bluuebunny/crossref_metadata_2025_split huggingface dataset:
Permutation tests for detecting and estimating mixtures in task performance within groups
Authors: Lo Yungtai , Matthysse Steven , Rubin Donald B. , Holzman Philip S. 
Published: October 2002

AbstractWe propose a two‐sample permutation test incorporating mixture models as a general tool for detecting and quantifying effects on task performance. We illustrate the proposed method with examples where the dependent measures under investigation are recorded for normal controls and relatives of patients with schizophrenia on a delayed response, spatial and object working memory task. Our mixture modelling in relatives allows the component distributions to arise from different continuous parametric families. We also investigate the effects of the within‐family correlation and the prior distribution of the mixing proportion on the test results. The power of the test depends on sample sizes, the mixing proportion, the difference in component means and the ratio of component variances. Copyright © 2002 John Wiley & Sons, Ltd.
On the issue of ‘multiple’ first failures in competing risks analysis
Authors: Tai Bee‐Choo , R White Ian , Gebski Val , Machin David 
Published: October 2002

AbstractIn the classical competing risks framework, a subject may only fail from one of several distinct causes. However, in the context of cancer clinical trials where information on first relapse is usually of interest, there could be occasions when ‘multiple’ first recurrences are identified at a particular follow‐up. In this instance, the competing risks methodology cannot be implemented without first tackling the issue of ‘tied’ first failure. When the tied events were substantial, Arriagadaet al. regarded each competing failure separately, and combined the ‘simultaneous’ failures into a single category for analysis. This paper describes two other methods of accounting for ‘multiple’ failures. First, the ties were dealt with by applying a weighting factor which was equal to the reciprocal of the number of ties. We also considered ‘jittering’ which randomly adds or subtracts a small number to each ‘tied’ event time to randomly break the tie. As illustrated using the data obtained from a randomized trial of patients with operable osteosarcoma, the estimates based on Arriagada's approach have larger standard errors. Estimates from the other alternative methods were similar. Multiple jittering has the advantage of wide applicability in any situation of tied survival times. However, it takes a longer computer running time, especially when the number of replicates is large. The weighted Cox approach is the method of choice where statistical software allows its implementation without extra programming effort. Copyright © 2002 John Wiley & Sons, Ltd.
Do make or buy decisions matter? The influence of organizational governance on technological performance
Authors: Leiblein Michael J. , Reuer Jeffrey J. , Dalsace Frédéric 
Published: October 2002

AbstractThis paper investigates how firms' decisions to outsource or internalize production affect their technological performance. While several popular arguments and some anecdotal evidence suggest a direct association between outsourcing and technological performance, the effects of firms' governance decisions are likely to be contingent upon several specific attributes underlying a given exchange. This paper first demonstrates how standard performance models can improperly suggest a positive relationship between firms' outsourcing decisions and their technological performance. Models that account for firm‐ and transaction‐specific features are then presented, which indicate that neither outsourcing nor internalization per se result in superior performance; rather, a firm's technological performance is contingent upon the alignment between firms' governance decisions and the degree of contractual hazards. Copyright © 2002 John Wiley & Sons, Ltd.
A page‐shift transformation format of ISO 10646
Authors: Wu Pei‐Chi 
Published: October 2002

AbstractISO 10646 Universal Character Set (UCS) or Unicode covers symbols in most of the World's written languages. There are various UCS transformation formats (UTF). UTF‐8 is compatible with systems that assume 8‐bit characters. One of the problems with UTF‐8 is its space efficiency. For files containing most Asian characters such as Han ideographs, the file sizes increase by about 50% by using UTF‐8. Although the Standard Compression Scheme for Unicode (SCSU) can compress Unicode strings to the size of a locale‐specific character set, it is complicated and is not intended to serve as a general purpose interchange format. This paper proposes a page‐shift transformation format of ISO 10646, called UTF‐S. There are four pages: 1‐byte, 2‐byte, 3‐byte and 4‐byte. Shift to page 0 uses a special code $00_{16}$; shift to page 1, 2, and 3 uses ISO 2022 shift codes SO, SS2, and SS3, respectively. We test several text files and compare these UTF with Big5, a locale‐specific character set. The result shows that the space efficiency of UTF‐S is better than that of UTF‐16 and UTF‐8 and is close to that of SCSU. UTF‐S is suitable for replacing locale‐specific character sets with ISO 10646 in Internet applications, such as the World Wide Web. Copyright © 2001 John Wiley & Sons, Ltd.
An object‐oriented interface for the dynamic memory management of sparse discrete mathematical operators in numerical scientific applications
Authors: Manzini G. , Mazet S. 
Published: October 2002

