bluuebunny/crossref_metadata_2025_split huggingface dataset:
Long‐term influences of interventions in the normal development of science: China and the Cultural Revolution
Authors: Jin Bihui , Li Ling , Rousseau Ronald 
Published: March 2004

AbstractIntellectual and technological talents and skills are the driving force for scientific and industrial development, especially in our times characterized by a knowledge‐based economy. Major events in society and related political decisions, however, can have a long‐term effect on a country's scientific well‐being. Although the Cultural Revolution took place from 1966 to 1976, its aftermath can still be felt. This is shown by this study of the production and productivity of Chinese scientists as a function of their age. Based on the 1995–2000 data from the Chinese Science Citation database (CSCD), this article investigates the year‐by‐year age distribution of scientific and technological personnel publishing in China. It is shown that the “Talent Fault” originating during the Cultural Revolution still exists, and that a new gap resulting from recent brain drain might be developing. The purpose of this work is to provide necessary information about the current situation and especially the existing problems of the S&T workforce in China.
Evaluation of a contraction flow field on hydrodynamic damage to entomopathogenic nematodes—A biological pest control agent
Authors: Fife Jane P. , Derksen Richard C. , Ozkan H. Erdal , Grewal Parwinder S. , Chalmers Jeffrey J. , Krause Charles R. 
Published: March 2004

AbstractMechanized production and delivery of biological pesticides presents challenges because the biological agents must remain viable during these processes. This study evaluates the effect of flow through an abrupt contraction, where flow characteristics similar to that found within bioprocesses and spray equipment are developed, on damage to a benchmark biological pest control agent, entomopathogenic nematodes (EPNs). An opposed‐pistons, contraction flow device generated volumetric flow rates ranging between 8.26 cm3/s and 41.3 cm3/s. Four EPN species were evaluated: Heterorhabditis bacteriophora, Heterorhabditis megidis, Steinernema carpocapsae, and Steinernema glaseri. Damage was quantified by counting living and dead EPNs. Optical and cold field emission scanning electron microscope (CFE‐SEM) images provided qualitative information to describe how the damage occurred. The experimental flow field was completely described using FLUENT, a computational fluid dynamics program. Local flow parameters computed in FLUENT were compared to EPN damage. The type and extent of damage varied between EPN species. Damaged Heterorhabditis spp. generally remained whole with an internal rupture located near the center of the body, while Steinernema spp. most often broke into several pieces. The fast‐transient stress field generated at the entrance to the contraction caused a momentary tensile loading and then relaxation that damaged the EPNs. At high flow rates, the tensile stresses became large enough to cause failure of the EPN structural membrane. The relative elasticity of the EPN structural membrane may explain the differences in damage observed between the species. It is speculated that the internal rupture of the Heterorhabditis spp. occurred during the processes of stretching and relaxing at the contraction entrance. Appreciable damage was observed at lower average energy dissipation rates for H. bacteriophora (1.23E + 8 W/m3), H. megidis (1.72E + 8 W/m3), and S. glaseri (2.89E + 8 W/m3) compared to S. carpocapsae (3.70E + 8 W/m3). Energy dissipation rates within an equipment component should be kept below 1E + 8 W/m3 to avoid hydrodynamic damage to EPNs. The relationship between average energy dissipation and EPN damage provides important information for future simulation efforts of actual spray equipment components. © 2004 Wiley Periodicals, Inc.
Synthetic extracellular matrices for in situ tissue engineering
Authors: Pratt Alison B. , Weber Franz E. , Schmoekel Hugo G. , Müller Ralph , Hubbell Jeffrey A. 
Published: March 2004

