bluuebunny/crossref_metadata_2025 huggingface dataset:
Earliest orchid macrofossils: Early Miocene Dendrobium and Earina (Orchidaceae: Epidendroideae) from New Zealand
Authors: Conran John G. , Bannister Jennifer M. , Lee Daphne E.
Published: January 2009

Fossil leaves of two Early Miocene orchids (Dendrobium and Earina) are reported from New Zealand. The distinctive, raised tetra‐ to cyclocytic stomatal subsidiary cells of Earina and characteristic papilla‐like absorbing glands and “ringed” guard cells of Dendrobium support the placement of the fossils into these genera. These therefore represent the first Orchidaceae macrofossils with cuticular preservation, the oldest records for subfamily Epidendroideae, as well as the first New Zealand and southern hemisphere fossil records for Orchidaceae. These taxa belong in basal clades to the Vandeae/Cymbideae or Epidendreae (Earina) and the Australasian clade of Dendrobium sensu lato. This phylogenetic placement demonstrates expansion of epiphytic orchids into Zealandia by the mid‐Cenozoic and an important role for southern continents in the diversification of Orchidaceae.
L'underground politique, artistique, rock (1970-1980)
Authors: Klaniczay Gábor
Published: January 2009

Résumé L’article tente d’analyser les liens d’imbrication entre la politique, les arts, la musique rock, l’opposition, la « contre-culture » et la « subculture » dans les milieux underground budapestois dans les dernières décennies du système socialiste. Après une discussion des traits communs et des différences significatives des concepts de « subculture », « culture populaire », « contre-culture » et «  underground  », l’article offre une description du contexte politique et artistique de ces phénomènes en Hongrie. L’émergence de la « nouvelle vague » du rock, concomitante de la création des espaces publics alternatifs par les dissidents politiques, offre un cas intéressant pour l’analyse historique et ethnologique.
Discussion du rapport de Bernard Brusset
Authors: Seabra Diniz João
Published: January 2009

Bernard Brusset fait le point sur un sujet difficile qui divise le monde psychanalytique. Avec une rigueur et une admirable concision, il nous rend un inestimable service de clarification et de synthèse. Les divers courants nous sont présentés, comparés, critiqués de façon à mettre à notre disposition toute une énorme richesse de connaissances, dont le rapprochement nous ouvre souvent de nouvelles perspectives.
M-Learning, Mobile Experimentation and Telepresence with Cell Phones and PDAs
Authors: Bischoff Andreas
Published: January 2009

Mobile devices such as notebooks and PDAs are very interesting tools for web-based teaching and distant teaching today. We have adapted Web-based remote laboratory environments to mobile devices like PDAs and smartphones to remotely control a Pioneer 3 AT mobile robot.
Mobile Learning in Context â?? Context-aware Hypermedia in the Wild
Authors: Hansen Frank Allan , Bouvin Niels Olof
Published: January 2009

Modern project-based education requires students to be able to work with digital materials both in and out of the classroom. Field trips are often an integral part of such projects and greatly benefit studentsâ?? learning by allowing them to engage with real-world environments first-hand. However, the infrastructure for accessing context sensitive information and supporting in-situ authoring by students while in the field is often lacking. In this paper we present the HyCon framework for mobile, context-aware, and multi-platform hypermedia that aims at supporting several aspects of fieldtrips and project-based education.
Microbiologically Influenced Corrosion
Authors: Little Brenda J. , Lee Jason S.
Published: January 2009

The term microbiologically influenced corrosion (MIC) is used to designate corrosion due to the presence and activities of microorganisms, ie, those organisms that cannot be seen individually with the unaided human eye, including microalgae, archaea, bacteria, and fungi. Microorganisms can accelerate rates of partial reactions in corrosion processes or shift the mechanism for corrosion. Microorganisms can influence pitting, dealloying, enhanced erosion corrosion, enhanced galvanic corrosion, stress corrosion cracking, and hydrogen embrittlement. Microbiologically influenced corrosion has been reported for all engineering metals and alloys with the exception of predominantly titanium and high chromium–nickel alloys. It has been documented for metals and nonmetals exposed to seawater, freshwater, distilled/demineralized water, crude and distillate hydrocarbon fuels, process chemicals, foodstuffs, soils, human plasma, saliva, and sewage. The following sections describe the estimated costs of MIC, mechanisms, and causative microorganisms contributing to MIC; techniques for diagnosing, measuring, and monitoring; engineering practices that influence MIC and strategies to prevent or mitigate MIC.
Reversible Addition–Fragmentation Chain Transfer Polymerization
Authors: Rizzardo Ezio , Moad Graeme , Thang San H.
Published: January 2009

This article reviews the mechanistic and practical aspects of free radical polymerization with reversible addition–fragmentation chain transfer—the reversible addition–fragmentation chain transfer (RAFT) process. RAFT is conducted by the addition of a thiocarbonylthio compound (ZC(S)SR) to a conventional radical polymerization. Suitable RAFT agents include dithioesters, trithiocarbonates, dithiocarbamates, and xanthates. These thiocarbonylthio compounds confer living characteristics to the radical polymerization by a mechanism of reversible addition–fragmentation chain transfer and provide exceptional control over molecular weight, molecular weight distribution, composition, and architecture of the resulting polymers. The process can be applied to most monomers polymerizable by radical polymerization and offers a convenient route to well‐defined homo‐, gradient, diblock, triblock, and star polymers as well as more complex architectures including microgels and polymer brushes.
Effect of metal‐support interface on hydrogen permeation through palladium membranes
Authors: Zhang Ke , Wei Xiaotong , Rui Zebao , Li Yongdan , Lin Y. S.
Published: January 2009

