bluuebunny/crossref_metadata_2025 huggingface dataset:
Scaled biotic disruption during early Eocene global warming events
Authors: Gibbs S. J. , Bown P. R. , Murphy B. H. , Sluijs A. , Edgar K. M. , Pälike H. , Bolton C. T. , Zachos J. C.
Published: November 2012

Abstract. Late Paleocene and early Eocene hyperthermals are transient warming events associated with massive perturbations of the global carbon cycle, and are considered partial analogues for current anthropogenic climate change. Because the magnitude of carbon release varied between the events, they are natural experiments ideal for exploring the relationship between carbon cycle perturbations, climate change and biotic response. Here we quantify marine biotic variability through three million years of the early Eocene that include five hyperthermals, utilizing a method that allows us to integrate the records of different plankton groups through scenarios ranging from background to major extinction events. Our long time-series calcareous nannoplankton record indicates a scaling of biotic disruption to climate change associated with the amount of carbon released during the various hyperthermals. Critically, only the three largest hyperthermals, the Paleocene–Eocene Thermal Maximum (PETM), Eocene Thermal Maximum 2 (ETM2) and the I1 event, show above-background variance, suggesting that the magnitude of carbon input and associated climate change needs to surpass a threshold value to cause significant biotic disruption.
Timing of fire relative to seed development controls availability of non-serotinous aerial seed banks
Authors: Michaletz S. T. , Johnson E. A. , Mell W. E. , Greene D. F.
Published: November 2012

Abstract. The existence of non-serotinous, non-sprouting species in fire regimes where serotiny confers an adaptive advantage is puzzling, particularly when these species recruit poorly from soil seed banks or from burn edges. In this paper, white spruce (Picea glauca (Moench) Voss) was used to show that the timing of fire relative to seed development can control aerial seed bank availability for non-serotinous species. To estimate seed survival in closed cones during crown fires, cone heating was simulated using a one-dimensional conduction model implemented in a computational fluid dynamics (Navier–Stokes) fire spread model. To quantify the area burned when germinable seed would be contained in closed cones, empirical fire occurrence and seed development (germinability and cone opening) data were compared for multiple locations across the white spruce range. Approximately 12% of cones contained viable seed following crown fire simulations (0.072 m s−1 mean spread rate; 9147 kW m−1 mean intensity), and roughly half of the historical area burned resulted from fires that occurred when closed cones would contain germinable seed. Post-fire recruitment from in situ aerial seed banks can occur for non-serotinous species, and may be an important cause of their existence in fire regimes to which they otherwise seem poorly suited.
Three-dimensional thermal structure of subduction zones: effects of obliquity and curvature
Authors: Bengtson A. K. , van Keken P. E.
Published: November 2012

Abstract. Quantifying the precise thermal structure of subduction zones is essential for understanding the nature of metamorphic dehydration reactions, arc volcanism, and intermediate depth seismicity. High resolution two-dimensional (2-D) models have shown that the rheology of the mantle wedge plays a critical role and establishes strong temperature gradients in the slab. The influence of three-dimensional (3-D) subduction zone geometry on thermal structure is however not yet well characterized. A common assumption for 2-D models is that the cross-section is taken normal to the strike of the trench with a corresponding velocity reduction in the case of oblique subduction, rather than taken parallel to velocity. A comparison between a full 3-D Cartesian model with oblique subduction and selected 2-D cross-sections demonstrates that the trench-normal cross-section provides a better reproduction of the slab thermal structure than the velocity-parallel cross-section. An exception is found in the case of a strongly curved trench, such as in the Marianas, where strong 3-D flow in the mantle wedge is generated. In this case it is shown that the full 3-D model should be evaluated for an accurate prediction of the slab thermal structure. The models demonstrate that the use of a dynamic slab and wedge, separated by a kinematic boundary, yields good results for describing slab velocities in 3-D.
Depression and Coronary Heart Disease
Authors: Davidson Karina W.
Published: November 2012

There are exciting findings in the field of depression and coronary heart disease. Whether diagnosed or simply self-reported, depression continues to mark very high risk for a recurrent acute coronary syndrome or for death in patients with coronary heart disease. Many intriguing mechanisms have been posited to be implicated in the association between depression and heart disease, and randomized controlled trials of depression treatment are beginning to delineate the types of depression management strategies that may benefit the many coronary heart disease patients with depression.
Improving Carrot Yield and Quality through the Use of Bio-slurry Manure
Authors: Jeptoo Agnes , Aguyoh Joseph N , Saidi Mwanarusi
Published: November 2012

Continuous cultivation of farms has led to decline in soil fertility due to constant removal of nutrients leading to reduction of carrot (Daucus carota L.) yields. A field study was carried out at Egerton University, Horticulture Research and Teaching field in two seasons (October 2010 to January 2011 and February to May 2011) with the aim of investigating the effects of decomposed cattle bio-slurry manure on carrot growth and performance. The experimental design was a Randomized Complete Block Design (RCBD) with 3 replications. Treatments comprised four levels (0, 2.6, 5.2 and 7.8 t/ha) of decomposed bio-slurry manure. Growth, yield and quality parameters were recorded and used to discern the treatment effects. Application of bio-slurry manure generally improved growth, yield and quality of carrots. Application of 7.8 t/ha of bio-slurry increased yields by 8.8% in season 1 and 23.5% in season 2 compared to the control. Leaf numbers, plant height, dry weights of shoot and roots and root volume were also generally higher for the 7.8 t/ha treatment compared to other treatments. Total Soluble Solids of roots from plant treated with 7.8 t/ha were higher by 12.7% in season 1 and 13.2% in season 2 compared to the control. The study recommends 7.8 t/ha of bio-slurry manure for enhanced yield and quality of carrot.
Experimental Study of the Methodology for the Modelling and Simulation of Mobile Manipulators
Authors: Aviles Luis Adrian Zuñiga , Ortega Jesus Carlos Pedraza , Hurtado Efren Gorrostieta
Published: November 2012

