bluuebunny/crossref_metadata_2025 huggingface dataset:
An analysis of primary site control and late effects according to local control modality in non‐metastatic Ewing sarcoma
Authors: Paulino Arnold C. , Nguyen Thanh X. , Mai Wei Y.
Published: January 2006

Purpose

To examine prognostic factors for primary site control and analyze late effects according to local treatment modality in non‐metastatic Ewing sarcoma (ES).

Materials and Methods

From 1976 to 2001, 76 patients with localized ES and a median age of 14.5 years were seen and treated at one institution. Tumors were located in the extremity in 38, pelvis in 13, spine in 11, trunk in 8, and head and neck in 6. Tumor size was ≤8 cm in 44 and >8 cm in 32. Local therapy included radiotherapy (RT) alone in 40, surgery (S) alone in 27, and surgery followed by postoperative radiotherapy (S + RT) in 9. Chemotherapy (CT) was delivered to 65 patients (86%). Median follow‐up for surviving patients was 9.7 years.

Results

The 5‐ and 10‐year overall survival rates were 57.5% and 52.1% while the 5‐ and 10‐year local control rate was 79.2%. The 5‐ and 10‐year local control rates were 78.2% for RT, 77.6% for surgery, and 88.9% for S + RT (P = 0.68). Multivariate analysis showed that only the use of CT was found to be a prognostic factor for local control (P = 0.014). The 5‐ and 10‐year local control rates were 83.7% for those receiving CT and 51.1% for those not receiving CT. For patients followed at least 5 years from diagnosis, late effects were seen in 10 of 19 (52.6%) receiving RT, 2 of 5 (40%) receiving S + RT, and 4 of 16 (25%) receiving surgery alone. The most common late effects with RT were muscular atrophy, limb length growth delay, and development of second malignancy. Scoliosis and decrease range of motion of an extremity were seen regardless of local treatment modality. Three patients who had surgery alone had an amputation whereas two who had RT had an amputation secondary to relapse or development of osteosarcoma.

Conclusion

In this single institution study, the use of CT was the only factor found to impact on local control. Late effects were common regardless of local control strategy. Pediatric Blood Cancer © 2006 Wiley‐Liss, Inc.
Low prevalence of complications in severe neutropenic children with cancer in the unprotected environment of an overnight camp
Authors: Tabori Uri , Jones Heather , Malkin David
Published: January 2006

Background

The high risk of infection and other complications in severely neutropenic pediatric oncology patients receiving chemotherapy has led to development of a variety of preventive measures including isolation and diet restrictions. In order to examine the potential impact of these measures, we evaluated the outcomes of such patients attending a recreational summer camp.

Methods

We collected data on all children who attended an overnight summer camp for children with cancer during the years 1999–2004, and who were either severely neutropenic or at a high‐intensity phase of chemotherapy. Outcome measures included fever, bleeding, hospitalization, and clinical or laboratory evidence of infection. The observation period included both, the 2‐week camp experience and 30 days post‐camp.

Results

The study group was comprised of 34 patients. Although nine (24%) were hospitalized for management of fever and neutropenia, only one patient had clinical or culture‐positive evidence of an invasive infectious agent. No bleeding episode was recorded and most patients attended all camp activities.

Conclusions

Our results support the safety and feasibility of severely neutropenic patients with cancer to attend the non‐isolated, non‐sterile environment of a summer camp. These findings may be applicable to school and other social settings. Pediatr Blood Cancer 2007;48:148–151. © 2006 Wiley‐Liss, Inc.
Quantitative bone mineral density assessment in malignant infantile osteopetrosis
Authors: Kaste Sue C. , Kasow Kimberly A. , Horwitz Edwin M.
Published: January 2006

Purpose

To investigate the use of quantitative computed tomography (QCT) and dual energy absorptiometry (DXA) for assessing bone mineral density (BMD) in the evaluation of children with malignant infantile osteopetrosis (MIOP).

Methods and Patients

We retrospectively reviewed QCT‐ and DXA‐determined BMD in six patients with infantile osteopetrosis and correlated BMD measured during the initial evaluation with patient characteristics.

Results

Five male and one female infant met the eligibility criteria. BMD was markedly elevated in all patients as determined by each modality, QCT or DXA. For QCT, in which age‐specific normal values are known, the BMD was found to be 22.4–32.6 standard deviations above the mean. Using DXA, the estimated BMD of the lumbar spine ranged from 0.45 to 0.8 g/cm2; children with similarly appearing bone radiographs had quite disparate BMD. While the qualitative trend of BMD among the patients was similar for both measures, the units and numerical values of BMD differed. We found no correlation between BMD results and hematopoiesis observed in the bone marrow or with visual evaluation of the radiographs.

