bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hazardous Substance Research Centers program: An incubator for remediation research
Authors: Lasat Mitch 
Published: June 2003

AbstractThe Hazardous Substance Research Center (HSRC) was established by the U.S. Environmental Protection
Agency (EPA) to assist in the implementation of Superfund and to address major hazardous substance
environmental problems at a regional level. Over the past 12 years, the HSRC program has produced more than
1,200 peer‐reviewed technical articles, 27 patents and licenses, 21 new technologies for the remediation
marketplace, and provided technical assistance to more than 300 communities. Research, technology transfer, and
training are conducted by five regional multi‐university centers, which focus on different aspects of
hazardous substance management. Areas of focus include urban environments, contaminated sediments, natural
remediation and restoration technologies, abandoned mine lands, and chlorinated solvents in groundwater. This
article provides an overview of the five HSRC programs including current areas of research, field studies, and
technology transfer Internet links to access research results and remediation technology information. ©
2003 Wiley Periodicals, Inc.
Fostering collaborative inquiries by prospective and practicing elementary and middle school teachers
Authors: van Zee Emily , Lay Diantha , Roberts Deborah 
Published: June 2003

AbstractThe purpose of this study was to document the perspectives and experiences of participants in a complex collaboration. Prospective teachers planned and conducted science lessons and small educational research projects with mentoring from teacher researchers who are science enthusiasts. These group investigations seemed to be effective in modifying the self‐perceptions of many of the prospective teachers enrolled in a course on methods of teaching science in elementary school. According to responses on an informal evaluation at the end of the Spring 2000 group investigation, for example, most of the prospective teachers indicated that they perceived themselves to be more confident and more competent to teach science than at the beginning of the course; a few indicated they had already felt confident and competent. Common themes in the prospective teachers' responses indicated that they had learned about teaching science through inquiry, taking ownership of their own learning, researching while teaching, working in groups, and understanding themselves as learners and teachers. The teacher researchers also perceived themselves as benefiting from the collaborative process. Their responses to an e‐mail questionnaire suggested that they found working with the prospective teachers to be stimulating and cheering. They enjoyed the discussions, appreciated the help with demanding activities, grew in their own knowledge about teaching and learning, and valued the opportunities for reflection. However, organizing the group investigation was complex, due to time issues, driving distances, school schedules, unexpected teacher responsibilities, and unpredictable weather. © 2003 Wiley Periodicals, Inc. Sci Ed 87:588–612, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/sce.10070
Designed curriculum and local culture: Acknowledging the primacy of classroom culture
Authors: Squire Kurt D. , MaKinster James G. , Barnett Michael , Luehmann April Lynn , Barab Sasha L. 
Published: June 2003

AbstractOne of the primary challenges facing designers today is how to design curricular innovations that are appealing and useful to teachers and at the same time bring about transformative practices. While we as a learning sciences community are relatively adept at facilitating innovative case examples, we need more empirical work that examines how curricular innovations become implemented across multiple classrooms. In this paper we examine a series of four teachers implementing our technology‐rich, project‐based curriculum. We then analyze and discuss each of the four cases across two themes by (a) examining how the project‐level question was contextualized to meet local needs and (b) examining the cultural context that surrounded the implementation of the curriculum. Our interpretations suggest that contextualizing the curriculum is ultimately a local phenomenon that arises as a result of a number of factors, including students' needs, students' goals, teachers' goals, local constraints, and teacher's pedagogical values. These cases illuminate the importance of school and classroom cultures in the learning process. Ultimately, curriculum designers need to acknowledge that their designs are not self‐sufficient entities; instead, during implementation, they become assimilated as part of the cultural systems in which they are being realized. © 2003 Wiley Periodicals, Inc. Sci Ed 87:468–489, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/sce.10084
A new perspective for evaluating innovative science programs
Authors: Hickey Daniel T. , Zuiker Steven J. 
Published: June 2003

AbstractThis paper outlines a stridently sociocultural perspective on educational program evaluation. This perspective emerged across successive attempts to evaluate science programs in a manner consistent with sociocultural views of knowing and learning, while still yielding conventional evidence of achievement. The perspective is characterized by (1) rigorous use of multiple‐choice tests, performance assessments, and interpretive event‐based analyses, (2) a dialectical approach to reconciling conflicting conclusions from different types of individual assessments, and between individual and event‐oriented assessments, and (3) a pragmatic focus on the differences among various implementations of the innovation, with judicious, targeted use of comparison groups. Innovators facing the tension between contemporary views of knowing and learning and conventional views of accountability should find this perspective particularly useful. It is relevant for a broad range of evaluation contexts, including large‐scale externally funded innovations as well as more informal practitioner‐initiated studies, and should be useful in many content domains. © 2003 Wiley Periodicals, Inc. Sci Ed 87:539–563, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/sce.10087
What does it mean to create sustainable science curriculum innovations? A commentary
Authors: Fishman Barry J. , Krajcik Joseph 
Published: June 2003

