bluuebunny/crossref_metadata_2025_split huggingface dataset:
A high frequency kriging approach for non‐stationary environmental processes
Authors: Fuentes Montserrat 
Published: August 2002

AbstractEmission reductions were mandated in the Clean Air Act Amendments of 1990 with the expectation that they would result in major reductions in the concentrations of atmospherically transported pollutants. The emission reductions are intended to reduce public health risks and to protect sensitive ecosystems. To determine whether the emission reductions are having the intended effect on atmospheric concentrations, monitoring data must be analyzed taking into consideration the spatial structure shown by the data. Maps of pollutant concentrations and fluxes are useful over different geopolitical boundaries, to discover when, where, and to what extent the U.S. Nation's air quality is improving or declining. Since the spatial covariance structure shown by the data changes with location, the standard kriging methodology for spatial interpolation cannot be used because it assumes stationarity of the process.We present a new methodology for spatial interpolation of non‐stationary processes. In this method the field is represented locally as a stationary isotropic random field, but the parameters of the stationary random field are allowed to vary across space. A procedure for interpolation is presented that uses an expression for the spectral density at high frequencies. New fitting algorithms are developed using spectral approaches. In cases where the data are distributed exactly or approximately on a lattice, it is argued that spectral approaches have potentially enormous computational benefits compared with maximum likelihood. The methods are extended to interpolation questions using approximate Bayesian approaches to account for parameter uncertainty. We develop applications to obtain the total loading of pollutant concentrations and fluxes over different geo‐political boundaries. Copyright © 2001 John Wiley & Sons, Ltd.
Runoff‐induced sediment yield over dune slopes in the Negev Desert. 2: Texture, carbonate and organic matter
Authors: Kidron Giora J. 
Published: August 2002

AbstractRunoff‐induced sediments were collected in the Hallamish dune field for four years (1990–1994). Runoff and consequently water‐transported sediments were generated on the dunes owing to the presence of a thin microbiotic crust. These sediments were analysed for their particle‐size distribution and carbonate content. In addition, the organic matter content was calculated by measuring the chlorophyll content within the runoff. The results were compared to the slope parent material, i.e. the crust and the underlying sand, as well as to playa sediments, which are scattered within the Hallamish interdunal areas, and which were previously hypothesized to originate from runoff‐induced sediments.Higher amounts of fines (silt and clay) and carbonate characterize the footslopes in comparison to the midslopes. Intermediate contents of fines (17 per cent) and carbonate (8 per cent) characterized the sediments in comparison to the fines (27 per cent) and carbonate (15 per cent) of the crust and to the fines (4 per cent) and carbonate (4 per cent) of the underlying sand. The runoff‐induced fines and carbonate contents were significantly different from those of the playas, suggesting that the playa flats do not originate from runoff‐induced sediments.The sediments were enriched with organic matter. Organic matter which originates from the crust amounted to 0·3–0·4 per cent as compared to ≤0·1 per cent in the bare sand. Nevertheless, the crust was found to be relatively resilient to water flow. Only 0·1–0·5 per cent of the crust was annually eroded off the slope by water, with south‐facing crusts showing higher resilience than north‐facing crusts. The data may thus assist in the evaluation of the crust's residence time. Copyright © 2001 John Wiley & Sons, Ltd.
Channel evolution of the pre‐channelized Danube River in Bratislava, Slovakia (1712–1886)
Authors: Pišút Peter 
Published: August 2002

