bluuebunny/crossref_metadata_2025 huggingface dataset:
Pasting Properties of Non‐waxy Rice Starch‐Hydrocolloid Mixtures
Authors: Song Ji‐Young , Kwon Ji‐Young , Choi Jungdo , Kim Young‐Chang , Shin Malshick
Published: May 2006

The swelling and pasting properties of non‐waxy rice starch‐hydrocolloid mixtures were investigated using commercial and laboratory‐generated hydrocolloids. The swelling power of the rice starch‐hydrocolloid mixtures was generally depressed at low concentration of hydrocolloids (0–0.05%), but increased directly with increasing hydrocolloid concentrations (0.05–0.1%). In gellan gum dispersion, the swelling power at 100°C was higher than that of control. The rice starch‐hydrocolloids mixtures showed shear‐thinning flow behavior (n = 0.26–0.49). Hydrocolloids except the exopolysaccharide from S. chungbukensis (EPS‐CB) increased apparent viscosity and consistency index (K) of rice starch dispersions, but decreased the n value. Hydrocolloids enhanced the trough and final viscosity of rice starch dispersions but EPS‐CB reduced the viscosity of rice starch pastes. Hydrocolloids lowered peak viscosity but addition of guar gum resulted in high peak viscosity, apparent viscosity, and consistency index of rice starch dispersions. Total setback viscosity appeared to be not affected by hydrocolloids at low concentration (0.05%). The hot and cold paste of the starch‐gellan gum mixture exhibited the highest viscosity values in the Brookfield viscometer.
Placental volume measured by three‐dimensional ultrasound in the prediction of fetal α0‐thalassemia: a preliminary report
Authors: Chen M. , Leung K. Y. , Lee C. P. , Tang M. H. Y. , Ho P. C.
Published: May 2006

Objective

To evaluate the use of placental volume measured by three‐dimensional (3D) ultrasound in predicting fetal homozygous α0‐thalassemia (Hb‐Bart's disease).

Methods

From June 2002 to May 2004 singleton pregnancies at risk of α0‐thalassemia and normal controls were studied prospectively at 9–12 weeks of gestation. Affected fetuses were suspected to have α0‐thalassemia by two‐dimensional (2D) ultrasound and confirmed by DNA analysis. Placental volume was measured on 3D ultrasound by a multiplanar technique. Intra‐ and interobserver agreement of measurements was assessed. The placental volume/crown–rump length quotient of the affected fetuses was compared with that of normal fetuses.

Results

The final study group comprised 105 pregnancies; 43 were at risk of α0‐thalassemia and 62 were normal controls. Eleven (10.5%) fetuses were affected by α0‐thalassemia, all from the at‐risk group, and the others were normal. Intra‐ and interobserver agreement of volume measurement by 3D ultrasound was relatively poor; this was reflected in the wide limits of agreement, which ranged from −10.82 to 40.86 mL. The mean ± SD placental volume/crown–rump length quotient in affected pregnancies was larger than that in unaffected pregnancies (1.37 ± 0.65 vs. 1.13 ± 0.39), but this difference was not significant (P > 0.05).

Conclusions

Assessment of placental volume by 3D ultrasound does not seem to be superior to 2D ultrasound in the first‐trimester prediction of α0‐thalassemia. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Crosslinking of PVC formulations treated with UV light
Authors: Arias G. , Benavides R. , Castillo Garza E.L. , Téllez Rosas M.M.
Published: May 2006

Typical wire and cable formulations of plasticized Poly(vinyl chloride) were prepared with three different stabilizer systems: Ca/Zn (2:1 or 1:1) and dibasic lead phthalate. The mixtures contained trimethylolpropane trimethacrylate (TMPTMA) as crosslinking agent and a UV photoinitiator (Irgacure 819). Mixtures were dry‐blended, then roll‐milled and to finally hot‐pressed at 180°C to obtain sheets of 1 and 1.5 mm thickness. Small specimens (3 × 3 cm) were irradiated with UV light for up to 10 days while monitoring changes at different time intervals. The presence of TMPTMA in the samples, as expected, influenced the storage modulus (E′) and gel content percentage, specifically for the thinner samples. These results indicated that UV irradiation produced surface crosslinking. The samples with crosslinking agent also reached higher carbonyl index values. The Ca/Zn formulations showed higher mechanical properties with respect to the Pb ones, thus suggesting that during the stabilization period of the Ca/Zn mixtures, an effective crosslinking was promoted. Irregular behavior was observed during the last days of treatment for both types of formulations, thereby suggesting an optimum irradiation time for this procedure. J. VINYL. ADDIT. TECHNOL. 12:49–54, 2006. © 2006 Society of Plastics Engineers.
Effect of a N,N′‐disubstituted phenylenediamine stabilizer and SB/EPDM compatibilizer on toughness and morphology of blends of pre‐aged polyethylene with high‐impact polystyrene
Authors: Michálková D. , Pospíšil J. , Fortelný I. , Šlouf M. , Kruliš Z.
Published: May 2006

The effect of a N,N′‐disubstituted 1,4‐phenylenediamine stabilizer and styrene‐butadiene block copolymer (SB)/ethylene‐propylene elastomer (EPDM) compatibilizer on mechanical properties and phase structure of pre‐aged low‐density polyethylene (LDPE; a model of aged recyclate)/high‐impact polystyrene (HIPS) blends was studied. A strong cooperative effect between the stabilizer and compatibilizer on the impact strength and fineness of the phase structure of LDPE/HIPS blends was found. Analysis of chemical reactions assumed to proceed in the system during processing led to the conclusion that improvement in the impact strength and phase structure was accounted for by reactive formation of a LDPE‐SB graft copolymer in a process supported by the presence of the bifunctional amine‐based stabilizer. The mixture of the amine stabilizer with SB/EPDM is a very promising upgrading system for post‐consumer plastic waste containing pre‐oxidized LDPE. J. VINYL. ADDIT. TECHNOL. 12:58–65, 2006. © 2006 Society of Plastics Engineers.
Processing highly filled pre‐compounded pellets on single screw extruders
Authors: Steward Edward L.
Published: May 2006