AbstractTwo key issues for research on the creation of sustainable science curricula are the following: (1) How do we create curriculum innovations that will be used in classrooms after the developers or researchers depart; and (2) How do we create curriculum innovations that are scalable, such that teachers who never have direct contact with the developers may successfully enact them? We introduce the idea of usability as a guiding principle for the successful design of sustainable and scalable curricula, present a framework for examining usability in school contexts, and critique the ideas presented in this issue of Science Education using this framework. © 2003 Wiley Periodicals, Inc. Sci Ed 87:564–573, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/sce.10088
A probability model for the meiosis I non‐disjunction fraction in numerical chromosomal anomalies
Authors: Franco Glaura C. , Lucio Paulo S. , Parra Flávia C. , Pena Sérgio D. J. 
Published: June 2003

AbstractNumerical chromosome abnormalities (aneuploidies) are among the most common known causes of mental retardation and the leading cause of pregnancy loss in humans. They primarily arise by the process of meiotic non‐disjunction. We still know very little about the contribution of genetic and environmental causes for non‐disjunction in humans. In order to increase our understanding of the epi‐ demiology of human trisomies, it is necessary to establish the proportion of cases occurring in the first or second division of meiosis. Trisomic patients will display, in study of microsatellite typed by the polymerase chain reaction (PCR), three fragment peaks of equal intensity, two fragments at an average 2: 1 dosage or one individual fragment. In this work we describe a statistical approach for estimation of the fraction of meiosis I non‐disjunctions (F) in the absence of the parental information. First we determine a probability model for the number of peaks in a polymorphic microsatellite locus, which is a function of F. Based on this model, we obtain a maximum likelihood estimator for F, using the observed proportion of one, two and three allele patterns in trisomic individuals. Relying on the properties of maximum likelihood theory, we also calculate the asymptotic variance and confidence intervals for F. Owing to the fact that the samples of trisomic patients are limited in number, the use of asymptotic theory may be compromised. Thus, we employ the bootstrap technique to build confidence intervals for F and compare the results with those obtained from the normal theory. This estimator that dispenses the need to study parents opens the possibility of using archival material for comparative epidemiological studies of Down's syndrome and other aneuploidies. In this paper we propose a probability model to estimate the fraction of meiosis I non‐disjunction, F, by only using the proportion of allele patterns of trisomy individuals, while traditional methods require typing pericentromeric markers from those affected and their parents. Copyright © 2003 John Wiley & Sons, Ltd.
Power calculations for large multi‐arm placebo‐controlled studies of dichotomous outcomes
Authors: Hasselblad Vic , Allen Andrew S. 
Published: June 2003

AbstractSeveral statistical methods can be used to test for differences in placebo‐controlled dichotomous multi‐arm studies. These tests include linear and quadratic trends, Dunnett's test, Hochberg's test, and the overall chi‐square test. We computed the power of these tests under a wide variety of alternatives. For two arms versus a control, the power was computed exactly. For more than two arms, the power was calculated from 100000 simulations per alternative. Against monotonic alternatives, the linear trend test tended to be superior. Against convex alternatives, the quadratic trend test tended to be superior. Against general alternatives, Dunnett's test, Hochberg's test, and the overall chi‐square test were superior and had very similar power curves. The Hochberg test was generally less powerful than Dunnett's test but the difference was offset by its increased power to reject multiple hypotheses. These results remained nearly constant over a wide range of sample sizes, average event rates and average effect sizes. Copyright © 2003 John Wiley & Sons, Ltd.
Three‐tier replication for FT‐CORBA infrastructures
Authors: Baldoni Roberto , Marchetti Carlo 
Published: June 2003

AbstractEnforcing strong replica consistency among a set of replicas of a service deployed across anasynchronousdistributed system in the presence of crash failures is a real practical challenge. If each replica runs the consistency protocol bundled with the actual service implementation, this target cannot be achieved, as replicas need to be located over apartially synchronous distributed systemto solve the distributed agreement problems underlying strong replica consistency.A three‐tier architecture for software replication enables the separation of the replication logic, i.e. protocols and mechanisms necessary for managing software replication, from both clients and server replicas. The replication logic is embedded in a middle‐tier that confines the need of partial synchrony and thus frees replica deployment.In this paper we first introduce the basic concepts underlying three‐tier replication. Then we present the interoperable replication logic (IRL) architecture, a fault‐tolerant CORBA compliant infrastructure. IRL exploits a three‐tier approach to replicate stateful deterministic CORBA objects and allows object replicas to run on object request brokers from different vendors. A description of an IRL prototype developed in our department is proposed along with an extensive performance analysis. Copyright © 2003 John Wiley & Sons, Ltd.
Grid Integration of Wind Farms
Authors: Tande John Olav Giæver 
Published: June 2003

