bluuebunny/crossref_metadata_2025_split huggingface dataset:
The return of a hysteretic Josephson junction to the zero-voltage state:   I-V characteristic and quantum retrapping
Authors: Chen Y. C. , Fisher Matthew P. A. , Leggett A. J. 
Published: July 2002

We study the behavior of a hysteretic current-biased Josephson junction in the vicinity of its return to the zero-voltage states, with primary though not exclusive emphasis on the limit of weak damping (βJ≪1), and under the assumption that the zero-point and thermal energies are both small compared to Icφ0 so that fluctuation effects are important only very close to the return point. We consider in detail the resistively shunted junction (RSJ) and quasiparticle-tunneling models, and also make predictions for more general models. Denoting the value of imposed current I at which return to the zero-voltage state would take place in the absence of fluctuations by Ir, we study in particular (a) the dc current-voltage characteristic in the running state for I−Ir≪Ir, and (b) the first-passage-time statistics of the return to the zero-voltage state induced by both classical and quantum fluctuations. With regard to (b), we express our results in the form of a prediction of the width σ of the distribution of retrapping events as a function of imposed current; this prediction extends down to zero temperature and can be compared directly with the experimentally measured widths.
Our two principal results are as follows: (a) In the running state, for I≪Ir, the current-voltage characteristic should be given quite generally by the formula (I−Ir)/Ir =[(AV0/V)+B]exp−V0/V, where A and B are constants specific to the model, and V0 is a characteristic voltage which for the simplest models is given in the weak-damping limit by V0=ωJφ0+0(β2J) , with ωJ the junction plasma resonance frequency at zero current bias. (b) The square σ2 of the width of the retrapping distribution plotted as a function of I/Ir is given to within logarithmic factors by σ2(T)=const μf(T), where μ≡ℏωJ/Icφ0, the constant is of order 1, and f(T) is a function which tends to 1 as T→0 and is proportional to T in the limit of high T; it is computed explicitly for the RSJ model. We also suggest an explanation (other than lead effects) of the ‘‘forbidden voltage regions’’ which appear to be a characteristic of many high-quality junctions. We discuss the application of our results to the determination of the parameters of Josephson junctions necessary for the investigation of quantum effects on the macroscopic level.
Monolayer adsorption on fractal surfaces: A simple two-dimensional simulation
Authors: Van Damme H. , Levitz P. , Bergaya F. , Alcover J. F. , Gatineau L. , Fripiat J. J. 
Published: July 2002

We have simulated the adsorption of homologous series of ‘‘molecules’’ on deterministic fractal curves in the whole range 1≤D&lt;2. Adsorption differs from a regular Hausdorf dimension determination in the sense that in the latter process the molecules are put with their center on the curve in order to cover it, whereas in the former process the molecules have to reach the curve, coming from one side only, and are not allowed to cross it. Three series of molecules were used: (i) circles of increasing diameter, r; (ii) rectangles of increasing height, t; (iii) rectangles of high aspect ratio (almost lines) and increasing length, l. The fractal exponents Dr, Dt, and Dl were derived from ln Nm vs ln r, ln t, and ln l plots, respectively, Nm being the number of molecules necessary to reach ‘‘monolayer’’ coverage. With linear molecules, we found Dl=1 in whole range 1≤D&lt;2. With the circular and rectangular molecules, two regimes were observed. In the range 1≤D&lt;1.5, Dr=D and Dt=D−1. These results are consistent with each other and suggest that, in the range 1≤D&lt;1.5, the ln Nm vs ln l surface is a plane of equation ln Nm=α ln l+β ln t+γ, with α=−1 and β=1−D. This provides the basis for predicting the size dependence of Nm for molecules of any aspect ratio. An entirely different regime
was observed in the range 1.5&lt;D&lt;2. Instead of increasing with D, Dr and Dt were found to decrease according to Dr=3−D and Dt=2−D, respectively. This can be assigned to the generation of pore necks as the fractal dimension and the local concavity of the curve increases, and can be rationalized in terms of the rules governing the intersection of fractals. The model has been extended to adsorption on fractal surfaces. The prediction is that the maximum fractal dimension which could be measured without error is D=2.5, with molecules with constant aspect ratio. Using molecules of different shape would lead to considerable errors. However, this conclusion only applies to the particular class of fractals that we have considered, i.e., those for which the fractal character is restricted to their boundary. Fractal particles in which the fractal character stems from a particular internal morphology (i.e., from the distribution of mass, like in sponges or aggregates) may lead to an entirely different behavior.
Mean-velocity scaling in and around a mild, turbulent separation bubble
Authors: Alving Amy E. , Fernholz H. H. 
Published: July 2002