This article discusses, in general terms, several approaches to producing highly filled plastics. Emphasis is on wood flour, with polyolefins as an example. Processing other highly filled polymer and filler choices follows the same logic. Successful approaches include the single screw machine being fed pre‐pelletized material. A large pelletizing twin screw compounder selected for compounding for its output rate isolates the complexities of the compounding step from the profile lines, which have their own unique challenges, such as sizing and cooling the part at good quality and with good tolerances. Operating a few big pelletizing twin screw machines would allow the simple single screw lines of various sizes to run at decent efficiencies on big or small profiles. Since not one machinery approach has monopolized this application to date, some of the major processing and equipment comparisons are discussed. J. VINYL. ADDIT. TECHNOL. 12:83–86, 2006. © 2006 Society of Plastics Engineers
Mobility changes anonymity: new passive threats in mobile ad hoc networks
Authors: Hong Xiaoyan , Kong Jiejun , Gerla Mario
Published: May 2006

Privacy in mobile ad hoc networks has new semantics in addition to the conventional notions for infrastructure networks. Mobility enabled by wireless communication has significantly changed privacy issues and anonymity research in many ways. In particular, mobility requires ad hoc routing schemes to transmit messages frequently in an open wireless medium. The routing traffic facilitates adversaries in conducting various attacks threatening the network security and privacy. In this work, we focus on passive routing attacks. We present an extensive study on new anonymity threats and classify the corresponding security demands into three new categories: (1)venue anonymity; (2)privacy of ad hoc network topology; and (3)privacy of motion pattern. These new aspects are all introduced by mobility and left unaddressed in fixed infrastructure. This leads us to investigate new design principles. Our study suggests thaton‐demand routing,identity‐free routing, andneighborhood traffic mixingare better design choices to defend against the new anonymity threats in mobile networks. The paper also demonstrates through examples on the visualization of the mobile anonymity attacks and on the quantification of the effectiveness of the attacks. Copyright © 2006 John Wiley & Sons, Ltd.
A secure incentive architecture for ad hoc networks
Authors: He Qi , Wu Dapeng , Khosla Pradeep
Published: May 2006

In an ad hoc network, intermediate nodes on a communication path are expected to forward packets of other nodes so that the mobile nodes can communicate beyond their wireless transmission range. However, because wireless mobile nodes are usually constrained by limited power and computation resources, a selfish node may be unwilling to spend its resources in forwarding packets which are not of its direct interest, even though it expects other nodes to forward its packets to the destination. It has been shown that the presence of such selfish nodes degrades the overall performance of a non‐cooperative ad hoc network. To address this problem, we propose a secure and objective reputation‐based incentive (SORI) architecture to encourage packet forwarding and discipline selfish behavior. Different from existing schemes, under our architecture, the reputation of a node is quantified by objective measures; the propagation of reputation is efficiently secured by a one‐way‐hash‐chain‐based authentication scheme; and secure routing is in place. Armed with the reputation‐based mechanism, we design a punishment scheme to penalize selfish nodes. The experimental results show that the proposed scheme can successfully identify selfish nodes and punish them accordingly. Copyright © 2006 John Wiley & Sons, Ltd.
DISPOSER: distributed secure position service in mobile ad hoc networks
Authors: Wu Xiaoxin
Published: May 2006

Position service is essential for position‐based ad hoc routing algorithms, which have proved to have decent network performance. As private information, node positions are valuable for attackers to locate their targets. Therefore, a secure position service system is needed. In this paper, a distributed secure position service system, named DISPOSER, is proposed and evaluated. A number of trusted servers are distributed in the network. Each node has a virtual home region (VHR). Servers residing in a node's VHR handle the position service regarding to the node, such as position update and position retrieving. DISPOSER keeps the position information private and prevents the position from being misused by a compromised user for tracing purposes. A region‐based local broadcast approach has been designed to reduce the control overhead for information distribution within a VHR. Mechanisms for improving system robustness have been proposed. Analytical results show that while DISPOSER meets the security requirements, it achieves a high system robustness at a relatively low control overhead. Copyright © 2006 John Wiley & Sons, Ltd.
Microarray detection of novel nuclear RNA substrates for the exosome
Authors: Houalla Rym , Devaux Frédéric , Fatica Alessandro , Kufel Joanna , Barrass David , Torchet Claire , Tollervey David
Published: May 2006

Microarray analyses were performed on yeast strains mutant for the nuclear‐specific exosome components Rrp6p and Rrp47p/Lrp1p or the core component Rrp41p/Ski6p, at permissive temperature and following transfer to 37 °C. 339 mRNAs showed clearly altered expression levels, with an unexpectedly high degree of heterogeneity in the different exosome mutants. In contrast, no clear alterations were seen in strains lacking the cytoplasmic exosome component Ski7p. 27 mRNAs that were overexpressed in each strain defective in the nuclear exosome are good candidates for regulation by nuclear turnover. These included the mRNA for the autoregulated RNA‐binding protein Nrd1p. Northern and primer extension analyses confirmed the elevated NRD1 mRNA levels in exosome mutants, and revealed the accumulation of truncated 5′ fragments of the mRNA. These contain a predicted Nrd1p‐binding site, potentially sequestering the protein and disrupting its autoregulation. Several genes located immediately downstream of independently transcribed snoRNA genes were overexpressed in exosome mutants, presumably due to stabilization of the products of transcription termination read‐through. Further analyses indicated that many snoRNA and snRNA genes are inefficiently terminated, but read‐through transcripts into downstream ORFs are normally rapidly degraded by the exosome. Copyright © 2006 John Wiley & Sons, Ltd.
Was that necessary?
Authors: Bulley Michael
Published: May 2006

