I IFN response in HepaRG-transduced cells. (Hepatology 2009.)
Imaging engineered tissues using structural and functional optical coherence tomography
Authors: Liang Xing , Graf Benedikt W. , Boppart Stephen A.
Published: August 2009

As the field of tissue engineering evolves, there will be an increasingly important need to visualize and track the complex dynamic changes that occur within three‐dimensional constructs. Optical coherence tomography (OCT), as an emerging imaging technology applied to biological materials, offers a number of significant advantages to visualize these changes. Structural OCT has been used to investigate the longitudinal development of engineered tissues and cell dynamics such as migration, proliferation, detachment, and cell‐material interactions. Optical techniques that image functional parameters or integrate multiple imaging modalities to provide complementary contrast mechanisms have been developed, such as the integration of optical coherence microscopy with multiphoton microscopy to image structural and functional information from cells in engineered tissue, optical coherence elastography to generate images or maps of strain to reflect the spatially‐dependent biomechanical properties, and spectroscopic OCT to differentiate different cell types. From these results, OCT demonstrates great promise for imaging and visualizing engineered tissues, and the complex cellular dynamics that directly affect their practical and clinical use. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Application of 99Mo/99mTc alumina generator in the labeling of metoprolol for diagnostic purposes
Authors: Amin A. M. , El‐Azony K. M. , Ibrahim I. T.
Published: August 2009

Labeling of metoprolol by technetium‐99m in pertechnetate form (99mTcO) eluted from a 99Mo/99mTc alumina generator in the presence of stannous chloride dihydrate was carried out via chelation reaction. The reaction parameters that affect the labeling yield such as metoprolol concentration, stannous chloride dihydrate concentration, reaction temperature, and pH of the reaction mixture were studied to optimize the labeling conditions. Using 1 GBq 99mTcO, 500 µg metoprolol as substrate dissolved in 500 µL phosphate buffer at pH 9 and 50 µL of stannous chloride as reducing agent (1 mg/mL) at 25°C for 30 min reaction time, a maximum radiochemical yield of 99mTc‐metoprolol (92%) was obtained. 99mTc‐metoprolol was characterized by thin layer chromatography (TLC) and by high pressure liquid chromatography (HPLC). The specific activity of 99mTc‐metoprolol obtained was 888 MBq/1.88 mmol. The biological distribution in normal mice showed that 99mTc‐metoprolol is rapidly concentrated after injection in the heart, which indicates its suitability for heart imaging. Copyright © 2009 John Wiley & Sons, Ltd.
Mass spectrometry combined with oxidative labeling for exploring protein structure and folding
Authors: Konermann Lars , Stocks Bradley B. , Pan Yan , Tong Xin
Published: August 2009

This review discusses various mass spectrometry (MS)‐based approaches for exploring structural aspects of proteins in solution. Electrospray ionization (ESI)–MS, in particular, has found fascinating applications in this area. For example, when used in conjunction with solution‐phase hydrogen/deuterium exchange (HDX), ESI–MS is a highly sensitive tool for probing conformational dynamics. The main focus of this article is a technique that is complementary to HDX, that is, the covalent labeling of proteins by hydroxyl radicals. The reactivity of individual amino acid side chains with.OH is strongly affected by their degree of solvent exposure. Thus, analysis of the oxidative labeling pattern by peptide mapping and tandem mass spectrometry provides detailed structural information. A convenient method for.OH production is the photolysis of H2O2by a pulsed UV laser, resulting in oxidative labeling on the microsecond time scale. Selected examples demonstrate the use of this technique for structural studies on membrane proteins, and the combination with rapid mixing devices for characterizing the properties of short‐lived protein (un)folding intermediates. © 2009 Wiley Periodicals, Inc., Mass Spec Rev 29:651–667, 2010
Valid inequalities for the fleet size and mix vehicle routing problem with fixed costs
Authors: Baldacci Roberto , Battarra Maria , Vigo Daniele
Published: August 2009

In the well‐known vehicle routing problem (VRP), a set of identical vehicles located at a central depot is to be optimally routed to supply customers with known demands subject to vehicle capacity constraints. An important variant of the VRP arises when a mixed fleet of vehicles, characterized by different capacities and costs, is available for distribution activities. The problem is known as fleet size and mix VRP with fixed costs FSMF and has several practical applications. In this article, we present a new mixed integer programming formulation for FSMF based on a two‐commodity network flow approach. New valid inequalities are proposed to strengthen the linear programming relaxation of the mathematical formulation. The effectiveness of the proposed cuts is extensively tested on benchmark instances. © 2009 Wiley Periodicals, Inc. NETWORKS, 2009
Min‐Max K‐vehicles windy rural postman problem
Authors: Benavent Enrique , Corberán Angel , Plana Isaac , Sanchis José M.
Published: August 2009

In this article the Min‐Max version of the windy rural postman problem with several vehicles is introduced. For this problem, in which the objective is to minimize the length of the longest tour in order to find a set of balanced tours for the vehicles, we present here an ILP formulation and study its associated polyhedron. Based on its partial description, a branch‐and‐cut algorithm has been implemented and computational results on a large set of instances are finally presented. © 2009 Wiley Periodicals, Inc. NETWORKS, 2009
Localization‐ and mutation‐dependent microRNA (miRNA) expression signatures in gastrointestinal stromal tumours (GISTs), with a cluster of co‐expressed miRNAs located at 14q32.31
Authors: Haller Florian , von Heydebreck Anja , Zhang Jitao David , Gunawan Bastian , Langer Claus , Ramadori Giuliano , Wiemann Stefan , Sahin Özgür
Published: August 2009

