bluuebunny/crossref_metadata_2025 huggingface dataset:
Nanoelectronic pulse generators based on gated resonant tunnelling diodes
Authors: Wernersson Lars‐Erik , Lindström Peter , Nauen André , Lind Erik
Published: September 2004

We study the operation of a gated resonant tunnel diode placed in an oscillator tank circuit for application as a pulse generator. The gated diode is realized by a metal gate placed 30nm away from a resonant tunnelling double barrier heterostructure, where the gate is used to control the current of the tunnelling diode. A large signal model is developed for the gated resonant tunnelling diode and we use this model to study the operation of the pulsed oscillator. It is demonstrated that the gate can be used to switch the oscillations on and off and to tune the oscillation frequency via changes in the internal capacitances in the gated diode. A modulation in the oscillation frequency of 7.6 GHz around 220 GHz is obtained for a change in the gate bias from 0.2 to −0.6V. Short pulses applied to the gate results in only four periods of oscillation with a broad power spectrum. Copyright © 2004 John Wiley & Sons, Ltd.
PAQM: an adaptive and proactive queue management for end‐to‐end TCP congestion control
Authors: Ryu Seungwan
Published: September 2004

Two functions, the congestion indicator (i.e. how to detect congestion) and the congestion control function (i.e. how to avoid and control congestion), are used at a router to support end‐to‐end congestion control in the Internet. Random early detection (RED) (IEEE/ACM Trans. Networking1993;1(4):397–413) enhanced the two functions by introducing queue length averaging and probabilistic early packet dropping. In particular, RED uses an exponentially weighted moving average (EWMA) queue length not only to detect incipient congestion but also to smooth the bursty incoming traffic and its resulting transient congestion. Following RED, many active queue management (AQM)‐based extensions have been proposed. However, many AQM proposals have shown severe problems with detection and control of the incipient congestion adaptively to the dynamically changing network situations. In this paper, we introduce and analyse a feedback control model of TCP/AQM dynamics. Then, we propose thePro‐active Queue Management(PAQM) mechanism, which is able to provide proactive congestion avoidance and control using an adaptive congestion indicator and a control function under a wide range of traffic environments. The PAQM stabilizes the queue length around the desired level while giving smooth and low packet loss rates and high network resource utilization. Copyright © 2004 John Wiley & Sons, Ltd.
Network dimensioning at the call level for the always‐on network
Authors: Nananukul Soracha
Published: September 2004

It is becoming common for the network to provide always‐on access services, where subscribers are guaranteed that their call requests will never be blocked. This paper studies the call‐level link dimensioning for the always‐on network with single‐class traffic. The call‐level QoS requirement is expressed in terms of the probability of a poor‐quality call, which is the probability that a call experiences packet‐level QoS violation at any time during its duration, as opposed to the probability of blocking in the network with call admission control (CAC). The system is modelled as the M/M/infinite system with finite population and an analytic expression for the probability of a poor‐quality call is derived based on performability analysis. The effects of the call‐level traffic characteristics on the required link resources are studied. It is also shown that the call‐level link dimensioning for the always‐on network needs more link resources than the network with CAC, and the call‐level link dimensioning based on the analytic expression can be used to conservatively dimension the always‐on network with arbitrarily distributed call holding time and inter‐call time. The paper also studies the problem of estimating the call‐level traffic characteristics when the knowledge of call boundaries is not available. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis, Structure, Optical Properties and Theoretical Studies of Pt(P−P)(CN)2 with P−P = 1,2‐Bis(diphenylphosphanyl)benzene and 2,2′‐Bis(diphenylphosphanyl)‐1,1′‐binaphthyl − Luminescence from Metal‐to‐Ligand Charge Transfer and Intraligand States
Authors: Pawlowski Valeri , Kunkely Horst , Lennartz Christian , Böhn Karlheinz , Vogler Arnd
Published: September 2004

The complexes PtII(P−P)(CN)2 with P−P = 1,2‐bis(diphenylphosphanyl)benzene (dppb) and 2,2′‐bis(diphenylphosphanyl)‐1,1′‐binaphthyl (binap) were synthesised and characterised by elemental analysis, ESI MS and electronic spectroscopy. The structure of Pt(dppb)(CN)2 was resolved by single‐crystal X‐ray diffraction. This compound consists of mononuclear PtII complexes with an almost planar PtP2C2 coordination. While both complexes are not luminescent in solution, they show an emission in the solid state under ambient conditions. It is suggested that the luminescence of Pt(dppb)(CN)2 originates from a (PtII→dppb) metal‐to‐ligand charge transfer (MLCT) triplet with some dppb intraligand (IL) contribution. This assignment is confirmed by calculations which provide further insight into the excited state properties of the complex. In solution the phosphorescence is absent because the MLCT/IL state is deactivated to a nonemissive ligand field (LF) triplet, which is located at rather low energies owing to its distortion towards a tetrahedral structure. In the solid state this distortion is hindered. In the case of solid Pt(binap)(CN)2, the phosphorescence is apparently of the IL type as the ππ* triplet of the binaphthyl chromophore occurs at low energies. Again, in solution the phosphorescence is absent owing to the interference by a distorted LF state. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Electronic Structure of High‐Spin Iron(IV) Complexes
Authors: Ghosh Abhik , Tangen Espen , Ryeng Hege , Taylor Peter R.
Published: September 2004