THE ORIGIN of this article, and of the first of its two topics, was the inclusion of relative pronouns that seemed to the author unnecessary and burdensome. He had been reading, out of duty rather than for pleasure, some texts written by professional classicists and grammarians and began to be aware that these writers, from Britain and the USA, nearly always included relative pronouns when they were not grammatically obligatory and where sometimes not having them would, in his view, have been to the benefit of the sentence.
Phonological resistance and innovation in the North-West of England
Authors: Watson Kevin
Published: May 2006

Over the past few decades, studies of dialect levelling have concluded that phonological convergence amongst varieties of British English is rife. This review attempts to demonstrate the opposite, in the variety of English spoken in Liverpool. Despite various media reports predicting the death of Liverpool English, evidence is provided here that the variety appears to be resisting the innovation of ‘T-glottalling’, a feature which is frequent elsewhere, and instead shows signs of divergence from any kind of supra-local regional norm.
A new Puumala hantavirus subtype in rodents associated with an outbreak of Nephropathia epidemica in South-East Germany in 2004
Authors: ESSBAUER S. , SCHMIDT J. , CONRATHS F. J. , FRIEDRICH R. , KOCH J. , HAUTMANN W. , PFEFFER M. , WÖLFEL R. , FINKE J. , DOBLER G. , ULRICH R.
Published: May 2006

A micro-epidemic of hantavirus infections occurred in Lower Bavaria, South-East Germany, starting in April 2004. While only three cases were registered from 2001 to 2003, a dramatically increased number of clinically apparent human hantavirus infections (n=38) was observed in 2004, plus seven additional cases by June 2005. To determine the reservoir responsible for the infections, a total of 43 rodents were trapped in Lower Bavaria. Serological and genetic investigations revealed that Puumala virus (PUUV) is dominant in the local population of bank voles. Partial PUUV S segment nucleotide sequences originating from bank voles at four different trapping sites in Lower Bavaria showed a low divergence (up to 3·1%). This is contrasted by a nucleotide sequence divergence of 14–16% to PUUV strains detected in Belgium, France, Slovakia or North-Western Germany. PUUV sequences from bank voles in Lower Bavaria represent a new PUUV subtype which seems to be responsible for the observed increase of human hantavirus infections in 2004–2005.
Outbreak of hepatitis A in two federal states of Germany: bakery products as vehicle of infection
Authors: SCHENKEL K. , BREMER V. , GRABE C. , VAN TREECK U. , SCHREIER E. , HÖHNE M. , AMMON A. , ALPERS K.
Published: May 2006

In April 2004, increased numbers of hepatitis A were noted in six neighbouring districts in Germany. Exploratory interviews showed that patients had consumed bakery products from company X where two employees had been diagnosed with hepatitis A in February. A case-control study of consumption of products of company X was carried out through telephone interviews. Altogether, 64 cases were identified. Fifty-two cases and 112 controls aged [ges ]16 years were included in the case-control study. In total, 46/52 cases and 37/112 controls had consumed company X products [odds ratio (OR) 15·5, 95% confidence interval (CI) 6·1–39·7]. Of these, 36/46 cases and 16/37 controls had consumed pastries (OR 4·7, 95% CI 1·8–12·3), 25/46 cases and 12/37 controls had consumed filled doughnuts (OR 2·5, 95% CI 1·0–6·1). Sequence analysis of the VP1-2A junction region indicated 100% strain homology between cases and an infected employee of company X. We recommended reinforcement of hygiene precautions, and consideration of a prolongation of compulsory work absence after post-exposure vaccination.
Antimicrobial susceptibility and serotype distribution of Streptococcus pneumoniae isolated from patients with community-acquired pneumonia and molecular analysis of multidrug-resistant serotype 19F and 23F strains in Japan
Authors: QIN L. , WATANABE H. , YOSHIMINE H. , GUIO H. , WATANABE K. , KAWAKAMI K. , IWAGAKI A. , NAGAI H. , GOTO H. , KURIYAMA T. , FUKUCHI Y. , MATSUSHIMA T. , KUDOH S. , SHIMADA K. , MATSUMOTO K. , NAGATAKE T. , MIZOTA T. , OISHI K.
Published: May 2006