Thin palladium membranes of different thicknesses were prepared on sol‐gel derived mesoporous γ‐alumina/α‐alumina and yttria‐stabilized zirconia/α‐alumina supports by a method combining sputter deposition and electroless plating. The effect of metal‐support interface on hydrogen transport permeation properties was investigated by comparing hydrogen permeation data for these membranes measured under different conditions. Hydrogen permeation fluxes for the Pd/γ‐Al2O3/α‐Al2O3 membranes are significantly smaller than those for the Pd/YSZ/α‐Al2O3 membranes under similar conditions. As the palladium membrane thickness increases, the difference in permeation fluxes between these two groups of membranes decreases and the pressure exponent for permeation flux approaches 0.5 from 1. Analysis of the permeation data with a permeation model shows that both groups of membranes have similar hydrogen permeability for bulk diffusion, but the Pd/γ‐Al2O3/α‐Al2O3 membranes exhibit a much lower surface reaction rate constant with higher activation energy, due possibly to the formation of Pd‐Al alloy, than the Pd/YSZ/α‐Al2O3 membranes. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Factors associated with cancer distress in the Asbestos Post‐Exposure Survey (APEXS)
Authors: Maurel Marion , Stoufflet Audrey , Thorel Laetitia , Berna Veronique , Gislard Antoine , Letourneux Marc , Pairon Jean‐Claude , Paris Christophe
Published: January 2009

Objectives

CT‐scan screening programs for lung cancer detection have been proposed in high‐risk subjects, and more recently in former asbestos‐exposed subjects. However, to date no data are available on psychological impact of such programs. The aim of this study is to examine the risk factors of psychological distress at baseline of a CT‐scan screening program among asbestos‐exposed subjects.

Methods

The Asbestos Post‐Exposure Survey (APEXS) was carried out in France between October 2003 and December 2005 in order to screen asbestos‐related diseases by CT‐scan. Volunteers underwent self‐administered questionnaires including an asbestos exposure assessment and, for a large sub‐sample, a validated psychological distress scale. Non‐exposed subjects were used as reference group.

Results

At baseline, a significant higher level of distress was observed in exposed subjects (n = 3,122) relative to the reference group (n = 486) after adjustment on age, sex, and tobacco status. This distress is associated independently with the self‐perception of (i) intensity of asbestos exposure and (ii) the risk of current or future disease related to the asbestos exposure. The perception of the cancer risk related to asbestos seems to play a fundamental role in this psychological distress.

Conclusion

In this study, asbestos‐exposed subjects experienced a higher significant cancer distress than previously described in literature. These findings may be of potential public health importance. First, the impact of such occupational exposures on quality of life of patients who suffer from cancer related to these exposures has to be appraised. Secondly, the assessment of psychological impact of CT‐scan screening programs among asbestos‐exposed subjects is also required. Am. J. Ind. Med. 52:288–296, 2009. © 2009 Wiley‐Liss, Inc.
Renovation of a “sick building”: The challenge of attaining the confidence of occupants
Authors: Lahtinen Marjaana , Salonen Heidi , Lappalainen Sanna , Huttunen Jukka , Reijula Kari
Published: January 2009

Background

This case study focused on the renovation of a building with severe mold and HVAC problems. The users did not trust the success of the planned remedies, and the situation became conflict‐prone. The aims of the study were to improve communication and cooperation between experts participating in the renovation process and the future users of the building and monitor the success of the remedies.

Methods

An intervention was implemented with the aim of making the renovation easily understood by the future users of the building and preventing the escalation of unnecessary concern among them. The follow‐up methods comprised a questionnaire study, technical inspections, quality measurements of the indoor air, structural follow‐up measurements, and interviews of key persons.

Results

The renovation itself seems to have been successful, and the model to improve communication and cooperation appears to be a promising one. The confidence of the future users was attained, and the relocation took place as planned.

Conclusions

In order to succeed in the renovation of a “sick building,” both technical expertise and investment in information and communication are needed. Am. J. Ind. Med. 52:438–445, 2009. © 2009 Wiley‐Liss, Inc.
Evidence for an interaction of schizophrenia susceptibility loci on chromosome 6q23.3 and 10q24.33–q26.13 in Arab Israeli families
Authors: Alkelai A. , Kohn Y. , Olender T. , Sarner‐Kanyas K. , Rigbi A. , Hamdan A. , Ben‐Asher E. , Lancet D. , Lerer B.
Published: January 2009