High‐spin (S = 2) iron(IV) species are rare but increasingly recognized as reactive intermediates in the catalytic cycles of several nonheme iron enzymes. A question of some interest, therefore, concerns how much higher in energy the low‐spin (S = 1) state is for these species. With the use of density functional theory (DFT) and high‐level ab initio calculations [CASPT2 and CCSD(T)], we have attempted to answer this question for the so‐called Collins complex, a square‐pyramidal FeIV complex with a tetraamido‐N equatorial ligand set, a chloride axial ligand, and an S = 2 ground state. The calculations suggest that relative to the ground state, the low‐spin state is higher in energy by at least 0.3 eV and possibly as much as 0.7 eV. Using DFT calculations, a broad quantum chemical survey of high‐spin FeIVO intermediates was also undertaken. A key finding is that the Fe−O distance and O spin population are quite similar across all mononuclear FeIVO species studied, regardless of the heme versus nonheme environment and of the S = 1 versus 2 spin state, reflecting the essential similarity of the Fe(dπ)−O(pπ) orbital interactions in all the species studied. However, the spin density profiles of high‐spin FeIVO species, currently believed to be known only as a nonheme iron enzyme (TauD) intermediate, are predicted to be very different from that of Collins’ high‐spin FeIV complex. Our calculations further suggest that with the help of sterically hindered ligands such as 6‐me3‐tpa, it might be possible to generate synthetic high‐spin FeIVO models of the unique TauD intermediate. Finally, our calculations confirm the aptness of describing the [(6‐me3‐tpa)FeIII(μ‐O)2FeIV(6‐me3‐tpa)]3+ cation as a flexible diamond core and indicate the presence of a fairly discrete high‐spin FeIVO unit within the dinuclear core. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Dinuclear, Tricyclometallated Platinum(II) Derivatives − Substitution Reactions and Reactivity of the Platinum−Carbon Bonds
Authors: Zucca Antonio , Cinellu Maria Agostina , Minghetti Giovanni , Stoccoro Sergio , Manassero Mario
Published: September 2004

In the recently reported dinuclear cyclometallated species [Pt2(R)(L)(DMSO)2] [H3L = 6‐phenyl‐2,2′‐bipyridine; R = Me (1a), Ph (1b)] the threefold deprotonated ligand L links the two platinum atoms acting as an N′,C(3) and a C,N,C donor. Aspects of their reactivity have been studied first with regards to the substitution of the two DMSO ligands, which are coordinated to the platinum atom trans to a nitrogen and a carbon atom, respectively. Substitution of DMSO with neutral two‐electron donors affords several new species, all having the same bridging ligand L: [Pt2(R)(L)(L′)2] [L′ = PPh3 (2a, 2b), CO (3a, 3b)] and [Pt2(R)(L)(L′)(DMSO)] [L′ =3,5‐Me2‐py (4a)]. The potentially bidentate diphosphane Ph2P(CH2)3PPh2 (dppp) gives a more complex specieshaving both chelating and bridging dppp ligands [{Pt(Me)(L)(dppp)}2(μ‐dppp)] (5a). The reactivity of the platinum−carbon bonds with HCl has been studied in complexes 1a, 1b and 2a, 2b and found to be strongly dependent on the nature of the ancillary ligands. To discern the most labile of the four metal−carbon bonds, the reaction has been carried out with 1 equiv. of HCl under mild conditions. Although the reaction is not selective and minor species are formed, cleavage of the Pt−Me (1a) and Pt−Ph (1b) bonds is favoured — [Pt2(L)Cl(DMSO)2] (6) can be isolated and spectroscopically characterised from the reaction with either 1a or 1b. Substitution of PPh3 for DMSO in 6 gives [Pt2(L)Cl(PPh3)2] (7) as the thermodynamically stable isomer having a trans Cl−Pt−C arrangement. The structure of complex 7 has been solved by X‐ray crystallography. In contrast, reaction of 2a or 2b with HCl proceeds by another route: even with excess HCl the Pt−Me and Pt−Ph bonds are unaffected whereas one of the Pt−C bonds of the pincerlike C,N,C system is cleaved to selectively give [Pt2(R)(HL)Cl(PPh3)2] [R = Me (8a), Ph (8b)]. The same bond is cleaved also in 1a and 1b by excess HCl to give [Pt2(HL)(Cl)2(DMSO)2] (9). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Monocyclooctatetraenyl(dithiolene)uranium Compounds
Authors: Arliguie Thérèse , Thuéry Pierre , Fourmigué Marc , Ephritikhine Michel
Published: September 2004

The neutral mononuclear dithiolene compounds [U(cot)(dithiolene)(tppo)2] [cot = η‐C8H8; dithiolene = dddt (9), dmio (10), mdt (11)], [U(cot)(dithiolene)(hmpa)2] [dithiolene = dddt (12), dmio (13), mdt (14)], [U(cot)(mdt)(bipy)] (15) and [U(cot)(mdt)(terpy)] (16) were obtained by treating the dimeric complexes [{U(cot)(dithiolene)}2] [dithiolene = dddt (3), dmio (4), mdt (5)] (dddt = 5,6‐dihydro‐1,4‐dithiine‐2,3‐dithiolate; dmio = 1,3‐dithiole‐2‐one‐4,5‐dithiolate; mdt = 1,3‐dithiole‐4,5‐dithiolate) with the corresponding Lewis base [triphenylphosphine oxide (tppo), hexamethylphosphoramide (hmpa), 2,2′‐bipyridine (bipy), or 2,2′:6′,2′′‐terpyridine (terpy)]. Complexes 9·2THF, 11·2THF, 12, 13, 14, 15 and 16·1.5py have been crystallographically characterized. The crystal structures show a significant interaction between the C=C double bond of the dithiolene ligand and the metal centre. The 1H NMR spectra reveal the fluxional behaviour of the compounds in solution in relation to the facile inversion of the dithiolene ring. The variation of the activation energies of the inversion process reflects the steric congestion of the complexes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
NMR Observations of Interligand Interference in the Molecular Motion of Double‐Stranded Dinuclear Helicates
Authors: Houjou Hirohiko , Schneider Nathanaëlle , Nagawa Yoshinobu , Kanesato Masatoshi , Ruppert Romain , Hiratani Kazuhisa
Published: September 2004