A nationwide study was undertaken to determine the susceptibility to penicillin and serotypes of Streptococcus pneumoniae in Japan. S. pneumoniae was isolated from 114 adult patients with community-acquired pneumonia over 22 months at 20 hospitals and medical centres in different regions in Japan. All but five isolates were from sputum. Forty-eight isolates (42·1%) were susceptible, 40 (35·1%) showed intermediate resistance (MIC, 0·12–1·0 μg/ml) and 26 (22·8%) were resistant (MIC, [ges ]2·0 μg/ml) to penicillin G. All isolates were susceptible to ceftriaxone (breakpoint 1 μg/ml), imipenem (4 μg/ml) and vancomycin (4 μg/ml). Most were resistant to erythromycin, clarithromycin and azithromycin; only two were resistant to levofloxacin. Differences were found in the distribution of serotypes among isolates showing susceptibility to penicillin (predominant types 3, 6B, and 19F), intermediate resistance (6B, 14, 19F, and 23F) and full resistance (19F and 23F). PFGE typing showed that 14 of the 25 strains of serotype 19F had a single DNA profile, pattern A, a pattern closely similar to that of the Taiwan multidrug-resistant 19F clone. Twelve pattern A strains were not susceptible to penicillin but carried the macrolide resistance gene mef(A). The DNA profiles of the 15 strains of 23F were also heterogeneous but six were highly similar (pattern b) yet distinct from the Spanish multidrug-resistant 23F clone although possibly related to the Taiwan multidrug-resistant 23F clone. The pattern b strains were not susceptible to penicillin and also harboured either mef(A) or erm(B). Our results indicate that multidrug-resistant pneumococci are spreading rapidly in Japan. Efforts to prevent the spread of the pandemic multidrug-resistant serotypes should be intensified.
Interpreting serological surveys using mixture models: the seroepidemiology of measles, mumps and rubella in England and Wales at the beginning of the 21st century
Authors: VYSE A. J. , GAY N. J. , HESKETH L. M. , PEBODY R. , MORGAN-CAPNER P. , MILLER E.
Published: May 2006

A mixture modelling technique is applied to age-specific frequency distributions of quantitative results from serological surveys for measles, mumps and rubella using samples collected across the age range in England and Wales in 2000. In accordance with previous studies the analysis suggests that the antibody response to natural infection is stronger than that produced by vaccination, that vaccine-induced antibody levels wane with time and that levels of vaccine-induced antibody response vary for each virus infection being strongest for rubella and weakest for mumps. The current mumps epidemic in the United Kingdom is focused in cohorts born during 1982–1987 who were too old to have received routine MMR vaccination. In the cohort born in 1981–1985 the model estimates that 7·5% have no evidence of mumps specific IgG and 24·9% have the lowest level of detectable antibody. The similar proportions of mumps antibody in these categories among cohorts with opportunity for 1 or 2 doses of vaccine is a concern, as the degree to which these individuals are protected is unclear. Investigations into the efficacy of two doses of a mumps containing vaccine should be a priority during the current epidemic.
The Influence of Distressing Information on Memory in Acute Stress Disorder
Authors: Moulds Michelle L. , Bryant Richard A.
Published: May 2006

Acute stress disorder (ASD) is purportedly characterized by impaired encoding of aversive material. In this study ASD, trauma-exposed non-ASD, and non-traumatized control participants (N = 45) were administered intermixed presentations of either distressing (i.e. disfigured) or neutral faces. For each presentation, two words were presented centrally to the image and two were presented peripherally. Participants were subsequently administered recall and recognition tests for the presented words. Participants recalled more words presented centrally to neutral images than those presented centrally to trauma images. Dissociative tendencies were negatively correlated with recognition of words centrally presented with distressing stimuli. These findings are consistent with the proposal that dissociative reactions are associated with impaired memory for distress-related information.
Kurzzeiteffekte des indizierten Präventionsprogramms für Expansives Problemverhalten (PEP) auf das elterliche Erziehungsverhalten und auf das kindliche Problemverhalten
Authors: Hanisch Charlotte , Plück Julia , Meyer Nicola , Brix Gabriele , Freund-Braier Inez , Hautmann Christopher , Döpfner Manfred
Published: May 2006

Zusammenfassung. Theoretischer Hintergrund: Verhaltenstherapeutisch orientierte Elterntrainings haben sich bei der Behandlung von Kinder mit ausgeprägten expansiven Verhaltensauffälligkeiten bewährt. Das Präventionsprogramm für Expansives Problemverhalten (PEP) wurde vor dem Hintergrund entwickelt, eine Verminderung des kindlichen Verhaltensauffälligkeiten in der Familie und im Kindergarten über eine Verbesserung der Erziehungskompetenzen der Eltern und der Erzieherinnen zu erreichen. PEP richtet sich schwerpunktmäßig an die Eltern und Erzieherinnen drei- bis sechsjähriger als expansiv auffällig indizierter Kinder. Fragestellung: Verbessert eine Teilnahme an PEP das elterliche Erziehungsverhalten und werden expansive Verhaltensauffälligkeiten der Kinder reduziert? Methode: Von 60 drei- bis sechsjährigen Kindern nahmen sowohl die Erzieherinnen als auch die Mütter am PEP-Training teil. 65 Kinder dienten als nicht-behandelte Kontrollgruppe. Erhoben wurden das Erziehungsverhalten der Mütter und das kindliche Problemverhalten aus Sicht der Mütter und der Erzieherinnen. Ergebnisse: Nach der Intervention zeigten sich in der Interventionsgruppe eine Verminderung des Problemverhaltens und eine Verbesserung des elterlichen Erziehungsverhaltens. In der Interventions- nicht aber in der Kontrollgruppe nahm aber der Anteil an Familien deutlich ab, die zu Beginn der Studie über unterdurchschnittlich gute Erziehungskompetenzen verfügten. Veränderungen von Erziehungs- und Problemverhalten wiesen eine signifikante Korrelation auf. Schlussfolgerungen: PEP ist somit geeignet, die elterliche Erziehungskompetenz zu steigern und darüber eine Reduktion kindlicher Verhaltensauffälligkeiten zu erreichen.
Der Einfluss von Anreizen auf die Rekrutierung von Eltern und auf die Effektivität eines präventiven Elterntrainings
Authors: Heinrichs Nina , Krüger Sonja , Guse Ute
Published: May 2006