The molecular biology and clinical behaviour of gastrointestinal stromal tumours (GISTs) are associated with their anatomical localization (stomach or intestine), and also with the mutation status of the receptor tyrosine kinases KIT and PDGFRA. Twelve GISTs were evaluated for differential miRNA expression signatures by use of microarrays representing 734 human miRNAs. Thirty‐two miRNAs were found to be differentially expressed according to localization and mutation status. Differential expression was further analysed and confirmed for four miRNAs (miR‐132, miR‐221, miR‐222, and miR‐504) by qRT‐PCR in 49 additional GISTs. Differentially expressed miRNAs were functionally mapped to KIT/PDGFRA signalling and G1/S‐phase transition of the cell cycle, revealing 22 predicted miRNA/mRNA interactions for ten gene targets from KIT/PDGFRA signalling, and 12 interactions for 12 gene targets of G1/S‐phase transition. Moreover, the expression of 44 miRNAs clustered in a genetically imprinted region at 14q32.31 was found to be strongly correlated in the microarray analysis. This was confirmed for two selected miRNAs (miR‐134 and miR‐370) from the 14q32.31 cluster by qRT‐PCR in 49 additional GISTs, and the expression of these two miRNAs was significantly lower in GISTs with 14q loss, and also in GISTs with tumour progress. miRNA profiling may prove to be a key determinant of the biology and clinical features of GISTs Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Multifunctional high density polyethylene nanocomposites produced by incorporation of exfoliated graphite nanoplatelets 1: Morphology and mechanical properties
Authors: Jiang Xian , Drzal Lawrence T.
Published: August 2009

This research explores the potential of using exfoliated graphite nanoplatelets, xGnP, as the reinforcement in high density polyethylene (HDPE). Two kinds of xGnP nanoparticles were used; xGnP‐1 has the thickness of 10 nm and a platelet diameter of 1 μm, whereas xGnP‐15 has the same thickness but the diameter is around 15 μm. HDPE/xGnP nanocomposite were fabricated first by melt blending and then followed by injection molding. The HDPE/xGnP nanocomposite's flexural strength, modulus and impact strength were evaluated and compared with composites filled with commercial reinforcements such as carbon fibers (CF), carbon black (CB) and glass fibers (GF). Polymer nanocomposites from HDPE/xGnP are equivalent in flexural stiffness and strength to HDPE composites reinforced with glass fibers and carbon black but slightly less than that of HDPE/carbon fiber composites at the same volume fraction. However, the Izod impact strength of HDPE/xGnP nanocomposites is significantly greater (∼250%) than all other reinforcements at the same volume fractions. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
Synthesis of protein kinase Cδ C1b domain by native chemical ligation methodology and characterization of its folding and ligand binding
Authors: Ohashi Nami , Nomura Wataru , Kato Mai , Narumi Tetsuo , Lewin Nancy E. , Blumberg Peter M. , Tamamura Hirokazu
Published: August 2009

The C1b domain of protein kinase Cδ (PKCδ), a potent receptor for ligands such as diacylglycerol and phorbol esters, was synthesized by utilizing native chemical ligation. With this synthetic strategy, the domain was efficiently constructed and shown to have high affinity ligand binding and correct folding. The C1b domain has been utilized for the development of novel ligands for the control of phosphorylation by PKC family members. This strategy will pave the way for the efficient construction of C1b domains modified with fluorescent dyes, biotin, etc. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.
Novel synthesis process for ceramic carbon nanotube nanocomposites with nanojunctions
Authors: Xu Yang , Li Zhongrui , Saini Viney , Watanabe Fumiya , Kunets Vasyl P. , Dervishi Enkeleda , Salamo Gregory J. , Biris Alexandru R. , Biris Alexandru S.
Published: August 2009

A single‐step process of radio frequency‐catalytic chemical vapor deposition (RF‐cCVD) was used for the synthesis of pelletized ceramic carbon nanotube (CNT) composites. The surface resistance of the insulating magnesium oxide (MgO) was found to drop dramatically as the result of the graphitic nanostructures formed within the ceramic matrix after the catalytic process. It was found that the electrical properties of the ceramic CNT composites were highly dependent on the concentration of the loading metal that was responsible for the formation of different carbon species on the MgO pellet. Hall effect measurements of ceramic single‐walled CNT composites indicated an n‐type electrical behavior with high carrier densities of around 2.5 × 1020/cm3 and electrical mobilities of 1.1 cm2/V s. The process is shown to be useful for generating ceramic CNT devices that may be used for a variety of applications.
Effects in CVD diamond exposed to fusion plasmas
Authors: Porro S. , De Temmerman G. , John P. , Lisgo S. , Villalpando I. , Wilson J. I. B.
Published: August 2009