Double‐stranded dinuclear complexes with either twisted or parallel arrangements were obtained by reaction between Schiff‐base ligands and PdII ions. Linear ligands mainly afforded twisted arrangements, while macrocyclic ligands forced the complex to adopt parallel arrangements. In these dinuclear complexes, one isomer could not be converted into the other even upon prolonged heating. The NMR spectra showed that the chemical shifts of the diastereotopic protons can be used as an indicator to distinguish between the arrangements. The NOE cross‐peak characteristics of the complexes with twisted arrangements are interpreted with reference to the crystal structure of a CuII complex as an isostructural model of the PdII complex. Variable‐temperature measurements revealed the rotational interference between the ligands of the counterpart strands, the first time that this has been observed for helically arranged complexes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Small Metal‐Containing Oligomers Using M2(dmpm)x and M2(dmb)y Luminescent Building Blocks (M = Cu, Ag; x = 2, 3; y = 1, 2)
Authors: Fournier Éric , Decken Andreas , Harvey Pierre D.
Published: September 2004

The luminescent binuclear complexes M2(dmpm)32+ [M = Cu, Ag; dmpm = bis(dimethylphosphanyl)methane], Ag2(dmpm)22+ and Cu2(dmpm)3(CN‐tBu)22+ (as BF4− salts), as well as the oligomers described as {Cu2(dmpm)3(dmb)1.332+}3 and {Ag2(dmpm)2(dmb)1.332+}3 (dmb = 1,8‐diisocyano‐p‐menthane), have been prepared and fully characterized in the solid state. These compounds exhibit emission maxima ranging from 445 to 485 nm with emission lifetimes in the μs time scale. The X‐ray structures for the M2(dmpm)32+ (M = Cu, Ag) and Cu2(dmpm)3(CN‐tBu)22+ complexes, XRD patterns (X‐ray powder diffraction), DSC (differential scanning calorimetry), TGA (thermal gravimetric analysis), and the solid‐state IR spectra have been examined in order to characterize these complexes and oligomers. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Cover Picture: Extending The Reaction Landscape of the {Pt(μ‐S)2Pt} Core: From Metal Centers to Non‐Metallic Electrophiles (Eur. J. Inorg. Chem. 18/2004)
Authors: González‐Duarte Pilar , Lledós Agustí , Mas‐Ballesté Rubén
Published: September 2004

The cover picture shows a butterfly mimicking the main features of compounds [L2Pt(ν‐S)2PtL2] (L2 = phosphane). Its flight simulates the flexibility of the {Pt(ν‐S)2Pt} core about the S−S axis; its body represents the strongly nucleophilic sulfide ligands and the wings the {PtL2} fragments. Exploration of the reactivity of the butterfly compounds has revealed an exceptionally rich and diverse chemistry. Details are discussed in the Microreview by P. Gonza�lez‐Duarte et al. on p. 3585 ff., who acknowledge Victor Sarto i Monteys for the butterfly picture (V. S. i M. holds the copyright).
Sensitivity Improvement of the Oxidation of Tetracycline at Acetylene Black Electrode in the Presence of Sodium Dodecyl Sulfate
Authors: Dang Xueping , Hu Chengguo , Wei Yingliang , Chen Wanhua , Hu Shengshui
Published: September 2004

The oxidation of tetracycline (TC) was investigated at an acetylene black electrode in the presence of sodium dodecyl sulfate (SDS). TC exhibited a sensitive oxidation peak in the medium system, which was attributed to the enhanced adsorption of protonated TC at the negatively charged SDS film on the electrode surface. The mechanism of the electrode process was discussed, and some experimental conditions were optimized. The oxidation peak current was proportional to TC concentration in the range of 1.2×10−7–6.0×10−5 M, and based on three times the background signal, a detection limit of 1.2×10−8 M was obtained for 150 s accumulations. The method has been used to determine TC in honey and pharmaceutical, and the results compared favorably.
Seismic performance evaluation of steel arch bridges against major earthquakes. Part 1: dynamic analysis approach
Authors: Usami Tsutomu , Lu Zhihao , Ge Hanbin , Kono Takeshi
Published: September 2004

In this study the inelastic behavior of steel arch bridges subjected to strong ground motions from major earthquakes is investigated by dynamic analyses of a typical steel arch bridge using a three‐dimensional (3D) analytical model, since checking seismic performance against severe earthquakes is not usually performed when designing such kinds of bridge. The bridge considered is an upper‐deck steel arch bridge having a reinforced concrete (RC) deck, steel I‐section girders and steel arch ribs. The input ground motions are accelerograms which are modified ground motions based on the records from the 1995 Hyogoken‐Nanbu earthquake. Both the longitudinal and transverse dynamic characteristics of the bridge are studied by investigation of time‐history responses of the main parameters. It is found that seismic responses are small when subjected to the longitudinal excitation, but significantly large under the transverse ground motion due to plasticization formed in some segments such as arch rib ends and side pier bases where axial force levels are very high. Finally, a seismic performance evaluation method based on the response strain index is proposed for such steel bridge structures. Copyright © 2004 John Wiley & Sons, Ltd.
Geomorphic controls on contaminant distribution along an ephemeral stream
Authors: Reneau Steven L. , Drakos Paul G. , Katzman Danny , Malmon Daniel V. , McDonald Eric V. , Ryti Randall T.
Published: September 2004