A genome scan for schizophrenia related loci in Arab Israeli families by Lerer et al. [Lerer et al. (2003); Mol Psychiatry 8:488–498] detected significant evidence for linkage at chromosome 6q23. Subsequent fine mapping [Levi et al. (2005); Eur J Hum Genet 13:763–771], association [Amann‐Zalcenstein et al. (2006); Eur J Hum Genet 14:1111–1119] and replication studies [Ingason et al. (2007); Eur J Hum Genet 15:988–991] identifiedAHI1as a putative susceptibility gene. The same genome scan revealed suggestive evidence for a schizophrenia susceptibility locus in the 10q23–26 region. Genes at these two loci may act independently in the pathogenesis of the disease in our homogeneous sample of Arab Israeli families or may interact with each other and with other factors in a common biological pathway. The purpose of our current study was to test the hypothesis of genetic interaction between these two loci and to identify the type of interaction between them. The initial stage of our study focused on the 10q23–q26 region which has not been explored further in our sample. The second stage of the study included a test for possible genetic interaction between the 6q23.3 locus and the refined 10q24.33–q26.13 locus. A final candidate region of 19.9 Mb between markers D10S222 (105.3 Mb) and D10S587 (125.2 Mb) was found on chromosome 10 by non‐parametric and parametric linkage analyses. These linkage findings are consistent with previous reports in the same chromosomal region. Two‐locus multipoint linkage analysis under three complex disease inheritance models (heterogeneity, multiplicative, and additive models) yielded a best maximum LOD score of 7.45 under the multiplicative model suggesting overlapping function of the 6q23.3 and 10q24.33–q26.13 loci. © 2009 Wiley‐Liss, Inc.
Profiling brain expression of the spermidine/spermine N1‐acetyltransferase 1 (SAT1) gene in suicide
Authors: Klempan Timothy A. , Rujescu Dan , Mérette Chantal , Himmelman Carla , Sequeira Adolfo , Canetti Lilian , Fiori Laura M. , Schneider Barbara , Bureau Alexandre , Turecki Gustavo
Published: January 2009

Altered stress reactivity is considered to be a risk factor for both major depressive disorder and suicidal behavior. The authors have sought to expand their previous findings implicating altered expression of spermidine/spermine N1‐acetyltransferase 1 (SAT1), the rate‐limiting enzyme involved in catabolism of the polyamines spermidine and spermine in the polyamine stress response (PSR), across multiple brain regions between control individuals and depressed individuals who have died by suicide. Microarray expression of probesets annotated to SAT1 were examined across 17 brain regions in 13 controls and 26 individuals who have died by suicide (16 with a diagnosis of major depression and 10 without), all of French‐Canadian origin. Profiling conducted on the Affymetrix U133A/B chipset was further examined on a second chipset (U133 Plus 2.0) using RT‐PCR, and analyzed in a second, independent sample. A reduction in SAT1 expression identified through multiple probesets was observed across 12 cortical regions in depressed individuals who have died by suicide compared with controls. Of these, five cortical regions showed statistically significant reductions which were supported by RT‐PCR and analysis on the additional chipset. SAT1 cortical expression levels were also found to be significantly lower in an independent sample of German subjects with major depression who died by suicide in comparison with controls. These findings suggest that downregulation of SAT1 expression may play a role in depression and suicidality, possibly by impeding the normal PSR program or through compensation for the increased polyamine metabolism accompanying the psychological distress associated with depressive disorders. © 2009 Wiley‐Liss, Inc.
Are Allenes with Zwitterionic Character Still Allenes? Of Course!
Authors: Lavallo Vincent , Dyker C. Adam , Donnadieu Bruno , Bertrand Guy
Published: January 2009

Der wahre Grundzustand von 1 ist Gegenstand der Debatte, zum Zweck einer klaren und einfachen Beschreibung ist aber die allenische Resonanzform 1 a am zweckdienlichsten. Es wird gezeigt, dass die Argumente, die Christl und Engels bezüglich der Aromatizität dieser Spezies anführen, inkorrekt sind.

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Plug‐Based Microfluidics with Defined Surface Chemistry to Miniaturize and Control Aggregation of Amyloidogenic Peptides
Authors: Meier Matthias , Kennedy‐Darling Julia , Choi Se Hoon , Norstrom Eric M. , Sisodia Sangram S. , Ismagilov Rustem F.
Published: January 2009

Die Miniaturisierung von Proteinaggregationsexperimenten erfordert die Kontrolle der Grenzflächenchemie, um Proteinaggregation aufgrund von Grenzflächenadsorption zu vermeiden. Pfropfenbasierte Mikrofluidik mit definierter Oberflächenchemie (siehe Bild) kann verwendet werden, um hunderte von Aggregationsexperimenten mit nur begrenzt verfügbaren Proben, z. B. der Rückenmarksflüssigkeit von Mäusen, auszuführen.

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Are Allenes with Zwitterionic Character Still Allenes? Of Course!
Authors: Lavallo Vincent , Dyker C. Adam , Donnadieu Bruno , Bertrand Guy
Published: January 2009

The true ground state of 1 is a matter of debate, but for clarity and convenience the allene resonance form 1 a, is the most appropriate. The arguments for aromaticity made by Christl and Engels are shown to be incorrect.

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Taming the Highly Reactive Oxonium Ion
Authors: Haley Michael M.
Published: January 2009

'Onium rings: Incorporation of the trivalent oxygen atom as a structural element within the tricyclic core of 1–3 imparts unprecedented stability to this “extraordinary” class of tertiary oxonium ions. Cation 1 is the least reactive and can be refluxed in water for 72 hours with no noticeable decomposition.