AbstractThis article gives an overview of grid integration of wind farms with respect to impact on voltage quality and power system stability. The recommended procedure for assessing the impact of wind turbines on voltage quality in distribution grids is presented. The procedure uses the power quality characteristic data of wind turbines to determine the impact on slow voltage variations, flicker, voltage dips and harmonics. The detailed assessment allows for substantially more wind power in distribution grids compared with previously used rule‐of‐thumb guidelines. Power system stability is a concern in conjunction with large wind farms or very weak grids. Assessment requires the use of power system simulation tools, and wind farm models for inclusion in such tools are presently being developed. A fixed‐speed wind turbine model is described. The model may be considered a good starting point for development of more advanced models, hereunder the concept of variable‐speed wind turbines with a doubly fed induction generator is briefly explained. The use of dynamic wind farm models as part of power system simulation tools allows for detailed studies and development of innovative grid integration techniques. It is demonstrated that the use of reactive compensation may relax the short‐term voltage stability limit and allow integration of significantly more wind power, and that application of automatic generation control technology may be an efficient means to circumvent thermal transmission capacity constraints. The continuous development of analysis tools and technology for cost‐effective and secure grid integration is an important aid to ensure the increasing use of wind energy. A key factor for success, however, is the communication of results and gained experience, and in this regard it is hoped that this article may contribute. Copyright © 2003 John Wiley & Sons, Ltd.
Developing wind energy to meet the Kyoto targets in the European union
Authors: Zervos Arthouros 
Published: June 2003

AbstractWind energy is the fastest‐growing electricity‐generating technology. The wind energy targets set during the last decade have all been surpassed. New targets are proposed for 2010 and 2020, since the existing European Commission and European Wind Energy Association targets do not reflect the trends in the market. The new targets and projections are used to define the role of wind energy in the electricity generation of the European Union during the next two decades. Estimation is made of the emission reductions which could be achieved with the use of wind energy by each Member State, and the contribution that wind energy could have in the process of the fulfilment of their Kyoto commitments is investigated. Finally an estimation of the costs involved is performed, with special reference to the avoided external costs. Copyright © 2003 John Wiley & Sons, Ltd.
Present Status of Aeroelasticity of Wind Turbines
Authors: Rasmussen Flemming , Hansen Morten Hartvig , Thomsen Kenneth , Larsen Torben Juul , Bertagnolio Franck , Johansen Jeppe , Madsen Helge Aagaard , Bak Christian , Hansen Anders Melchior 
Published: June 2003

AbstractAeroelasticity is a key issue in the continuing development of wind turbines towards large, flexible, highly optimized machines. The steadily increasing technology level is reflected not necessarily by the complexity of the turbines, but by the level of knowledge and advanced principles that are taken into account during the design process and incorporated in the final optimized design. This article examines some of the main uncertainties within aeroelastic modelling of wind turbines that have been hard to resolve over the years of research, and also presents perspectives for the new aeroelastic challenges, both from the viewpoint of the researchers at Risø National Laboratory. Copyright © 2003 John Wiley & Sons, Ltd.
The Status of Lecanora zosterae in the British Isles
Authors: Laundon Jack Rodney 
Published: June 2003

AbstractLecanora zosterae (Ach.) Nyl. is a distinct species belonging to the Lecanora dispersa group. In the British Isles it is confined to the coast where it grows mostly on the exposed turf above sea cliffs. Some 76% of the population occurs on decayed thrift Armeria maritima. The related Lecanora umbrina (Ach.) A. Massal. is lectotypified; it is the correct name for Lecanora hagenii auct.
Studies of new polysaccharides from lasallia pustulata (L.) Hoffm
Authors: Pereyra M. T. , Prieto A. , Bernabé M. , Leal J. A. 
Published: June 2003

AbstractPolysaccharides from thalli of Lasallia pustulata were extracted and characterized. The major fractions were characterized as pustulan, a β-glucan-chitin complex and a β-(1→3)-glucan. Other polysaccharides, which are minor components (less than 5%) solubilized with water from the alkali extracts of thalli, were shown to be galactomannans with a backbone of α-(l→6)- mannose partially substituted at positions 2 by galactofuranose and/or mannopyranose side chains of variable length. The relationship between these polysaccharides and those obtained by the same method from free-living fungi is discussed. The proportion or composition of the different polysaccharides studied was not affected by seasonal environmental conditions over a 2-year period.
The Lichen genus Ramalina Ach. (Ramalinaceae) on the Outlying Islands of the New Zealand geographic area
Authors: Bannister J. M. , Blanchon D. J. 
Published: June 2003