This paper examines the question of the scaling of mean-velocity profiles in adverse-pressure-gradient flows. In these flows, the mean velocity scaling must be different than in zero-pressure-gradient flows, because the friction velocity used in the latter case can become vanishingly small in the former. Two decades ago, Perry and Schofield [Phys. Fluids 16, 2068 (1973)] proposed a new outer-region scaling law to be used when the boundary layer approaches separation. Since that time, a number of sets of experimental data close to separation have been shown to fall on a universal curve when the profiles are plotted in Perry–Schofield coordinates, and the profile shape was given by Dengel and Fernholz [J. Fluid Mech. 212, 615 (1990)]. Recently, however, a new set of scaling laws has been proposed by Durbin and Belcher [J. Fluid Mech. 238, 699 (1992)] as a result of their asymptotic analysis, in which they assumed the appropriate near-wall velocity scale to be based on the local strength of the pressure gradient. The resulting scaling laws are different than Perry and Schofield’s scaling and, in fact, predict a three-layered rather than a two-layered boundary-layer structure. Here, experimental results are shown for an adverse-pressure-gradient boundary layer which separates from and then reattaches to a smooth surface. These data provide a wide range of flow conditions for comparing the conflicting scaling laws mentioned above, under conditions of both decreasing and increasing skin friction, with and without instantaneous reverse flow.
It is found that the Perry–Schofield coordinates provide better collapse, over a wider range of streamwise positions and over a larger fraction of the boundary layer, than the scaling laws of Durbin and Belcher. Other proposed scaling laws are also evaluated. Yaglom’s half-power law is shown to hold for a subset of the profiles which fall on Dengel and Fernholz’s universal profile. And the data provide a test of the range of validity of the (zero-pressure-gradient) logarithmic law of the wall. The law is violated here when instantaneous reverse flow exists in the boundary layer and/or when the local pressure gradient is strong enough, as is consistent with earlier work. However, after reattachment these criteria are insufficient to indicate the return to the log law, and several bubble lengths are required after reattachment before the universal log law is satisfied. The wake region responds to reattachment more slowly and does not appear fully recovered six bubble lengths (twenty boundary-layer thicknesses) after reattachment.
Testing the modernization hypothesis and the socialist ideology hypothesis: a comparative sibling analysis of educational attainment and occupational status
Authors: Sieben Inge , de Graaf Paul M. 
Published: July 2002

ABSTRACTIn this study, we present a comparative sibling analysis. This enables us to test two major social mobility hypotheses, i.e. the modernization hypothesis and the socialist ideology hypothesis. We employ survey data on brothers in England, Hungary, the Netherlands, Scotland, Spain, and the USA, covering a historical period from 1916 till 1990. Results show that the effects of parental social class on educational attainment are smaller in technologically advanced societies, and that the effects of parental social class on occupational status are smaller in social‐democratic and communist societies. In addition, the total family impact on occupational status declines with modernization. But overall, we observe that the family of origin has not lost its importance for its sons' educational attainment and occupational status yet.
Childhood poverty, early motherhood and adult social exclusion
Authors: Hobcraft John , Kiernan Kathleen 
Published: July 2002