Zusammenfassung. Theoretischer Hintergrund: Es gibt kaum theoretische Modelle darüber, wie Eltern am besten für die Teilnahme an Präventionsangeboten zu gewinnen wären. Fragestellung: Wirken sich unterschiedliche Anreize auf die Teilnahme an einem kognitiv-behavioralen Elterntraining aus? Haben die Anreize Auswirkung auf die Wirksamkeit des Programms? Methode: Hundertsiebenundneunzig Eltern aus 15 Kindertagesstätten in sozial benachteiligten Stadtgebieten nahmen an dem Training teil, nachdem ihre Kita randomisiert einer der vier nachfolgenden Bedingungen zugewiesen wurde: Training einzeln/unbezahlt, Training einzeln/bezahlt, Training in Gruppe/unbezahlt, Training in Gruppe/bezahlt. Ergebnisse: Es zeigte sich, dass (1) das Elterntraining auch in einer sozial benachteiligten Umgebung deutliche Effekte hervorrief, und (2) die beiden Anreizbedingungen auf Teilnahme und Wirksamkeit differenziell Einfluss nahmen. Während Bezahlung (nicht so das Setting) die Teilnahmebereitschaft von Eltern deutlich erhöhte, wirkte sich das Setting auf die Wirksamkeit aus: Im Einzeltraining veränderte sich das Erziehungsverhalten stärker als im Gruppentraining. In allen anderen untersuchten Bereichen gab es keine Unterschiede in der Wirksamkeit in Abhängigkeit von den Rekrutierungsstrategien. Schlussfolgerung: Diese Ergebnisse unterstützen die Empfehlung, Eltern aus sozial benachteiligten Gebieten für die Teilnahme an präventiven Programmen zu bezahlen, da (1) ein größerer Teil der fokussierten Population erreicht wird und (2) die Bezahlung keine nachteilige Auswirkung auf die kurzfristige Effektivität zeigt.
Yeast Gal4: a transcriptional paradigm revisited
Authors: Traven Ana , Jelicic Branka , Sopta Mary
Published: May 2006

During the past two decades, the yeast Gal4 protein has been used as a model for studying transcriptional activation in eukaryotes. Many of the properties of transcriptional regulation first demonstrated for Gal4 have since been shown to be reiterated in the function of several other eukaryotic transcriptional regulators. Technological advances based on the transcriptional properties of this factor—such as the two‐hybrid technology and Gal4‐inducible systems for controlled gene expression—have had far‐reaching influences in fields beyond transcription. In this review, we provide an updated account of Gal4 function, including data from new technologies that have been recently applied to the study of the GAL network.
High-resolution laser excitation spectroscopy of the ÃE2-X̃A12 transition of SrCH3
Authors: Dick M. J. , Sheridan P. M. , Wang J.-G. , Bernath P. F.
Published: May 2006

High-resolution laser excitation spectroscopy has been used to record the ÃE2-X̃A12 electronic transition of SrCH3 in a laser ablation/molecular jet source. Transitions arising from the K′=1←K″=0, K′=0←K″=1, and K′=2←K″=1 subbands have been observed and assigned. The data were modeled with E2 and A12 symmetric top Hamiltonian matrices in a Hund’s case (a) basis, using a least squares fitting program. Rotational and fine structure parameters for the ÃE2 state were determined. A comparison of the spin-orbit energy separation in the ÃE2 state to other strontium containing free radicals showed that the Jahn-Teller effect is negligible. The spin-rotation constants for the ÃE2 state were calculated using the pure precession model and were found to be in good agreement with the experimentally determined parameters. These calculations suggest that the ÃE2 state of SrCH3 is not entirely of p orbital character. The rotational constants were used to estimate the structural parameters of SrCH3 in the ÃE2 state. The strontium-carbon bond length was found to decrease by ∼0.006Å, and the hydrogen-carbon-hydrogen bond angle opened by ∼0.8° compared to the X̃A12 state, similar to the geometry changes observed for CaCH3.
Coherent ultrafast photoelectron spectroscopy in Br2: An alternative method for measuring Δv≠ transitions in Rydberg-to-Rydberg excitations
Authors: Stavros Vasilios G. , Lau Lana , Strasser Daniel , Leone Stephen R.
Published: May 2006

A two-state vibrational wave packet is prepared in a low-lying 4d[1∕2]1or2 Rydberg state of jet cooled Br2 (4d, v′=3 and v′=4) by two-photon excitation with 266.5nm pulses from an ultrafast laser. The wave packet is detected by autoionization following excitation with time-delayed 800nm pulses to the n=8 (v+=4) and n=9 (v+=3) Rydberg states in the Π1∕22 angular momentum core state. Autoionization of each state occurs to the Π3∕22 state of the ion through spin-orbit ionization. Photoelectron spectroscopy is used to differentiate between the n=8 and n=9 ejected photoelectrons. Detection of the wave packet recurrences via the n=8 and n=9 Rydberg states reveals a π phase-shift difference of the recurrences between the two final states. In each case, Δv≠0 transitions are observed since wave packet recurrences are detected. By fitting the observed phase change of the recurrences with a simple model for the overlap amplitudes and assumptions about the potentials, we estimate, within the context of the model, that approximately 0.6% of the transitions may be attributed to Δv=±1 transitions between the initial Rydberg superposition state and the final Rydberg detection state.
A nonmonotonic dependence of standard rate constant on reorganization energy for heterogeneous electron transfer processes on electrode surface
Authors: Xu Weilin , Li Songtao , Zhou Xiaochun , Xing Wei , Huang Mingyou , Lu Tianhong , Liu Changpeng
Published: May 2006

