bluuebunny/crossref_metadata_2025 huggingface dataset:
Classification of reaches in the Missouri and lower Yellowstone Rivers based on flow characteristics
Authors: Pegg Mark A. , Pierce Clay L.
Published: August 2002

Several aspects of flow have been shown to be important determinants of biological community structure and function in streams, yet direct application of this approach to large rivers has been limited. Using a multivariate approach, we grouped flow gauges into hydrologically similar units in the Missouri and lower Yellowstone Rivers and developed a model based on flow variability parameters that could be used to test hypotheses about the role of flow in determining aquatic community structure. This model could also be used for future comparisons as the hydrological regime changes. A suite of hydrological parameters for the recent, post‐impoundment period (1 October 1966–30 September 1996) for each of 15 gauges along the Missouri and lower Yellowstone Rivers were initially used. Preliminary graphical exploration identified five variables for use in further multivariate analyses. Six hydrologically distinct units composed of gauges exhibiting similar flow characteristics were then identified using cluster analysis. Discriminant analyses identified the three most influential variables as flow per unit drainage area, coefficient of variation of mean annual flow, and flow constancy. One surprising result was the relative similarity of flow regimes between the two uppermost and three lowermost gauges, despite large differences in magnitude of flow and separation by roughly 3000 km. Our results synthesize, simplify and interpret the complex changes in flow occurring along the Missouri and lower Yellowstone Rivers, and provide an objective grouping for future tests of how these changes may affect biological communities. Copyright © 2002 John Wiley & Sons, Ltd.
Linear waste of best fit bin packing on skewed distributions
Authors: Kenyon Claire , Mitzenmacher Michael
Published: August 2002

We prove that Best Fit bin packing has linear waste on the discrete distribution U{j, k} (where items are drawn uniformly from the set {1/k, 2/k, …, j/k}) for sufficiently large k when j = αk and 0.66 ≤ α < 2/3. Our results extend to continuous skewed distributions, where items are drawn uniformly on [0, a], for 0.66 ≤ a < 2/3. This implies that the expected asymptotic performance ratio of Best Fit is strictly greater than 1 for these distributions. © 2002 Wiley Periodicals, Inc. Random Struct. Alg., 20:441–464, 2002
A note on disagreement percolation
Authors: Häggström Olle
Published: August 2002

We construct a coupling of two distinct Gibbs measures for Markov random fields with the same specifications, such that the existence of an infinite path of disagreements between the two configurations has probability 0. This shows that the independence assumption in the disagreement percolation method for proving Gibbsian uniqueness cannot be dropped without being replaced by other conditions. A similar counterexample is given for couplings of Markov chains. © 2001 John Wiley & Sons, Inc. Random Struct. Alg., 18, 267–278, 2001
Authentic inquiry: Introduction to the special section
Authors: Chinn Clark A. , Hmelo‐Silver Cindy E.
Published: August 2002

© 2002 Wiley Periodicals, Inc. Sci Ed 86:171–174, 2002; DOI 10.1002/sce.10000
Science and ethics: Some issues for education
Authors: Andrew Jennifer , Robottom Ian
Published: August 2002

Ethical issues concerning pain and suffering of animals are necessarily a consideration when it comes to killing “pest” or “feral” species in Australia. Within a continent where there are no large predators, many introduced animal species such as rabbits, foxes, horses, donkeys, camels, goats, and mice have been able to thrive, competing with the interests of farmers and graziers, and livestock and food production. These species, thus, gain the label of “pest.” Many methods now exist to kill these species and, consequently, ethical issues arise concerning the possible pain and suffering caused as a direct result of these methods. Yet within government and scientific communities, ethical issues are reduced to a secondary consideration without serious debate or contention. Ethical issues appear to be at odds with scientific agendas. How can environmental ethics be incorporated as part of science‐based decision making that appeals to objectivity and scientific evidence? Within educational institutions as well, the same dilemma exists: How can ethical issues be addressed within the science curriculum and in the classroom? A greater understanding of various perspectives on the subject of environmental ethics and the value positions advocated by proponents of these perspectives may help teachers consider ways of handling such issues in the science classroom. © 2001 John Wiley & Sons, Inc. Sci Ed 85:769–780, 2001.
An algorithm for region extraction based on an elastic–plastic deformation model
Authors: Ikuta Mikito , Minagawa Akihiro , Gotoh Toshiyuki
Published: August 2002