This paper describes an experimental study of a novel methodology for the positioning of a multi-articulated wheeled mobile manipulator with 12 degrees of freedom used for handling tasks with explosive devices. The approach is based on an extension of a homogenous transformation graph (HTG), which is adapted to be used in the kinematic modelling of manipulators as well as mobile manipulators. The positioning of a mobile manipulator is desirable when: ( 1 ) the manipulation task requires the orientation of the whole system towards the objective; ( 2 ) the tracking trajectories are performed upon approaching the explosive device's location on the horizontal and inclined planes; ( 3 ) the application requires the manipulation of the explosive device; ( 4 ) the system requires the extension of its vertical scope; and ( 5 ) the system is required to climb stairs using its front arms. All of the aforementioned desirable features are analysed using the HTG, which establishes the appropriate transformations and interaction parameters of the coupled system. The methodology is tested with simulations and real experiments of the system where the error RMS average of the positioning task is 7. 91 mm, which is an acceptable parameter for performance of the mobile manipulator.
Design and Development of a Real-Time GPS-Aided SINU System
Authors: Lim Chot Hun , Lim Tien Sze , Koo Voon Chet
Published: November 2012

A Strapdown Inertial Navigation Unit (SINU) is a low cost motion measurement device commonly used for navigation solutions. Global Positioning System (GPS) is usually adopted as an external reference source to minimize the SINU's accumulation errors by applying a Kalman filter to obtain best estimations in positions, velocities and orientations. However, due to the low sampling rate of GPS, such a configuration does not provide intensive orientation estimation. In this paper, a new and efficient real-time GPS-aided SINU system with incorporated magnetometers is developed to enhance the orientation estimation. An intensive orientation estimation algorithm is developed by combining the extra sensory inputs from magnetometers with the inputs from accelerometers. The estimated orientation was applied in the Kalman filtering, replacing the GPS-aided orientation estimation. The offline implementation shows promising results in reducing both the accelerometers' and gyroscopes' errors. Finally, the design is successfully implemented in real-time.
Flexible Structural Design for Side-Sliding Force Reduction for a Caterpillar Climbing Robot
Authors: Cui Weina , Wang Wei , Zhao Longchao , Zhang Houxiang
Published: November 2012

Due to sliding force arising from the closed chain mechanism among the adhering points of a climbing caterpillar robot (CCR), a sliding phenomenon will happen at the adhering points, e.g., the vacuum pads or claws holding the surface. This sliding force makes the attachment of the climbing robot unsteady and reducesthe motion efficiency. According to the new bionic research on the soft-body structure of caterpillars, some flexible structures made of natural rubber bars are applied in CCRs correspondingly as an improvement to the old rigid mechanical design of the robotic structure. This paper firstly establishes the static model of the sliding forces, the distortion of flexible bars and the driving torques of joints. Then, a method to reduce the sliding force by exerting a compensating angle to an active joint of the CCR is presented. The analyses and experimental results indicate that the flexible structure and the compensating angle method can reduce the sliding forces remarkably.
On the Robot Singularity: A Novel Geometric Approach
Authors: Hong Man Bok
Published: November 2012

This paper addresses a novel geometric analysis method of the singularity and kinestatic characteristics of robots. For non-redundant robots, there exist two uniquely determined Jacobians – the screw-based Jacobian and the reciprocal Jacobian. Here, it is shown that if some of the reciprocal products between the column screws of the two Jacobians are close to zero, the robot is in the vicinity of a singular configuration and the corresponding columns of the Jacobian are involved in the singularity. From this observation, an invariant measure of closeness to a singularity is presented using the reciprocal products. Furthermore, by considering the reciprocal products between the actuated joint screws and column screws of the Jacobian, this measure is extended so that the concept of the kinestatic characterization index is presented for parallel robots. Since it is defined as the ratio of reciprocal products from the uniqueness of the two Jacobians, it represents a unique invariant characteristic of robots. From the singularity analyses of the planar 4-bar linkage and the 3-DOF parallel manipulator with PRS-serial chains, the validity of the proposed index is examined and the concept of a kinestatically balanced configuration is introduced as well.
Adult HIV care resources, management practices and patient characteristics in the Phase 1 IeDEA Central Africa cohort
Authors: Divaris Kimon , Newman Jamie , Hemingway‐Foday Jennifer , Akam Wilfred , Balimba Ashu , Dusengamungu Cyrille , Kalenga Lucien , Mbaya Marcel , Molu Brigitte Mfangam , Mugisha Veronicah , Mukumbi Henri , Mushingantahe Jules , Nash Denis , Niyongabo Théodore , Atibu Joseph , Azinyue Innocent , Kiumbu Modeste , Woelk Godfrey
Published: November 2012

Introduction

Despite recent advances in the management of HIV infection and increased access to treatment, prevention, care and support, the HIV/AIDS epidemic continues to be a major global health problem, with sub‐Saharan Africa suffering by far the greatest humanitarian, demographic and socio‐economic burden of the epidemic. Information on HIV/AIDS clinical care and established cohorts’ characteristics in the Central Africa region are sparse.