Conclusion

Both QCT and DXA are effective quantitative measures of BMD in children with MIOP. However, the same modality should be employed for longitudinal evaluation of a given patient. Each technique has unique advantages and disadvantages and may complement one another in the evaluation of MIOP or other bone disorders. Quantitative assessment of BMD in children with MIOP will likely serve to further characterize this disease. Pediatr Blood Cancer 2007;48:181–185. © 2006 Wiley‐Liss, Inc.
Effects of human monoclonal antibody 216 on B‐progenitor acute lymphoblastic leukemia in vitro
Authors: Bieber Marcia M , Twist Clare J , Bhat Neelima M , Teng Nelson N H
Published: January 2006

Background

Human monoclonal antibody (mAb) 216 is a naturally occurring IgM cytotoxic mAb that binds to a glycosylated epitope on the surface of B‐lymphocytes. This study investigated if this mAb could bind and kill acute lymphoblastic leukemia (ALL) B‐progenitor lymphoblasts in vitro. ALL cell lines were used to determine if combining mAb 216 with chemotherapeutic drugs would enhance killing and cell lines were used to measure cytotoxicity by mAb 216 with human complement.

Procedure

Expression of cell surface markers and mAb 216 epitope on fresh and banked ALL bone marrow samples was determined by flow cytometry. Fresh lymphoblasts were incubated for 20 hr with mAb 216 without complement to measure cytotoxicity. Cytotoxicity of ALL cell lines incubated with mAb 216 and vincristine (VCR) or human complement was determined using flow cytometry.

Results

Pre‐B‐ALL cells but not T‐ALL cells are bound and killed by mAb 216. The combination of mAb 216 and VCR at sub‐therapeutic levels demonstrated enhanced cytotoxicity beyond that observed for either agent alone. Incubation of mAb 216 with human complement increased cytotoxicity of ALL cell lines.

Conclusion

This increased cytotoxicity with chemotherapy and the functional ability of mAb 216 to use multiple pathways to induce cell death identify mAb 216 as a potentially novel therapeutic tool in the treatment of B‐progenitor ALL. Based on the results from this preclinical study, a Phase I clinical trial with mAb 216 for the treatment of patients with relapsed or refractory B‐lineage ALL is ongoing. Pediatric Blood Cancer © 2006 Wiley‐Liss, Inc.
Electronic Fock space as associative superalgebra
Authors: Panin A. I.
Published: January 2006

A new algebraic structure on a finite dimensional electronic Fock space is studied in detail. This structure is defined in terms of a certain multiplication of many electron wave functions and has close interrelation with coupled cluster and similar approaches. Its study simplifies the mathematical backgrounds of these approaches. Even more, it leads to relations that would be very difficult to derive using conventional technique. Formulas for action of the creation‐annihilation operators on products of state vectors are derived. Explicit expressions for action of simplest particle‐conserving products of the creation‐annihilation operators on powers of state vectors are given. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Use of simulation and modelling to develop a sustainable production system
Authors: Taplin David M. R. , Spedding Trevor A. , Khoo Hsien H.
Published: January 2006

This paper seeks to establish a practical definition of the term sustainable development, and relate it to a company's performance. Simulation and modelling tools are applied to gain a holistic view of the activities associated with a metal casting company, which includes production, transportation and recycling. In the simulation model, four case scenarios are investigated, including the comparison of original and re‐designed cast products of 20% runner weight reduction, and the recycling of scrap metal at two different remelters. The focus of the case study is to monitor the amount of scrap, dross, carbon dioxide emissions from both energy consumption and transportation, productivity and costs during the metal material cycle. From the case study, various ‘sustainability indicators’ are highlighted. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment.
DNA polymerization by the reverse transcriptase of the human L1 retrotransposon on its own template in vitro
Authors: Piskareva Olga , Schmatchenko Vadim
Published: January 2006

L1 elements (LINE‐1s) account for 17% of the human genome and have achieved this abundance by transpositions via an RNA intermediate, or retrotransposition. Reverse transcription is a crucial event in the retrotransposition of the active human L1 element and is carried out by the L1‐encoded ORF2 protein. Previously, we performed biochemical characterization of the human L1 ORF2 protein with reverse transcriptase (RT) activity (referred to as L1 RT), expressed in baculovirus‐infected insect cells. In the present study, we describe the properties of DNA‐ and RNA‐dependent DNA synthesis catalyzed by the L1 RT on the L1 templates in vitro. We found that L1 RT synthesized at least 620 of nucleotides per template binding event utilizing L1 RNA in vitro. Under processive conditions the L1 RT synthesized cDNA over 5 times longer than that Moloney murine leukemia virus RT on the heteropolymeric RNA template used in these studies. These data are the first to demonstrate that RT from the human L1 element is a highly processive polymerase among RT enzymes. This report also presents a strong evidence of lack of RNase H activity for the L1 ORF2 protein in vitro, distinguishing L1 RT from retroviral RTs. Finally, we found strong pausing for of the L1 RT during DNA polymerization within the 3′ untranslated region of L1 mRNA, that is result of contribution both rGs runs of the polypurine stretch and immediately adjacent stem–loop structure. A mechanism facilitating minus‐strand DNA synthesis during reverse transcription of L1 element in vivo is discussed.
Taking Responsibility for Our Common Morality
Authors: Dyck Arthur J.
Published: January 2006