This paper proposes a new region extraction method, in which a two‐dimensional pixel image or three‐dimensional voxel image is modeled as an elastic film or body with an elasticity distribution corresponding to the density gradient or some other image property, and is segmented according to this elasticity distribution. The proposed method uses a higher‐dimension space formed by introducing a deformation axis that is orthogonal to the two‐dimensional image plane or the three‐dimensional image space, making it possible to calculate the equilibrium state at low computational cost. Region extraction then consists of simulating elastic–plastic deformation by displacing the internal pixels of the region in the direction of the deformation axis, with the ends of the image fixed. Experimental results show that the method is effective when applied to two‐dimensional real pixel images and three‐dimensional real voxel images. © 2001 Scripta Technica, Syst Comp Jpn, 32(5): 46–54, 2001
DIPS: Diagrammatic arithmetic problem solver
Authors: Murata Tsuyoshi , Kato Hiroki , Shimura Masamichi , Numao Masayuki
Published: August 2002

When solving a problem, humans often draw diagrams in order to acquire useful information such as the conditions that are not clearly specified. The importance of using diagrams for reasoning and problem solving lies not only in clarifying humans' intellectual activities, but also in developing efficient user interfaces. There are several studies in the field of problem solving systems that use diagrammatic information such as those of determining object positions in physics problems, and those of corresponding between diagrams and given problem descriptions. However, there are few studies for the processes of drawing diagrams derived from the textual description of the problem and for enumerating quantities or finding patterns. This paper proposes a method for solving arithmetic problems using diagrams, and describes our problem solver called Diagrammatic Arithmetic Problem Solver (DIPS). DIPS employs an extended semantic network as its representation of diagrams, and it successfully solves arithmetic problems by drawing diagrams from the descriptions of the problems. It also has the abilities of discovering formulas from the regularities of drawn diagrams. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(6): 112–120, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.1138
Adhesion imaging of carbon‐fibre‐reinforced materials in the pulsed force mode of the atomic force microscope
Authors: Pfrang A. , Hüttinger K. J. , Schimmel Th.
Published: August 2002

The microstructure and microscopic mechanical and adhesive properties of carbon‐fibre bundles infiltrated with pyrolytic carbon were investigated using a combination of different scanning force techniques. Contact mode atomic force microscopy imaging was combined with lateral force imaging and adhesion force and local stiffness imaging in the pulsed force mode of the atomic force microscope. A clear material contrast was obtained between carbon fibre and pyrocarbon matrix in the adhesion and stiffness images, as well as in the friction force images, which gives valuable information about the different microscopic properties of the fibre and matrix. The significantly higher adhesive forces determined on the fibres compared with the carbon matrix may be attributed to a higher concentration of polar groups on the fibre cross‐sections due to the high degree of orientation of the graphene layers along the fibre axis. In addition, a much higher degree of spatial variation of adhesive and frictional forces is observed within the fibre compared with the matrix, indicating a higher degree of homogeneity within the pyrocarbon matrix. The data derived from the experiments give microscopic information that is essential for a more detailed understanding of the resulting macroscopic properties of these materials. Copyright © 2002 John Wiley & Sons, Ltd.
Adsorption of alginic acid to titanium investigated using x‐ray photoelectron spectroscopy and atomic force microscopy
Authors: Brizzolara Robert A.
Published: August 2002

X‐ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) have been used to characterize the adsorption of alginic acid to titanium as a function of alginic acid solution pH. It was found that alginic acid adsorbs in greater quantity at acidic pH than at basic pH. The results provide evidence for an anion‐exchange adsorption mechanism at weakly acidic pH. Addition of calcium chloride to the alginic acid solution results in a reduction of alginic acid adsorption at acidic pH and an increase at basic pH. This behavior can be explained by inhibition of anion exchange by the calcium cation at acidic pH and mediation of a bond between alginic acid and the titanium surface at basic pH. Elucidation of the adsorption chemistry of biofilm components to the surfaces of engineering materials is a prerequisite to developing surface modification strategies to reduce biofouling adhesion. Data presented herein can be used in the future as a baseline for comparison with data for such modified surfaces. Published in 2002 John Wiley & Sons, Ltd.
Characterization of the spatial distributions of entrapped polymers following the surface engineering of poly(lactic acid)
Authors: Quirk Robin A. , Briggs David , Davies Martyn C. , Tendler Saul J. B. , Shakesheff Kevin M.
Published: August 2002