Methods

A survey of clinical care resources, management practices and patient characteristics was undertaken among 12 adult HIV care sites in four countries of the International Epidemiologic Databases to Evaluate AIDS Central Africa (IeDEA‐CA) Phase 1 regional network in October 2009. These facilities served predominantly urban populations and offered primary care in the Democratic Republic of Congo (DRC; six sites), secondary care in Rwanda (two sites) and tertiary care in Cameroon (three sites) and Burundi (one site).

Results

Despite some variation in facility characteristics, sites reported high levels of monitoring resources, including electronic databases, as well as linkages to prevention of mother‐to‐child HIV transmission programs. At the time of the survey, there were 21,599 HIV‐positive adults (median age=37 years) enrolled in the clinical cohort. Though two‐thirds were women, few adults (6.5%) entered HIV care through prevention of mother‐to‐child transmission services, whereas 55% of the cohort entered care through voluntary counselling and testing. Two‐thirds of patients at sites in Cameroon and DRC were in WHO Stage III and IV at baseline, whereas nearly all patients in the Rwanda facilities with clinical stage information available were in Stage I and II. WHO criteria were used for antiretroviral therapy initiation. The most common treatment regimen was stavudine/lamivudine/nevirapine (64%), followed by zidovudine/lamivudine/nevirapine (19%).

Conclusions

Our findings demonstrate the feasibility of establishing large clinical cohorts of HIV‐positive individuals in a relatively short amount of time in spite of challenges experienced by clinics in resource‐limited settings such as those in this region. Country differences in the cohort's site and patient characteristics were noted. This information sets the stage for the development of research initiatives and additional programs to enhance adult HIV care and treatment in Central Africa.
Are HIV‐related factors associated with pre‐term delivery in a UK inner city setting?
Authors: Cheshire M , Kingston M , McQuillan O , Gittins M
Published: November 2012

Purpose

In the UK the accepted standards for the management of HIV‐positive pregnant women are the British HIV Association Guidelines [1]. The guidelines were updated in 2012 and make reference to conflicting evidence regarding the risk of premature birth; some studies suggest an increased risk of preterm delivery (PTD) in women treated with protease inhibitors (PIs) but others do not. Several of these studies have been conducted in developing countries and not in a setting analogous to UK healthcare. The aim of this study was to examine data from HIV‐positive pregnant women attending a large UK teaching hospital, comparing the rates of PTD in women on PI‐based regimes to those on non‐PI based regimes. In addition, known and possible confounding risk factors for prematurity were considered.

Methods

We analysed retrospective data from the files of HIV‐positive women attending a UK maternity center with specialist HIV care between 2003 and 2012. Inclusion criteria were women who delivered live‐born infant(s) beyond 24 weeks gestation, and who were taking anti‐retroviral treatment at some point during the first 37 weeks of their pregnancy. Preterm delivery was defined as delivery at less than 37 weeks. Multi‐variable logistic regression adjusted for repeated measures was used to compare the rates of PTD in women on non‐PI‐based regimes with those on PI‐based regimes; adjusting for possible covariates, including the percentage increase in CD4 count during pregnancy, the timing of HAART initiation, and concurrent genital tract infections.

Results

A total of 208 pregnancies in 157 women were included in the study. The overall prematurity rate was 11.1% (PI=11.1%, non‐PI=10.8%), of which 5.8% were before 34 weeks. Analysis of the data demonstrated no statistically significant increased risk between PI and non‐PI based regimes, which persisted following adjustments for known and possible confounding factors.

Conclusions

In this study 11.1% of HIV‐positive women experienced PTD; in the general UK population 7.5% of pregnancies end in PTD [2]. The inclusion of a PI in the mother's HIV drug regime was not associated with an increased risk for PTD. An association between PTD and CD4 count increase in pregnancy of borderline significance was noted; p=0.053. This is particularly relevant for women commencing HAART during pregnancy in whom, although over 1.5 times as likely to have PTD as those on treatment at conception, this was not statistically significant.
HIV‐1 genetic variants in Kyrgyzstan
Authors: Laga V , Kazennova E , Vasilyev A , Lapovok I , Ismailova A , Beysheeva N , Asybalieva N , Bobkova M
Published: November 2012

Objectives

During the last two decades, HIV‐1 has been spreading rapidly in former Soviet Union republics including Kyrgyzstan. The current molecular monitoring of HIV‐infection epidemic is carried out in Russia only with no or limited data from the other FSU countries. The aim of this work was to investigate the prevalence of HIV‐1 genetic variants circulating in Kyrgyzstan.

Methods

Blood collection from the HIV‐infected patients was carried out by local specialists with the informed consent and the questionnaire was answered by each of the patients. The total number of samples was 100. The washed cell pellets were transferred to Moscow following with proviral DNA extraction, PCR amplification and gag, pol and env genes sequencing. The phylogenetic analysis of nucleotide sequences using neighbor‐joining method was carried out by MEGA 3 program. The preliminary data were obtained in 22 samples isolated from PBMC of HIV‐infected patients from Kyrgyzstan.