Sediment‐borne contamination in a watershed can be highly variable as a result of ﬂuvial processes operating over a range of time scales. This study presents a detailed analysis of the distribution of one contaminant along an ephemeral stream after 55 years of sediment transport, deposition, and exchange by ﬂash ﬂoods. Wastewater containing plutonium was discharged into the Pueblo Canyon watershed from 1945 until 1964, and plutonium concentrations in ﬂuvial deposits vary over ﬁve orders of magnitude. These variations can be attributed to three primary factors: time since contaminant releases, particle‐size sorting, and mixing of sediment from different sources. The highest concentrations occur in ﬁne‐grained sediment deposits near the source that date to the period of efﬂuent releases, and concentrations are lower in younger deposits, in coarser‐grained deposits, and in deposits farther downstream. The spatial distribution of plutonium is strongly affected by longitudinal variations in the size of sediment deposits of different age. A major aggradation–degradation cycle in the lower canyon overlapped with the period of active efﬂuent releases, and a signiﬁcant portion of the total plutonium inventory is contained within large coarse‐grained deposits below ﬁll terraces that post‐date 1945. The spatial pattern of contamination is thus determined by the speciﬁc geomorphic history of the watershed, in addition to processes of mixing and sorting during transport that occur in all ﬂuvial systems. Copyright © 2004 John Wiley & Sons, Ltd.
Highly restricted expression of Cre recombinase in cerebellar Purkinje cells
Authors: Zhang Xin‐Mei , Ng Alam Hoi‐Lam , Tanner Julian A. , Wu Wu‐Tian , Copeland Neal G. , Jenkins Nancy A. , Huang Jian‐Dong
Published: September 2004

The Purkinje neuron, one of the most fascinating components of the cerebellar cortex, is involved in motor learning, motor coordination, and cognitive function. Purkinje cell protein 2 (Pcp2/L7) expression is highly restricted to Purkinje and retinal bipolar cells, where it has been exploited to enable highly specific, Cre recombinase‐mediated, site‐specific recombination. Previous studies showed that mice carrying a Cre transgene produced by insertion of Cre cDNA into a small 2.88‐kb Pcp2 DNA fragment expressed Cre in Purkinje cells; however, some Cre activity was also observed outside the target tissues. Here, we used Red‐mediated recombineering to insert Cre cDNA into a 173‐kb BAC carrying the entire intact Pcp2 gene, and characterize the resultant BAC/Cre transgenic mice for Cre expression. We show that BAC/Cre transgenic mice have exclusive Cre expression in Purkinje and bipolar cells and nowhere else. These mice will facilitate Purkinje cell and retinal bipolar cell‐specific genetic manipulation. genesis 40:45–51, 2004. © 2004 Wiley‐Liss, Inc.
Terrestrial trace fossils from the Lower Old Red Sandstone, southwest Wales
Authors: Morrissey Lance B. , Braddy Simon J.
Published: September 2004

An assemblage of terrestrial trace fossils is described from the Lower Old Red Sandstone of Pembrokeshire, southwest Wales, preserved in mainly fine‐grained alluvial facies (channel and overbank sediments, deposited by predominantly ephemeral flows within a semi‐arid environment), and thin tuffaceous horizons. The ichnofauna is dominated by an extensive, but low diversity Beaconites ichnocoenosis, comprising the meniscate backfilled burrow Beaconites barretti. Concentrations of these burrows (up to 30 per square metre) show normal size distributions, representing periodic colonization events (inferred as a response to seasonal desiccation) of subaerially exposed (partly indurated) sediments, probably by a population of eoarthropleurid myriapods penetrating the substrate to the level of the water table in order to aestivate and/or moult. Arthropod trackways also characterize an active arthropod epifauna of arachnids (Paleohelcura; first Welsh record) and myriapods (two forms of Diplichnites up to 160 mm wide) and Diplopodichnus. Additional ichnotaxa include arthropod foraging and resting traces (bilobed trails, Tumblagoodichnus and Selenichnites), ‘scratch arrays’ and worm burrows (Cochlichnus, and Palaeophycus) and faecal pellets all representative of the Scoyenia ichnofacies. Copyright © 2004 John Wiley & Sons, Ltd.
Variable alluvial sandstone architecture within the Lower Old Red Sandstone, southwest Wales
Authors: Williams Brian P. J. , Hillier Robert D.
Published: September 2004

Sandstone bodies within the Lower Old Red Sandstone (ORS) in southern Pembrokeshire exhibit variability in architecture, sediment grade and composition both spatially and temporally. Four architectural styles are observed, namely decimetre‐ to metre‐thick sheets, metre‐thick multi‐storey amalgamations, inclined‐heterolithic units and ribbon geometries. Sandstone bodies in the Freshwater East Formation are sheet‐like, heterolithic units several metres thick. An association with lingulids and wave ripples alludes to a marine influence, possibly estuarine tidal flats or storm washovers. Within the Moor Cliffs Formation, the most common sandstone bodies are centimetre‐ to metre‐thick sheets with high width‐to‐depth ratios. Fine‐grained sandstones represent sheet‐flood deposition on unconfined, planar surfaces, whereas coarser‐grained sandstones constitute distinctive amalgamations of discrete flood events, reflecting either a change in provenance or tectonic influence. Clear incision of coarse‐grained, multi‐storey units within the Inter‐Tuff Moor Cliffs Formation reflects a change in relative sea‐level, possibly tectonically induced.

The base of the Conigar Pit Sandstone Member (CPSM) is marked by a distinctive, exotic‐clast conglomerate defining the base to heterolithic, lateral‐accretion bedsets and sandstone sheets. This association defines a significant influx of coarse‐grained sediment post‐Chapel Point Calcrete formation, an interval of presumed topographic stability across the Anglo‐Welsh Basin. This influx must reflect rejuvenation of source regions, with changes in base‐level reflecting either eustatic or tectonic influences. Commonly observed in the CPSM are fine‐grained, inclined‐heterolithic bedsets recording deposition by highly sinuous rivers with flashy discharge. Up‐sequence within the CPSM are metre‐thick, multi‐storey amalgamations of predominatly trough cross‐stratified medium‐ to coarse‐grained sandstone. It is likely that these units are genetically related to contemporaneous decimetre‐thick sandstone sheets, the latter being ‘splay’ events marginal to the main channel axis. The interbedding of multi‐storey sandstones and fine‐grained laterally accreted units reflects changes in provenance, slope and/or climate.