In the present work a nonmonotonic dependence of standard rate constant (k0) on reorganization energy (λ) was discovered qualitatively from electron transfer (Marcus-Hush-Levich) theory for heterogeneous electron transfer processes on electrode surface. It was found that the nonmonotonic dependence of k0 on λ is another result, besides the disappearance of the famous Marcus inverted region, coming from the continuum of electronic states in electrode: with the increase of λ, the states for both Process I and Process II ET processes all vary from nonadiabatic to adiabatic state continuously, and the λ dependence of k0 for Process I is monotonic thoroughly, while for Process II on electrode surface the λ dependence of k0 could show a nonmonotonicity.
Monte Carlo simulation of crystal-fluid coexistence states in the hard-sphere system under gravity with stepwise control
Authors: Mori Atsushi , Yanagiya Shin-ichiro , Suzuki Yoshihisa , Sawada Tsutomu , Ito Kensaku
Published: May 2006

Monte Carlo (MC) simulations were performed for hard spheres (with diameter σ and mass m) placed between well-separated upper and lower hard walls. A periodic boundary condition was imposed in the horizontal direction. The system was exposed to the gravitational field with the acceleration due to gravity g. After preparing a melt as the initial state, g was increased stepwise up to mgσ∕kBT(≡g*)=1.5 or 2.0 with an increment Δg*=0.1; kBT is the temperature multiplied by Boltzmann’s constant. We maintained g* at each value for 2.0×105 MC cycles. The transition of the system into a metastable state such as a polycrystalline state due to trapping phenomena was successfully avoided. A monotonic increase and subsequent saturation were observed for the development of the crystalline region formed at the bottom of the system. The development of this region accompanied a shrinkage of the defective (or less ordered) crystalline region that was formed between the bottom region and the fluid phase. As the development of the bottom region almost saturated, the defective region grew upward again.
Ultraviolet electroluminescence and blue-green phosphorescence using an organic diphosphine oxide charge transporting layer
Authors: Burrows P. E. , Padmaperuma A. B. , Sapochak L. S. , Djurovich P. , Thompson M. E.
Published: May 2006

We report electroluminescence at 338nm from a simple bilayer organic light-emitting device (OLED) made using 4,4′-bis(diphenylphosphine oxide) biphenyl (PO1). In an OLED geometry, the material is preferentially electron transporting. Doping the PO1 layer with iridium(III)bis(4,6-(di-fluorophenyl)-pyridinato-N,C2′)picolinate (FIrpic) gives rise to electrophosphorescence with a peak external quantum efficiency of 7.8% at 0.09mA∕cm2 and 5.9% at 13mA∕cm2. The latter current density is obtained at 6.3V applied forward bias.
Structural, electronic, and magnetic properties of manganese-doped Zn12O12 clusters: A first-principles study
Authors: Liu Haitao , Wang Shanying , Zhou Gang , Wu Jian , Duan Wenhui
Published: May 2006

A first-principles study has been performed to evaluate the structural, electronic, and magnetic properties of Zn12O12 clusters doped with one or two Mn atoms. The substitutional, exohedral, and endohedral dopings are taken into account. For the monodoped clusters, the substitutional isomer is most energetically favorable, and an exohedral isomer may appear as a low-lying metastable state. All isomers present 5μB magnetic moment that is mainly contributed by the Mn-3d component. For the bidoped clusters, the antiferromagnetic state is degenerate with the ferromagnetic state at larger Mn–Mn distance (>5Å), while it is more energetically favorable at smaller Mn–Mn distance. Thus, the cohesion of bidoped isomer is sensitive to the magnetic coupling or chemical bonding. The endohedral bidoped isomer is found to be a stable local minimum, and the direct Mn–Mn interaction causes the reduction of local magnetic moment of Mn to about 4μB.
Soft-state biomicrofluidic pulse generator for single cell analysis
Authors: Sabounchi Poorya , Ionescu-Zanetti Cristian , Chen Roger , Karandikar Manjiree , Seo Jeonggi , Lee Luke P.
Published: May 2006

We present the design, fabrication, and characterization of a soft-state biomicrofluidic pulse generator for single cell analysis. Hydrodynamic cell trapping via lateral microfluidic junctions allows the trapping of single cells from a bulk suspension. Microfluidic injection sites adjacent to the cell-trapping channels enable the pulsed delivery of nanoliter volumes of biochemical reagent. We demonstrated the application and removal of reagent at a frequency of 10Hz with a rise time of less than 33ms and a reagent consumption rate of 0.2nL∕s. It is shown that this system operates as a low-pass filter with a cutoff frequency of 7Hz.
An experimental value for the B1u C–H stretch mode in benzene
Authors: Erlekam Undine , Frankowski Marcin , Meijer Gerard , von Helden Gert
Published: May 2006

We here present experimental infrared spectra on two (C6H6)(C6D6) benzene dimer isomers in the gas phase. The spectra show that the two benzene molecules in the dimer are symmetrically inequivalent and have distinct IR signatures. One of the two molecules is in a site of low symmetry, which leads to the IR activation of fundamental modes that are IR forbidden by symmetry in the monomer. In the spectra, all four fundamental C–H stretch modes of benzene are observed. Modes in the dimer are shifted up to 3cm−1 to the red, compared to the modes that are known for the monomer. For the ν13B1u C–H stretch fundamental mode of benzene, a first experimental value of 3015+2−5cm−1 is determined, in excellent agreement with anharmonic frequency calculations presented here.
Surface optical phonon Raman scattering in Zn∕ZnO core-shell structured nanoparticles
Authors: Zeng Haibo , Cai Weiping , Cao Bingqiang , Hu Jinlian , Li Yue , Liu Peisheng
Published: May 2006