AbstractChannel adjustments of the Danube River near Bratislava, Slovakia, are reconstructed from historical river maps for 1712–1886, the period preceding mid‐course channelization. The study reach comprised an anastomosing–meandering planform, characteristic of the upper area of a large alluvial fan. The key mechanisms of channel change were avulsions through channel switching into chute channels, meander development through progression and cutoffs, and abandonment of secondary channels. The gravel‐bed Danube River was characterized by rapid rates of lateral erosion (maxima from 7·5 to 37 m a−1), and extensive areas of point bars and gravel bars. Within three to seven years, new bars were stabilized by Salici–Populetum woodlands which subsequently developed into more stable vegetated islands. Human interventions were relatively common and frequent in the past, though increasing fluvial activity during the 18th century was responsible for their limited effectiveness. Uncontrollable lateral erosion at Petržalka village, terminated only by a switch in position of the Danube River upstream from Bratislava (1766–1774), appears to be closely related to increasing ice‐floods and other high magnitude flood events in the latter half of the 18th century. These events were coincident with the peak of the Little Ice Age. The effect of floods was probably amplified by human works which resulted in stabilization of secondary channels, simplification of the river pattern, and concentration and widening of the main channel. A further sign of channel readjustment to new conditions was the evolution of new large meanders, a tendency for channel switching and production of new anastomosing–meandering parallel channels. Copyright © 2002 John Wiley & Sons, Ltd.
Extraction and isolation of Salvia desoleana and Mentha spicata subsp. insularis essential oils by supercritical CO2
Authors: Marongiu Bruno , Porcedda Silvia , Porta Giovanna Della , Reverchon Ernesto 
Published: August 2002

AbstractDried and ground leaves of different endemic plants of Sardinia (Italy), such as mint, Mentha spicata ssp. insularis, and sage, Salvia desoleana, were used for supercritical extraction with carbon dioxide to isolate the corresponding essential oils. The vegetable fragrances were isolated by supercritical CO2 extraction coupled to a fractional separation technique. GC–MS analysis of the extract allowed the identification of constituents of the oils. The process was carried out by operating at 90 bar and 50 °C in the extraction vessel, at 90 bar and below −5 °C in the first separator to selectively precipitate the cuticular waxes, and at a pressure of 15–20 bar and temperatures in the range 15–21 °C in the second separator to recover the volatile oil. In the case of Salvia desoleana, a comparison with the product obtained by hydrodistillation is also given. Copyright © 2001 John Wiley & Sons, Ltd.
Volatile constituents of Lippia lupulina Cham.
Authors: Zoghbi Maria das Graças B. , Andrade Eloisa Helena A. , da Silva Milton Helio L. , Maia José Guilherme S. 
Published: August 2002

AbstractThe essential oils of Lippia lupulina, collected in three localities of the state of Mato Grosso, Brazil, were obtained by hydrodistillation and analysed by GC–MS. The major components identified in the oil from stalks and their leaves of the specimen collected at Chapada dos Guimarães, were terpinen‐4‐ol (41.3%), terpinolene (10.4%) and α‐terpineol (9.2%). The main compounds found in the oil from the same aerial parts of the specimen located at Poxoréo were 1,8‐cineole (15.5%), β‐caryophyllene (12.3%) and endo‐fenchol (10.4%). The oils from stalks and their leaves and flowers of the specimen collected at Santo Antonio do Leverger consisted largely of germacrene D (14.8%, 12.9%), β‐caryophyllene (12.7%, 10.2%) and bicyclogermacrene (11.2%, 15.4%), respectively. Copyright © 2001 John Wiley & Sons, Ltd.
Localities and seasonal variations in the chemical composition of essential oils of Satureja montana L. and S. cuneifolia Ten
Authors: Milos M. , Radonic A. , Bezic N. , Dunkic V. 
Published: August 2002

AbstractThe essential oils of Satureja montana L. and Satureja cuneifolia Ten. were subjected to detailed GC–MS analysis in order to determine possible similarities between them and also the differences in their chemical compositions, depending on the locality and the stage of development. The plant materials were collected prior to, during and after flowering from three different locations in the central part of Dalmatia (Croatia). For both plants the qualitative composition of the components appeared to be constant in three phenological stages and in three different localities. However, considerable differences were found to exist in the amounts of several compounds. Copyright © 2001 John Wiley & Sons, Ltd.
Essential oils of Hypericum olympicum L. and Hypericum perforatum L.
Authors: Gudžić Branislav , Dordević Siniša , Palić Radosav , Stojanović Gordana 
Published: August 2002

AbstractThe essential oil of Hypericum olympicum L. was analysed for the first time and was compared to the essential oil of Hypericum perforatum L. from the same location. Eighteen components were common for both species. The main components of H. olympicim oil were (E)‐anethole (30.7%) and β‐farnesene (12.4%), and for H. perforatum oil they were β‐caryophyllene (14.2%) and 2‐methyl‐octane (13.1%). Copyright © 2001 John Wiley & Sons, Ltd.
Numerical simulation of the vertical structure of discontinuous flows
Authors: Stelling Guus S. , Busnelli Marcela M. 
Published: August 2002