Thickness variations within the Lower ORS detail significant thickening of all units northward into the Benton Fault. It seems likely that this thickening reflects variable accommodation space development associated with active growth along this and other WNW–ESE‐trending faults, and migration of channel belts toward the footwall. Copyright © 2004 John Wiley & Sons, Ltd.
Health insurance and treatment seeking behaviour: evidence from a low‐income country
Authors: Jowett Matthew , Deolalikar Anil , Martinsson Peter
Published: September 2004

This paper analyses the effect of being insured under the voluntary component of Vietnamese Health Insurance, on patterns of treatment seeking behaviour. A multinomial logit model is estimated using household survey data from three provinces in Vietnam. Decisions regarding both the type of provider sought and type of care received are analysed. Insurance status is treated as both exogenous and endogenous to account for potential selection bias. The results indicate that, overall, insured patients are more likely to use outpatient facilities, and public providers, an effect that is particularly strong at lower income levels. Copyright © 2004 John Wiley & Sons, Ltd.
A longitudinal analysis of mental health mobility in Britain
Authors: Hauck Katharina , Rice Nigel
Published: September 2004

This paper is concerned with quantifying the level of mental health mobility in the British Household Panel Survey (BHPS). We investigate whether the extent of intertemporal fluctuations in mental health is different across categories of socio‐economic group such as income quintiles, educational attainment and social class. Our measure of mental health is the 12‐item version of the General Health Questionnaire (GHQ) that serves as a self‐administered screening test aimed at detecting psychiatric disorders. Using 11 waves of the BHPS and a variety of methods we show there is much mobility in mental health from one wave to the next. Further the extent of mobility varies across socio‐economic categories with greatest persistence observed in more disadvantaged groups. In general, these groups suffer poorer mental health and experience more periods of ill‐health. Our results have implications for the design of appropriate prevention policies targeting mental illness within different risk groups, and also for the measurement of long‐term inequalities in mental health across socioeconomic groups. Copyright © 2004 John Wiley & Sons, Ltd.
Surgical treatment outcomes of localized squamous carcinoma of buccal mucosa
Authors: Ganpathi Iyer Shridhar , Pradhan S. A. , Pai P. S. , Patil S.
Published: September 2004

Background.

The purpose of the study was to analyze the outcomes after surgical therapy (peroral wide excision) for early squamous carcinoma of the buccal mucosa.

Methods.

This is a retrospective study of localized squamous carcinoma of the buccal mucosa treated with peroral wide excision at a major tertiary‐care hospital.

Results.

A total of 147 consecutive patients were analyzed. One hundred eight patients (73.5%) had no recurrence, whereas 18 (12.2%) had a local recurrence, 11 (7.5%) had regional metastasis, and 10 (6.8%) had locoregional recurrence over a median follow‐up of 46 months. Most patients with local recurrences (15 patients, 83.3%) and regional metastases (eight patients, 72%) could be salvaged with treatment. In contrast, only four patients (40%) with locoregional recurrence could be salvaged. Most of the recurrences in this study group occurred within 2 years of primary treatment (29 [74%] of 39 patients). Three‐year actuarial overall survival rate and disease‐free survival rates were 91% and 77%, respectively.

Conclusions.

Peroral wide excision seems to be an adequate procedure for early squamous carcinoma of buccal mucosa. Histologic grade of the tumor emerged as the only prognostic factor of significance for recurrence in this study. © 2004 Wiley Periodicals, Inc. Head Neck 26: 897–902, 2004
Motivation to learn and diversity training: Application of the theory of planned behavior
Authors: Wiethoff Carolyn
Published: September 2004

Although training programs are an important component in most companies' diversity initiatives, little theoretical guidance is available for their implementation. This article proposes a model based on the theory of planned behavior, which addresses the roles of attitude, subjective norms, and perceived behavioral control in motivation to learn from a diversity training program. The model suggests a number of hypotheses that could be tested to enhance our understanding of the motivation‐to‐learn construct. Additionally, the model provides practical advice for companies seeking to implement successful diversity training programs.
Recent advances in tumour antigen‐specific therapy: In vivo veritas
Authors: Mahnke Yolanda D. , Speiser Daniel , Luescher Immanuel F. , Cerottini Jean‐Charles , Romero Pedro
Published: September 2004

Modern cancer therapies should strive not only to eliminate malignant tissues but also to preserve healthy tissues and the patient's quality of life. Antigen‐specific immunotherapy approaches are promising for either aspect since they are designed to only act against tissues expressing 1 or more specified tumour antigens. In order to develop successful vaccine and adoptive transfer protocols, longitudinal monitoring of cancer patients taking part in clinical trials is mandatory. Here, in vivo expansion of antigen‐specific cells, as well as their ex vivo functional status represent important parameters to be analysed. To obtain results that most closely reflect the cells' in vivo status, functional assays must be carried out with as little in vitro culturing as possible. The present minireview discusses recent advances in these domains.
Poverty, underdevelopment, and infant mental health
Authors: Richter Linda M.
Published: September 2004

Great advances have occurred in disciplinary and professional knowledge of infant development and its influence on subsequent development. This expertise includes the ways in which early experiences affect the capacity of mature individuals for social adjustment and productive competence and promising methods of intervention to promote infant mental health and prevent adverse sequelae of risk conditions. However, very little of this knowledge has been applied in work amongst infants and children living in conditions of poverty and underdevelopment. This lack of application continues despite the enormous threats to the well being of infants and young children brought about by the combined effects of poverty and the AIDS pandemic, especially in southern Africa. Protein–energy malnutrition, maternal depression, and institutional care of infants and small children are cited as illustrative of areas in which interventions and their evaluation are desperately needed in resource‐poor countries. An argument is made for the critical importance of considering and addressing psychological factors in caregivers and children in conditions of extreme material need. An example is provided of a simple intervention model based on sound developmental principles that can be implemented by trained non‐professionals in conditions of poverty and underdevelopment.
Leadership perspectives on the role of character development in higher education
Authors: Yanikoski Richard
Published: September 2004