AbstractThis paper describes an object‐oriented interface for the memory management of sparse discrete mathematical operators in numerical scientific applications. The basic data structure we propose is intended to implement and cope with mathematical vectors in sparse format. This structure allows an effective implementation of more complex data structures, such as matrix and matrix‐like objects, to represent the discrete version of differential operators in numerical application codes. A research example concerning adaptive wavelet algorithms illustrates the possible applications.Copyright © 2002 John Wiley & Sons, Ltd.
A microscale test to measure petroleum oil toxicity to mummichog embryos
Authors: Couillard C. M. 
Published: October 2002

AbstractA test was developed to compare the toxicity of different petroleum oils to mummichog (Fundulus heteroclitus) embryos. Fertilized eggs were incubated for 11 days at 22.5°C directly on the surface of oil‐contaminated sand without a superficial water layer. The mortality rates, the stage of development, and the prevalence of malformations were determined. No effect was found in controls incubated on sand with water and mineral oil as compared with controls on sand with water alone. Two weathered oils, an Alaska North Slope crude oil (ANCO) and a Mesa light crude oil (MLCO), produced similar symptoms of toxicity: retarded growth and development, pericardial edema, hemostasis, hemorrhages, and spinal deformities. These symptoms are consistent with those observed in other fish species exposed to petroleum oils, suggesting that the results of the bioassay would be applicable to other species. MLCO was more embryotoxic than ANCO. The minimal oil concentrations causing a significant reduction in body length were 4.5 μg oil/g sand for MLCO and 12.7 μg oil/g for ANCO, indicating the assay is sensitive. The slopes and the intercepts of the relationships between concentration and growth did not differ in three dose–response experiments conducted with each oil, indicating that the assay is reliable. Finally, the bioassay is less costly than other available options to assess the toxicity of petroleum oils to marine fish embryos. Further work to improve the standardization of the assay will involve comparison of the toxicity of petroleum oils with reference toxicants and selection of a standard substrate. © 2002 Wiley Periodicals, Inc. Environ Toxicol 17: 195–202, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/tox.10049
Assessment of mutagenicity and toxicity of different‐size fractions of air particulates from La Plata, Argentina, and Leipzig, Germany
Authors: Massolo L. , Müller A. , Tueros M. , Rehwagen M. , Franck U. , Ronco A. , Herbarth O. 
Published: October 2002

AbstractAirborne particulates, especially fine particles and bound chemical compounds, are a potential mediator of adverse health effects. In this study an analysis was done of the concentration and size distribution of air particulate matter, the content of bound polycyclic aromatic hydrocarbons (PAHs), and the biological effects of organic extracts from different fractions of dust that had been influenced by urban and industrial emissions from the regions of La Plata, Argentina, and Leipzig, Germany, along with samples from control areas. Air particulate matter was sampled in summer and winter in each region using a high‐volume sampler with a six‐stage cascade impactor, classifying dust in six size fractions from 10‐μm particles to those less than 0.49 μm in size. Organic extracts of dust were tested for mutagenicity (Ames test, Salmonella typhimurium TA98 strain, S9+) and cytotoxicity (Tetrahymena pyriformis test system, growth rate, cell respiration). The content of PAHs was analyzed by high‐performance liquid chromatography (HPLC) with diode array and fluorescence detection. Mutagenic and cytotoxic effects were found to be associated with very fine (<0.49 μm) and fine (<1.5 μm) particle‐bound compounds, corresponding to a higher content of PAHs. The mutagenic potency (revertants/m3) associated with particles less than 0.49 μm from urban areas of La Plata was about 1 order of magnitude higher than in particles in the range of 3.0 to 0.49 μm. Fine fractions from sites with an industrial burden were also found to exhibit high mutagenic potency. A similar tendency was observed in cytotoxicity tests with T. pyriformis. This cell system proved to be very sensitive to toxicants in tested dust fractions. The observed biological effects were found to be correlated significantly with concentrations of total PAH, carcinogenic PAHs, and benzo[a]pyrene. © 2002 Wiley Periodicals, Inc. Environ Toxicol 17: 219–231, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/tox.10054
Production of drinking water from raw water containing cyanobacteria—pilot plant studies for assessing the risk of microcystin breakthrough
Authors: Schmidt Wido , Willmitzer Hartmut , Bornmann Katrin , Pietsch Jörg 
Published: October 2002