Micro and nanocrystalline diamond layers have been deposited on molybdenum substrates by hot‐filament CVD, and tested in the Mega Amp Spherical Tokamak as a protective coating of fusion plasma‐facing materials. The modification of surface properties induced by high density plasma was investigated by SEM, X‐ray photoelectron spectroscopy and Raman spectroscopy. Although some modifications of the coating, amorphization and some traces of arcing, diamond proved to be a viable protection as most of the samples were still coated after the plasma exposure. Fuel retention measurements, evaluated by nuclear reaction analysis, showed that a small amount of deuterium was trapped in the surface of the coatings. The chemical erosion of the layers was 50% lower than graphite, as evaluated by dedicated experiments in Pilot‐PSI, a linear plasma simulator device.
Calibration of turbidity meter and acoustic doppler velocimetry (Triton‐ADV) for sediment types present in drained peatland headwaters: Focus on particulate organic peat
Authors: Marttila Hannu , Postila Heini , Kløve Bjørn
Published: August 2009

Suspended sediments have a clear impact on fluvial water quality and aquatic habitats. As the concentrations are highly variable, continuous measurement offers a good way to provide accurate and precise values of sediment concentration and yield. However, there is a lack of information regarding the effect of organic peat particles, which typically appear in boreal fluvial systems. In the present study, the effect of different types of suspended sediments on calibration of a turbidity meter and an acoustic Doppler velocimetry (Triton‐ADV) was studied in laboratory conditions. The measurements were performed using particulate organic peat, clay and silt with several concentrations ranging from clear water to 3500 mg L−1. The present study primarily provides organic peat sediment calibration data for used sensors. Regression equations were developed for the different sediment. The results indicate that particle size, shape, concentration and sediment type have an effect on calibration. When the turbidity and the ADV calibration were performed for different particle size groups, sediment types and concentrations, the calibration and suspended solids calculation error was reduced. For the turbidity sensor used, the reliable upper continuous measurement limit for clay, peat and silt sediments was found to be at 1000, 2500 and 3500 mg L−1, respectively. The ADV‐sensor was noticed to be reliable only with fine particles. The results enable easy and first step calibration and error assessment for automatic turbidity and acoustic monitoring of the suspended sediment quality typically present in headwater fluvial systems. This study can be used to evaluate the effect of different sediments on turbidity and ADV‐measuring error and reliability during changing particles size distributions, characteristics and concentrations. The laboratory‐based approach used in this study indicates that the shape of organic peat particles has an influence on sensor calibration, especially when suspended sediment concentrations are high. Copyright © 2009 John Wiley & Sons, Ltd.
A survey on mobile satellite systems
Authors: Chini Paolo , Giambene Giovanni , Kota Sastri
Published: August 2009

Satellite systems represent a significant solution to provide communication services to mobile users in under‐populated regions, in emergency areas, on planes, trains, and ships. In all these cases, satellite systems have unique capabilities in terms of robustness, wide area coverage, and broadcast/multicast capabilities. This paper surveys current mobile satellite networks and services from different standpoints, encompassing research issues, recent standardization advances (e.g. mobile extension for DVB‐S2/‐RCS, DVB‐SH) and some operational systems (e.g. Globalstar, Inmarsat BGAN, Iridium, and Thuraya). The last part of this paper is devoted to qualitative and quantitative comparisons of the different mobile satellite systems to understand their characteristics in terms of services, capacity, resource utilization efficiency, and user mobility degree.Copyright © 2009 John Wiley & Sons, Ltd.
Immobilization of metallothionein on highly oriented pyrolytic graphite for biosensor design
Authors: Bin Yannan , Gao Yu , Xiang Juan , Ren Bin
Published: August 2009

Immobilization of protein molecules on solid supports or surfaces in a controlled fashion is an important task for protein analysis at the solid/solution or solid/gas interface and biosensor fabrication. In this paper, the structure and biological activities of metallothionein (MT) layers immobilized on highly oriented pyrolytic graphite (HOPG) surfaces by means of two different strategies based on unspecific adsorption/chemisorption (MT‐HOPG system) and covalent binding (MT‐modified HOPG system) were studied respectively. The MT layers obtained by covalent binding to a previously functionalized HOPG surface are smooth and show a close‐packed ordered monolayer in contrast to those obtained by direct adsorption of the protein on substrate, which are disordered and relatively rough. Both adsorbed proteins exhibit reversible electron transfer at 0.25 V (Ag/AgCl) after immersion in CuSO4 solution, whereas redox current of MT‐modified HOPG system is four times larger than that of MT‐HOPG system. Moreover, the MTs adsorbed on bare HOPG surfaces are obviously denatured. All the above results show that covalent binding strategies lead to high structural regularity and mechanical stability of the adsorbed protein molecules with a maintained biological activity, which is prospective for applications in immobilizing MT on a transducer for biosensor design. Copyright © 2009 John Wiley & Sons, Ltd.
Collection and detection of latent fingermarks contaminated with cosmetics on nonporous and porous surfaces
Authors: Ricci Camilla , Kazarian Sergei G.
Published: August 2009