Scholars in all fields should hold themselves morally responsible for what they publish and teach. One would think that everyone would take this for granted, but Hilary Putnam, for one, has earnestly warned that we dare not. As he writes, “To-day, as we face the twenty-first century, our task is not to repeat the mistakes of the twentieth century.” He sounded this warning at the conclusion of his analysis of Jacques Derrida's philosophical works. Putnam regrets that philosophers reside among the all too numerous scholars whose publications and instruction aided and abetted the development of the “political tragedy” exemplified by the regimes of Hitler and Stalin. Derrida the philosopher counts among current scholars whose thinking raises the specter of repeating those mistakes of the twentieth century and their horrendous aftermath. Taking the renewal of philosophy as the theme for his Gifford Lectures of 1990, Putnam characterized the writings of Derrida as not only philosophically unsound, but also as dangerous and irresponsible.
Young adult outcome of attention deficit hyperactivity disorder: a controlled 10-year follow-up study
Authors: BIEDERMAN JOSEPH , MONUTEAUX MICHAEL C. , MICK ERIC , SPENCER THOMAS , WILENS TIMOTHY E. , SILVA JULIE M. , SNYDER LINDSEY E. , FARAONE STEPHEN V.
Published: January 2006

Background. Our objective was to estimate the lifetime prevalence of psychopathology in a sample of youth with and without attention deficit hyperactivity disorder (ADHD) through young adulthood using contemporaneous diagnostic and analytic techniques.

Method. We conducted a case-control, 10-year prospective study of ADHD youth. At baseline, we assessed consecutively referred male, Caucasian children with (n=140) and without (n=120) DSM-III-R ADHD, aged 6–18 years, ascertained from psychiatric and pediatric sources to allow for generalizability of results. At the 10-year follow-up, 112 (80%) and 105 (88%) of the ADHD and control children, respectively, were reassessed (mean age 22 years). We created the following categories of psychiatric disorders: Major Psychopathology (mood disorders and psychosis), Anxiety Disorders, Antisocial Disorders (conduct, oppositional-defiant, and antisocial personality disorder), Developmental Disorders (elimination, language, and tics disorder), and Substance Dependence Disorders (alcohol, drug, and nicotine dependence), as measured by blinded structured diagnostic interview.

Results. The lifetime prevalence for all categories of psychopathology were significantly greater in ADHD young adults compared to controls, with hazard ratios and 95% confidence intervals of 6·1 (3·5–10·7), 2·2 (1·5–3·2), 5·9 (3·9–8·8), 2·5 (1·7–3·6), and 2·0 (1·3–3·0), respectively, for the categories described above.

Conclusions. By their young adult years, ADHD youth were at high risk for a wide range of adverse psychiatric outcomes including markedly elevated rates of antisocial, addictive, mood and anxiety disorders. These prospective findings provide further evidence for the high morbidity associated with ADHD across the life-cycle and stress the importance of early recognition of this disorder for prevention and intervention strategies.
An outbreak of human salmonellosis caused by ampicillin-resistant Salmonella enterica serovar Enteritidis PT13 in the Czech Republic
Authors: HRADECKA H. , KOLACKOVA I. , KARPISKOVA R. , RYCHLIK I.
Published: January 2006

In summer 2004, an outbreak caused by Salmonella enterica serovar Enteritidis phage type 13 (S. Enteritidis PT13) was recorded in the Czech Republic. As well being a relatively rare phage type the strain was also ampicillin resistant. Outbreak (n=39) and pre-outbreak isolates (n=13) were characterized by pulsed-field gel electrophoresis (PFGE), β-lactamase gene polymerase chain reaction and plasmid profile. The majority of outbreak isolates (n=37) were identical in XbaI PFGE profile, and two other outbreak isolates each differed from this profile by one or two fragments respectively. The pre-outbreak isolates were uniform in PFGE profile but distinct from the outbreak strain. Ampicillin resistance was confirmed to be encoded by the blaTEM gene located on the TnA transposon. This gene was readily transferable to a S. Enteritidis recipient strain and was associated with the transfer of a 200-kb plasmid. Our results indicate that all S. Enteritidis PT13 tested from 2004 belonged to a single outbreak strain which prior to 2004 had not been recognized in the Czech Republic.
Interpretation and Judgmental Biases in Socially Anxious and Nonanxious Individuals
Authors: Vassilopoulos Stephanos Ph.
Published: January 2006

Interpretation and judgmental biases for threat-relevant stimuli are thought to play a role in anxiety disorders. To investigate whether social anxiety is associated with interpretation and judgmental biases for unambiguous external social events, individuals high and low in social anxiety (N = 36 per group) were presented with unambiguous scenarios depicting positive and mildly negative social events. Interpretations were assessed by participants' answers to open-ended questions and by their ratings for experimenter-provided, alternative explanations. In addition, for each event, participants indicated the probability that the event would happen to them and estimated their own emotional reaction to it. Compared to low socially anxious group, individuals high in social anxiety were more likely to interpret positive social events in a negative way and to catastrophize in response to unambiguous, mildly negative social events. Also, they estimated the emotional cost of negative social events as higher and the probabilities of positive social events as lower.
Chirality-induced signals in coherent multidimensional spectroscopy of excitons
Authors: Abramavicius Darius , Mukamel Shaul
Published: January 2006