In earlier studies we have demonstrated physical entrapment as a method of surface‐modifying poly(lactic acid) (PLA) by immobilizing poly(L‐lysine) (PLL) and poly(ethylene glycol) (PEG) at the PLA surface. In this study, we have used a combination of time‐of‐flight (ToF) SIMS and XPS image analysis to determine the surface homogeneity of these systems. The ToF‐SIMS imaging was used to investigate the effect of various surface‐engineering conditions on the lateral distribution of PLL‐modified PLA. The PLA surface modification was revealed to produce micron‐scale PLL‐rich domains following prolonged exposure to the partial solvent system that is used during the entrapment process. As the static SIMS analysis of PEG/PLA surfaces did not produce distinguishing ions of a sufficient intensity between the two polymers, this technique could not generate lateral contrast, and imaging XPS was therefore employed to determine the surface distributions of these two species. Phase separation was again detected under extended surface engineering conditions. With both systems, optimization of the process conditions was shown to inhibit the creation of a heterogeneous surface. Surface segregation may result in suboptimal performance of the biomaterial and this study therefore highlights the importance of determining spatial organizations when modifying polymer interfaces. Copyright © 2001 John Wiley & Sons, Ltd.
Quantification of the surface composition of low‐work function surfaces using low‐energy ion scattering
Authors: Cortenraad R. , Denier van der Gon A. W. , Brongersma H. H. , Ermolov S. N. , Glebovsky V. G.
Published: August 2002

Quantification of the surface composition of low‐work function systems using low‐energy noble gas ion scattering is strongly influenced by resonant neutralization. Below a certain threshold in the work function, resonant neutralization to the first excited level of the ion is possible and the neutralization probability of the ions increases exponentially with decreasing work function. We show how to correct for the influence of the work function and perform the quantification using the characteristic velocity method. The discussion and conclusions here are relevant for all ion scattering studies using low‐energy noble gas ions on surfaces with a work function below ∼4 eV. Copyright © 2001 John Wiley & Sons, Ltd.
Discussion: Teaching hypothesis tests: time for significant change?
Authors: Palmer Christopher R.
Published: August 2002

This is an opportune time to ask whether there should be important changes in the statistical syllabus for today's medical students, and in particular with regard to hypothesis tests, given the justified trend for preferring the confidence interval approach to inference. In discussing Jonathan Sterne's paper, I focus on teaching aspects, rather than the philosophical or historical elements, beginning with broader questions concerning overall course aims and objectives. To raise statistical awareness among future doctors, I argue that precisely what we teach is actually less important than how we teach. I discuss implications that only some medical students go on to become producers, as opposed to consumers, of research. I conclude that, for the time being at least, p‐values are here to stay and hence still need to be taught but only alongside careful description of their various limitations. Copyright © 2002 John Wiley & Sons, Ltd.
Statistical perspectives on confidentiality and data access in public health
Authors: Fienberg Stephen E.
Published: August 2002

Confidentiality and disclosure limitation are topics that are inherently statistical but, until recently, they have received limited attention from statistical methodologists. That situation has changed considerably in the present decade. In this paper, we provide an introduction and overview of some statistical disclosure limitation issues that are of special relevance to public health studies and surveys, and the linkages to current research on bounds for multi‐dimensional contingency table entries and ‘simulated’ categorical data. We also describe how these research methods relate to a new data access query system being developed for use by NCHS and other statistical agencies. Copyright © 2001 John Wiley & Sons, Ltd.
Power comparison of robust approximate and non‐parametric tests for the analysis of cross‐over trials
Authors: Correa José A. , Bellavance François
Published: August 2002