Attenuated total reflection (ATR)‐Fourier transform infrared (FTIR) spectroscopic imaging combined with a gelatine tape lift method was applied to fingermarks contaminated with various types of cosmetic residues and drugs. This approach allowed not only the imaging of partial fingermarks but also demonstrated the advantage of this chemical imaging methodology in being able to detect heterogeneously distributed localized compounds after surfaces contaminated with various types of cosmetics or drug residues had been handled. This is the first time that the detection of cosmetics in fingermarks deposited on nonporous and porous surfaces has been performed. These results show a potential extension of the applicability of ATR‐FTIR imaging to forensic science. Copyright © 2009 John Wiley & Sons, Ltd.
Structure, Stereochemistry and Dynamics of Tetranuclear Polyhydride Clusters Containing Chiral Heterobidentate Phosphanes
Authors: Ponomarenko Vadim I. , Krupenya Dmitrii V. , Grachova Elena V. , Gindin Vladimir A. , Selivanov Stanislav I. , Koshevoy Igor O. , Tunik Sergey P. , Haukka Matti , Pursiainen Jouni , Pirilä Päivi
Published: August 2009

A novel chiral phosphane (S)‐2‐(4‐isopropyl‐2‐oxazoline‐2‐yl)phenyl‐di‐N‐pyrrolylphosphane (S‐PyrPOx) based on asymmetric oxazoline ring has been prepared and characterised. Reaction of this ligand and its phenyl‐substituted analogue (S‐PhPOx) with H4Ru4(CO)12 and H3RhOs3(CO)12 gave substituted derivatives H4Ru4(CO)10(1,1‐PhPOx) (2), H4Ru4(CO)10(1,1‐PyrPOx) (3), and H3RhOs3(CO)10(1,1‐PyrPOx) (4), which were structurally characterised by X‐ray crystallography in solid state and by a variety of multinuclear NMR spectroscopic measurements in solution. In all studied clusters the coordinated ligands form five‐membered chelate rings through phosphorus and nitrogen atoms of oxazoline moiety to afford a novel chiral center associated with the substituted metal atom. The substitution reactions demonstrate extremely high stereoselectivity, which results in formation of only one diastereomer in all three cases to give S,S isomer in 2 and S,R isomer in 3 and 4.
Early neonatal inflammation affects adult pain reactivity and anxiety related traits in mice: genetic background counts
Authors: Benatti Cristina , Alboni Silvia , Capone Giacomo , Corsini Daniela , Caggia Federica , Brunello Nicoletta , Tascedda Fabio , Blom Joan M.C.
Published: August 2009

Protracted or recurrent pain and inflammation in the early neonatal period may cause long‐lasting changes in central neural function. However, more research is necessary to better characterize the long‐term behavioral sequelae of such exposure in the neonatal period. Objectives: (1) to study whether timing of postnatal exposure to persistent inflammation alters responsiveness to thermal pain in the adult animal; (2) to assess whether animals experiencing early postnatal chronic inflammation display altered anxiety related behavior; (3) to study the importance of genetic background. Newborn mice (outbred strain, CD1 and F1 hybrid strain, B6C3F1) received an injection of Complete Freund's Adjuvant (CFA) or saline on either postnatal day 1 or 14 (PND1; PND14) into the left hind paw. Pain to radiant heat and anxiety were examined in 12‐week‐old adult animals. Adult baseline PWL was significantly decreased in CD1 mice exposed to CFA on PND 1 and 14 as compared to their saline treated counterparts. B6C3F1 mice exposed to CFA on PND14 showed markedly reduced baseline PWL compared to the PND14 saline group. Persistent inflammation experienced by B6C3F1 mice on PND1 failed to affect baseline adult thermal responsiveness. Adult mice, CD1 and B6C3F1, displayed low anxiety traits only if they had been exposed to persistent inflammation on PND1 and not on PND14. Our research suggests a role for genetic background in modulating long‐term behavioral consequences of neonatal persistent inflammation: the data support the hypothesis that pain experienced very early in life differentially affects adult behavioral and emotional responsiveness in outbred (CD1) and hybrid mice (B6C3F1).
The pineal volume: a three‐dimensional volumetric study in healthy young adults using 3.0 T MR data
Authors: Sun Bo , Wang Dan , Tang Yuchun , Fan Lingzhong , Lin Xiangtao , Yu Taifei , Qi Hengtao , Li Zhenping , Liu Shuwei
Published: August 2009

It is usually difficult to distinguish small pineal tumors via routine or enhanced magnetic resonance (MR) scan. The knowledge of normal pineal size is helpful to detect small pineal lesions, while very few true volumetric data of pineal glands have been reported. Therefore, we obtained the accurate reference range of normal pineal volumes in 112 individuals aged 20–30 years recruited randomly from a healthy community sample. Transverse and sagittal 3.0 T magnetic resonance data were obtained using three‐dimensional (3D) T1‐weighted FSPGR and T2‐weighted SE sequences. True pineal volumes were measured from T1‐weighted images, while estimated volumes were calculated using pineal length, width and height. All the glands were divided into three types according to the maximum inner diameter of pineal cysts. The prevalence of asymptomatic pineal cyst is 25.00%, with a slight female predominance. In the whole sample, we found no gender differences of pineal volume, but a significant gender difference of pineal volume index. A significant correlation between pineal volume and asymptomatic cyst was found. After excluding cases with big pineal cysts, there were significant correlations between pineal volume and head circumference, body height and body weight, respectively. This study suggests that asymptomatic pineal cysts may exert an important influence on pineal volume.
Quaternary evolution of the intermontane Val d'Agri Basin, Southern Apennines
Authors: Zembo Irene , Panzeri Laura , Galli Anna , Bersezio Riccardo , Martini Marco , Sibilia Emanuela
Published: August 2009