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On‐line evaluation of the stability of an inspection process
Authors: González Isabel , Sánchez Ismael
Published: January 2009

This article proposes control charts to monitor an inspection process based on the defective proportion of the inspected parts. The focus is on inspection process where the incoming parts form a sequence of independent units, such as unrelated clients arriving at a service facility. An example of this kind of inspection process is the periodic motor vehicle (PMVI) inspection. The effectiveness of the proposed control is evaluated using Monte Carlo experiments and is applied to an actual PMVI station. Copyright © 2009 John Wiley & Sons, Ltd.
Simultaneous analysis of physiological and electrical output changes in an operating microbial fuel cell with Shewanella oneidensis
Authors: Biffinger Justin C. , Ray Ricky , Little Brenda J. , Fitzgerald Lisa A. , Ribbens Meghann , Finkel Steven E. , Ringeisen Bradley R.
Published: January 2009

Changes in metabolism and cellular physiology of facultative anaerobes during oxygen exposure can be substantial, but little is known about how these changes connect with electrical current output from an operating microbial fuel cell (MFC). A high‐throughput voltage based screening assay (VBSA) was used to correlate current output from a MFC containing Shewanella oneidensis MR‐1 to carbon source (glucose or lactate) utilization, culture conditions, and biofilm coverage over 250 h. Lactate induced an immediate current response from S. oneidensis MR‐1, with both air‐exposed and anaerobic anodes throughout the duration of the experiments. Glucose was initially utilized for current output by MR‐1 when cultured and maintained in the presence of air. However, after repeated additions of glucose, the current output from the MFC decreased substantially while viable planktonic cell counts and biofilm coverage remained constant suggesting that extracellular electron transfer pathways were being inhibited. Shewanella maintained under an anaerobic atmosphere did not utilize glucose consistent with literature precedents. Operation of the VBSA permitted data collection from nine simultaneous S. oneidensis MR‐1 MFC experiments in which each experiment was able to demonstrate organic carbon source utilization and oxygen dependent biofilm formation on a carbon electrode. These data provide the first direct evidence of complex cellular responses to electron donor and oxygen tension by Shewanella in an operating MFC at select time points. Biotechnol. Bioeng. 2009;103: 524–531. Published 2009 Wiley Periodicals, Inc.
Synthesis of a Phosphonate‐Linked Aminoglycoside–Coenzyme A Bisubstrate and Use in Mechanistic Studies of an Enzyme Involved in Aminoglycoside Resistance
Authors: Gao Feng , Yan Xuxu , Auclair Karine
Published: January 2009

Just five steps! The synthesis of a phosphonate‐linked aminoglycoside‐coenzyme A derivative (see scheme) that includes a Michael addition in water has been realized in just five steps.

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Aminoglycoside N‐6′‐acetyltransferases (AAC(6′)s) are important determinants of antibiotic resistance. A good mechanistic understanding of these enzymes is essential to overcome aminoglycoside resistance. We have previously reported the synthesis of amide‐ and sulfonamide‐linked aminoglycoside–coenzyme A conjugates, which were useful mechanistic and structural probes of AAC(6′)s. We report here the synthesis of a phosphonate‐linked aminoglycoside–coenzyme A variant, which is expected to be a superior mimic of the tetrahedral intermediate proposed for catalysis by AAC(6′)s. This synthetic target is especially challenging for a number of reasons, including the presence of multiple functional groups, the water solubility of both starting materials, and incompatibility of PIII chemistry with water. We have overcome these challenges by adding the expensive coenzyme A in the last step by means of an elegant Michael‐type addition onto a vinylphosphonate in water. Overall, a single protection step was needed. The decreased inhibitory potency of this bisubstrate compared to that of the amide‐linked analogue suggests that Enterococcus faecium AAC(6′)‐Ii may not stabilize the proposed tetrahedral intermediate, and may act mainly through proximity catalysis.
Synthesis of Organometallic Poly(dendrimer)s by Macromonomer Polymerization: Effect of Dendrimer Size and Structural Rigidity on the Polymerization Efficiency
Authors: Cheung Siu‐Yin , Chow Hak‐Fun , Ngai To , Wei Xiaoling
Published: January 2009

Cyclization versus propagation: The copolymerization behavior of a dendritic macromonomer with a metal‐containing linker is controlled by the dendrimer size and its structural rigidity. Structurally more flexible dendritic monomers tend to form more cyclic oligomers than structurally rigid monomers (see figure).

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Two series of first to third generation (G1–G3) oligoether dendrimers, one bearing a shorter spacer chain (CO) and the other having a longer spacer branch (CCCO) were prepared. Both series of compounds, containing two reactive CCH moieties on the dendrimer surface, were used as macromonomers and copolymerized with trans‐[Pt(PEt3)2Cl2] to form organometallic poly(dendrimer)s by an outer‐sphere–outer‐sphere connection strategy. It was found that concentration of monomer used in the polymerization, the dendrimer generation, and, most strikingly, the length of the spacer were key factors that determined the polymerization efficiency. Hence, the structurally more rigid and compact CO linked dendrimers formed poly(dendrimer)s with a higher degree of polymerization than the structurally less rigid and more bulky CCCO dendrimers. This result was due to the higher tendency to form cyclic oligomers in the latter series of compounds. In addition, the differences in the polymerization efficiency among the three generations of dendrimers could be explained by the gradual decrease of reactive functional group density on the dendrimer surface.
Cytotoxicities and Structure–Activity Relationships of Natural and Unnatural Lamellarins toward Cancer Cell Lines
Authors: Chittchang Montakarn , Batsomboon Paratchata , Ruchirawat Somsak , Ploypradith Poonsakdi
Published: January 2009

Shedding light on the lamellarins: Structural determinants for potent cytotoxic activity toward various cancer cell lines were systematically investigated to establish SARs for the marine alkaloids in the lamellarin family. The C5C6 double bond ensures not only the planarity of the D‐ring, but also proper alignment of the substituents on the E‐ring with their respective moieties of the target. The importance of the C7 OH group is also revealed for the first time.