AbstractCell interactions with the extracellular matrix play important roles in guiding tissue morphogenesis. The matrix stimulates cells to influence such things as differentiation and the cells actively remodel the matrix via local proteolytic activity. We have designed synthetic hydrogel networks that participate in this interplay: They signal cells via bound adhesion and growth factors, and they also respond to the remodeling influence of cell‐associated proteases. Poly(ethylene glycol)‐bis‐vinylsulfone was crosslinked by a Michael‐type addition reaction with a peptide containing three cysteine residues, the peptide sequence being cleavable between each cysteine residue by the cell‐associated protease plasmin. Cells were able to invade gel networks that contained adhesion peptides and were crosslinked by plasmin‐sensitive peptides, while materials lacking either of these two characteristics resisted cell infiltration. Incorporated bone morphogenetic protein‐2 (BMP‐2) induced bone healing in a rat model in materials that were both adhesive and plasmin‐sensitive, while materials lacking plasmin sensitivity resisted formation of bone within the material. Furthermore, when a heparin bridge was incorporated as a BMP‐2 affinity site, mimicking yet another characteristic of the extracellular matrix, statistically improved bone regeneration was observed. © 2004 Wiley Periodicals, Inc.
Oxygen gradients in tissue‐engineered Pegt/Pbt cartilaginous constructs: Measurement and modeling
Authors: Malda J. , Rouwkema J. , Martens D. E. , le Comte E. P. , Kooy F. K. , Tramper J. , van Blitterswijk C. A. , Riesle J. 
Published: March 2004

AbstractThe supply of oxygen within three‐dimensional tissue‐engineered (TE) cartilage polymer constructs is mainly by diffusion. Oxygen consumption by cells results in gradients in the oxygen concentration. The aims of this study were, firstly, to identify the gradients within TE cartilage polymer constructs and, secondly, to predict the profiles during in vitro culture. A glass microelectrode system was adapted and used to penetrate cartilage and TE cartilaginous constructs, yielding reproducible measurements with high spatial resolution. Cartilage polymer constructs were cultured for up to 41 days in vitro. Oxygen concentrations, as low as 2–5%, were measured within the center of these constructs. At the beginning of in vitro culture, the oxygen gradients were steeper in TE constructs in comparison to native tissue. Nevertheless, during the course of culture, oxygen concentrations approached the values measured in native tissue. A mathematical model was developed which yields oxygen profiles within cartilage explants and TE constructs. Model input parameters were assessed, including the diffusion coefficient of cartilage (2.2 × 10−9) + (0.4 × 10−9 m2 s−1), 70% of the diffusion coefficient of water and the diffusion coefficient of constructs (3.8 × 10−10 m2 s−1). The model confirmed that chondrocytes in polymer constructs cultured for 27 days have low oxygen requirements (0.8 × 10−19 mol m−3 s−1), even lower than chondrocytes in native cartilage. The ability to measure and predict local oxygen tensions offers new opportunities to obtain more insight in the relation between oxygen tension and chondrogenesis. © 2004 Wiley Periodicals, Inc.
Solubilization and concentration of carbon dioxide: Novel spray reactors with immobilized carbonic anhydrase
Authors: Bhattacharya Sumana , Nayak Amiya , Schiavone Marc , K. Bhattacharya Sanjoy 
Published: March 2004

AbstractNovel spray reactors are described that employ immobilized biocatalyst (carbonic anhydrase), enabling concentration and solubilization of emitted CO2 by allowing catalytic contact with water spray. The reactors were fed with simulated emission gas. The performance of the reactors was investigated with respect to operation variable: emission flow rate; gas composition in the emission stream; water flow rate; area‐to‐volume ratio of immobilized reactor core; and the enzyme load within the core. The reactors were also investigated for pressure drop and extractability of CO2 from the emission with single vs. multiple reactors (of combined equal volume). The biotechnological process of solubilization and concentration of CO2 from emission exhausts or streams occurring in the spray reactors could be coupled for further biochemical/chemical conversion of the concentrated CO2. © 2004 Wiley Periodicals, Inc.
τ‐AIMD for asynchronous receiver feedback
Authors: Lahanas Adrian , Tsaoussidis Vassilis 
Published: March 2004