Results

Among the samples studied 6 (27.3%) samples belonged to a subtype CRF02_AG, 16 samples ‐ to subtype A (A1). One of the samples belonging to CRF02_AG, probably, is a recombinant between CRF02_AG and A1. There was no major drug resistance mutations in the samples studied. The minor mutations were presented in small proportions: 1 in PR (L10I), 6 in RT (A62V ‐ in 3 samples, V108G, E138A, Y181F, M184I, L210M ‐ on one sample) and 1 in IN (L74M). It was impossible to associate the distribution of mutations with HIV‐1 genetic variant. The V3 loop (env gene) in 17 samples was analyzed for tropism using geno2pheno program; all samples were found to be R5‐viruses.

Conclusion

The HIV‐1 subtype A seems to dominate in Kyrgyzstan like in other FSU countries. The recombinant CRF02_AG epidemiologically linked to Uzbekistan is quite widespread. The rest of Kyrgyzstan collection is under investigation and the data will be refined soon.
An Anti‐PSMA Bivalent Immunotoxin Exhibits Specificity and Efficacy for Prostate Cancer Imaging and Therapy
Authors: Zhang Fayun , Shan Liang , Liu Yuanyi , Neville David , Woo Jung‐Hee , Chen Yue , Korotcov Alexandru , Lin Stephen , Huang Sophia , Sridhar Rajagopalan , Liang Wei , Wang Paul C.
Published: November 2012

Prostate specific membrane antigen (PSMA) is overexpressed on prostate tumor cells and the neovascular endothelia various solid tumors. A bivalent immunotoxin generated by fusing a fold‐back single‐chain diabody derived from the Fv fragments of an anti‐PSMA monoclonal antibody with a truncated diphtheria toxin (DT) containing the activity and translocation domains [A‐dmDT390‐scfbDb(PSMA)] might be suitable for targeted therapy of tumors that overexpress PSMA. In this study, a PSMA‐positive and a PSMA‐negative prostate cancer cell lines were treated with immunotoxin A‐dmDT390‐scfbDb(PSMA) in order to study the tumor targeting specificity and therapeutic potential of the immunotoxin. The cellular uptake and selective toxicity of the immunotoxin were evident in monolayer cultures of PSMA‐positive LNCaP prostate cancer cells but not in cultures of PSMA‐negative PC‐3 prostate cancer cells. Cellular accumulation of A‐dmDT390‐scfbDb(PSMA) increased with increasing incubation times and concentrations in LNCaP cells. The proportion of apoptotic LNCaP cells increased upon incubation with increasing doses of the fold‐back immunotoxin. Optical imaging and MRI with the Alexa Fluor 680‐labeled A‐dmDT390‐scfbDb(PSMA) confirmed the specific targeting and therapeutic efficacy of this immunotoxin towards PSMA‐positive LNCaP solid tumor xenografts in athymic nude mice.
Microgels composed of poly(ethylene imine) and carboxymethoxycoumarin: pH‐dependent and photodependent integrity
Authors: Ju Cha Hyun , Dai Jing , Kim Jin‐Chul
Published: November 2012

We developed novel microgels by taking advantage of electrostatic interactions between poly(ethylene imine) (PEI) and carboxymethoxycoumarin (CMC) and hydrophobic interactions among CMCs. CMC was obtained by the hydrolysis of 7‐ethoxycarbonyl methoxycoumarin, which was derivatized from 7‐hydroxycoumarin. The microgels were prepared by the mixture of PEI solutions (pH 5.0 and 7.5) with CMC solutions of the same pHs so that the molar ratio of PEI to CMC was 1:23. The size of the microgels prepared at pH 7.5 (a few nanometers) was much smaller than that of the microgels prepared at pH 5.0 (a few micrometers); this was possibly due to the more electrostatic interaction of the PEIs and CMCs at higher pH values. The microgels disintegrated when the pH of medium (e.g., pH 7.5) changed to strongly acidic (e.g., pH 3.0) and strongly alkaline (e.g., pH 9.0). Under acidic conditions, PEI hardly interacted with CMC because of the lack of ionization. Under alkaline conditions, the PEI was electrically neutralized, so no electrostatic repulsion developed, and this led to collapsed microgels. In addition, CMCs contained in the microgels were readily photodimerized as much as free CMCs. The microgels developed in this study could be used as drug vehicles that respond to pH changes and photoirradiation. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Reversibly crosslinked self‐healing PCL‐based networks
Authors: Mallek Hichem , Jegat Corinne , Mignard Nathalie , Abid Majdi , Abid Souhir , Taha Mohamed
Published: November 2012

Poly(ε‐caprolactone) (PCL)‐based thermoreversible networks with self‐healing properties were prepared through Diels–Alder (DA) and retro‐DA reactions. Bis‐ or Tris‐maleimide compounds and a series of copolymer(caprolactone‐diene) PCLXFY (X: degree of polymerization and Y: furan‐average functionality) with Y between 2.4 and 4.9 were used. The successive sequences of formation and dissociation of polycaprolactone networks via DA and retro‐DA reactions were observed repeatedly by dynamic mechanical analyses (DMA) and their gel‐temperatures determined. The cross‐linking densities, thermal properties, and thermal reversibility of the PCLXFY/multimaleimide polymers have been modulated by the structure and functionalities of the used diene and dienophile moieties. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Manganese‐Doped Highly Ordered Mesoporous Silicate with High Efficiency for Oxidation Suppression
Authors: Kim Chang Woo , Kang Minhyuk , Moon Bongjin , Kim Jinheung , Kang Young Soo
Published: November 2012