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Twenty‐two naturally occurring and three unnatural lamellarins were synthesized and evaluated for their cytotoxicities against cancer cells. Across eleven cancer cell lines derived from six different cancer types, the IC50 values of these compounds ranged from sub‐nanomolar (0.08 nM) to micromolar (>97.0 μM). About one‐fourth (6/25) and one‐half (11/25) of these lamellarins are more potent than the positive control, etoposide, against at least six different cell lines and three different cell types, respectively. In general, lamellarins D, X, ε, M, N, and dehydrolamellarin J are significantly more potent than the other lamellarins. The IC50 values were used to perform structure–activity relationship (SAR) studies by comparing the cytotoxic activities of several pairs of lamellarin structures that differ in selected substitution patterns. Our results not only reveal the importance of specific hydroxylation or methoxylation patterns for the first time, but also confirm prior findings and clarify some previous uncertainties.
Daxabe – A Xanthene‐Based Fluorescent Sensor for 3,5‐Dinitrobenzoic Acid and Anions
Authors: Muñiz Francisco M. , Alcázar Victoria , Simón Luis , Raposo César , Calle Emilio , Morán Joaquín R.
Published: January 2009

A new set of receptors based on a dimethylxanthene skeleton has been synthesized. Owing to its suitable oxyanion hole structure, these receptors can associate with carboxylic acids. The combination of this skeleton with a fluorescent unit such as dansyl allows the detection of small amounts of carboxylic acids by making use of fluorescent techniques, such that the response of daxabe depends on the nature of the guest. Anions such as halogenides are also suitable guests for daxabe and can be associated. This receptor also afforded good results in the extraction of zwitterionic amino acids from the aqueous to the organic layer in the presence of 18‐crown‐6 ether. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Sequential 1,3‐Dipolar Cycloaddition of Nitrones to β‐(2‐Aminophenyl) α,β‐Ynones and Cyclocondensation: A New Entry to the Isoxazolino[4,5‐c]quinoline Ring
Authors: Abbiati Giorgio , Arcadi Antonio , Marinelli Fabio , Rossi Elisabetta , Verdecchia Mirella
Published: January 2009

The reaction of β‐(2‐aminophenyl) α,β‐ynones with N‐methyl nitrones provides a simple and efficient entry to the isoxazolino[4,5‐c]quinoline ring system through a sequential 1,3‐dipolar cycloaddition/annulation process. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Determination of Arsenic(III) Using Platinum Nanoparticle‐Modified Screen‐Printed Carbon‐Based Electrodes
Authors: Sanllorente‐Méndez Silvia , Domínguez‐Renedo Olga , Arcos‐Martínez M. Julia
Published: January 2009

The electrochemical detection of arsenic(III) was investigated on platinum nanoparticle‐modified carbon‐based screen‐printed electrodes (PtNPs/SPCEs) in 1 M aqueous H2SO4. PtNPs/SPCEs were prepared by electrochemical deposition of K2PtCl6. The resulting electrode surfaces were characterized with scanning electron microscopy (SEM). By using the As(III) oxidation peak for the analytical determination, there is no interference from Cu(II) if present in contrast to the other metal surfaces typically used for the detection of arsenic in electrochemistry. Precision of the proposed method was very good and a relative good accuracy determined by analysis of a certificate sample and in a spiked tap water sample. Electroinactive As(V) was reduced to As(III) by sodium thiosulfate prior to determination. The detection limit for As(III) obtained was 5.68 μg L−1. In terms of reproducibility, the precision of the above mentioned method in % RSD was calculated at 2.27%.
Composite Bioelectrodes Based on Lipidic Cubic Phase with Carbon Nanotube Network
Authors: Nazaruk Ewa , Sadowska Kamila , Madrak Karolina , Biernat Jan F. , Rogalski Jerzy , Bilewicz Renata
Published: January 2009

Glassy carbon electrodes modified with films composed of a network of single‐wall carbon nanotubes (SWCNTs) and liquid‐crystalline cubic phase were used for dioxygen reduction catalyzed by laccase. In the presence of pristine SWCNTs, the overpotential of dioxygen reduction was decreased by 0.5 V (E1/2=−0.09 V). Adding laccase to the system shifted the potential of oxygen reduction to +0.52 V vs. Ag/AgCl reference electrode. Carbon nanotubes increased the electrode working area and improved the conductivity of the film. The current density of oxygen reduction was further enhanced by using a common mediator, 2,2′‐azino‐bis‐(3‐ethylbenzothiazoline‐6‐sulfonate) diammonium salt (ABTS). Two procedures for modifying carbon nanotubes with ABTS were compared: by adsorption and by covalent binding. Covalent binding of ABTS to the nanotubes is advantageous since it completely eliminates leaching of mediator to the solution and leads to a stable biocathode system.
Switchable Electrodes: How Can the System Complexity be Scaled up?
Authors: Pita Marcos , Katz Evgeny
Published: January 2009