AbstractIn this work we first describe an asynchronous‐feedback model which corresponds to the diverse roundtrip times (RTTs) of competing flows within the same communication channel. We show that even when the feedback of the receivers/network is asynchronous, the duration of a congestion epoch represents ‘common knowledge’ for the competing flows. Based on this property, we propose a diverse linear increase scheme in proportion to the RTT of each flow and we adjust periodically the windows of the competing flows accordingly, in order to enhance fairness of asynchronous‐feedback environments. We name this scheme τ‐AIMD and show that fairness of flows in asynchronous systems is improved since the increase‐rate diversity of long and short RTT flows is largely canceled. We use the max–min notion of fairness to show that τ‐AIMD can constitute the foundation for other window‐based, end‐to‐end algorithms that target a good balance between efficiency and fairness. Copyright © 2004 John Wiley & Sons, Ltd.
Which survey indicators are useful for monitoring consumption? Evidence from European countries
Authors: Nahuis Niek J. , Jansen W. Jos 
Published: March 2004

AbstractThis paper assesses the information content of two survey indicators for consumption developments in the near future for eight European countries in the period 1985–1998. Empirical work on this topic typically focuses on consumer confidence, the perceptions of buyers of consumption goods. This paper examines whether perceptions of sellers of consumption goods, measured by retail trade surveys, may also improve short‐term monitoring of consumption. We find that both consumer confidence and retailer confidence embody valuable information, when analysed in isolation. For France, Italy and Spain we conclude that adding retail confidence does not improve the indicator model once consumer confidence has been included. For the UK the reverse case is obtained. For the remaining four countries we show that combining consumer sentiment and retail trade confidence into a composite indicator leads to optimal results. Our results suggest that incorporating information from retail trade surveys may offer significant benefits for the analysis of short‐term prospects of consumption. Copyright © 2004 John Wiley & Sons, Ltd.
Can out‐of‐sample forecast comparisons help prevent overfitting?
Authors: Clark Todd E. 
Published: March 2004

AbstractThis paper shows that out‐of‐sample forecast comparisons can help prevent data mining‐induced overfitting. The basic results are drawn from simulations of a simple Monte Carlo design and a real data‐based design similar to those used in some previous studies. In each simulation, a general‐to‐specific procedure is used to arrive at a model. If the selected specification includes any of the candidate explanatory variables, forecasts from the model are compared to forecasts from a benchmark model that is nested within the selected model. In particular, the competing forecasts are tested for equal MSE and encompassing. The simulations indicate most of the post‐sample tests are roughly correctly sized. Moreover, the tests have relatively good power, although some are consistently more powerful than others. The paper concludes with an application, modelling quarterly US inflation. Copyright © 2004 John Wiley & Sons, Ltd.
Cambro‐Ordovician trace fossils from the SW‐Norwegian Caledonides
Authors: Knaust Dirk 
Published: March 2004

AbstractA diverse trace fossil association is described for the first time from low‐grade metamorphic rocks of the SW‐Norwegian Caledonides. The investigated cliff sections with autochthonous to parautochthonous metasediments comprise a coarsening‐ and thickening‐upward succession interpreted as prograding delta deposits. Sedimentary features indicate a tide‐influenced environment. Twenty‐one ichnospecies have been identified and assigned to the Cruziana and Skolithos ichnofacies, including the oldest record of Beaconites capronus and Macaronichnus segregatis. Cruziana ichnostratigraphy (sensu lato), previously rarely used in other palaeocontinents than Gondwana, allows an age determination for these metasediments of Middle Cambrian to Lower Ordovician as indicated by the presence of Cruziana barbata, C. furcifera, C. rugosa, C. semiplicata, Didymaulichnus rouaulti and Rusophycus ramellensis. Baltica was geographically the most isolated from the other three large continents (Gondwana, Laurentia and Siberia) during Cambro‐Ordovician time, and provinciality of faunal assemblages (e.g. brachiopods, conodonts) has been proved and is also supposed for trilobites by some authors. However, although the Cruziana ichnospecies result from a high specialization of their tracemakers, and therefore only a small group of trilobite species is eligible for its origin, the ichnospecies reported from Baltica occur also on other palaeocontinents and do not support the assumption of trilobite provincialism. Copyright © 2004 John Wiley & Sons, Ltd.
Mud volcanoes of Italy
Authors: Martinelli Giovanni , Judd Alan 
Published: March 2004