Herein, we demonstrate a facile approach to manganese‐doped highly ordered mesoporous silicate with oxidation‐suppression function. As biocompatible supports of guest ions, the ordered mesoporous silicate was synthesized by evaporation‐induced self‐assembly. The phase‐transition from disordered to lamellar structures in the highly ordered mesoporous structure of these porosity‐tuned materials was controlled by adjusting the concentration of a lab‐made polystyrene‐b‐polyethylene oxide copolymer. Manganese was successfully incorporated as a guest in the hexagonally packed mesoporous silicate by using an ultrasound‐assisted technique. The incorporation of manganese ions into the pores of a mesoporous silicate support could be induced for host–guest functional applications. Manganese‐doped mesoporous silicate structures have been examined for their use as antioxidizing agents by electron spin resonance (ESR) measurements and radical‐scavenging tests. The manganese atoms in the mesoporous structures could act in a free‐radical‐scavenging capacity, much like manganese nanoparticles. The high efficiency of their oxidation‐suppression function is extended for application to catalytic products.
Reversible Phase Transformation and Luminescence of Cadmium(II)–Dipyridylamide‐Based Coordination Frameworks
Authors: Tzeng Biing‐Chiau , Wei Sheng‐Luen , Chang Tsung‐Yi
Published: November 2012

We have synthesized a series of 1D double‐zigzag ({[Cd(paps)2(H2O)2](ClO4)2}n (1), {[Cd(papo)2(H2O)2](ClO4)2}n (3), and {[Cd(papc)2(H2O)2](ClO4)2}n (5)) and 2D polyrotaxane frameworks ([Cd(papc)2(ClO4)2]n (6)) by the reaction of Cd(ClO4)2 with dipyridylamide ligands N,N′‐bis(pyridylcarbonyl)‐4,4′‐diaminodiphenyl thioether (paps), N,N′‐bis(pyridylcarbonyl)‐4,4′‐diaminodiphenyl ether (papo), and N,N′‐(methylenedi‐p‐phenylene)bispyridine‐4‐carboxamide (papc), respectively, where their molecular structures have been determined by X‐ray diffraction studies. Based on the powder X‐ray data (PXRD) of compound 3 and its ZnII analogue, heating the double‐zigzag framework of compound 3 can give the polyrotaxane framework of [Cd(papo)2(ClO4)2]n (4) and grinding this powder sample in the presence of moisture resulted in its complete conversion back into the pure double‐zigzag framework. In addition, heating the double‐zigzag frameworks of compounds 1 and 5 can induce structural transformation into their respective polyrotaxanes, whereas grinding these solid samples in the presence of moisture did not lead to the formation of the double zigzags. Herein, we investigated the effect of the metal (from ZnII to CdII) on the assembly process and luminescence properties, as well as on the particularly intriguing structural transformation of a series of papx‐based frameworks. In fact, the assembly behavior and luminescence properties of the CdIIpapx and ZnIIpapx frameworks were really similar. However, both ZnIIpapx (x=s, o) frameworks can perform reversible structural transformation, but only the CdIIpapo framework can do it. Therefore, a delicate metal effect on such a new structural transformation can be observed.
Technology Synergy, Product Characteristics, and New Product Performance: A Meta‐Analytic Review
Authors: Tsai Kuen‐Hung , Huang Chi‐Tsun
Published: November 2012

The associations of technology synergy, product characteristics, and new product performance are widely spread in the marketing and innovation management literatures. However, little research integrates these associations. This study adopts a meta‐analytic approach to aggregate prior findings across studies published before 2010 to review the relationships between technology synergy, product characteristics, and new product performance. Structural equation analysis reveals that technology synergy has: (a) a positive medium effect on new product performance; (b) a positive and strong impact on product advantage, which then affects new product performance; and (c) an indirect effect on new product performance through product innovativeness and product advantage. These findings suggest that product innovation and advantage are important intermediaries between technology synergy and new product performance—as yet unrevealed in extant literature. Copyright © 2012 ASAC. Published by John Wiley & Sons, Ltd.
Comparison of two methods for extraction of volatiles from marine PL emulsions
Authors: Henna Lu F. S. , Nielsen Nina S. , Jacobsen Charlotte
Published: November 2012

The dynamic headspace (DHS) thermal desorption principle using Tenax GR tube, as well as the solid phase micro‐extraction (SPME) tool with carboxen/polydimethylsiloxane 50/30 µm CAR/PDMS SPME fiber, both coupled to GC/MS were implemented for the isolation and identification of both lipid and Strecker derived volatiles in marine phospholipids (PL) emulsions. Comparison of volatile extraction efficiency was made between the methods. For marine PL emulsions with a highly complex composition of volatiles headspace, a fiber saturation problem was encountered when using CAR/PDMS‐SPME for volatiles analysis. However, the CAR/PDMS‐SPME technique was efficient for lipid oxidation analysis in emulsions of less complex headspace. The SPME method extracted volatiles of lower molecular weights more efficient than the DHS method. On the other hand, DHS Tenax GR appeared to be more efficient in extracting volatiles of higher molecular weights and it provided a broader volatile spectrum for marine PL emulsion than the CAR/PDMS‐SPME method.
2D difference gel electrophoresis reference map of a Fusarium graminearum nivalenol producing strain
Authors: Pasquali Matias , Serchi Tommaso , Renaut Jenny , Hoffmann Lucien , Bohn Torsten
Published: November 2012