The nonlocal second- and third-order susceptibilities of an isotropic ensemble of aggregates are calculated by solving the nonlinear exciton equations which map the system into coupled anharmonic oscillators. Both electric and magnetic contributions are included using the minimal-coupling Hamiltonian. The various tensor components are evaluated to first order in the optical wave vector k. Additional structural information about the interchromophore distances, which is not accessible through zeroth-order contributions (the dipole approximation), is contained to the first order in k. New resonant second- and third-order signals predicted for chiral molecules provide multidimensional extensions of circular dichroism spectroscopy. Numerical simulations demonstrate the sensitivity of third-order signals to the secondary structural motiffs of peptides.
A double-stage pulsed discharge fluorine atom beam source
Authors: Ren Zefeng , Qiu Minghui , Che Li , Dai Dongxu , Wang Xiuyan , Yang Xueming
Published: January 2006

Molecular-beam intensity and speed ratio are two major limiting factors in many molecular-beam experiments. This article reports a high-intensity, high-speed-ratio, pulsed supersonic fluorine atom beam source using a double-stage discharge beam source. Its performance is indicated by the high-resolution time-of-flight spectrum in the crossed beam experiment of F(P2)+para-H2.
Ultrasensitive method for current noise measurements
Authors: Giusi G. , Crupi F. , Ciofi C. , Pace C.
Published: January 2006

In this article we propose a method for current noise measurements which allows, at least in principle, the complete elimination of the noise introduced by the measurement amplifiers. We present a detailed circuit analysis which illustrates the advantages of the proposed measurement procedure with respect to the conventional techniques. The validity of this measurement method is confirmed by the results obtained by means of SPICE simulations and by measurements performed on a prototype circuit.
Comparing reactions of H and Cl with C–H stretch-excited CHD3
Authors: Camden Jon P. , Bechtel Hans A. , Ankeny Brown Davida J. , Zare Richard N.
Published: January 2006

We report the methyl radical product state distributions for the reactions of H and Cl with CHD3(ν1=1,2) at collision energies of 1.53 and 0.18 eV, respectively. Both reactions demonstrate mode selectivity. The resulting state distributions from the H+CHD3(ν1=1,2) reactions are well described by a spectator model. The reactions Cl+CHD3(ν1=1,2) exhibit similar behavior, but in some aspects the spectator model breaks down. We attribute this breakdown to enhanced intramolecular vibrational redistribution in the Cl+CHD3(ν1=1,2) reactions compared to the H+CHD3(ν1=1,2) reactions, caused by the interaction of the slower Cl atom with the vibrationally excited CHD3, which is promoted either by its longer collision duration, its stronger coupling, or both.
A photodissociation study of CH2BrCl in the A-band using the time-sliced ion velocity imaging method
Authors: Zhou Jingang , Lau Kai-Chung , Hassanein Elsayed , Xu Haifeng , Tian Shan-Xi , Jones Brant , Ng C. Y.
Published: January 2006

Employing a high-resolution (velocity resolution Δν∕ν<1.5%) time-sliced ion velocity imaging apparatus, we have examined the photodissociation of CH2BrCl in the photon energy range of 448.6–618.5kJ∕mol (193.3–266.6nm). Precise translational and angular distributions for the dominant Br(P3∕22) and Br(P1∕22) channels have been determined from the ion images observed for Br(P3∕22) and Br(P1∕22). In confirmation with the previous studies, the kinetic-energy distributions for the Br(P1∕22) channel are found to fit well with one Gaussian function, whereas the kinetic- energy distributions for the Br(P3∕22) channel exhibit bimodal structures and can be decomposed into a slow and a fast Gaussian component. The observed kinetic-energy distributions are consistent with the conclusion that the formation of the Br(P3∕22) and Br(P1∕22) channels takes place on a repulsive potential-energy surface, resulting in a significant fraction (0.40–0.47) of available energy to appear as translational energy for the photofragments. On the basis of the detailed kinetic-energy distributions and anisotropy parameters obtained in the present study, together with the specific features and relative absorption cross sections of the excited 2A′, 1A″, 3A′, 4A′, and 2A″ states estimated in previous studies, we have rationalized the dissociation pathways of CH2BrCl in the A-band, leading to the formation of the Br(P3∕22) and Br(P1∕22) channels. The analysis of the ion images observed at 235nm for Cl(P3∕2,1∕22) provides strong evidence that the formation of Cl mainly arises from the secondary photodissociation process CH2Cl+hν→CH2+Cl.
New exchange-Coulomb N2–Ar potential-energy surface and its comparison with other recent N2–Ar potential-energy surfaces
Authors: Dham Ashok K. , Meath William J. , Jechow Jason W. , McCourt Frederick R. W.
Published: January 2006