Optically Stimulated Luminescence (OSL) enables the chronology of the late Pleistocene evolution for the Val d'Agri intermontane basin of Southern Apennines to be defined in the frame of Mediterranean geodynamic and climate changes. Quartz sand from braided floodplain and alluvial fan depositional systems was analyzed using the coarse-grained, single-aliquot regenerative-dose (SAR) technique. The obtained optical ages are mostly consistent with other assessments (radiocarbon, tephrochronology) and stratigraphic constraints. OSL allows for the dating to 56–43 ka of an asymmetric subsidence stage that forced alluvial fan progradation, filling of a former lacustrine area, and development of an axial alluvial plain. A short period of Mediterranean-type pedogenesis, recorded at the top of the prograding-aggrading fans (OSL age bracket 43–32 ka), corresponds with MIS 3. During the subsequent stage of decline of vegetation cover, possibly corresponding to MIS 2, the latest progradation of alluvial fans occurred. The subsequent uplift and breakthrough of the basin threshold during the latest Pleistocene and Holocene induced entrenchment of the drainage network. The results presented here provide an example of the usefulness of OSL dating in intermontane continental settings where other geochronological constraints are scarce.
Spatial patterns of Holocene glacier advance and retreat in Central Asia
Authors: Rupper Summer , Roe Gerard , Gillespie Alan
Published: August 2009

Glaciers in the southern Himalayas advanced in the early Holocene despite an increase in incoming summer solar insolation at the top of the atmosphere. These glacier advances are in contrast to the smaller alpine glaciers in the western and northern regions of Central Asia. Two different glacier mass-balance models are used to reconcile this Holocene glacier history with climate by quantifying the change in equilibrium-line altitudes (ELA) for simulated changes in Holocene climate. Both ELA models clearly show that the lowering of ELAs in the southern Himalayas is largely due to a decrease in summer temperatures, and that an increase in monsoonal precipitation accounts for less than 30% of the total ELA changes. The decrease in summer temperatures is a dynamic response to the changes in solar insolation, resulting in both a decrease in incoming shortwave radiation at the surface due to an increase in cloudiness and an increase in evaporative cooling. In the western and northern zones of Central Asia, both ELA models show a rise in ELAs in response to a general increase in summer temperatures. This increase in temperatures in the more northern regions is a direct radiative response to the increase in summer solar insolation.
Enzyme supplementation of dry and wet wheat-based feeds for broiler chickens: performance and gut responses
Authors: Yasar S. , Forbes J. M.
Published: August 2009

To test whether the improvements in digestive efficiency due to either wetting of the food or inclusion of enzymes are accompanied by the same changes in gut function, foods with a high content of wheat were fed to broiler chicks from 1–42 d old. Twenty-four birds were caged individually while a further sixty-four were in group pens in experiments of 2 × 2 factorial design with two levels of enzyme (0 or 1 g/kg, designed for wheat) and two levels of water addition (0 and 1300 g/kg). Food intake and live-weight gain were significantly increased by wet feeding (from 89·3 to 153·4 g/d and from 39·7 to 65·4 g/d respectively), the differences increasing with age, while the enzyme had no significant effect (120·5 and 122·2 g/d and 51·9 and 53·1g/week respectively). The viscosity of digesta was greatly reduced both by wetting (from 4·40 to 2·64 kPa · s) and enzyme (from 4·47 to 2·57 kPa · s) but there was a significant interaction with age in which the viscosity was low throughout in the wet only, enzyme only and wet + enzyme treatments but declined with age from a very high level in the dry, no enzyme treatment (11·5 kPa · s at 14 d). While wetting increased weight and length of digestive tract and thickness of some parts of the gut, enzyme had no significant effect, tending to reduce gut wall thickness. Crypt cell proliferation rate (CCPR) was significantly reduced by wet feeding (from 39·4 to 28·7 cells/crypt per 2 h) and by enzyme supplementation (from 38·9 to 29·2 cells/crypt per 2 h). Therefore, while both wetting and enzyme addition to the food reduced digesta viscosity and CCPR to a similar extent, the former had marked stimulatory effects on food intake and weight gain while the latter had little effect. The mode of action of wet feeding is therefore deduced to be not primarily through its effects on viscosity and CCPR.
Poisson automorphisms and quiver moduli
Authors: Reineke Markus
Published: August 2009

A factorization formula for certain automorphisms of a Poisson algebra associated with a quiver is proved, which involves framed versions of moduli spaces of quiver representations. This factorization formula is related to wall-crossing formulae for Donaldson–Thomas type invariants of Kontsevich and Soibelman.
Adenosine deaminase enhances T‐cell response elicited by dendritic cells loaded with inactivated HIV
Authors: Climent Núria , Martinez‐Navio José M , Gil Cristina , Garcia Felipe , Rovira Cristina , Hurtado Carmen , Miralles Laia , Gatell José M , Gallart Teresa , Mallol Josefa , Lluis Carme , Franco Rafael
Published: August 2009