ABSTRACTChildhood poverty and early parenthood are both high on the current political agenda. The key new issue that this research addresses is the relative importance of childhood poverty and of early motherhood as correlates of outcomes later in life. How far are the ‘effects’ of early motherhood on later outcomes due to childhood precursors, especially experience of childhood poverty? Subsidiary questions relate to the magnitude of these associations, the particular levels of childhood poverty that prove most critical, and whether, as often assumed, only teenage mothers are subsequently disadvantaged, or are those who have their first birth in their early twenties similarly disadvantaged? The source of data for this study is the National Child Development Study.We examine outcomes at age 33 for several domains of adult social exclusion: welfare, socio‐economic, physical health, emotional well‐being and demographic behaviour. We control for a wide range of childhood factors: poverty; social class of origin and of father; mother's and father's school leaving age; family structure; housing tenure; mother's and father's interest in education; personality attributes; performance on educational tests; and contact with the police by age 16. There are clear associations for the adult outcomes with age at first birth, even after controlling for childhood poverty and the other childhood background factors. Moreover, we demonstrate that the widest gulf in adult outcomes occurs for those who enter motherhood early (before age 23), though further rein‐forced by teenage motherhood for most adult outcomes. We also show that any experience of childhood poverty is clearly associated with adverse outcomes in adulthood, with reinforcement for higher levels of childhood poverty for a few outcomes.
The feasibility of abrupt methadone‐buprenorphine transfer in British opiate addicts in an outpatient setting
Authors: LAW F. D. , BAILEY J. E. , ALLEN D. S. , MELICHAR J. K. , MYLES J. S. , MITCHESON M. C. , LEWIS J. W. , NUTT D. J. 
Published: July 2002

AbstractAbstract A study of 13 male opiate addicts was undertaken to investigate the feasibility of transferring abruptly from methadone maintenance treatment to buprenorphine in an outpatient setting. The mean age of subjects was 30 years (range 18‐45) and all fulfilled DSM‐III‐R criteria for opioid dependence. All were maintained on a methadone dose of 20‐30 mg mixture daily and were transferred for 3 days to 4 mg buprenorphine sublingually 24‐26 hours after their last dose of methadone. On day 1 repeated measures of drug effects were performed, including agonist and withdrawal effects, and this was complemented by saccadic eye movements, a potential new measure of central opioid effects. These recordings were repeated once on days 2 and 3 and the subjects returned to their previous dose of methadone on day 4. Buprenorphine caused no detectable agonist effects or drug “high”, but had “good” effects, was “liked” and well tolerated, suggesting that subjects would comply with buprenorphine treatment despite the lack of reinforcing effects. A mild increase in subjective withdrawal symptoms, which was not clinically significant, was seen in association with an increase in saccadic peak velocity on day 2 of the study but no withdrawal occurred on the other days, indicating that the abrupt transfer technique was acceptable.
Mechanism of Cdc42-induced Actin Polymerization in Neutrophil Extracts
Authors: Zigmond Sally H. , Joyce Michael , Yang Changsong , Brown Kevin , Huang Minzhou , Pring Martin 
Published: July 2002

Cdc42, activated with GTPγS, induces actin polymerization in supernatants of lysed neutrophils. This polymerization, like that induced by agonists, requires elongation at filament barbed ends. To determine if creation of free barbed ends was sufficient to induce actin polymerization, free barbed ends in the form of spectrin-actin seeds or sheared F-actin filaments were added to cell supernatants. Neither induced polymerization. Furthermore, the presence of spectrin-actin seeds did not increase the rate of Cdc42-induced polymerization, suggesting that the presence of Cdc42 did not facilitate polymerization from spectrin-actin seeds such as might have been the case if Cdc42 inhibited capping or released G-actin from a sequestered pool.
Electron microscopy revealed that Cdc42-induced filaments elongated rapidly, achieving a mean length greater than 1 μm in 15 s. The mean length of filaments formed from spectrin-actin seeds was &lt;0.4 μm. Had spectrin-actin seeds elongated at comparable rates before they were capped, they would have induced longer filaments. There was little change in mean length of Cdc42-induced filaments between 15 s and 5 min, suggesting that the increase in F-actin over this time was due to an increase in filament number. These data suggest that Cdc42 induction of actin polymerization requires both creation of free barbed ends and facilitated elongation at these ends.
In-vitro activity of levofloxacin, ofloxacin and d -ofloxacin against coryneform bacteria and Listeria monocytogenes
Authors: Martínez-Martínez L. , Pascual A. , Suárez A. I. , Perea E. J. 
Published: July 2002