The reliability of five N2–Ar potential-energy surfaces in representing the N2–Ar interaction has been investigated by comparing their abilities to reproduce a variety of experimental results, including interaction second virial coefficients, bulk transport properties, relaxation phenomena, differential scattering cross sections, and the microwave and infrared spectra of the van der Waals complexes. Four of the surfaces are the result of high-level ab initio quantal calculations; one of them utilized fine tuning by fitting to microwave data. To date, these four potential-energy surfaces have only been tested against experimental microwave data. The fifth potential-energy surface, based upon the exchange-Coulomb potential-energy model for the interaction of closed-shell species, is developed herein: it is a combination of a damped dispersion energy series and ab initio calculations of the Heitler-London interaction energy, and has adjustable parameters determined by requiring essentially simultaneous agreement with selected quality interaction second virial coefficient and microwave data. Comparisons are also made with the predictions of three other very good literature potential-energy surfaces, including the precursor of the new exchange-Coulomb potential-energy surface developed here. Based upon an analysis of a large body of information, the new exchange-Coulomb and microwave-tuned ab initio potential-energy surfaces provide the best representations of the N2–Ar interaction; nevertheless, the other potential-energy surfaces examined still have considerable merit with respect to the prediction of specific properties of the N2–Ar van der Waals complex. Of the two recommended surfaces, the new exchange-Coulomb surface is preferred on balance due to its superior predictions of the effective cross sections related to various relaxation phenomena, and to its reliable, and relatively simple, representation of the long-range part of the potential-energy surface. Moreover, the flexibility still inherent in the exchange-Coulomb potential form can be further exploited, if required, in future studies of the N2–Ar interaction.
Calculations of crystal-melt interfacial free energies by nonequilibrium work measurements
Authors: Mu Yan , Song Xueyu
Published: January 2006

We developed a multistep thermodynamic perturbation method to compute the interfacial free energies by nonequilibrium work measurements with cleaving potential procedure. Using this method, we calculated the interfacial free energies of different crystal orientations for the Lennard-Jones system. Our results are in good agreement with the results by thermodynamic integration method. Compared with thermodynamic integration method, the multistep thermodynamic perturbation method is more efficient. For each stage of the cleaving process, only a few thermodynamic perturbation steps are needed, and there is no requirement on the reversibility of the path.
The decomposition of an orthogonal transformation as a product of reflections
Authors: Aragón-González G. , Aragón J. L. , Rodríguez-Andrade M. A.
Published: January 2006

In this work, an algorithm to decompose a given orthogonal transformation as a product of reflections through hyperplanes is presented. This in fact constitutes a constructive proof of a Cartan theorem, valid over any field K=Q, R or C. Clifford algebras are used to explicitly calculate the reflections that decompose a given orthogonal transformation. Our algorithm may have application in fields such as computer graphics or crystallography, and can also play an important role in orthogonal elimination and the solution of equations systems. An explicit example is provided and we apply our results to the crystallographic problem of coincidence lattices.
Theoretical study of vibration-phonon coupling of H adsorbed on a Si(100) surface
Authors: Andrianov Ivan , Saalfrank Peter
Published: January 2006

In this paper a perturbation-theory study of vibrational lifetimes for the bending and stretching modes of hydrogen adsorbed on a Si(100) surface is presented. The hydrogen-silicon interaction is treated with a semiempirical bond-order potential. Calculations are performed for H–Si clusters of different sizes. The finite lifetime is due to vibration-phonon coupling, which is assumed to be linear or bilinear in the phonon and nonlinear in the H–Si stretching and bending modes. Lifetimes and vibrational transition rates are evaluated with one- and two-phonon processes taken into account. Temperature effects are also discussed. In agreement with the experiment and previous theoretical treatment it is found that the H–Si (υs=1) stretching vibration decays on a nanosecond timescale, whereas for the H–Si (υb=1) bending mode a picosecond decay is predicted. For higher-excited vibrations, simple scaling laws are found if the excitation energies are not too large. The relaxation mechanisms for the excited H–Si stretching and the H–Si bending modes are analyzed in detail.
Two-component desorption from anisotropic pore networks
Authors: Bräuer Peter , Brzank Andreas , Kärger Jörg
Published: January 2006

Dynamic Monte Carlo simulations are performed to explore molecular desorption of a two-component mixture from a mode adsorbent of adsorbate-related anisotropy. The intrinsic dynamics of the adsorbent-adsorbate host-guest system is described by assuming a situation typical of a “molecular-traffic-control” system, where the hopping rates of the two components in two directions, perpendicular to each other, are identical, while for each component, perpendicular to that direction of preferential propagation, the hopping rates are reduced. The resulting desorption patterns are discussed in terms of the jump probabilities and are shown to approach the corresponding analytical solutions in the limiting cases of isotropic and unidirectional diffusions.
Formation of nanoporous noble metal thin films by electrochemical dealloying of PtxSi1−x
Authors: Thorp J. C. , Sieradzki K. , Tang Lei , Crozier P. A. , Misra Amit , Nastasi Michael , Mitlin David , Picraux S. T.
Published: January 2006

We demonstrate the synthesis of nanoporous Pt thin films on Si by electrochemical dealloying. Amorphous PtxSi1−x films (∼100–250nm thick) are formed by electron beam codeposition and dealloyed in aqueous HF solutions at an electrochemical potential sufficient to selectively remove Si while allowing self-assembly of Pt into a nanoporous structure. The Pt nanoporous layers have a pore size of 5–20nm, ligament thickness ∼5nm, a surface area enhancements >20 times, and an ultrafine grain polycrystalline microstructure.
Compact extended-cavity diode laser for atomic spectroscopy and metrology
Authors: Vassiliev V. V. , Zibrov S. A. , Velichansky V. L.
Published: January 2006