AbstractThe locations and information about the sizes of 61 mud volcanoes on the Italian mainland and Sicily, plus an area of mud diapirism in the Italian Adriatic Sea, are presented. Data about the emission products are also provided. The majority of these mud volcanoes are found where thick sedimentary sequences occur within a zone of tectonic compression associated with local plate tectonic activity: the movement of the Adriatic microplate between the converging African and Eurasian plates. The principal gas emitted by these mud volcanoes is methane, which probably originates from deep within the sediments. Other mud volcanoes, associated with igneous volcanism, produce mainly carbon dioxide. The mud diapirs in the Adriatic Sea are thought to form as a result of the mobilization of shallow gassy sediments. It has been shown that radon emissions from mud volcanoes are indicators of forthcoming earthquake events. Copyright © 2004 John Wiley & Sons, Ltd.
Mantle‐derived and crustal melts dichotomy in northern Greece: spatiotemporal and geodynamic implications
Authors: Perugini Diego , Poli Giampiero , Christofides George , Eleftheriadis George , Koroneos Antonis , Soldatos Triantafyllos 
Published: March 2004

AbstractTwo distinct groups of subduction‐related (orogenic) granitoid rocks, one Jurassic and the other Tertiary, occur in the area between the Vardar (Axios) Zone and the Rhodope Massif in northern Greece. The two groups of granitoids differ in many respects. The first group shows evolved geochemical characters, it is not associated with mafic facies, and evidence of magmatic interaction between mantle‐ and crustal‐derived melts is lacking. The second group has less evolved geochemical characters, it is associated with larger amount of mafic facies, and magmatic interaction processes between mantle‐derived and crustal melts are ubiquitous as evidenced by mafic microgranular enclaves and synplutonic dykes showing different enrichment in K2O, Ti, and incompatible elements. This kind of magmatism can be attributed to the complex geodynamic evolution of the area. In particular, we suggest that two successive subduction events related to the closure of the Vardar and the Pindos oceans, respectively, occurred in the investigated area from Late Jurassic to Tertiary. We relate the genesis of Jurassic granitoids to the first subduction event, whereas Tertiary granitoids are associated with the second subduction. Fluids released by the two subducted slabs induced metasomatic processes generating a ‘leopard skin’ mantle wedge able to produce mafic melts ranging from typical calc‐alkaline to ultra‐potassic. Such melts interacted in various amounts with crustal calc‐alkaline anatectic melts to generate the wide spectrum of Tertiary granitoids occurring in the study area. Copyright © 2004 John Wiley & Sons, Ltd.
Structural evolution of the southern Rif Cordillera (Morocco): tectonics and synsedimentary fault processes
Authors: Zouhri Lahcen 
Published: March 2004

AbstractThis paper attempts to investigate the tectonics of the southern Rif Cordillera. Hydrogeological and oil well data, together with interpretation of seismic reflection lines help to characterize the architecture of the Rharb–Mamora Basin located in the frontal region of the Gibraltar Arc.The facies map constructed from the drilling data exhibits four main types of Pliocene facies: (i) conglomerates; (ii) limestones; (iii) sandstones and sands more or less rich with shelly remains; (iv) clays. The lateral variation of deposits is accompanied by thickening, which can reach a few tens of metres. Thickening of layers and lithofacies variation indicate synsedimentary faulting processes. Two major fault zones have been identified: Kenitra–Sidi Slimane Fault Zone (K2SFZ) and Rabat–Kenitra Fault Zone (RKFZ). In the western coastal area, the geometrical configuration suggests a partition into horsts and grabens in the southern part, and a system of three geological units in the northern part.The analysis and interpretation of the gravity data reveal an important gravity anomaly, referred to as the Kenitra Gravity Anomaly. It corresponds to the Hercynian faults deduced by the seismic reflection line interpretation: K2SFZ and RKFZ. From Larache to El Jadida cities, the Kenitra area represents the hinge between the positive and negative gravity values, with a major negative anomaly in the eastern part of Kenitra. Copyright © 2004 John Wiley & Sons, Ltd.
Implications of dissected drift at Stockdale Head, western Lake District, northern England
Authors: Wilson Peter 
Published: March 2004