Fusarium graminearum is widely studied as a model for toxin production among plant pathogenic fungi. A 2D DIGE reference map for the nivalenol‐producing strain 453 was established. Based on a whole protein extract, all reproducible spots were systematically picked and analyzed by MALDI‐TOF/TOF, leading to the identification of 1102 protein species. The obtained map contributes to the annotation of the genome by identifying previously nondescribed hypothetical proteins and will serve as a reference for future studies aiming at deciphering F. graminearum biology and chemotype diversity.
Automatic particle detection and sorting in an electrokinetic microfluidic chip
Authors: Song Yongxin , Peng Ran , Wang Junsheng , Pan Xinxiang , Sun Yeqing , Li Dongqing
Published: November 2012

This paper reports a lab‐on‐a‐chip device that can automatically detect and sort particles based on their size differences with a high resolution. The PDMS‐glass microfluidic chip is made by soft‐lithography technique. A differential resistive pulse sensor is employed to electrically detect the sizes of the particles in EOF generated by applying DC voltages across channels. The detected resistive pulse sensor signals, whose amplitudes are proportional to particles’ sizes, will automatically trigger the sorting process that is controlled by applying a voltage pulse (36 V) whenever a target particle is detected. This method was applied to automatically detect and sort polystyrene particles and microalgae in aqueous solutions. Sorting 5 μm polymer particle from a mixture of 4‐ and 5‐μm polystyrene particles in aqueous solution, i.e. 1 μm sorting resolution, was demonstrated. The device described in this paper is simple, automatic, and label‐free with high sorting resolution. It has wide applications in sample pretreatment and target particles detection.
CE with a boron‐doped diamond electrode for trace detection of endocrine disruptors in water samples
Authors: Browne Damien J. , Zhou Lin , Luong John H. T. , Glennon Jeremy D.
Published: November 2012

Off‐line SPE and CE coupled with electrochemical detection have been used for the determination of bisphenol A (BPA), bisphenol F, 4‐ethylphenol, and bisphenol A diglycidyl ether in bottled drinking water. The use of boron‐doped diamond electrode as an electrochemical detector in amperometric mode that provides a favorable analytical performance for detecting these endocrine‐disrupting compounds, such as lower noise levels, higher peak resolution with enhanced sensitivity, and improved resistance against electrode passivation. The oxidative electrochemical detection of the endocrine‐disrupting compounds was accomplished by boron‐doped diamond electrode poised at +1.4 V versus Ag/AgCl without electrode pretreatment. An off‐line SPE procedure (Bond Elut® C18 SPE cartridge) was utilized to extract and preconcentrate the compounds prior to separation and detection. The minimum concentration detectable for all four compounds ranged from 0.01 to 0.06 μM, having S/N equal to three. After exposing the plastic bottle water container under sunlight for 7 days, the estimated concentration of BPA in the bottled drinking water was estimated to be 0.03 μM. This proposed approach has great potential for rapid and effective determination of BPA content present in water packaging of plastic bottles that have been exposed to sunlight for an extended period of time.
Electrochemical degradation and mechanistic analysis of microcystin‐LR
Authors: Zhang Yanrong , Zhang Ying , Yang Nan , Liao Wenjuan , Yoshihara Sachio
Published: November 2012

Background

Microcystin‐LR (MC‐LR) is very stable under natural sunlight and resistant to high temperatures and UV radiation. Conventional treatment techniques are found to be inefficient in removing these toxins from potable water systems. Advanced oxidation technologies (AOTs) are considered a promising technique for the destruction of microcystins. Among the various AOTs, electrochemical oxidation (EO) has been proved to be very successful in degrading the organic pollutants. The purpose of this study was therefore, to determine the feasibility of MC‐LR removal and its mechanism by EO. The effect of operational parameters on the degradation efficiency of MC‐LR has been studied.

Results

The degradation of MC‐LR followed a pseudo‐first‐order kinetic with a rate constant (k1) of 0.017 min−1. Current density and electrolytes can affect the degradation rate; the pH of the different anionic solutions had a negligible effect on the degradation of MC‐LR. The destruction of the key functional groups of MC‐LR effectively inhibits its toxicity, which is confirmed by toxicity tests.