We report on a compact, inexpensive, and durable extended-cavity diode laser (ECDL) of an original mechanical concept. The independent temperature control of a laser diode and an extended cavity provides a low-frequency drift. The linewidth of a few hundred kilohertz was measured by taking a beating of two identical ECDLs. The continuous tuning range of about 1Å is achieved by the synchronous scan of two piezotransducers translating and rotating an external diffraction grating. The laser has been used in high-resolution spectroscopy, atom cooling, metrology, and precise interferometry.
In situ calibration of atmospheric air conductivity instruments
Authors: Bennett A. J. , Harrison R. G.
Published: January 2006

A new method of measuring the total conductivity of atmospheric air is described. It depends on determination of the electrical relaxation time of a horizontal wire, mounted between two insulators, which is initially grounded and then allowed to charge freely. The total air conductivity derived is compared with that from an ion mobility spectrometer. Results from the two techniques agreed to within 1.2fSm−1.
Actively tuned and spatially trapped polaritons
Authors: Balili R. B. , Snoke D. W. , Pfeiffer L. , West K.
Published: January 2006

We report active tuning of the polariton resonance of quantum well excitons in a semiconductor microcavity using applied stress. Starting with the quantum well exciton energy higher than the cavity photon mode, we use stress to reduce the exciton energy and bring it into resonance with the photon mode. At the point of zero detuning, line narrowing and strong increase of the photoluminescence are seen. By the same means, we create an in-plane harmonic potential for the polaritons, which allows trapping, potentially making possible Bose-Einstein condensation of polaritons analogous to trapped atoms. We demonstrate drift of the polaritons into this trap.
Terahertz response of hot electrons in dilute nitride Ga(AsN) alloys
Authors: Ignatov A. , Patanè A. , Makarovsky O. , Eaves L.
Published: January 2006

We model theoretically an unusual ac negative differential mobility (NDM) effect that occurs when electrons are accelerated by an electric field in the highly nonparabolic conduction band of dilute nitride Ga(AsN) alloys. By solving balance equations that take into account the negative effective mass of electrons and the velocity and energy relaxation processes, we derive an expression for the maximum response frequency, fmax, associated with the NDM. Our predicted values of fmax depend on material composition and can be tuned by the applied electric field up to terahertz frequencies.
Room-temperature chemical vapor deposition and mass detection on a heated atomic force microscope cantilever
Authors: Sunden Erik O. , Wright Tanya L. , Lee Jungchul , King William P. , Graham Samuel
Published: January 2006

This letter reports the localized room-temperature chemical vapor deposition of carbon nanotubes (CNTs) onto an atomic force microscope cantilever having an integrated heater, using the cantilever self-heating to provide temperatures required for CNT growth. Precise temperature calibration of the cantilever was possible and the CNTs were synthesized at a cantilever heater temperature of 800°C in reactive gases at room temperature. Scanning electron microscopy confirmed the CNTs were vertically aligned and highly localized to only the heater area of the cantilever. The cantilever mechanical resonance decreased from 119.10kHzto118.23kHz upon CNT growth, and then returned to 119.09kHz following cantilever cleaning, indicating a CNT mass of 1.4×10−14kg. This technique for highly local growth and measurement of deposited CNTs creates new opportunities for interfacing nanomaterials with microstructures.
Strong electron correlation effects in nonvolatile electronic memory devices
Authors: Rozenberg M. J. , Inoue I. H. , Sánchez M. J.
Published: January 2006

We investigate hysteresis effects in a model for nonvolatile memory devices. Two mechanisms are found to produce hysteresis effects qualitatively similar to those often experimentally observed in heterostructures of transition metal oxides. One of them is a switching effect based on a metal-insulator transition due to strong electron correlations at the dielectric/metal interface. The observed resistance switching phenomenon could be the experimental realization of a strongly correlated electron device.
High-efficiency polymer light-emitting diodes based on poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene] with plasma-polymerized CHF3-modified indium tin oxide as an anode
Authors: Hsiao Chung-Chin , Chang Chih-Hao , Jen Tzu-Hao , Hung Ming-Chin , Chen Show-An
Published: January 2006

We demonstrate that introducing a thin CFx film formed by plasma polymerization of CHF3 on an indium tin oxide (ITO) anode surface for a polymer light-emitting diode with the structure, ITO∕CFx∕poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene](MEH-PPV)∕Ca∕Al, can lead to a high device performance (5.1cd∕A and 24000cd∕m2). The high device performance can be attributed to a better balance between hole and electron fluxes, resulting from a formation of interfacial dipole at the CFx∕MEH-PPV interface to provide a hole blocking effect and an enhancement of electron/hole recombination.
Quadratic electro-optic effect in a nano-optical material based on the nonconjugated conductive polymer, poly(β-pinene)
Authors: Rajagopalan H. , Vippa P. , Thakur M.
Published: January 2006

Large quadratic electro-optic effect has been observed in a nano-optical material based on a nonconjugated conductive polymer, poly(β-pinene). Doping of poly(β-pinene) leads to subnanometer size charge-transfer sites with positive charges (holes). The observed large electro-optic effect has been attributed to these confined systems with special structures. The magnitude of the Kerr constant increases with the concentration of the dopant or charge-transfer sites. The maximum Kerr coefficient at 633nm which is close to resonance is about 50 times that of nitrobenzene.
Predictive aberration correction for multilayer optical data storage
Authors: Booth Martin J. , Schwertner Michael , Wilson Tony , Nakano Masaharu , Kawata Yoshimasa , Nakabayashi Masahito , Miyata Sou
Published: January 2006