AbstractToxins in cyanobacteria are a recognized risk in the treatment of drinking‐water treatment. Cyanotoxins can occur in two modifications: cell bound and dissolved in water. The process of toxin release may occur naturally, but it also may be induced through the processes of drinking‐water treatment. Both causes of release are relevant to the safety of drinking water. This study investigated cyanotoxin release and elimination through different treatment trains in systematic pilot‐scale studies with water from the Weida Reservoir, in Thuringia, Germany. The Weida Reservoir is a dimictic mesoeutrophic reservoir typical for a number of mountainous areas in Europe, with Planktothrix rubescens as the dominant phytoplankton species, and shows a characteristic seasonal pattern of population development and microcystin occurrence. To assess the risk of microcystin breakthrough, the pilot‐scale results as well as results of laboratory‐scale experiments were used for developing a kinetic model of toxin release in relation to elimination. By calculating removal efficiency of total microcystins (cell bound and dissolved) for different treatment trains, raw water quality was related to the quality targets for finished water, and breakthrough risks could be calculated for given treatment trains and varying cyanobacterial population densities in the reservoir. © 2002 Wiley Periodicals, Inc. Environ Toxicol 17: 375–385, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/tox.10067
Outage probability of cellular mobile radio systems with selective co‐channel interference cancellation receiver in overloaded array environments
Authors: Annamalai A. , Srivastava V. 
Published: October 2002

AbstractThis article outlines a general numerical procedure for computing the probability of outage of a cellular mobile radio system that is equipped with a smart antenna to suppress a few strongest co‐channel interferers (CCI) out of a total ofNIactive interferers by adaptive null‐steering. Aside from the interference‐limited case, refined outage criterion that either treat receiver noise as CCI or consider a minimum detectable receiver signal threshold are studied. Exact closed‐form expressions for both the basic and refined outage criterion are also derived by assuming that all the CCI signals are subject to Nakagami‐mfading with a positive integer fading severity index. Selected numerical examples are provided to illustrate the application of the theory which includes the investigation into the effects of fade distribution of the CCI signals and traffic loading on the outage probability, and also the study of spectrum utilization efficiency improvement using a selective co‐channel interference nulling (cancellation) technique. Copyright © 2002 John Wiley & Sons, Ltd.
Parallel interference cancellation employing RAKE receiver with selection diversity for multiuser asynchronous DS/CDMA detectors in multipath Rayleigh fading channels
Authors: Al‐Hussaini Emad K. , Mourad Hebatallah M. , Gohary Ramy H. 
Published: October 2002

AbstractIn this paper, we propose and analyse parallel CCI multistage cancellation by combining RAKE and selection diversity. In order to account for channel variations, adaptive implementation of decision thresholds at the RAKE output is suggested. It is shown to provide significant improvement over either hard or soft decision techniques especially in the near‐far situation. Investigation of the system robustness to imperfect channel parameter estimation is also presented. The communication channel is modelled as slowly varying Rayleigh fading discrete multipath channel. Copyright © 2002 John Wiley & Sons, Ltd.
Investigation of the influence of particle size on the quantitative analysis of glasses by energy‐dispersive micro x‐ray fluorescence spectrometry
Authors: Roedel T. C. , Bronk H. , Haschke M. 
Published: October 2002

AbstractMicro x‐ray fluorescence analyses were undertaken on individual glass particles of different compositions for selected particle sizes between 50 µm and ≥1 mm. These experiments revealed a complex behaviour in the fluorescence spectra; this behaviour is influenced by the glass matrix, topology, particle volume, energy range and polycapillary properties and cannot be corrected by simple approaches. Net fluorescence intensities and reproducibility measured with two different polycapillaries (40 and 60 µm) were evaluated for six element lines between 1 and 10 keV and compared with the same standard glasses provided as ideal specimens (i.e. with flat, polished surface and of ‘infinite’ thickness). A standardless quantification using the fundamental parameter model gave a reasonable accuracy for particle sizes ≥1 mm (ca 15% relative standard deviations for the main elements) without further sample preparation. The feasibility of principal components analysis for a fast identification of compositional types using the measurement data of individual particles was demonstrated. Copyright © 2002 John Wiley & Sons, Ltd.
Sequential leaching of trace elements in fine‐particle aerosol samples on Teflon filters
Authors: Moloi K. , Viksna A. , Selin Lindgren E. , Standzenieks P. 
Published: October 2002