AbstractA numerical method to solve the Reynolds‐averaged Navier–Stokes equations with the presence of discontinuities is outlined and discussed. The pressure is decomposed into the sum of a hydrostatic component and a hydrodynamic component. The numerical technique is based upon the classical staggered grids and semi‐implicit finite difference methods applied for quasi‐ and non‐hydrostatic flows. The advection terms in the momentum equations are approximated in order to conserve mass and momentum following the principles recently developed for the numerical simulation of shallow water flows with large gradients. Conservation of these properties is the most important aspect to represent near local discontinuities in the solution, following from sharp bottom gradients or hydraulic jumps. The model is applied to reproduce the flow over a step where a hydraulic jump forms downstream. The hydrostatic pressure assumption fails to represent this type of flow mainly because of the pressure deviation from the hydrostatic values downstream the step. Fairly accurate results are obtained from the numerical model compared with experimental data. Deviation from the data is found to be inherent to the standard k–ε model implemented. Copyright © 2001 John Wiley & Sons, Ltd.
A coupled lattice BGK model for the Boussinesq equations
Authors: Guo Zhaoli , Shi Baochang , Zheng Chuguang 
Published: August 2002

AbstractIn this paper, a thermal lattice BGK model is developed for the Boussinesq incompressible fluids. The basic idea is to solve the velocity field and the temperature field using two independent lattice BGK equations, respectively, and then combine them into one coupled model for the whole system. The porous plate problem and the two‐dimensional natural convection flow in a square cavity with Pr=0.71 and various of Rayleigh numbers are simulated using the model. The numerical results are found to be in good agreement with the analytical solutions or those of previous studies. Copyright © 2002 John Wiley & Sons, Ltd.
Forecasting Hong Kong's container throughput: an error‐correction model
Authors: Fung Michael K. 
Published: August 2002

AbstractA three‐player oligopoly model is devised to capture the competitive interaction between operators of the Hong Kong container terminals, the Hong Kong midstream and the Singapore container terminals in providing container handling services. The oligopoly model is then estimated statistically and thereby the structural parameters can be identified. The results of the estimation confirm a substitutability between the services supplied by operators of different types (terminal versus midstream) and different locations (Hong Kong versus Singapore). Moreover, the model proposed in this article generates forecasts of demand for Hong Kong's container handling services that are more accurate than those reported by the government authority, and suggests an earlier construction of new terminals to meet future demand. Copyright © 2002 John Wiley & Sons, Ltd.
Heterogeneous expectations of traders in speculative futures markets
Authors: Frechette Darren L. , Weaver Robert D. 
Published: August 2002

AbstractThe representative agent hypothesis is disputable on theoretical grounds because it is inconsistent with observed trading behavior and the existence of speculative markets. In such markets, the representative agent hypothesis implies agents hold homogeneous expectations. If this were true, speculative markets would fail as only one side of the market would be represented, either demand or supply. Nonetheless, the homogeneity assumption has been maintained in the past to ensure tractability because of the difficulty of explicit aggregation across heterogeneous expectations. In this article, we present and apply an approach for analyzing heterogeneity in specific market settings. To do so, our approach specifies an underlying distribution of expectations that is consistent with heterogeneity across expectations. To demonstrate the utility of the approach, we present results from its application to a time series of commodity futures prices. Results are consistent with the conclusion that significant heterogeneity in expectations exists in speculative futures markets. © 2001 John Wiley & Sons, Inc. Jrl Fut Mark 21:429–446, 2001
Genomic gains and losses are similar in genetic and histologic subsets of rhabdomyosarcoma, whereas amplification predominates in embryonal with anaplasia and alveolar subtypes
Authors: Bridge Julia A. , Liu Jian , Qualman Stephen J. , Suijkerbuijk Ron , Wenger Gail , Zhang Ji , Wan Xiaoying , Baker K. Scott , Sorensen Poul , Barr Frederic G. 
Published: August 2002