The recording of data in multiple layers, rather than a single layer, permits a significant increase in the capacity of optical data storage devices. However, focusing to the different layers introduces different amounts of depth-dependent aberrations. Variable aberration correction is therefore necessary to maintain diffraction-limited operation. We demonstrate the use of adaptive optics to predict and correct these aberrations for both the recording and read-out of such media.
Real-time monitoring of plasma oxidation dynamics of subnanometer Al2O3 barriers for magnetic tunnel junctions
Authors: Fabrie C. G. C. H. M. , Knechten K. , Kohlhepp J. T. , Swagten H. J. M. , Koopmans B. , de Jonge W. J. M.
Published: January 2006

We show that over-oxidation of sub-nm thin Al2O3 barriers of magnetic tunnel junctions can be observed in real time using in situ differential ellipsometry measurements. The change in ellipsometry signal of Al layers grown on CoFe films is proportional to the amount of oxidized metallic material. As a result, the derivative of this signal is a direct measure of the oxidation rate. Further analysis of this oxidation rate allows us to determine the onset of the CoFe oxidation. We found the onset to be proportional to the deposited Al layer thickness. The amount of CoO determined from in situ x-ray photoelectron spectroscopy data on identical samples was found to be proportional to that obtained from ellipsometry.
Foreign Direct Investment and the Flying Geese Model: Japanese Electronics Firms in Asia-Pacific
Authors: Edgington David W , Hayter Roger
Published: January 2006

This paper is a critical examination of the ‘flying geese’ and ‘billiard ball’ models of foreign direct investment (FDI) and their ability to explain the spatial expansion of Japanese electronics multinationals (MNCs) in Asia-Pacific countries from 1985 to 1996. Data on Japanese FDI are analyzed in this region at the aggregate, sectoral, and firm level. The paper commences with a review of the flying geese model, especially that version which interprets Japanese FDI as a catalyst for Asian development, and the billiard ball metaphor which suggests a mechanism for host countries to ‘catch up’ with Japan. The authors then turn to an analysis of Japanese FDI in Asia-Pacific together with employment data for fourteen major firms. This allows an evaluation of the two models in terms of recent geographical patterns of investment and employment growth by electronics MNCs. A special case study of Matsushita Electric Industrial Co. Ltd (MEI) helps flesh out the evolving geography of Japanese electronics firms in Asia-Pacific. Although the results support the overall patterns suggested by the two models, the authors argue that metaphors and analogies such as flying geese and billiard balls should not be used casually and as a substitute for analysis.
Going round the Back? Complex Networks and Informal Action in Local Planning Processes
Authors: Hillier Jean
Published: January 2006

In negotiated land-use planning decisions there may be intractable opposition and the use of strength, strategy, and influence outside of formal public participation processes—forms of communicative behaviour neglected by Habermasian theory. I investigate the empirical reality of the importance of networks and lobbying as a form of informal action in influencing planning outcomes through a case study in Western Australia. I map the networks of social relations within which stakeholders act and the links and energy flows between them. I examine stakeholders' utterances and questions of who networks and acts informally; why, when, and how they do so, and with what implications.
The (mis)Representation of Rural Deprivation
Authors: Martin David , Brigham Philip , Roderick Paul , Barnett Sarah , Diamond Ian
Published: January 2006

The authors consider the definition and measurement of deprivation and of rurality in the context of health-care research. Parallels are drawn between the methodological issues involved in the measurement of deprivation and of rurality. An empirical study of the South West of England reveals the extent of disagreement between standard rurality measures; in particular, the authors suggest that rural deprivation will be poorly represented by the conventional approaches. They argue for the development of new approaches to the measurement of deprivation in rural areas, in which advantage is taken of contemporary data sources.
Mutuality at a Distance? Risk and Regulation in Marine Insurance Clubs
Authors: Bennett Paul
Published: January 2006

In this paper I investigate an institution which combines two forms of risk regulation commonly regarded as antithetical. In the governmental mode, associated with the rise of capitalism, the welfare state, and commercial insurance, regulation is centralised and spatially removed from the risk itself, and involves the surveillance, prediction, and control of risks posed by large-scale populations of atomised individuals or companies. This is in contrast to the older mutual form, in which social relations within communities allocate and minimise risks, evident in the moral economy of the peasantry, friendly societies, and the resurgence of discourses of community responsibility in the 1990s. Protection and Indemnity (P&I) Clubs are mutual associations of the world's shipowners, which insure marine liabilities (including environmental risks). Their communal structure and self-interest in minimising risks means that they could, and to an extent do, play an important role in regulating marine safety and environmental performance. However, their global scale means that social relations between shipowners are not simply analogous to those within a local community. The P&I Clubs do, in practice, employ centralised managers responsible for determining entry standards, setting premiums, handling claims, and engaging in loss prevention. These activities rest upon the ‘scientific’ calculation, allocation, and management of risks. At the same time the aim is to ‘maintain mutuality’ amongst members, and tacit knowledge and actively produced trust are essential to this end. I argue that the combination of a mutual structure and a global scale produces a hybrid style of regulation, and the successful application of rules, incentives, sanctions, and surveillance depends as much on the construction of specific sociospatial relations as on organisational form, with implications for new regulatory designs.
“Pay Attention in Class… [and] Don't Get Pregnant”: A Discourse of Academic Success among Adolescent Latinas
Authors: Hyams Melissa S
Published: January 2006