Electrodes modified with different signal‐responsive materials were designed as switchable electrochemical interfaces controlled by various physical or chemical signals. Electrodes with the electrochemical activity switched ON and OFF by light signals were developed using monolayers or thin films of photoisomerizable compounds. Functionalized magnetic particles associated with the electrode surfaces allowed the switching processes controlled by an external magnetic field. Electrochemical transformations proceeding at modified electrode surfaces upon application of different potentials were able to switch the interfacial resistance between low and high values, thus affecting electrochemical properties of the surfaces. Electrode surfaces functionalized with materials responding to chemical signals allowed the switching processes controlled by chemical or biochemical inputs. Most of the designed switchable electrode interfaces have very limited possibilities for scaling up the complexity of the information processing systems associated with the electrode surfaces. Recent advances in biocomputing and specifically in the design of enzyme‐based logic systems allow their coupling with switchable electrodes resulting in very sophisticated interfaces for processing biochemical information and its transduction into electronic signals. Future applications of the signal‐responsive electrodes integrated with the biocomputing systems in ‘smart’ biochemically controlled biosensors, biofuel cells and chemical actuators could be envisaged.
Global damage indexes for the seismic performance assessement of RC structures
Authors: Scotta Roberto , Tesser Leopoldo , Vitaliani Renato , Saetta Anna
Published: January 2009

When performing the seismic risk assessment of new or existing buildings, the definition of compact indexes able to measure the damaging and safety level of structures is essential, also in view of the economic considerations on buildings rehabilitation. This paper proposes two series of indexes, named, respectively, Global Damage Indexes (GDIs), which are representative of the overall structure performance, and Section Damage Indexes (SDIs), which assess the conditions of reinforced concrete (RC) beam‐column sections. Such indexes are evaluated by means of an efficient numerical model able to perform nonlinear analyses of the RC frame, based on the continuum damage mechanics theory and fiber approach. An improvement of a two‐parameter damage model for concrete, developed by some of the authors, which guarantees a better correlation between the Local Damage Indexes (LDIs) and the material's mechanical characteristics, is also presented. For the reinforcement, a specific LDI, named ‘steel damage index’, which takes into account the plastic strain development and the bar buckling effect, is proposed. The numerical model has been employed to simulate several experimental tests, in order to verify the accuracy of the proposed approach in predicting the RC member's behavior. Nonlinear static and dynamic analyses of two RC frames are carried out. The robustness of the method, as well as the effectiveness of the GDIs in assessing the structural conditions, are demonstrated here. Finally, comparisons between the evolution of GDIs and the achievement of the performance levels as proposed in FEMA 356 are reported. Copyright © 2009 John Wiley & Sons, Ltd.
Modelling and forecasting snowmelt runoff process using the HBV model in the eastern part of Turkey
Authors: Şorman A. Arda , Şensoy A. , Tekeli A. E. , Şorman A. Ü. , Akyürek Z.
Published: January 2009

Snowmelt runoff in the mountainous eastern part of Turkey is of great importance as it constitutes 60–70% in volume of the total yearly runoff during spring and early summer months. Therefore, determining the amount and timing of snowmelt runoff especially in the Euphrates basin, where large dams are located, is an important task in order to use the water resources of the country in an optimal manner.

The HBV model, being one of the well‐known conceptual hydrological models used more than 45 countries over the world, is applied for the first time in Turkey to a small basin of 242 km2 on the headwaters of Euphrates river for 2002–2004 water years. The input data are provided from the automatic snow‐meteorological stations installed at various locations and altitudes in upper Euphrates basin operating in real‐time. Since ground‐based observations can only represent a small part of the region of interest, spatially and temporally distributed snow cover data are acquired through the use of Moderate Resolution Imaging Spectroradiometer (MODIS) optical satellite. In the first part of the study, an automatic model parameter estimation method, Shuffled Complex Evolution, University of Arizona (SCE‐UA), is utilized to calibrate the HBV model parameters with a multi‐variable criteria using runoff as well as snow‐covered area (SCA) to ensure the internal validity of the model. Results show that calibrations against SCA in addition to discharge simulate discharge nearly as well as calibrations against discharge only, but further suggest that longer time periods and more study catchments should be included to achieve more comprehensible conclusions. In the second part of the study, the calibrated HBV model is applied to forecast runoff with a 1‐day lead time using gridded input data from Mesoscale Model 5 (MM5) for the 2004 snowmelt period. Promising results indicate the possible operational use of runoff forecasting driven by numerical weather prediction data for flood mitigation, reservoir operation and dam safety. Copyright © 2009 John Wiley & Sons, Ltd.
Reconstructing snow water equivalent in the Rio Grande headwaters using remotely sensed snow cover data and a spatially distributed snowmelt model
Authors: Molotch Noah P.
Published: January 2009

Snow covered area (SCA) observations from the Landsat Enhanced Thematic Mapper (ETM+) were used in combination with a distributed snowmelt model to estimate snow water equivalent (SWE) in the headwaters of the Rio Grande basin (3,419 km2) ‐ a spatial scale that is an order of magnitude greater than previous reconstruction model applications. In this reconstruction approach, modeled snowmelt over each pixel is integrated over the time of ETM+ observed snow cover to estimate SWE. Considerable differences in the magnitude of SWE were simulated during the study. Basin‐wide mean SWE was 2·6 times greater in April 2001 versus 2002. Despite these climatological differences, the model adequately recovered SWE at intensive study areas (ISAs); mean absolute SWE error was 23% relative to observed SWE. Reconstruction model SWE errors were within one standard deviation of the mean observed SWE over 37 and 55% of the four 16‐km2 intensive field campaign study sites in 2001 and 2002, respectively; a result comparable to previous works at much smaller scales. A key strength of the technique is that spatially distributed SWE estimates are not dependent upon ground‐based observations of SWE. Moreover, the model was relatively insensitive to the location of forcing observations relative to commonly used statistical SWE interpolation models. Hence, the reconstruction technique is a viable approach for obtaining high‐resolution SWE estimates at larger scales (e.g. >1000 km2) and in locations where detailed hydrometeorological observations are scarce. Copyright © 2009 John Wiley & Sons, Ltd.
Towards a technological ripening index for olive oil fruits
Authors: Cherubini Chiara , Migliorini Marzia , Mugelli Marco , Viti Paolo , Berti Andrea , Cini Enrico , Zanoni Bruno
Published: January 2009