AbstractIn this investigation, we selected PAX3/FKHR and PAX7/FKHR fusion transcript–positive and –negative alveolar rhabdomyosarcomas (ARMSs) and embryonal rhabdomyosarcomas (ERMSs) with and without anaplastic features, to ascertain genomic imbalance differences and/or similarities within these histopathologic and genetic rhabdomyosarcoma (RMS) variants. Comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH) studies were performed on 45 rhabdomyosarcoma specimens consisting of 23 ARMSs and 22 ERMSs (12 ERMS cases were included from an earlier study). The anaplastic variant of RMS has not previously been subjected to CGH analysis. Overall, the most prominent imbalances were gain of chromosomes or chromosomal regions 2/2q (40%), 7/7q (31%), 8/8p (53%), 11/11q (31%), 12q13‐15 (49%), 13q14 (22%), and 20/20p (31%), and loss of 1p36 (27%), 3p14‐21 (22%), 9q21‐22 (33%), 10q22‐qter (18%), 16q (27%), 17p (22%), and 22 (22%). These gains and losses were distributed equally between ARMS and ERMS histologic subtypes (excluding 7/7q and 11/11q gain that were observed chiefly in ERMS), demonstrating that these entities are similar with respect to recurrent genomic imbalances. Moreover, genomic imbalances were also evenly distributed among the ARMS fusion transcript subtypes, providing evidence for a genetic kinship despite the absence of a fusion transcript in some cases. Genomic amplification was detected in 26% and 23% of the ARMS and ERMS cases, respectively (with nearly all of the latter subset exhibiting anaplastic features). One amplicon, involving 15q25‐26, corresponds to the locus of the insulin‐like growth factor type I receptor (IGF1R) gene. Amplification of IGF1R was confirmed molecularly in the cases exhibiting a 15q25‐26 amplicon. In summary, these results indicate that genomic gains and losses involve alike chromosomes with similar frequencies within the histopathologic and genetic subtypes of rhabdomyosarcoma, that genomic amplification is frequent not only in the alveolar histologic subtype of rhabdomyosarcoma but also in ERMS with anaplasia, and that amplification of IGF1R possibly plays a role in the development or progression of a subset of rhabdomyosarcomas. © 2002 Wiley‐Liss, Inc.
Genetic analysis of mediastinal nonseminomatous germ cell tumors in children and adolescents
Authors: Schneider Dominik T. , Schuster Amy E. , Fritsch Michael K. , Calaminus Gabriele , Göbel Ulrich , Harms Dieter , Lauer Stephen , Olson Thomas , Perlman Elizabeth J. 
Published: August 2002

AbstractPrimary mediastinal germ cell tumors (M‐GCTs) represent a heterogeneous group of tumors that varies with regard to age at presentation, histologic differentiation, and outcome. We retrospectively analyzed archival tissue samples of mediastinal mature and immature teratomas (n = 15) and malignant nonseminomatous M‐GCTs (n = 20) with comparative genomic hybridization (CGH). The aim of this study was to define distinct genetic subgroups of M‐GCT among the pediatric cohort that may differ in their clinical behavior and prognosis. All pure teratomas showed normal CGH profiles. Malignant M‐GCTs in infants and children < 8 years old most frequently showed a gain of 1q, 3, and 20q and a loss of 1p, 4q, and 6q. Gain of 12p and sex chromosomal abnormalities were not observed in this age group. In contrast, the gain of 12p was the most common aberration in M‐GCTs that arose in children ≥ 8 years old. Additional recurrent changes included the loss of chromosome 13 and the gain of chromosome 21. All ten adolescents with malignant M‐GCT were male, and five showed a gain of the X chromosome. In two of these five patients, Klinefelter syndrome was confirmed by cytogenetic analysis or by fluorescence in situ hybridization (FISH). In conclusion, CGH analysis of M‐GCTs defines distinct genetic subgroups. Mediastinal teratomas show no genetic gains or losses. Malignant M‐GCTs in children < 8 years old show the same pattern of gains and losses identified in sacrococcygeal and testicular GCTs at this age, and they lack sex‐chromosomal abnormalities. Malignant M‐GCTs in children ≥ 8 years old show the same genetic profile previously reported in gonadal GCTs at this age. In addition, approximately 50% demonstrate a gain of the X chromosome, consistent with Klinefelter syndrome. Cooperative group studies reveal a significantly better prognosis of malignant M‐GCT arising in infants compared to that in adolescents, suggesting that these genetic differences are associated with differences in clinical behavior. © 2002 Wiley‐Liss, Inc.
Dynamic landscapes, artifact taphonomy, and landuse modeling in the western Mediterranean
Authors: Barton C. Michael , Bernabeu Joan , Aura J. Emili , Garcia Oreto , La Roca Neus 
Published: August 2002