The focus of this paper is the significance of an urban high school in the process of gender and sexual identity construction for a group of adolescent Latinas in Los Angeles. I explore multiple discourses of adolescent femininity, masculinity, sexual morality, and achievement conveyed through consecutive, in-depth group discussions with friendship groups of young Latinas. I argue that for these young women, studenthood is not a generic stage in the life course, but one that is embedded in society's expectations of and anxieties about young women. In and through dominant discourses and institutional practices they are constituted as vulnerable and as out of control in terms of sexual desire (their own as well as others' for them). In a ‘spatiality of protection’ they are positioned, precariously, as singularly responsible for both their academic diligence and their bounded sexuality in order to succeed as young women in high school and realise their goals as adult women beyond high school.
RAMBLAS: A Regional Planning Model Based on the Microsimulation of Daily Activity Travel Patterns
Authors: Veldhuisen Jan , Timmermans Harry , Kapoen Loek
Published: January 2006

In this paper we report on the development of a microsimulation model of daily activity patterns in the context of a regional planning model. One of the aims of the simulation model is to predict traffic flows on a transportation network for various times of the day by using available statistical data sources as input. We first discuss the general conceptual underpinnings of the model, and against a brief discussion of existing activity-based models of transport demand we outline the major differences between these models and the current one. Next, major operational decisions, data input, and model architecture are discussed, followed by an illustration of the model for the Eindhoven region in the Netherlands. We conclude the paper by critically discussing its basic assumptions and identifying avenues of future research.
State, Capital, and Space in China in an Age of Volatile Globalization
Authors: Lin George C S
Published: January 2006

The interrelationship between state, capital, and space is central both to the debate on globalization and to various interpretations of the changing nature of the Chinese political economy. This study of China's economic performance against the recent Asian financial turmoil suggests that the Chinese central state has played a crucial role in the growth and restructuring of the national economy. The immediate impact of the financial crisis on China has been limited although the long-term effects remain uncertain. China has so far narrowly escaped the crisis primarily because of a state-led capital injection in mid-1998 to stop economic downturn, an austerity program that led the overheated economy to ‘soft-land’ prior to the crisis, and stringent state control of capital flow into and out of the country. Contrary to the ‘end of the nation-state’ claim made by many globalization prophets, the Chinese socialist state has remained an active agent interacting with global market forces. The interplay between the socialist state and transnational capital has been a place-specific phenomenon despite the pervasive assertion of ‘the end of geography’. A dialectical approach is needed for analyzing the triangular nexus of interaction between the central state, local state, and global market forces in China in the current age of volatile globalization.
Call Centre Growth and Location: Corporate Strategy and the Spatial Division of Labour
Authors: Bristow Gillian , Munday Max , Gripaios Peter
Published: January 2006

The authors contribute to the developing literature on call centres by providing detailed empirical evidence on the spatial unevenness in the distribution of call centre activity. They argue that the driving forces of call centre growth, whether as the rationalisation of back-office functions or as entirely new entities, have been corporate strategy and the pursuit of low-cost competitive advantage. Thus, although technological developments at the heart of call centre operations render them relatively ‘footloose’ in locational terms, the search for specific characteristics makes certain regions (and parts of regions) more attractive than others. By using a sample database of call centres, the authors describe the characteristics of call centres in the United Kingdom in terms of size, sector, and spatial distribution. They then attempt to explain the determinants of call centre location at the county level through a multiple regression analysis. The results indicate that there is a propensity to site call centres close to existing concentrations of allied activity, with preferences for densely populated areas mediated by needs to maintain employee access and avoid staff turnover problems. This has important implications for the spatial division of labour, with call centre growth likely to reinforce existing spatial unevenness in employment in key service activities. The authors conclude by considering the implications of these findings for contemporary urban and regional development, as well as providing a number of suggestions for future research.
Urban Form and Watershed Management: How Zoning Influences Residential Stormwater Volumes
Authors: Stone Brian , Bullen Jessica L
Published: January 2006

This paper reports the results of a study on residential parcel design and development-induced stormwater runoff in the City of Madison, Wisconsin. To assess the influence of municipal zoning and subdivision regulations on residential stormwater production, high-resolution aerial photography and property tax data for over 38000 single-family residential parcels were used to measure the impervious cover and modeled runoff associated with a typical two-year storm. The results of the analysis suggest that stormwater runoff volumes could be significantly reduced with only modest changes to municipal land-development regulations and with no reduction in the size of the residential structure. Following the presentation of the methodology and findings, the paper concludes with a discussion of targeted revisions to zoning and subdivision regulations that, if implemented, could reduce the runoff volume from new residential parcels in Madison by over 30%.