The author examines why educational leaders are voicing increasing support for attending to the moral, ethical, and civic development of college students and what can be done to enhance these efforts.
CCAAT/enhancer binding protein δ (C/EBPδ) regulation and expression in human mammary epithelial cells: II. Analysis of activating signal transduction pathways, transcriptional, post‐transcriptional, and post‐translational control
Authors: Sivko G.S. , Sanford D.C. , Dearth L.D. , Tang D. , DeWille J.W.
Published: September 2004

CCAAT/enhancer binding protein δ (C/EBPδ) plays a key role in mammary epithelial cell G0 growth arrest. C/EBPδ gene expression is down‐regulated in rodent mammary tumorigenesis and in human breast cancer, suggesting that “loss of function” alterations in C/EBPδ gene expression are common in mammary gland malignancies. The goal of this study was to systematically investigate the mechanisms controlling C/EBPδ gene expression in MCF‐10A and MCF‐12A human mammary epithelial cell lines. The results demonstrate that G0 growth arrest conditions (i.e., serum and growth factor withdrawal or Oncostatin M (OSM) treatment) result in the activation of JAK1, JAK2, and Tyk 2, members of the Janus kinase family of non‐receptor tyrosine kinases, in MCF‐10A and MCF‐12A cells. Growth arrest or OSM treatment also specifically increases activated (phosphorylated) signal transduction and activators of transcription 3 (STAT3) levels, demonstrating that STAT3, not STAT1 or STAT5, is the downstream target of the activated Janus kinases in MCF‐10A and MCF‐12A cells. Whole cell lysates from G0 growth arrested (GA) and OSM‐treated MCF‐12A cells exhibit increased acute phase response element (APRE) binding compared to lysates from growing (GR) MCF‐12A cells. Transient transfection using C/EBPδ promoter‐luciferase constructs demonstrated that the APRE (STAT3) consensus binding site is essential for growth arrest or OSM induction of the C/EBPδ promoter. Mutation of the C/EBPδ promoter STAT3 site or expression of a dominant negative STAT3 construct (STAT3β) reduces C/EBPδ promoter activity in response to growth arrest conditions. The human C/EBPδ promoter also contains an Sp1 site at −61 bp (relative to the transcriptional start site) which is required for basal transcriptional activation. Mutation or deletion of the Sp1 site decreases promoter activity in response to growth arrest conditions. Treatment with the transcriptional inhibitor actinomycin D demonstrated that the C/EBPδ mRNA exhibits a relatively short half‐life (∼40 min). Similarly, treatment with the translational inhibitor anisomysin demonstrated that the C/EBPδ protein half‐life was also relatively short (∼160 min). These results indicate that the human C/EBPδ gene is controlled at multiple levels, consistent with a role for C/EBPδ in cell cycle control and/or cell fate determination. © 2004 Wiley‐Liss, Inc.
Molecular pathways involved in the anti‐apoptotic effect of 1,25‐dihydroxyvitamin D3 in primary human keratinocytes
Authors: De Haes Petra , Garmyn Marjan , Carmeliet Geert , Degreef Hugo , Vantieghem Katleen , Bouillon Roger , Segaert Siegfried
Published: September 2004

We previously reported that 1,25‐dihydroxyvitamin D3 [1,25(OH)2D3] protects primary human keratinocytes against ultraviolet (UV)B‐induced apoptosis. Here, we confirmed the anti‐apoptotic effect of 1,25(OH)2D3 in keratinocytes, using cisplatin and doxorubicin as apoptotic triggers. We further showed that 1,25(OH)2D3 activates two survival pathways in keratinocytes: the MEK/extracellular signal regulated kinase (ERK) and the phosphatidylinositol 3‐kinase (PI‐3K)/Akt pathway. Activation of ERK and Akt by 1,25(OH)2D3 was transient, required a minimal dose of 10−9 M and could be blocked by actinomycin D and cycloheximide. Moreover, inhibition of Akt or ERK activity with respectively a PI‐3K inhibitor (LY294002) or MEK inhibitors (PD98059, UO126), partially or totally suppressed the anti‐apoptotic capacity of 1,25(OH)2D3. Finally, 1,25(OH)2D3 changed the expression of different apoptosis regulators belonging to the Bcl‐2 family. Indeed, 1,25(OH)2D3 treatment increased levels of the anti‐apoptotic protein Bcl‐2 and decreased levels of the pro‐apoptotic proteins Bax and Bad in a time‐ and dose‐dependent way. Induction of Bcl‐2 by 1,25(OH)2D3 was further shown to be mediated by ERK and, to a lesser extent, by Akt. In conclusion, 1,25(OH)2D3 clearly protects keratinocytes against apoptosis (1) by activating the MEK/ERK and the PI‐3K/Akt survival pathways and (2) by increasing the Bcl‐2 to Bax and Bad ratio. © 2004 Wiley‐Liss, Inc.
Identification of alternative transcripts of the TRF1/Pin2 gene
Authors: Silva Lages Céline , Etienne Olivier , Comte Julien , Gauthier Laurent R. , Granotier Christine , Pennarun Gaëlle , Boussin François D.
Published: September 2004