BACKGROUND: The aim of this work was to study the evolution of sugar and oil contents in Frantoio cultivar olives during ripening in order to propose a technological ripening index for olive oil fruits. Olive fruits were picked at nine different farms once a week from the beginning of September to the beginning of December during three crop seasons.

RESULTS: As a result of the biochemical phenomenon of oil formation in olive fruits, sugar concentration during ripening was shown to follow a sigmoidal decrease, which recurred periodically in different microclimates over years. This trend resulted to be the cause of an opposite sigmoidal increase in oil content. Experimental data for sugar and oil contents were also statistically related by significant linear relationships. In addition, it was observed that reaching a minimum environmental temperature of ⩽10 °C resulted in a definite minimum asymptotic value for sugars.

CONCLUSION: Sugar concentration can be proposed as an accurate, reproducible index for technological ripening of olive oil fruits by the following prediction function: proper ripening degree of olives corresponds to achievement of a constant minimum value for sugar content and, consequently, a constant maximum value for oil content, associated with reduced risk of fermentation activities of olive paste. Copyright © 2009 Society of Chemical Industry
Plasmonic metasurfaces for waveguiding and field enhancement
Authors: Radko I.P. , Volkov V.S. , Beermann J. , Evlyukhin A.B. , Søndergaard T. , Boltasseva A. , Bozhevolnyi S.I.
Published: January 2009

The explosive progress in nanoscience has led to uncovering and exploring numerous physical phenomena occurring at nanoscale, especially when metal nanostructures are involved so that optical fields and electronic oscillations can be resonantly coupled. The latter is the subject of (nano) plasmonics with implications extending from subwavelength waveguiding to localized field enhancements. In this review paper, we consider making use of various phenomena related to multiple scattering of surface plasmons (SPs) at periodically and randomly (nano) structured metal surfaces. After reviewing the SP waveguiding along channels in nanostructured areas exhibiting band‐gap and localization effects, SP‐driven field enhancement in random structures and plasmonic fractal drums is discussed in detail. SP manipulation and waveguiding using periodic nanostructures on the long‐wavelength side of the band gap is also considered.
A simple mathematical model for seasonal planktonic blooms
Authors: Chatterjee Samrat , Venturino Ezio , Chakraborty Subhendu , Chattopadhyay Joydev
Published: January 2009

We show how the inclusion of the defense strategy by different species can alter the prediction of simple models. One of the defense strategy by the phytoplankton population against their grazer is the release of toxic chemicals. In turn the zooplankton population reduces there predation rate over toxin producing phytoplankton (TPP) to protect themselves from those toxic chemicals. Thus, when the level of toxicity is high, the grazing pressure is low and when the level of toxicity is low or when the toxin is absent, the grazing pressure is high. Here we have considered a TPP–zooplankton system where the rate of toxin liberation and the predation rate vary with zooplankton abundance. We observe that our proposed model has the potential to show different dynamical behaviour that are similar to that seen in real‐world situations. Further, we consider three different functional forms for the distribution of the toxins and compare them using latin hypercube sampling technique and found that the functional forms seem to have no effect in determining the final outcome of the system. Copyright © 2009 John Wiley & Sons, Ltd.
Examining how advocacy groups build relationships on the Internet
Authors: Waters Richard D. , Lord Meredith
Published: January 2009

In 2006, the Animal Enterprise Terrorism Act (AETA) became American law after brief Congressional discussions despite the public outcries from animal rights organizations. The AETA made it a federal terrorist crime to harm any animal enterprise financially, which could include legal forms of protests and boycotts. Members of the “Stop AETA” coalition failed to draw attention to the legislation. The relationship management theory of public relations provides a framework to determine how well the coalition members developed relationships with like‐minded individuals and the media. Results from a content analysis of the coalition members' Web sites revealed that nonprofit organizations and citizen‐advocacy groups attempted to develop relationships through a variety of strategies, including making the visit a positive experience, being open and transparent in their advocacy efforts, and providing access to coalition leaders. The results suggest that the coalition was unable to generate much news coverage for the issue because coalition members did not sufficiently reach out to cultivate relationships with journalists. Specific suggestions are provided for future advocacy groups to use the Internet to develop and cultivate relationships with key stakeholder groups.

Copyright © 2009 John Wiley & Sons, Ltd.
Smoking and acute urinary retention: The Olmsted County study of urinary symptoms and health status among men
Authors: Sarma Aruna V. , Jacobson Debra J. , St. Sauver Jennifer L. , Lieber Michael M. , Girman Cynthia J. , Nehra Ajay , Jacobsen Steven J.
Published: January 2009

BACKGROUND

Previous reports have suggested an inverse relationship between smoking and surgery for benign prostatic hyperplasia (BPH). We hypothesized that acute urinary retention (AUR), an adverse outcome of this disease and indication for surgical treatment, may be related to smoking.