As host immunological defenses are impaired during HIV infection, it is difficult to elicit good responses when attempting to develop therapeutic vaccines against HIV. To try to solve this situation, adjuvants, particularly cytokines, are currently under evaluation. Owing to the fact that adenosine deaminase (ADA) is a member of the family of growth factor with deaminase activity, we tested whether it could improve immune responses in the development of HIV dendritic‐cell‐based therapeutic vaccines. A co‐culture model approach has been used to test the usefulness of ADA as adjuvant. Monocyte‐derived dendritic cells from HIV‐infected patients were pulsed with inactivated HIV, matured and co‐cultured with autologous T cells. Addition of ADA to the co‐cultures resulted in enhanced CD4+ and CD8+ T‐cell proliferation and robust ADA‐induced increase in cytokine production (IFN‐γ, TNF‐α and IL‐6). As IFN‐γ, TNF‐α and IL‐6 promote the Th1 versus Th2 phenotype and improve T helper proliferation responses and antigen‐specific CTL responses ADA may be considered a promising candidate for therapeutic vaccine adjuvant.
Gate-bias stress in amorphous oxide semiconductors thin-film transistors
Authors: Lopes M. E. , Gomes H. L. , Medeiros M. C. R. , Barquinha P. , Pereira L. , Fortunato E. , Martins R. , Ferreira I.
Published: August 2009

A quantitative study of the dynamics of threshold-voltage shifts with time in gallium-indium zinc oxide amorphous thin-film transistors is presented using standard analysis based on the stretched exponential relaxation. For devices using thermal silicon oxide as gate dielectric, the relaxation time is 3×105 s at room temperature with activation energy of 0.68 eV. These transistors approach the stability of the amorphous silicon transistors. The threshold voltage shift is faster after water vapor exposure suggesting that the origin of this instability is charge trapping at residual-water-related trap sites.
Real time synchrotron x-ray diffraction measurements to determine material strength of shocked single crystals following compression and release
Authors: Turneaure Stefan J. , Gupta Y. M.
Published: August 2009

We present a method to use real time, synchrotron x-ray diffraction measurements to determine the strength of shocked single crystals following compression and release during uniaxial strain loading. Aluminum and copper single crystals shocked along [111] were examined to peak stresses ranging from 2 to 6 GPa. Synchrotron x rays were used to probe the longitudinal lattice strains near the rear free surface (16 and 5 μm depths for Al and Cu, respectively) of the metal crystals following shock compression and release. The 111 diffraction peaks showed broadening indicating a heterogeneous microstructure in the released state. The diffraction peaks also shifted to lower Bragg angles relative to the ambient Bragg angle; the magnitude of the shift increased with increasing impact stress. The Bragg angle shifts and appropriate averaging procedures were used to determine the macroscopic or continuum strength following compression and release. For both crystals, the strengths upon release increased with increasing impact stress and provide a quantitative measure of the strain hardening that occurs in Al(111) and Cu(111) during the shock and release process. Our results for Al(111) are in reasonable agreement with a previous determination based solely on continuum measurements. Two points are noteworthy about the developments presented here: Synchrotron x rays are needed because they provide the resolution required for analyzing the data in the released state; the method presented here can be extended to the shocked state but will require additional measurements.
On the modeling of modes coupling in dissipative fluid-filled waveguide with corrugated surfaces
Authors: Valier-Brasier Tony , Potel Catherine , Bruneau Michel
Published: August 2009

This paper aims at providing an alternative analytical model, which would be more suitable than a previous one [C. Potel and M. Bruneau, J. Sound Vib. 313, 738 (2008)], to describe the mode coupling due to scattering on small one-dimensional irregularities (parallel ridges) of the surfaces of a fluid-filled waveguide. Both models rely on standard integral formulation and modal analysis, the acoustic field being expressed as a coupling between eigenmodes of a regularly shaped waveguide, which bounds outwardly the corrugated waveguide considered. But the model presented here departs from the previous one essentially because it starts from the integral formulation for the acoustic pressure field, the solution relying on a modal expansion, whereas the previous one starts from the inner product of the set of differential equations (which govern the acoustic pressure field) and the appropriate eigenfunctions, the solution being obtained from using a one-dimensional integral formulation. Substituting this alternative model for the previous one clearly accelerates convergences (even permits to avoid divergences) of the iterative process used to solve the problem. Finally, complex eigenfunctions are introduced here in order to account for the dissipative effects due to thermoviscous phenomena (through an impedancelike boundary condition), which is of importance at the cut-off frequencies.
Suppressing high-power microwave dielectric multipactor by the sawtooth surface
Authors: Chang C. , Liu G. Z. , Huang H. J. , Chen C. H. , Fang J. Y.
Published: August 2009

This paper theoretically and experimentally researches the effect of a periodic sawtooth surface on vacuum multipactor. Dynamic calculation and particle-in-cell simulation are applied to analyze the electron impact energy and multipactor scenario on the periodic isosceles triangular surface with different slope angles and heights. It has been discovered that, with the slope angle increasing, the impact energy significantly decreases to be lower than the first crossover energy of the secondary yield curve, leading to suppressed multipactor. S-band high power microwave dielectric breakdown experiment, with microsecond pulse length, was conducted. It is confirmed by experiment that the periodic sawtooth surface with sufficiently large slope angle (such as 45°) can effectively increase the breakdown threshold of about 2 compared to the flat surface.
High contact angle hysteresis of superhydrophobic surfaces: Hydrophobic defects
Authors: Chang Feng-Ming , Hong Siang-Jie , Sheng Yu-Jane , Tsao Heng-Kwong
Published: August 2009