AbstractThe mobility of different elements in the environment is an important factor to consider when assessing the risk of pollution. Airborne particles of micrometre or smaller sizes are known to be transported over vast distances, and may therefore affect regions far away from their sources. As a complement to the more traditional element analysis of fine‐particle aerosols, the possibility of obtaining information on the element contents in particle fractions of different environmental mobilities and/or character was explored. A four‐stage sequential leaching procedure was tested and applied to establish the distribution of metals in four different fine‐particle fractions, namely (1) the fraction considered to be mobile in the environment, (2) the fraction bound to carbonates and oxides, (3) the fraction bound to organic matter, and (4) the fraction bound to silicates. Subtraction of energy‐dispersive x‐ray fluorescence (XRF) spectra was used to evaluate the element concentrations in the filters. For validation, total‐reflection XRF was used in a few cases for analysis of leachates. The methods were applied to airborne particles collected in two locations in Botswana. In both locations the K, Ca, Mn, Zn, Br and Pb compounds were found to occur extensively in the environmentally mobile fraction, whereas Ti and Fe were found to dominate in the silicate fraction. Copyright © 2002 John Wiley & Sons, Ltd.
Fit values of M subshell fluorescence yields and Coster–Kronig transitions for elements with 20 ≤ Z ≤ 90
Authors: Söǧüt Ö. , Büyükkasap E. , Küçükönder A. , Ertuǧrul M. , Doǧan O. , Erdoǧan H. , Şimşek Ö. 
Published: October 2002

AbstractMost probable values of Mi subshell fluorescence yields (i = 1–5) and Coster–Kronig (CK) transition Sij probabilities (S12, S13, S14, S15, S23, S24, S35, S34, S35 and f45) were determined by using least squares fitted to obtain the polynomials, which were plotted by using McGuire's values, representing them as a function of atomic number. Values of Mi subshell fluorescence yields (i = 1–5) and ϖM and CK transition Sij probabilities as above are presented in tables. Copyright © 2002 John Wiley & Sons, Ltd.
Saccharomyces cerevisiae Big1p, a putative endoplasmic reticulum membrane protein required for normal levels of cell wall β‐1,6‐glucan
Authors: Azuma Masayuki , Levinson Joshua N. , Pagé Nicolas , Bussey Howard 
Published: October 2002

AbstractDeletion of Saccharomyces cerevisiae BIG1 causes an approximately 95% reduction in cell wall β‐1,6‐glucan, an essential polymer involved in the cell wall attachment of many surface mannoproteins. The big1 deletion mutant grows very slowly, but growth can be enhanced if cells are given osmotic support. We have begun a cell biological and genetic analysis of its product. We demonstrate, using a Big1p–GFP fusion construct, that Big1p is an N‐glycosylated integral membrane protein with a Type I topology that is located in the endoplasmic reticulum (ER). Some phenotypes of a big1Δ mutant resemble those of strains disrupted for KRE5, which encodes another ER protein affecting β‐l,6‐glucan levels to a similar extent. In a big1Δkre5Δ double mutant, both the growth and alkali‐soluble β‐l,6‐glucan levels were reduced as compared to either single mutant. Thus, while Big1p and Kre5p may have similar effects on β‐l,6‐glucan synthesis, these effects are at least partially distinct. Residual β‐l,6‐glucan levels in the big1Δkre5Δ double mutant indicate that these gene products are unlikely to be β‐l,6‐glucan synthase subunits, but rather may play some ancillary roles in β‐l,6‐glucan synthase assembly or function, or in modifying proteins for attachment of β‐l,6‐glucan. Copyright © 2002 John Wiley & Sons, Ltd.
Effect of dietary calcium and phosphorus vitamin D metabolites 25(OH)D and 1,25(OH)2D, and response to bPTH (1‐34) in blue duikers
Authors: Roeder Beverly L. , Varga Gabriella A. , Wideman Robert F. , Hollis Bruce W. 
Published: October 2002