METHODS

Study subjects were randomly selected from Olmsted County men aged 40–79 identified through the Rochester Epidemiology Project. Of the 3,854 eligible men, 2,089 (54%) completed a questionnaire that included the American Urological Association Symptom Score and assessed smoking status. Community medical records were examined for occurrence of AUR with documented catheterization in the subsequent 10 years and occurrence of BPH surgery. Proportional hazard models were used to assess the relationship between baseline smoking status and subsequent retention.

RESULTS

In the 18,307 person‐years of follow‐up, 114 men had AUR. When compared to 727 never‐smokers, there was a trend among the 336 current smokers to be at lower risk (Relative risk (RR) = 0.62, 95% Confidence Interval (CI) = 0.33, 1.18) whereas the 1,026 former smokers were at similar risk to non‐smokers (RR = 1.0, 95%CI = 0.67, 1.46). Among men with moderate‐severe symptoms at baseline, current smokers were at lower risk of retention compared to non‐smokers (RR = 0.65, 95%CI = 0.22, 1.91) but the association approached the null among those with none‐mild symptoms (RR = 0.91, 95% CI = 0.40, 2.06).

CONCLUSIONS

Community‐dwelling men who currently smoke may be at a modestly reduced risk of AUR. The magnitude of this association is sufficiently small that it seems unlikely that this explains a sizable proportion of the inverse association between smoking and surgically treated BPH. Prostate 69: 699–705, 2009. © 2009 Wiley‐Liss, Inc.
Asymmetry effect on the spin relaxation in quantum dot structures
Authors: Zinovieva A. F. , Dvurechenskii A. V. , Stepina N. P. , Deryabin A. S. , Nikiforov A. I. , Rubinger R. M. , Sobolev N. A. , Leitão J. P. , Carmo M. C.
Published: January 2009

Spin resonance of electron states in a Ge/Si heterosystem with Ge quantum dots has been investigated. Electron localization in the strain‐induced potential wells in Si in the vicinity of the Ge dots is confirmed by an analysis of the obtained g‐tensor values. A well pronounced anisotropy of the linewidth is explained in terms of an effective magnetic field lying in the plane of the quantum dot array. This magnetic field arises during the tunnelling of electrons between quantum dots and leads to an acceleration of the spin relaxation. The origin of the field is the structure‐induced asymmetry of electron potential wells. Two ways of increasing the spin lifetime are suggested: 1) creation of a higher‐symmetry confinement potential for electrons; 2) growth of a well‐separated quantum dot array (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth of 3C‐SiC nanowires on nickel coated Si(100) substrate using dichloromethylvinylsilane and diethylmethylsilane by MOCVD method
Authors: Hyun J.‐S. , Nam S.‐H. , Kang B.‐C. , Boo J.‐H.
Published: January 2009

We have grown 3C‐SiC nanowires on nickel coated Si(100) substrates using single source precursors by thermal metal‐organic chemical vapor deposition (MOCVD) method. Dichloromethylvinylsilane (CH2CHSi(CH3)Cl2) and diethylmethylsilane (CH3SiH(C2H5)2) were used as a single precursor without any carrier and bubbler gas. 3C‐SiC nanowires with 40 ∼ 100 nm diameter could grow on substrates at temperature as low as 900 °C. XRD pattern showed that SiC nano‐wires were cubic silicon carbide. TEM analysis showed that an amorphous carbon layer surrounds the as‐deposited SiC nanowires, and the 3C‐SiC nanowire has [111] growth direction with well‐crystallized structure. XPS and EDX analyses showed that the as‐obtained SiC nanowire has an atomic Si and C composition of about 1.0:1.2, suggesting possible applications for both electronic devices and field emitters. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Polarization control of nonpolar‐oriented InGaN quantum‐well emission by utilizing (Al)InGaN alloy substrates
Authors: Yamaguchi A. Atsushi
Published: January 2009

The polarization properties of InGaN quantum wells on nonpolar AlInGaN alloy substrates are calculated numerically using the 6×6 k·p Hamiltonian. It is shown that the polarization direction of quantum‐well emission changes, depending on the substrate alloy composition and quantum well width, and that these polarization switches are caused by the strain anisotropy and quantum confinement effects in the quantum wells. The calculations indicate that the utilization of InGaN or AlInGaN alloy substrates can be beneficial in obtaining desirable polarization properties for the formation of cleaved‐facet cavity mirrors in laser diodes on nonpolar substrates. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dislocation density in AlN grown on multistacked GaN/AlN quantum dot layers by molecular beam epitaxy
Authors: Managaki Nobuto , Iizuka Norio
Published: January 2009

The influence of GaN/AlN quantum dots (QDs) on crystalline quality of AlN grown on multistacked QD layers was studied as a function of the GaN deposition. Dislocations in the AlN grown on the QD layers were bent by the existence of the QD layers and the dislocation density in the AlN was one order of magnitude smaller than that in AlN grown on sapphire substrate. In the measurement of Raman spectra, AlN E2 frequency and GaN A1 (LO) frequency depended on the deposition of GaN. The dependence of these two frequencies was strongly correlated. This suggests that the crystalline quality of AlN is affected by the growth condition of the GaN QDs and size distribution of QDs was of great importance in reduction of the dislocation density in AlN by using the QD layers as a buffer layer. The reduction of dislocation in the AlN is efficient when the small QDs are grown uniformly but inefficient when the large QDs are grown. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)