TRF1 and Pin2 play an essential role in telomere homeostasis, by regulating telomere maintenance. They are generated from the same gene, TRF1/Pin2, by alternative splicing but no functional differences between these proteins have been demonstrated. We report here the detection of new alternative transcripts of the TRF1/Pin2 gene in peripheral blood lymphocytes resulting from a 76 nt insertion. Real‐time RT‐PCR showed that these transcripts were also produced in various normal human cells and tissues and in immortalized cell lines, but at levels lower (by a factor of 8–111) than those for the TRF1 and Pin2 transcripts. These new transcripts are predicted to encode polypeptides identical to TRF1/Pin2 at the C‐terminal end but entirely lacking the acid domain and the amino‐terminal part of the homodimerization domain of TRF1/Pin2. These proteins, fused at their N‐terminal ends to enhanced green fluorescent protein (EGFP), were found to be located at telomeres and to induce apoptosis in cell lines with short telomeres, thereby displaying similar activity to TRF1/Pin2. However, these putative proteins lack regions important for interactions with other proteins and for homodimerization. Unlike TRF1/Pin2, they were unable to interact with tankyrase 1, suggesting that these proteins may play a role in telomere homeostasis different from those of TRF1/Pin2. The production of these alternative transcripts was down‐regulated in peripheral blood lymphocytes following PHA‐p activation, suggesting a possible role in resting lymphocytes. © 2004 Wiley‐Liss, Inc.
Vascular smooth muscle cell‐specific regulation of cyclin‐dependent kinase inhibitor p21WAF1/Cip1 transcription by Sp1 is mediated via distinct cis‐acting positive and negative regulatory elements in the proximal p21WAF1/Cip1 promoter
Authors: Kavurma Mary M. , Khachigian Levon M.
Published: September 2004

Smooth muscle cells (SMC) play a central role in common vascular pathologies such as atherosclerosis and restenosis. Understanding the molecular regulation of SMC proliferation at a transcriptional level may provide important clues for the targeted control of vascular hyperplasia. We recently reported the capacity of the transcription factor Sp1 to down‐regulate p21WAF1/Cip1 production thereby reducing p21WAF1/Cip1–cyclin D1–Cdk4 complex formation and inhibiting vascular SMC proliferation (Kavurma and Khachigian [2003] J. Biol. Chem. 278, 32537–32543). We have now localized the Sp1‐response elements in the p21WAF1/Cip1 promoter responsible for p21WAF1/Cip1 repression in WKY12‐22 SMCs. The proximal region of the p21WAF1/Cip1 promoter contains five distinct Sp1‐binding elements that we have termed A, B, C, D, and E. Electrophoretic mobility shift analysis revealed that SMC nuclear Sp1 interacts with all five Sp1‐binding sites, and each of these sites is critical for Sp1 repression of the p21WAF1/Cip1 promoter, since mutation in any one element ablates repression, and in some cases results in activation. In contrast, only elements C, D, and E are bound by Sp1 in endothelial cells. Sp1 overexpression activates the p21WAF1/Cip1 promoter in this cell type. Furthermore, mutation in any of these five elements is not sufficient to prevent activation of the p21WAF1/Cip1 promoter by Sp1 in endothelial cells. Surprisingly, double mutations of elements C and E facilitates superactivation by Sp1 in both cell types, whereas triple mutations of C, D, and E inactivate the promoter. These findings demonstrate cell type‐specific regulation of p21WAF1/Cip1 transcription by Sp1 via distinct cis‐acting positive and negative regulatory elements in the proximal p21WAF1/Cip1 promoter. © 2004 Wiley‐Liss, Inc.
Production of the chemokine eotaxin‐1 in osteoarthritis and its role in cartilage degradation
Authors: Hsu Yi‐Hsin , Hsieh Ming‐Shium , Liang Yu‐Chih , Li Chao‐Yi , Sheu Ming‐Thau , Chou Der‐Tsay , Chen Tzeng‐Fu , Chen Chien‐Ho
Published: September 2004

The expression of the chemokine, eotaxin‐1, and its receptors in normal and osteoarthritic human chondrocytes was examined, and its role in cartilage degradation was elucidated in this study. Results indicated that plasma concentrations of eotaxin‐1 as well as the chemokines, RANTES, and MCP‐1α, were higher in patients with osteoarthritis (OA) than those in normal humans. Stimulation of chondrocytes with IL‐1β or TNF‐α significantly induced eotaxin‐1 expression. The production of eotaxin‐1 induced expression of its own receptor of CCR3 and CCR5 on the cell surface of chondrosarcomas, suggesting that an autocrine/paracrine pathway is involved in eotaxin‐1's action. In addition, eotaxin‐1 markedly increased the expressions of MMP‐3 and MMP‐13 mRNA, but had no effect on TIMP‐1 expression in chondrocytes. However, pretreatment of anti‐eotaxin‐1 antibody significantly decreased the MMP‐3 expression induced by IL‐1β. These results first demonstrate that human chondrocytes express the chemokine, eotaxin‐1, and that its expression is induced by treatment with IL‐1β and TNF‐α. The cytokine‐triggered induction of eotaxin‐1 further results in enhanced expressions of its own receptor of CCR3, CCR5, and MMPs, suggesting that eotaxin‐1 plays an important role in cartilage degradation in OA. © 2004 Wiley‐Liss, Inc.
Adenoviral down‐regulation of osteopontin inhibits human osteoclast differentiation in vitro
Authors: Aitken Cathy J. , Hodge Jason M. , Nicholson Geoffrey C.
Published: September 2004