AbstractThe diversity of species of Ramalina occurring on the outlying islands of the New Zealand geographic area is linked to their methods of dispersal and the origin and principal climatic features of the islands themselves. It appears that species of Ramalina have reached these islands by transoceanic, wind-borne dispersal of ascospores and soredia, not necessarily in the direction of the prevailing winds. Species have become established on the islands only if both climatic and habitat requirements have been met.
Spatial organization of three‐dimensional cocultures of adriamycin‐sensitive and ‐resistant human breast cancer MCF‐7 cells
Authors: Starzec A. , Briane D. , Kraemer M. , Kouyoumdjian J.‐C. , Moretti J.‐L. , Beaupain R. , Oudar O. 
Published: June 2003

AbstractGenetic and cellular heterogeneity is one of mechanisms involved in increasing tumour aggressiveness during neoplastic progression. Development of drug‐resistant tumour cell subpopulations is a major problem in clinical oncology. Multi‐drug resistant tumour cells survive when exposed to cytotoxic agents. Here, we studied in a three‐dimensional (3D) coculture system, called “ex vivo nodules”, how drug‐resistant and sensitive tumour cells settle down in a 3D space. For this, we cocultured adriamycin‐sensitive (MCF‐7S) and ‐resistant (MCF‐7R) human breast cancer cells in long term nodules. We showed that both types of cells are able to grow separately or in coculture until five weeks in spheroidal forms. MCF‐7R cells did not loose their multi‐drug resistance when cultured in nodules as measured by RT‐PCR. Curiously, the exterior aspects of mixed (MCF‐7S/ MCF‐7R) nodules and MCF‐7R nodules were similar whereas MCF‐7S nodules were completely different. Nevertheless, morphologically these three nodule types were distinct, in particular in their density. Immunostaining showed that in mixed nodules, MCF‐7R cells were arranged at the periphery, whereas the MCF‐7S cells are in the central part of the nodules.Even if the mechanism of this arrangement remained unclear, this work shows that three‐dimensional cell culture is well adapted to the study of the relationships between adhesion mechanisms and drug‐resistance.
Ascidians as a vertebrate‐like model organism for physiological studies of Rho GTPase signaling
Authors: Philips Alexandre , Blein Marion , Robert Agnès , Chambon Jean‐Philippe , Baghdiguian Stephen , Weill Mylène , Fort Philippe 
Published: June 2003

AbstractGTPases of the Rho family are evolutionarily conserved proteins that control cell shape dynamics during physiological processes as diverse as cell migration and polarity, axon outgrowth and guidance, apoptosis and phagocytosis. In mammals, 18 Rho proteins are distributed in 7 subfamilies. Rho, Rac and Cdc42 are the best‐characterized ones, benefiting from the use of worm and drosophila, which only express these 3 subfamilies. An additional model would therefore help understand the physiological role of other mammalian subfamilies. We identified in genome databases the complete Rho family of two ascidians, Ciona intestinalis and Ciona savignyi, and showed that these families contain single ancestors of most mammalian Rho subfamilies. In Ciona intestinalis, all Rho genes are expressed and display specific developmental variations of mRNA expression during tadpole formation. Although C. intestinalis expresses five additional Rac compared to the closely related Ciona savignyi, only two appeared fully active in functional assays. Last, we identified in Ciona intestinalis database more than 50 Rho regulators (RhoGEFs and RhoGAPs) and 20 effector targets, whose analysis further supports the notion that Rho signaling components are of comparable complexity in mammals and ascidians. Since the tadpole of ascidians combines vertebrate‐like developmental features with reduced cell number, particularly adapted to evolutionary and developmental biology studies, our data advocate this model for physiological studies of Rho signaling pathways.
Misexpression of mouse porcupine isoforms modulates the differentiation of P19 embryonic carcinoma cells
Authors: Tanaka Kimiko , Kitagawa Yasuo , Kadowaki Tatsuhiko 
Published: June 2003

AbstractDrosophila porcupine (porc) encodes an ER membrane protein that is required for the processing of the Drosophila Wnt family. Homologs of porc have been identified in various multicellular organisms and have been implicated in the biosynthesis of Wnt proteins. In contrast to Drosophila, vertebrates generate four different porc mRNAs (A—D) by alternative splicing. Murine porcD (MporcD) mRNA levels transiently increase during the neuroectodermal differentiation of P19 cells, but diminish during mesodermal differentiation. P19 cells constitutively expressing mouse porcA (MporcA), but not MporcD, undergo apoptosis by the induction of neuroectodermal differentiation. Meanwhile, P19 cells constitutively expressing MporcD, but not MporcA, do not adopt mesodermal cell morphology and fail to express myf‐5 when induced to mesodermal differentiation. These results therefore demonstrate that the alternative splicing of Mporc is regulated in a cell‐type specific manner, and the resulting Mporc isoforms have different functions in the neuroectodermal and mesodermal differentiation of P19 cells.