Surface optical (SO) phonon vibration mode predominant Raman scattering spectra were observed in the range of 545–565cm−1 in metal-semiconductor Zn∕ZnO core-shell structured nanoparticles, prepared by laser ablation of a zinc target in a surfactant aqueous solution. The SO phonon mode exhibits significant size confinement effect. Such SO dominant Raman scattering is attributed to the existence of a large number of disorderly arranged areas among ultrafine ZnO grains formed under the extreme condition of laser ablation. This study demonstrates that the properties of surface phonons can availably reflect some important physical information.
Microscopic investigation of the poly(9,9-dioctylfluorene) photoluminescence dependence on the deposition conditions by confocal laser microscopy
Authors: Caruso M. E. , Lattante S. , Cingolani R. , Anni M.
Published: May 2006

We studied the microscopic dependence of poly(9,9-dioctylfluorene) photoluminescence (PL) on the deposition conditions. We show that in films spin coated from chloroform phase separation of β and glassy phases is present, with micrometric β phase clusters covering about 6% of the sample surface. The exposure to toluene vapors leads to the disappearance of the β phase clusters, but increases the β phase content in the films due to swelling induced polyfluorene chain planarization. The deposition from toluene solution leads to nonuniform PL intensity, dominated by the β phase emission, attributed to an interplay between aggregation during the solvent evaporation and solvent swelling induced chain planarization.
Polarity control of GaN grown on ZnO (0001¯) surfaces
Authors: Kobayashi Atsushi , Kawaguchi Yuji , Ohta Jitsuo , Fujioka Hiroshi , Fujiwara Katsutoshi , Ishii Akira
Published: May 2006

We have investigated the growth temperature dependence of the structural properties of GaN deposited on O-polarity ZnO (0001¯) using pulsed laser deposition. We have found that atomically abrupt GaN∕ZnO heterointerfaces are obtained at growth temperatures reduced to below 500°C. We have also found that GaN grown at room temperature (RT) exhibits a Ga polarity while that grown at 700°C exhibits a N polarity. However, it is possible to grow Ga-polarity GaN at 700°C by the introduction of a RT buffer layer. First principles calculations well explain how Ga-polarity GaN may be grown on atomically flat O-polarity ZnO surfaces at low temperatures.
Resonance enhancement of optical second harmonic generation in a ZnO nanowire
Authors: Prasanth R. , van Vugt L. K. , Vanmaekelbergh D. A. M. , Gerritsen H. C.
Published: May 2006

Two-photon absorption measurement has been carried out in a single 80nm×10μm ZnO nanowire using femtosecond laser pulses in the wavelength range of 700–800nm. In addition to the deep-level green emission around 530nm due to surface defects and the near band-edge ultraviolet emission around 360nm due to the exciton, a second harmonic peak has been observed. The strength of the frequency-doubled component is found to enhance while the two-photon absorption wavelength is tuned towards the exciton wavelength of the nanowire. This behavior can be ascribed to the resonant exciton absorption in ZnO nanowires.
Dielectric characteristic of photoinduced isomerization in azo-dye doped polymeric matrices
Authors: Luo Duanbin , Deng Li
Published: May 2006

The dielectric permittivities and losses of poly(methyl methacrylate) doped with different concentrations of azo dye are investigated under the irradiation of 532nm light for the first time. The dielectric permittivities increase with the concentration of chromophores increasing, and the dielectric relaxation is mainly influenced by the doped azo-dye chromophores. Given the dye concentration, the dielectric permittivities depend on the pump power of 532nm light. With the increase of pumping light power, the low frequency dielectric losses increase while the high frequency dielectric losses decrease. The results are explained based on the photoinduced isomerization of chromophores and the interaction between the chromophores and polymer matrices.
Probing carrier dynamics in implanted and annealed polycrystalline silicon thin films using white light
Authors: Lioudakis Emmanouil , Othonos Andreas , Nassiopoulou A. G.
Published: May 2006

Polycrystalline silicon thin film samples implanted and annealed at various temperatures have been studied using ultrafast laser pulse excitation. Nondegenerate pump-probe technique has been utilized to investigate carrier dynamics in the highly implanted samples at a relatively small fluence. A model based on two coupled differential equations has been used to fit the experimental data, giving a simple but adequate picture of the dynamics of this system. Basic sample parameters such as carrier trapping times, diffusion coefficient, and penetration depths have been extracted, providing a dependence on the annealing temperature for the samples under investigation.
Fabrication and efficiency improvement of micropillar InGaN∕Cu light-emitting diodes with vertical electrodes
Authors: Wang W. K. , Huang S. Y. , Huang S. H. , Wen K. S. , Wuu D. S. , Horng R. H.
Published: May 2006

We present a micropillar surface structure based on the enhancement of the light extraction efficiency of the near-ultraviolet (409nm) vertical-conducting InGaN light-emitting diode (LED) with an electroplated Cu substrate. The micropillar InGaN∕Cu LED (chip size: 1×1mm2) was fabricated using a combination of patterned sapphire substrate (PSS), laser lift-off, and copper electroplating processes. The PSS and Cu substrate can offer the advantages of dislocation reduction and thermal heat sink, respectively. It was found that the light output power (at 350mA) of the micropillar InGaN∕Cu LED sample can be improved by 39% as compared with that of the conventional InGaN∕Cu LED one. This significant enhancement in output power could be attributed to the increase of the extraction efficiency which is a result of the increase in photon escaping probability caused by scattering the emission light at the micropillar surface. The light extraction efficiency can be further optimized by tuning the micropillar spacing, as evidenced by the ray-tracing simulation result.
Hard and fragile holmium-based bulk metallic glasses
Authors: Luo Q. , Zhao D. Q. , Pan M. X. , Wang R. J. , Wang W. H.
Published: May 2006