Conclusion

The results demonstrated the feasibility of electrochemical oxidation on boron‐doped electrode for the removal of MC‐LR from the aquatic environment. © 2012 Society of Chemical Industry
Hydrolysis of sugarcane bagasse using supercritical carbon dioxide to obtain fermentable sugars
Authors: Benazzi Tássio , Calgaroto Selma , Dalla Rosa Clarissa , Vladimir Oliveira J. , Mazutti Marcio A.
Published: November 2012

This work evaluates the hydrolysis of sugarcane bagasse using supercritical carbon dioxide to obtain fermentable sugars in a single‐step process. The effects of temperature, pressure, despressurization rate, moisture content and reaction time on the amount of fermentable sugars released were assessed. Results obtained showed the feasibility of adopting the present procedure since it produced about 287 g of fermentable sugars per kg of dry bagasse, which corresponds to 60% yield on the basis of total cellulose. Such a result is very attractive from an industrial viewpoint because there is no use of toxic solvent, solvent removal is completed (no residues), and the method has very low water consumption since the process is a solid–gas reaction. © 2012 Society of Chemical Industry
Olig2‐lineage cells preferentially differentiate into oligodendrocytes but their processes degenerate at the chronic demyelinating stage of proteolipid protein‐overexpressing mouse
Authors: Shimizu Takahiro , Tanaka Kenji F. , Takebayashi Hirohide , Higashi Mikito , Wisesmith Wilaiwan , Ono Katsuhiko , Hitoshi Seiji , Ikenaka Kazuhiro
Published: November 2012

In chronic demyelinating lesions of the central nervous system, insufficient generation of oligodendrocytes (OLs) is not due to a lack of oligodendrocyte precursor cells (OPCs), because the accumulation of OPCs and premyelinating OLs can be observed within these lesions. Here we sought to identify the basis for the failure of OLs to achieve terminal differentiation in chronic demyelinating lesions through the utilization of plp1‐overexpressing (Plp
tg/−) mice. These mice are characterized by progressive demyelination in young adults and chronic demyelinating lesions at more mature stages. We show that neural stem cells, which are the precursors of OL‐lineage cells, are present in the Plp
tg/− mouse brain and that their multipotentiality and ability to self‐renew are comparable to those of wild‐type adults in culture. Lineage‐tracing experiments using a transgenic mouse line, in which an inducible Cre recombinase is knocked in at the Olig2 locus, revealed that Olig2‐lineage cells preferentially differentiated into OPCs and premyelinating OLs, but not into astrocytes, in the Plp
tg/− mouse brain. These Olig2‐lineage cells matured to express myelin basic protein but after that their processes degenerated in the chronic demyelinating lesions of the Plp
tg/− brain. These results indicate that in chronic demyelinated lesions more OL‐lineage cells are produced as part of the repair process, but their processes degenerate after maturation. © 2012 Wiley Periodicals, Inc.
Characterization of new soil thermophilic bacteria potentially involved in soil fertilization
Authors: Santana Margarida M. , Portillo Maria C. , Gonzalez Juan M. , Clara Maria I. E.
Published: November 2012

Thermophilic bacteria were isolated from a soil of an olive grove in Alentejo (Portugal) and characterized morphologically, physiologically, and at the molecular level by partial sequencing of the 16S ribosomal RNA genes, followed by subsequent phylogenetic analysis. The isolates were shown to be gram‐positive rods, motile, and to belong to the Firmicutes Phylum. They were able to produce ammonium and sulfate during growth, the levels of which vary among the bacterial isolates. This ability suggests that these bacteria may have an important role in the mobilization of organic S and N in the soil and therefore in providing essential nutrients for plant growth. Tests using two isolates indicated a positive effect on initial seedling development suggesting their potential use in soil nutrient supplementation. The presence of these thermophiles in arable temperate soils might be increasingly important, particularly when the predicted global climate warming is considered, and their features are discussed in this context and considering actual strategies to improve soil fertilization.
Character‐contrast measurements on emissive displays using replica masks under uniform ambient illumination
Authors: Kelley Edward F. , Eghtesadi Caesar , Blubaugh Morgan , Reuschel William
Published: November 2012

A replica‐mask method is presented to measure the contrast of character strokes on emissive displays under carefully controlled illumination. The method accounts for veiling glare introduced into the detector by the bright areas surrounding the dark characters. A sampling sphere is used to provide a uniform diffuse surround. Measurements of the diffuse reflectances are provided with specular included and with specular excluded. For emissive displays, the contrast depends both upon the darkroom characteristics of the emissive display and its reflective characteristics. Details are provided to replicate the measurement procedure.
On the Importance of Accurate Internal Temperature Measurements in the Microwave Dielectric Heating of Viscous Systems and Polymer Synthesis
Authors: Hayden Stephan , Damm Markus , Kappe C. Oliver
Published: November 2012

The relationship among viscosity and microwave absorptivity of organic solvents/polymers, the stirring rate, and the resulting errors in temperature measurement upon microwave dielectric heating is investigated. For a set of common solvents and polymers covering a broad range of viscosities and microwave absorptivities significant variations in the temperatures simultaneously recorded by external infrared sensors and internal fiber‐optic probes are experienced. The implications of these apparent difficulties in establishing the genuine reaction temperature for microwave‐heated viscous reaction systems are evaluated for a ring‐opening polymerization and for the synthesis of a surfactant.
A New Coarse Grained Particle‐To‐Mesh Scheme for Modeling Soft Matter
Authors: Zhang Guojie , Daoulas Kostas C. , Kremer Kurt
Published: November 2012