A typical superhydrophobic surface is essentially nonadhesive and exhibits very low water contact angle (CA) hysteresis, so-called Lotus effect. However, leaves of some plants such as scallion and garlic with an advancing angle exceeding 150° show very serious CA hysteresis. Although surface roughness and epicuticular wax can explain the very high advancing CA, our analysis indicates that the unusual hydrophobic defect, diallyl disulfide, is the key element responsible for contact line pinning on allium leaves. After smearing diallyl disulfide on an extended polytetrafluoroethylene (PTFE) film, which is originally absent of CA hysteresis, the surface remains superhydrophobic but becomes highly adhesive.
A multiscale approach to diffraction tomography of complex three-dimensional objects
Authors: Simonetti F. , Huang L. , Duric N.
Published: August 2009

Tomography of complex three-dimensional objects with diffractive waves remains an open challenge due to the large number of scattering measurements required to obtain a stable solution to the inverse problem of reconstructing an image of the object from a set of independent scattering experiments. Here, this problem is addressed with a multiscale approach that is demonstrated experimentally using ultrasonic waves and which leads to high resolution images comparable to x-ray computerized tomography but without the limitations associated with ionizing radiation.
Doping nanowires grown by the vapor-liquid-solid mechanism
Authors: Schwalbach E. J. , Voorhees P. W.
Published: August 2009

The ability to dope semiconductor nanowires during growth is an important step toward making functional devices. We develop a model for steady state vapor-liquid-solid growth of a ternary semiconductor-catalyst-dopant nanowire. Our analysis shows that the relative flux of dopant atoms through the liquid controls the mole fraction of dopant in the solid wire, and that local equilibrium constrains the catalyst composition in the solid and the compositions of the dopant and catalyst in the liquid. We find that the phase diagram can be used to determine an upper limit on the dopant composition in the solid.
The frequency of polyploid speciation in vascular plants
Authors: Wood Troy E. , Takebayashi Naoki , Barker Michael S. , Mayrose Itay , Greenspoon Philip B. , Rieseberg Loren H.
Published: August 2009

Since its discovery in 1907, polyploidy has been recognized as an important phenomenon in vascular plants, and several lines of evidence indicate that most, if not all, plant species ultimately have a polyploid ancestry. However, previous estimates of the frequency of polyploid speciation suggest that the formation and establishment of neopolyploid species is rare. By combining information from the botanical community's vast cytogenetic and phylogenetic databases, we establish that 15% of angiosperm and 31% of fern speciation events are accompanied by ploidy increase. These frequency estimates are higher by a factor of four than earlier estimates and lead to a standing incidence of polyploid species within genera of 35% (
n
= 1,506). Despite this high incidence, we find no direct evidence that polyploid lines, once established, enjoy greater net species diversification. Thus, the widespread occurrence of polyploid taxa appears to result from the substantial contribution of polyploidy to cladogenesis, but not from subsequent increases in diversification rates of polyploid lines.
The N-terminal peptide of the syntaxin Tlg2p modulates binding of its closed conformation to Vps45p
Authors: Furgason Melonnie L. M. , MacDonald Chris , Shanks Scott G. , Ryder Sean P. , Bryant Nia J. , Munson Mary
Published: August 2009

The Sec1/Munc18 (SM) protein family regulates intracellular trafficking through interactions with individual SNARE proteins and assembled SNARE complexes. Revealing a common mechanism of this regulation has been challenging, largely because of the multiple modes of interaction observed between SM proteins and their cognate syntaxin-type SNAREs. These modes include binding of the SM to a closed conformation of syntaxin, binding to the N-terminal peptide of syntaxin, binding to assembled SNARE complexes, and/or binding to nonsyntaxin SNAREs. The SM protein Vps45p, which regulates endosomal trafficking in yeast, binds the conserved N-terminal peptide of the syntaxin Tlg2p. We used size exclusion chromatography and a quantitative fluorescent gel mobility shift assay to reveal an additional binding site that does not require the Tlg2p N-peptide. Characterization of Tlg2p mutants and truncations indicate that this binding site corresponds to a closed conformation of Tlg2p. Furthermore, the Tlg2p N-peptide competes with the closed conformation for binding, suggesting a fundamental regulatory mechanism for SM–syntaxin interactions in SNARE assembly and membrane fusion.
Evolutionary and functional insights into the mechanism underlying high-altitude adaptation of deer mouse hemoglobin
Authors: Storz Jay F. , Runck Amy M. , Sabatino Stephen J. , Kelly John K. , Ferrand Nuno , Moriyama Hideaki , Weber Roy E. , Fago Angela
Published: August 2009