A family of holmium-based bulk metallic glasses (BMGs) with high glass-forming ability is obtained. The Ho-based BMGs exhibit much larger elastic moduli and high thermal stability in contrast to other known rare-earth (RE)-based BMGs. In particular, the BMGs show a large value of fragility. It is expected that the hard RE-based glasses with high glass-forming ability and fragile behaviors make them the appropriate candidate for glass transition study.
Impact of Political Incidents, Financial Crises, and Severe Acute Respiratory Syndrome on Hong Kong Property Buyers
Authors: Lai Lawrence W C , Chau Kwong Wing , Ho Daniel C W , Lin Veronica Y Y
Published: May 2006

In this paper, the first part of our study, we use a linear statistical technique to examine the impact of the announcement of China's decision to take back Hong Kong from the United Kingdom in 1982, the Tiananmen Square incident of 4 June 1989, the Asian financial crisis (AFC) of 1997, and the outbreak of severe acute respiratory syndrome (SARS) in 2003 on Hong Kong's housing market in terms of prices. A total of 11362 residential transactions from a cluster of data for a large private-housing estate, considered to be representative of Hong Kong's private residential market, were used to test four hypotheses that evaluate the impact of shocks on property prices through the use of a hedonic price model. The influences based on the statistical findings, which satisfy the relevant goodness-of-fit tests, are (a) that the sovereignty crisis exerted immediate significant negative price effect, but property prices rebounded after a big decline when open diplomatic dialogue between the Chinese and UK governments began, (b) that the Tiananmen Square (4 June) incident had no significant price effect; (c) that the AFC caused a drastic decline in property prices; and (d) that the impact of the SARS outbreak was significantly negative for Amoy Gardens but not so for estates with fewer reported SARS cases.
Planning on the Edge: England's Rural — Urban Fringe and the Spatial-Planning Agenda
Authors: Gallent Nick , Bianconi Marco , Andersson Johan
Published: May 2006

Planning at the edge of cities has, in the past, largely been concerned with containment, with the promotion of more compact urban form, and with the planned separation of rural and urban land use and activities. However, there has been some inevitable blurring of these uses, to create a unique landscape—an interface between town and country—sometimes labelled the rural–urban fringe. This landscape has been created more by fortune than design: less favoured urban uses—sewage works, mental institutions, asylum centres, breakers' yards, etc—have been pushed away from residential areas. Rural uses, mainly farming and forestry, have become mingled with this particular assemblage of urban activities to create a hybrid landscape. Planning, however, has been a relatively inert force at the edge: seeking to contain (perhaps through greenbelts) but not seeking to improve or to manage. In England, our principal focus in this paper, a number of commentators have expressed a concern for this apparent inertia, arguing that planning could do more to ‘manage’ the fringe, creating new social, economic, and environmental opportunities. We draw on a review of policies and programmes affecting the fringe, and argue that spatial planning—able to integrate land uses, and different activities and interests-may create such opportunities. We highlight what planning might seek to achieve at the edge, and how any programme of change might be driven forward.
Does the Compact-City Paradigm Foster Sustainability? An Empirical Study in Taiwan
Authors: Lin Jen-Jia , Yang An-Tsei
Published: May 2006

The compact-city paradigm has received increased attention worldwide for its ability to achieve sustainable development. However, the claim that the compact-city paradigm contributes to sustainability has not been sufficiently verified. In this study we evaluate how major concepts in the compact-city paradigm affect urban sustainability. Correspondingly, the complementary strategies for facilitating compact-city progress are recommended. Structural equation modeling was applied to ninety-two samples of medium-sized or small-sized cities in Taiwan. Latent variables and observed variables were analyzed in the model's structure. According to the results a high-density pattern and intensification negatively affect the environmental and social sustainability, but positively affect economic sustainability. Furthermore, mixture of land use is beneficial to economic sustainability, and does not significantly affect environmental or social sustainability. On the basis of the empirical results, strategies that guide the compact-city paradigm toward the goals of sustainability are also proposed.
Novel aspects of cyanogenesis in Eucalyptus camphora subsp. humeana
Authors: Neilson Elizabeth H. , Goodger Jason Q. D. , Woodrow Ian E.
Published: May 2006

Cyanogenesis is the release of cyanide from certain organisms upon tissue disruption. Tissue disruption, such as that caused by folivory, brings cyanogenic glycosides into contact with catabolic enzymes and toxic HCN is subsequently released. The process provides a measure of defence against generalist herbivores. Within the genus Eucalyptus, several species have been identified as cyanogenic and all of these store cyanide exclusively in the form of the cyanogenic glycoside prunasin. Here we report for the first time cyanogenesis in Eucalyptus camphora subsp. humeana L.A.S. Johnson & K.D. Hill. We found that foliage contains at least five different cyanogenic glycosides, three of which were purified and identified (prunasin, sambunigrin and amygdalin). Two natural populations of E. camphora trees were screened for cyanogenesis, and quantitative polymorphism was measured at both sites. Trees varied in their capacity for cyanogenesis from 0.014 to 0.543 mg CN g–1 DW in one population and from 0.011 to 0.371 mg CN g–1 DW in the other. A progeny trial, testing both cyanogenesis and carbon-based defence (namely total phenolics and condensed tannins), was performed with seed sourced from two cyanogenic, open-pollinated maternal trees. Interestingly, the seedlings exhibited markedly lower levels of cyanogenesis and condensed tannins than the adult population, with some individuals completely lacking one or both of the chemical defences. Total phenolic concentrations, however, were significantly higher in the seedlings than in the parental population from which the seed was sourced. Eucalyptus camphora is relatively unique among cyanogenic trees having multiple foliar cyanogenic glycosides and an apparently marked ontogenetic regulation of cyanogenic capacity.