A recently proposed model of high‐molecular‐weight polymers is employed to develop a grid‐based Monte Carlo method for efficient modeling of dense systems, for example, melts. The polymers are described as chains of soft spheres with fluctuating size. The spheres correspond to Gaussian density distributions of the microscopic segments and represent whole subchains. Their coordinates and radii are defined in continuum space and simple potentials keep the chain connectivity. A density functional defines the nonbonded interactions by mapping the density distributions onto a grid, without a neighbor list. The high accuracy of the scheme is demonstrated by comparing with data obtained from the standard potential‐based formulation of the model. Contrary to most lattice models, the method allows for NPT simulations.
On selective laser melting of ultra high carbon steel: Effect of scan speed and post heat treatment
Authors: Taha M. A. , Yousef A. F. , Gany K. A. , Sabour H. A.
Published: November 2012

Selective laser melting is a laser‐based additive manufacturing process applying layer manufacturing technology and is used to produce dense parts from metallic powders. The application of selective laser melting on carbon steels is still limited due to difficulties arising from carbon content. This experimental investigation aims at gaining an understanding of the application of the process on ultra high carbon steel, which is a special alloy with remarkable structural properties suitable for different industrial applications. The feedstock ultra high carbon steel (2.1% C) powder, 20 μm to 106 μm was prepared by water atomizing technique. This powder was used for the selective laser melting to build specimens 10×10×40 mm in dimensions. To decrease the thermal stresses during layer by layer building, laser scanning was done through 5×5 mm random island patterns while layer thickness was 30 μm. Laser beam diameter, maximum power output, layer thickness and scan speed range were 0.2 mm, 100 W, 30 μm and 50–200 mm/s respectively. The process was done inside high purity nitrogen environment, with less than 0.5% oxygen content. The results illustrate the influence of scan speed from 50 to 200 mm/s on product geometry and dimensions, surface roughness, internal porosity and cracks, microstructure and surface hardness. The effect of post heat treatment by heating and holding for one hour (annealing) at different temperatures of 700°C, 750°C, 950°C is studied. The results indicate that selective laser melting is able to produce near to 95% density of ultra high carbon steel parts with acceptable geometry and surface quality. Porosity cracks, and microstructure formed during the process could be controlled through proper selection of process parameters and post heat treatment. Industrial ultra high carbon steel products can be rapidly fabricated by selective laser melting.
Rheological properties of aqueous alumina suspensions
Authors: Majić Renjo M. , Lalić M. , Ćurković L. , Matijašić G.
Published: November 2012

The aim of the present work was to investigate rheological behaviour of alumina suspensions, considering different amounts of polyvinyl alcohol (PVAL) as a binder. Three different aqueous suspensions were prepared, containing 60, 70 and 80 wt.% of alumina powder. Spinel was added as a sintering agent and Darvan 821‐A as a dispersant, in an amount of 0.08 and 0.4 wt.% of dry powder weight, respectively. The alumina suspensions flow curves were recorded and fitted satisfactorily to the power law, Herschel‐Bulkley and Bingham models. Obtained results indicate that apparent viscosity of alumina suspensions increases with increasing Al2O3 and polyvinyl alcohol amount.
Influence of cooling rates on temperatures phase transitions and on microstructure of aluminium alloy EN AW‐5083
Authors: Dolić N. , Medved J. , Mrvar P. , Unkić F.
Published: November 2012

The casting of different forms and dimensions of aluminium alloy EN WA‐5083 test samples and the usage of different types of mould materials resulted in achieving different cooling rates of samples. The methods used were simple thermal analysis, using casting into a measuring cell made by the Croning process and using casting into a cone‐shaped measuring cell, as well as simultaneous thermal analysis using the method of differential scanning calorimetry. Significant temperature phase transitions and times of solidification were determined, and the dependence model of the solidification time on the sample cooling rate was obtained. Determining the mean number of grains per unit area on samples after having performed the simple thermal analysis and differential scanning calorimetry makes it possible to develop a dependence model of the mean number of grains per unit area on the cooling rate. These models are the basis for carrying out numerical simulations of solidification and microstructure development in the cone‐shaped measuring cell, and the comparison of the distribution of the mean number of grains per unit area obtained by simulation with the one obtained experimentally. The obtained results represent a part of the preliminary tests of the microstructure development of industrially cast ingots of EN AW‐5083 alloy depending on the local ingot cooling rate.
Effect of formalin fixation on biexponential modeling of diffusion decay in prostate tissue
Authors: Bourne Roger , Bongers Andre , Charles Ned , Power Carl , Sved Paul , Watson Geoffrey
Published: November 2012

Purpose

To evaluate the effect of formalin fixation on biexponential modeling of diffusion decay in prostate tissue.

Methods

Three whole prostate specimens were imaged unfixed immediately postsurgery, and again after formalin fixation. Diffusion‐weighted imaging was performed over an extended range of b‐values and a biexponential model fitted to the signal decay curves.

Results

Tissue fixation resulted in a 35%, 20%, and 20% reduction in mean apparent diffusion coefficient of the higher diffusivity fit component for the three organs, respectively, and a 64%, 57%, and 45% reduction in mean apparent diffusion coefficient of the lower diffusivity component. The mean signal fraction of the higher diffusivity component was increased by 23%, 5%, and 1%, respectively. The effect of fixation did not appear to vary according to tissue type or glandular zone.

Conclusion

Formalin fixed tissue appears to provide a stable model for detailed investigation of the microscopic biophysical basis of diffusion phenomena observed in vivo. Diffusivity changes that result from fixation may provide information about the microscopic environments of the biexponential components. Magn Reson Med, 70:1160–1166, 2013. © 2012 Wiley Periodicals, Inc.