Although osteopontin (OPN) is highly expressed in osteoclasts, OPN‐deficient mice have a near‐normal bone phenotype and its role in osteoclast differentiation and function remains uncertain. We used an adenoviral OPN‐antisense vector (AdOPN‐AS) to down‐regulate OPN expression in a human in vitro osteoclastogenesis model employing CFU‐GM precursors treated with RANKL and M‐CSF. Cultures infected with AdOPN‐AS showed reduced secretion of OPN compared to cultures infected with a control adenoviral vector expressing β‐galactosidase. Infection with AdOPN‐AS co‐incident with exposure to RANKL was associated with substantial (approximately 50%) inhibition of osteoclast formation with a concomitant reduction in dentine resorption. There was also a small reduction in the size of generated osteoclasts but no significant effect on the size of resorption pits/tracks nor on the amount of resorption per osteoclast. When the cultures were infected with AdOPN‐AS after 4 days exposure to RANKL only minor effects on osteoclastogenesis were seen. Our data demonstrate that early down‐regulation of OPN in vitro inhibits human osteoclastogenesis. Since mice totally lacking OPN do not have reduced osteoclast numbers our results imply the existence in vivo of an alternative molecular pathway(s). © 2004 Wiley‐Liss, Inc.
Etiology of Paget's disease and osteoclast abnormalities
Authors: Reddy Sakamuri V.
Published: September 2004

Paget's disease of bone is a chronic focal skeletal disorder that affects up to 2–3% of the population over the age of 60 years. Paget's disease is primarily a disease of the osteoclast. The pathologic abnormality in patients with Paget's disease involves increased bone resorption by the osteoclasts, followed by abundant new bone formation that is of poor quality. Genetic linkage analysis indicated that 40% of patients with Paget's disease have an affected first degree relative and 1% of patients develop osteosarcoma. Paget's disease is an autosomal dominant trait with genetic heterogeneity. Recurrent mutations in the ubiquitin‐associated (UBA) domain of sequestosome 1 (SQSTM1/p62) are identified in patients with Paget's disease. Osteoclasts and osteoclast precursors from patients with Paget's disease contain paramyxoviral transcripts and appear hyperresponsive to 1,25‐(OH)2D3 and RANK ligand (RANKL). It has been suggested that the enhanced sensitivity of osteoclast precursors for 1,25‐(OH)2D3 in Paget's disease results from increased expression of coactivators of vitamin D receptor (VDR). However, a cause and effect relationship for the paramyxoviral infection and SQSTM1/p62 gene mutations associated with this disease and osteoclast abnormalities are unclear. Therefore, the etiology of Paget's disease remains uncertain. © 2004 Wiley‐Liss, Inc.
Transactivation of the epidermal growth factor receptor mediates muscarinic stimulation of focal adhesion kinase in intestinal epithelial cells
Authors: Calandrella Sean O. , Barrett Kim E. , Keely Stephen J.
Published: September 2004

We have previously shown that the Gq protein coupled receptor (GqPCR) agonist, carbachol (CCh), transactivates and recruits epidermal growth factor receptor (EGFr)‐dependent signaling mechanisms in intestinal epithelial cells. Increasing evidence suggests that GqPCR agonists can also recruit focal adhesion‐dependent signaling pathways in some cell types. Therefore, the aim of the present study was to investigate if CCh stimulates activation of the focal adhesion‐associated protein, focal adhesion kinase (FAK), in intestinal epithelia and, if so, to examine the signaling mechanisms involved. Experiments were carried out on monolayers of T84 cells grown on permeable supports. CCh rapidly induced tyrosine phosphorylation of FAK in T84 cells. This effect was accompanied by phosphorylation of another focal adhesion‐associated protein, paxillin, and association of FAK with paxillin. CCh‐stimulated FAK phosphorylation was inhibited by a chelator of intracellular Ca2+, BAPTA/AM (20 μM), and was mimicked by thapsigargin (2 μM), which mobilizes intracellular Ca2+ in a receptor‐independent fashion. CCh also induced association of FAK with the EGFr and FAK phosphorylation was attenuated by an EGFr inhibitor, tyrphostin AG1478, and an inhibitor of Src family kinases, PP2. The actin cytoskeleton disruptor, cytochalasin D (20 μM), abolished FAK phosphorylation in response to CCh but did not alter CCh‐induced EGFr or ERK MAPK activation. In summary, these data demonstrate that agonists of GqPCRs have the ability to induce FAK activation in intestinal epithelial cells. GqPCR‐induced FAK activation is mediated by via a pathway involving transactivation of the EGFr and alterations in the actin cytoskeleton. © 2004 Wiley‐Liss, Inc.
Mechanistic understanding of the fermentative L‐glutamic acid overproduction by Corynebacterium glutamicum through combined metabolic flux profiling and transmembrane transport characteristics
Authors: Tryfona Theodora , Bustard Mark T
Published: September 2004

Since the 1950s when Micrococcus glutamicus later renamed Corynebacterium glutamicum was discovered, the production of amino acids by fermentative methods has become an important aspect of industrial microbiology. Numerous studies to understand and improve the metabolic conditions leading to amino acid overproduction have been carried out. Most amino acids are currently produced by use of mutants that contain combinations of auxotrophic and regulatory mutations. L‐Glutamic acid is the amino acid produced in the greatest quantities (106 tonnes per year) and Corynebacteria are central to its industrial production. However, further improvements to strain performance are difficult to obtain by empirical optimization and a more rational approach is required. The use of metabolic flux analysis provides valuable information regarding bottlenecks in the formation of desired metabolites. Such techniques have found application in elucidating flux control, provided insight into metabolic network function and developed methods to amplify or redirect fluxes in engineered bioprocesses. Hence, branch points in biosynthesis, precursor supply in fuelling reactions and export of metabolites can be manipulated, resulting in high glutamic acid overproduction by Corynebacterium glutamicum fermentations. In this review, in addition to reviewing the state of play in metabolic flux analysis for glutamate overproduction, the metabolic pathways involved in the production of L‐glutamic acid, the mechanisms mediating its efflux and secretion as well as their manipulation to achieve higher glutamate production, are discussed. The link between metabolic flux and transmembrane transport of glutamic acid are also considered. Copyright © 2004 Society of Chemical Industry