Adaptive modifications of heteromeric proteins may involve genetically based changes in single subunit polypeptides or parallel changes in multiple genes that encode distinct, interacting subunits. Here we investigate these possibilities by conducting a combined evolutionary and functional analysis of duplicated globin genes in natural populations of deer mice (Peromyscus maniculatus) that are adapted to different elevational zones. A multilocus analysis of nucleotide polymorphism and linkage disequilibrium revealed that high-altitude adaptation of deer mouse hemoglobin involves parallel functional differentiation at multiple unlinked gene duplicates: two α-globin paralogs on chromosome 8 and two β-globin paralogs on chromosome 1. Differences in O2-binding affinity of the alternative β-chain hemoglobin isoforms were entirely attributable to allelic differences in sensitivity to 2,3-diphosphoglycerate (DPG), an allosteric cofactor that stabilizes the low-affinity, deoxygenated conformation of the hemoglobin tetramer. The two-locus β-globin haplotype that predominates at high altitude is associated with suppressed DPG-sensitivity (and hence, increased hemoglobin-O2affinity), which enhances pulmonary O2loading under hypoxia. The discovery that allelic differences in DPG-sensitivity contribute to adaptive variation in hemoglobin–O2affinity illustrates the value of integrating evolutionary analyses of sequence variation with mechanistic appraisals of protein function. Investigation into the functional significance of the deer mouse β-globin polymorphism was motivated by the results of population genetic analyses which revealed evidence for a history of divergent selection between elevational zones. The experimental measures of O2-binding properties corroborated the tests of selection by demonstrating a functional difference between the products of alternative alleles.
R1441C mutation in LRRK2 impairs dopaminergic neurotransmission in mice
Authors: Tong Youren , Pisani Antonio , Martella Giuseppina , Karouani Maha , Yamaguchi Hiroo , Pothos Emmanuel N. , Shen Jie
Published: August 2009

Dominantly inherited mutations in leucine-rich repeat kinase 2 (LRRK2) are a common genetic cause of Parkinson's disease (PD). The importance of the R1441 residue in the pathogenesis is highlighted by the identification of three distinct missense mutations. To investigate the pathogenic mechanism underlying LRRK2 dysfunction, we generated a knockin (KI) mouse in which the R1441C mutation is expressed under the control of the endogenous regulatory elements. Homozygous R1441C KI mice appear grossly normal and exhibit no dopaminergic (DA) neurodegeneration or alterations in steady-state levels of striatal dopamine up to 2 years of age. However, these KI mice show reductions in amphetamine (AMPH)-induced locomotor activity and stimulated catecholamine release in cultured chromaffin cells. The introduction of the R1441C mutation also impairs dopamine D2 receptor function, as suggested by decreased responses of KI mice in locomotor activity to the inhibitory effect of a D2 receptor agonist, quinpirole. Furthermore, the firing of nigral neurons in R1441C KI mice show reduced sensitivity to suppression induced by quinpirole, dopamine, or AMPH. Together, our data suggest that the R1441C mutation in LRRK2 impairs stimulated dopamine neurotransmission and D2 receptor function, which may represent pathogenic precursors preceding dopaminergic degeneration in PD brains.
A role for the TGFβ-Par6 polarity pathway in breast cancer progression
Authors: Viloria-Petit Alicia M. , David Laurent , Jia Jun Yong , Erdemir Tuba , Bane Anita L. , Pinnaduwage Dushanthi , Roncari Luba , Narimatsu Masahiro , Bose Rohit , Moffat Jason , Wong John W. , Kerbel Robert S. , O'Malley Frances P. , Andrulis Irene L. , Wrana Jeffrey L.
Published: August 2009

The role of polarity signaling in cancer metastasis is ill defined. Using two three-dimensional culture models of mammary epithelial cells and an orthotopic mouse model of breast cancer, we reveal that Par6 signaling, which is regulated directly by TGFβ, plays a role in breast cancer metastasis. Interference with Par6 signaling blocked TGFβ-dependent loss of polarity in acini-like structures formed by non-transformed mammary cells grown in three-dimensional structures and suppressed the protrusive morphology of mesenchymal-like invasive mammary tumor cells without rescuing E-cadherin expression. Moreover, blockade of Par6 signaling in an in vivo orthotopic model of metastatic breast cancer induced the formation of ZO-1-positive epithelium-like structures in the primary tumor and suppressed metastasis to the lungs. Analysis of the pathway in tissue microarrays of human breast tumors further revealed that Par6 activation correlated with markers of the basal carcinoma subtype in
BRCA1
-associated tumors. These studies thus reveal a key role for polarity signaling and the control of morphologic transformation in breast cancer metastasis.
Microanalysis of organic pigments and glazes in polychrome works of art by surface-enhanced resonance Raman scattering
Authors: Leona Marco
Published: August 2009

Scientific studies of works of art are usually limited by severe sampling restrictions. The identification of organic colorants, a class of compounds relevant for attribution and provenance studies, is further complicated by the low concentrations at which these compounds are used and by the interference of the protein-, gum-, or oil-binding media present in pigment and glaze samples. Surface-enhanced resonance Raman scattering (SERRS) was successfully used to identify natural organic colorants in archaeological objects, polychrome sculptures, and paintings from samples smaller than 25 μm in diameter. The key factors in achieving the necessary sensitivity were a highly active stabilized silver colloid, obtained by the reproducible microwave-supported reduction of silver sulfate with glucose and sodium citrate, and a non-extractive hydrolysis sample treatment procedure that maximizes dye adsorption on the colloid. Among the examples presented are the earliest so far found occurrence of madder lake (in a 4,000 years old Egyptian object dating to the Middle Kingdom period), and the earliest known occurrence in Europe of the South Asian dyestuff lac (in the Morgan Madonna, a 12thcentury polychrome sculpture from Auvergne, France).