AbstractThe Polop Alto valley, in eastern Spain, is characteristic of many Mediterranean landscapes. It has been sporadically reoccupied over the course of at least 80 kyr. Its landforms have undergone various geomorphic processes resulting from late Quaternary environmental fluctuations. During the Holocene, the valley has been modified by millennia of extensive land clearance, cultivation, and terracing. As a result, the evidence for human activity and landuse is a cumulative, but discontiguous palimpsest of the most durable behavioral residues—primarily stone and ceramic artifacts—whose distributions have been affected by diverse natural and cultural formation processes. Human occupation of the Polop Alto spans the evolution of morphologically modern humans and the replacement of foraging economies by farming, arguably the two most significant biobehavioral transitions for human life today. To better understand the changes in human landuse that accompanied these important transitions, we have employed an integrated suite of techniques aimed at unmixing the diverse formation processes that have affected Polop Alto landscapes and material culture. These include patch‐based survey methods, photogrammetry, GIS‐based spatial analysis, and using artifact morphology and distribution to assess artifact taphonomy. This has permitted us to develop a diachronic settlement model for the 80 kyr of human occupation in the Polop Alto. © 2002 John Wiley & Sons, Inc.
Quantitative sourcing of slackwater deposits at Boila rockshelter: A record of lateglacial flooding and Paleolithic settlement in the Pindus Mountains, Northwest Greece
Authors: Woodward J.C. , Hamlin R.H.B. , Macklin M.G. , Karkanas P. , Kotjabopoulou E. 
Published: August 2002

AbstractEvidence for large floods in the Pindus Mountains of Northwest Greece during the Lateglacial period is provided by a sequence of fine‐grained slackwater sediments preserved beneath the Late Upper Paleolithic deposits at Boila rockshelter in the Voidomatis River basin. We have applied a quantitative sediment fingerprinting approach to estimate the relative contributions from different catchment sediment sources to these flood sediments. Our approach utilizes recent developments in hydrology and fluvial geomorphology where researchers have used sediment properties to establish the source of suspended sediments transported in rivers during present‐day flood events. The data set used to create the composite sediment source fingerprint comprised nine tracer properties including eight trace elements (determined by X‐ray fluorescence techniques) and magnetic susceptibility. The Boila sequence has been dated by conventional and AMS radiocarbon techniques, and the central and upper part of the flood sediments were deposited between ca. 14,310 ± 200 and 13,960 ± 260 radiocarbon yr B.P. These flood events took place during the global cooling associated with Heinrich event 1, although the sediment fingerprinting data indicate that glacial activity in the Voidomatis basin was no longer supplying large volumes of sediment to the fluvial system at this time. The slackwater deposits are mainly derived from flysch sediments and soils from nonglaciated parts of the Voidomatis River basin. The results of this approach compare well with lithological estimates based on micromorphological analyses and are in good agreement with existing data on the Late Pleistocene and Holocene behavior of this river system. The slackwater sediments offer important insights into the nature of the river environment and the wider catchment system during the Lateglacial period when the Klithi rockshelter (ca. 2 km upstream of Boila) was the focus of Paleolithic activity in the Voidomatis Gorge. In appropriate depositional contexts, quantitative sediment fingerprinting constitutes a valuable geoarchaeological tool for the investigation of rockshelter and cave sediment records that can improve our understanding of site formation processes and their broader environmental context. This approach is a valuable complement to the micromorphological investigation of rockshelter sediment records. © 2001 John Wiley & Sons, Inc.