AbstractIn a colony of blue duiker antelope (Cephalophus monticola bicolor) at Pennsylvania State University, many animals had reversed Ca:P ratios and acid‐base imbalance, and some developed urinary calculi. The purpose of this study was to investigate the relationship between age, dietary Ca, P, and the homeostatic mechanisms controlling their extracellular fluid levels. Sixteen males (1–5 years old) had serum and urine electrolytes and vitamin D metabolites evaluated before, during, and after bPTH (1‐34) intravenous infusion while consuming 1.38%Ca:0.66%P, and after consuming one of four experimental diets (Ca and P: 0.5:0.4%, 0.8:0.8%, 0.8:0.4%, 1.25:0.4%) for four months. Pretrial, all duikers responded similarly to bPTH. Post‐trial bPTH caused an increase in serum Ca and a decrease in P followed by a rebound in P in duikers consuming 0.4% P and either 0.5, 0.8, or 1.25% Ca, whereas the 0.8:0.8% (high P diet) caused a decline in serum Ca and no change in P, followed by an increase in serum P to higher levels than baseline. Vitamin D metabolites pretrial were similar between age groups and assigned treatment. Post‐trial 1,25(OH)2D was significantly lower in younger males consuming diets with %Ca > %P than in older males. 25(OH)D was similar between age groups. Ca intake inversely affected 25(OH)D (P < 0.002) and was directly related to 1,25(OH)2D. P intake inversely affected 1,25(OH)2D (P < 0.04) and was directly related to 25(OH)D. This suggests that blue duikers have a unique ruminant response to PTH that is related to vitamin D metabolism as influenced by the dietary level of Ca and P, and the age of the animal. This may indicate an age‐related impairment of 25(OH)D metabolism in young duikers, or a dependence on increased 1,25(OH)2D to maintain Ca and P homeostasis in older animals. Zoo Biol 21:171–183, 2002. © 2002 Wiley‐Liss, Inc.
Hurricane intensity changes associated with geomagnetic variation
Authors: Elsner James B. , Kavlakov S. P. 
Published: October 2002

AbstractRecently some indications have appeared that several purely meteorological processes in the terrestrial atmosphere are dependent upon magnetosphere variations. To analyse the possible relationship with North Atlantic hurricane intensification, the authors examine geomagnetic data for ten days prior to all hurricanes over the last 50 years (1950–1999). A significant positive correlation between the averaged Kp index of global geomagnetic activity and hurricane intensity as measured by maximum sustained wind speed is identified for baroclinically‐initiated hurricanes. Results are consistent with a mechanism whereby ionization processes trigger glaciation at cloud top which leads to hurricane intensification through upper tropospheric latent heat release. Copyright © 2003 Royal Meteorological Society.
Binding of low mobility group proteins with DNA examined in homologous and heterologous systems by Gel retardation assay.
Authors: Wiland Eva , Siemieniako Barbara , Trzeciak Wieslaw H. 
Published: October 2002

AbstractThe interaction of low mobility group proteins (LMG), isolated from chromatin of pancreatic carcinoma cells (CAPAN‐2), with fragments of 5′‐flanking region of the antigen 17‐1A gene was studied by gel retardation assay. The LMG proteins, which formed complexes with DNA were extracted from the gels and identified by polyacrylamide gel electrophoresis under denaturing conditions. The proteins of Mw about 100, 60, 55 and 48 kDa, which formed specific complexes with fragments of 5′‐flanking region of the antigen 17‐1A gene, were identified.
Helical inclusions with nucleopore‐like characteristics in the cytoplasm of swiss 3T3 Cells: A preliminary communication.
Authors: Wheatley Denys N. 
Published: October 2002

AbstractHelical inclusions have been observed at sites remote from the nucleus in the cytoplasm of Swiss 3T3 fibroblasts. Because of the interest shown in their unusual nucleopore complex‐like nature, this preliminary communication briefly reports their existence and describes their essential ultrastructural features. Although they could be found singly, most formed collections of up to about 30 inclusions in which different planes of section were represented. TS profiles with hexagonal packing showed apparently identical eight‐fold symmetry and dimensions to pores in the nuclear envelope of 3T3 cells. No membranes were associated with the inclusions, nor was there any suggestion of the strict vertical plate‐like stacking found in annulate lamellae (AL). Furthermore, the inclusions were undoubtedly helical, and in all probability composed of several strands.