Abstract
The objective of this study was to evaluate the in-vitro activity of levofloxacin, ofloxacin and d -ofloxacin compared with ciprofloxacin, norfloxacin and sparfloxacin against coryneform bacteria and Listeria monocytogenes isolated from clinical samples. The following organisms (and number of strains) were studied: Corynebacterium jeikeium (20), Corynebacterium urealyticum (20), Corynebacterium minutissimum (20), Corynebacterium striatum (20), Corynebacterium amycolatum (30), Brevibacterium spp. (15) and Listeria monocytogenes (15). Antimicrobial activity was determined by microdilution using cation-adjusted Mueller–Hinton broth supplemented with 0.5% Tween 80 when testing C. jeikeium or C. urealyticum. Fluoroquinolones were used in the range 0.015–16 mg/L. Plates were incubated in air at 35°C for 18–20 h (24 h when testing C. jeikeium or C. urealyticum ). The following MIC 50 values were obtained for all 140 organisms tested: levofloxacin, 1 mg/L; ofloxacin, 2 mg/L; d -ofloxacin, &gt;16 mg/L; ciprofloxacin, 1 mg/L; norfloxacin, 16 mg/L; sparfloxacin, 1 mg/L. MIC 90 values were &gt;16 mg/L for all test antibiotics with the exception of levofloxacin, which had an MIC 90 value of 16 mg/L. At a concentration of 2 mg/L, levofloxacin inhibited all L. monocytogenes strains and 35–93% of the remaining species. MIC 90 values of ofloxacin were one dilution step higher than those of levofloxacin against C. minutissimum,C. striatum,Brevibacterium spp. and L. monocytogenes. Levofloxacin showed similar ( C. jeikeium,C. urealyticum,C. amycolatum and Brevibacterium spp.) or greater ( C. minutissimum and C. striatum ) activity than ciprofloxacin and sparfloxacin, and higher than d -ofloxacin or norfloxacin against all species studied. In conclusion, levofloxacin was the most active of the six fluoroquinolones evaluated against coryneform bacteria isolated from clinical samples and could therefore be a promising treatment option in this setting.
Offline recommender system evaluation: Challenges and new directions
Authors: Castells Pablo , Moffat Alistair 
Published: June 2022

AbstractOffline evaluation is an essential complement to online experiments in the selection, improvement, tuning, and deployment of recommender systems. Offline methodologies for recommender system evaluation evolved from experimental practice in Machine Learning (ML) and Information Retrieval (IR). However, evaluating recommendations involves particularities that pose challenges to the assumptions upon which the ML and IR methodologies were developed. We recap and reflect on the development and current status of recommender system evaluation, providing an updated perspective. With a focus on offline evaluation, we review the adaptation of IR principles, procedures and metrics, and the implications of those techniques when applied to recommender systems. At the same time, we identify the singularities of recommendation that require different responses, or involve specific new needs. In addition, we provide an overview of important choices in the configuration of experiments that require particular care and understanding; discuss broader perspectives of evaluation such as recommendation value beyond accuracy; and survey open challenges such as experimental biases, and the cyclic dimension of recommendation.
Sustainable and Bench‐Stable Photoactive Aqueous Nanoaggregates of Cu(II) for ppm Level Cu(I) Catalysis in Water
Authors: Sharma Sudripet , Parmar Saurav , Ibrahim Faisal , Clark Adam H. , Nachtegaal Maarten , Jasinski Jacek B. , Gallou Fabrice , Kozlowski Pawel M. , Handa Sachin 
Published: June 2022

AbstractThe nanomaterial containing amphiphile‐stabilized mononuclear Cu(II) is developed. The material is characterized by various spectroscopic techniques, such as X‐ray absorption spectrscopy (XAS), high‐resolution transmission electron microscopy, nuclear magnetic resonance (NMR), UV‐vis, and infrared spectroscopies. Since the structural data for the amphiphile‐bound Cu(II) center is not available, a theoretical model based on DFT calculations is employed. The analyses based on NMR spectroscopic data, including the isotope labeling, support that the tertiary amide group of the amphiphile binds to the Cu surface. Likewise, the bond distances found by XAS spectroscopy agree with the theoretical model. Time‐dependent DFT studies predict that the low‐lying excited state has a dominant ligand‐to‐metal charge transfer (LMCT) character. Cu(II) changes to Cu(I) assisted by the LMCT excitation upon visible light irradiation, generating robust catalytically active species. The catalytic activity for domino azidation‐[3+2] cycloaddition reactions in water is investigated. The catalytic protocol is applicable on various substrates, and the catalytic material is stable under ambient conditions for up to three months.
Nonvolatile Control of Metal–Insulator Transition in VO2 by Ferroelectric Gating
Authors: Lee Yoon Jung , Hong Kootak , Na Kyeongho , Yang Jiwoong , Lee Tae Hyung , Kim Byungsoo , Bark Chung Wung , Kim Jae Young , Park Sung Hyuk , Lee Sanghan , Jang Ho Won 
Published: June 2022