AbstractFrom mapping and consideration of prominent drift ridges at Stockdale Head, western Lake District, northern England it is inferred that the ridges are the products of dissection of a glacigenic or soliflual drift sheet rather than landforms constructed at the margins of a Loch Lomond Stade (LLS) valley‐head glacier. This proposal has implications for the recognition of LLS glacier limits and, possibly, understanding the dearth of moraine ridges associated with Dimlington ice in Lake District valleys. Copyright © 2004 John Wiley & Sons, Ltd.
Neural substrates of tactile object recognition: An fMRI study
Authors: Reed Catherine L. , Shoham Shy , Halgren Eric 
Published: March 2004

AbstractA functional magnetic resonance imaging (fMRI) study was conducted during which seven subjects carried out naturalistic tactile object recognition (TOR) of real objects. Activation maps, conjunctions across subjects, were compared between tasks involving TOR of common real objects, palpation of “nonsense” objects, and rest. The tactile tasks involved similar motor and sensory stimulation, allowing higher tactile recognition processes to be isolated. Compared to nonsense object palpation, the most prominent activation evoked by TOR was in secondary somatosensory areas in the parietal operculum (SII) and insula, confirming a modality‐specific path for TOR. Prominent activation was also present in medial and lateral secondary motor cortices, but not in primary motor areas, supporting the high level of sensory and motor integration characteristic of object recognition in the tactile modality. Activation in a lateral occipitotemporal area associated previously with visual object recognition may support cross‐modal collateral activation. Finally, activation in medial temporal and prefrontal areas may reflect a common final pathway of modality‐independent object recognition. This study suggests that TOR involves a complex network including parietal and insular somatosensory association cortices, as well as occipitotemporal visual areas, prefrontal, and medial temporal supramodal areas, and medial and lateral secondary motor cortices. It confirms the involvement of somatosensory association areas in the recognition component of TOR, and the existence of a ventrolateral somatosensory pathway for TOR in intact subjects. It challenges the results of previous studies that emphasize the role of visual cortex rather than somatosensory association cortices in higher‐level somatosensory cognition. Hum. Brain Mapping 21:236–246, 2004. © 2004 Wiley‐Liss, Inc.
Neural correlates of switching set as measured in fast, event‐related functional magnetic resonance imaging
Authors: Smith Anna B. , Taylor Eric , Brammer Mick , Rubia Katya 
Published: March 2004

AbstractAttentional switching has shown to involve several prefrontal and parietal brain regions. Most cognitive paradigms used to measure cognitive switching such as the Wisconsin Card Sorting Task (WCST) involve additional cognitive processes besides switching, in particular working memory (WM). It is, therefore, questionable whether prefrontal brain regions activated in these conditions, especially dorsolateral prefrontal cortex (DLPFC), are involved in cognitive switching per se, or are related to WM components involved in switching tasks. Functional magnetic resonance imaging (fMRI) was used to examine neural correlates of pure switching using a paradigm purposely designed to minimize WM functions. The switching paradigm required subjects to switch unpredictably between two spatial dimensions, clearly indicated throughout the task before each trial. Fast, event‐related fMRI was used to compare neural activation associated with switch trials to that related to repeat trials in 20 healthy, right‐handed, adult males. A large cluster of activation was observed in the right hemisphere, extending from inferior prefrontal and pre‐ and postcentral gyri to superior temporal and inferior parietal cortices. A smaller and more caudal cluster of homologous activation in the left hemisphere was accompanied by activation of left dorsolateral prefrontal cortex (DLPFC). We conclude that left DLPFC activation is involved directly in cognitive switching, in conjunction with parietal and temporal brain regions. Pre‐ and postcentral gyrus activation may be related to motor components of switching set. Hum. Brain Mapp.21:247–256, 2004. © 2004 Wiley‐Liss, Inc.