AbstractControlling phase transitions in correlated materials yields emergent functional properties, providing new aspects to future electronics and a fundamental understanding of condensed matter systems. With vanadium dioxide (VO2), a representative correlated material, an approach to control a metal–insulator transition (MIT) behavior is developed by employing a heteroepitaxial structure with a ferroelectric BiFeO3 (BFO) layer to modulate the interaction of correlated electrons. Owing to the defect‐alleviated interfaces, the enhanced coupling between the correlated electrons and ferroelectric polarization is successfully demonstrated by showing a nonvolatile control of MIT of VO2 at room temperature. The ferroelectrically‐tunable MIT can be realized through the Mott transistor (VO2/BFO/SrRuO3) with a remanent polarization of 80 µC cm−2, leading to a nonvolatile MIT behavior through the reversible electrical conductance with a large on/off ratio (≈102), long retention time (≈104 s), and high endurance (≈103 cycles). Furthermore, the structural phase transition of VO2 is corroborated by ferroelectric polarization through in situ Raman mapping analysis. This study provides novel design principles for heteroepitaxial correlated materials and innovative insight to modulate multifunctional properties.
A Potent Micron Neoantigen Tumor Vaccine GP‐Neoantigen Induces Robust Antitumor Activity in Multiple Tumor Models
Authors: Jing Zhe , Wang Shuqing , Xu Keyuan , Tang Qian , Li Wenjing , Zheng Wei , Shi Haobo , Su Kailing , Liu Yanting , Hong Zhangyong 
Published: June 2022

AbstractTherapeutic tumor neoantigen vaccines have been widely studied given their good safety profile and ability to avoid central thymic tolerance. However, targeting antigen‐presenting cells (APCs) and inducing robust neoantigen‐specific cellular immunity remain challenges. Here, a safe and broad‐spectrum neoantigen vaccine delivery system is proposed (GP‐Neoantigen) based on β‐1,3‐glucan particles (GPs) derived from Saccharomyces cerevisiae and coupling peptide antigens with GPs through convenient click chemistry. The prepared system has a highly uniform particle size and high APC targeting specificity. In mice, the vaccine system induced a robust specific CD8+ T cell immune response and humoral immune response against various conjugated peptide antigens and showed strong tumor growth inhibitory activity in EG7·OVA lymphoma, B16F10 melanoma, 4T1 breast cancer, and CT26 colon cancer models. The combination of the toll‐like receptors (TLRs) agonist PolyI:C and CpG 2395 further enhanced the antitumor response of the particle system, achieving complete tumor clearance in multiple mouse models and inducing long‐term rejection of reinoculated tumors. These results provide the broad possibility for its further clinical promotion and personalized vaccine treatment.
Transparent Conducting Films Based on Carbon Nanotubes: Rational Design toward the Theoretical Limit
Authors: Ilatovskii Daniil A. , Gilshtein Evgeniia P. , Glukhova Olga E. , Nasibulin Albert G. 
Published: June 2022

AbstractElectrically conductive thin‐film materials possessing high transparency are essential components for many optoelectronic devices. The advancement in the transparent conductor applications requires a replacement of indium tin oxide (ITO), one of the key materials in electronics. ITO and other transparent conductive metal oxides have several drawbacks, including poor flexibility, high refractive index and haze, limited chemical stability, and depleted raw material supply. Single‐walled carbon nanotubes (SWCNTs) are a promising alternative for transparent conducting films (TCFs) because of their unique and excellent chemical and physical properties. Here, the latest achievements in the optoelectronic performance of TCFs based on SWCNTs are analyzed. Various approaches to evaluate the performance of transparent electrodes are briefly reviewed. A roadmap for further research and development of the transparent conductors using “rational design,” which breaks the deadlock for obtaining the TCFs with a performance close to the theoretical limit, is also described.