The main advantage of cross‐over designs in practice is the use of a smaller number of subjects to produce treatment comparisons with sufficient precision. Bellavance and Tardif proposed a non‐parametric approach to test the hypotheses of direct treatment and carry‐over effects for the three‐treatment three‐period and six sequences cross‐over design and showed the high asymptotic efficiency of their approach relative to the classical F‐test based on ordinary least squares (OLS). In a more recent paper, Öhrvik suggested another non‐parametric method for the analysis of cross‐over trials. The power of these two non‐parametric approaches is evaluated for small sample sizes via simulations, and compared to the power of the usual analysis of variance model based on OLS and a modified F‐test approximation that take into account the correlation structure of the repeated measurements within subjects. Different covariance structures, sample sizes, and probability distributions for the responses, namely normal and gamma, are used in the simulations to evaluate the power and robustness of these different methods of analysis. Copyright © 2001 John Wiley & Sons, Ltd.
Two‐phase shelf‐life estimation
Authors: Shao Jun , Chow Shein‐Chung
Published: August 2002

Unlike most drug products, some drug products must be stored at several temperatures, such as −20°C, 5°C and 25°C, in order to maintain the stability of the drug products. Drug products of this kind are usually referred to as frozen drug products. The determination of shelf‐life for frozen drug products involves the estimation of drug shelf‐lives at different temperatures, which requires multiple phase linear regression. Mellon suggested obtaining a combined shelf‐life by determining shelf‐lives based on data available at different temperatures. This method, however, does not account for the fact that the shelf‐life at the second‐phase would depend on the shelf‐life at the first phase. As an alternative, we propose a method for determination of drug shelf‐lives for the two phases using a two‐phase regression analysis based on the statistical principle described in the FDA guideline and the ICH guideline. A numerical example is presented to illustrate the proposed method. Copyright © 2001 John Wiley & Sons, Ltd.
Group sequential monitoring of years of life saved with paired censored survival data
Authors: Murray Susan
Published: August 2002

This research develops non‐parametric methodology for sequential monitoring of paired time‐to‐event data when comparing years of life saved, or years where any unpleasant outcome is delayed, is of interest. The recommended family of test statistics uses integrated differences in survival estimates that are available during the study period, where adjustments are made for dependence in the survival and censoring outcomes under comparison. In the context of paired censored survival data, the joint asymptotic closed form distribution of these sequentially monitored test statistics is developed and shown to have a dependent increments structure. Simulations verifying nice operating characteristics of the proposed monitoring methods also reveal consequences of ignoring an underlying paired data structure in terms of size and power properties. A motivating example is also presented via the Early Treatment Diabetic Retinopathy Study, which did not have methods available for sequentially monitoring paired censored survival data at the time. Copyright © 2002 John Wiley & Sons, Ltd.
Is there a liability of foreignness in global banking? An empirical test of banks' X‐efficiency
Authors: Miller Stewart R. , Parkhe Arvind
Published: August 2002

When a company operates outside of its home country, it may suffer a ‘liability of foreignness.’ Does this a priori theoretical expectation hold in the global banking industry? Banks increasingly compete outside of their home countries, and operating environments often differ sharply across countries, both in terms of financial markets and credit risk. In this paper, we report the results of an empirical test of the liability of foreignness in the global banking industry, using Fitch–IBCA BankScope data for the period 1989–96. Our findings strongly support the liability of foreignness hypothesis. Further, the data show some evidence that the X‐efficiency of a foreign‐owned bank is strongly influenced by the competitiveness of its home country and the host country in which it operates. Lastly, we find that in some environments U.S.‐owned banks are more X‐efficient than other foreign‐owned banks in some environments, but less X‐efficient in others. Copyright © 2002 John Wiley & Sons, Ltd.
Asset accumulation, interdependence and technological change: evidence from pharmaceutical drug discovery
Authors: Thomke Stefan , Kuemmerle Walter
Published: August 2002

Although the resource‐based view of the firm has been written about extensively, the process by which firm assets are accumulated has not been explored in detail. That is, we know little about the micro‐level mechanisms by which assets are built, nor do we have sufficient empirical evidence why some assets are more difficult to imitate, trade, or substitute. In this exploratory paper, we attempt to provide a better understanding of asset accumulation via an empirical research program in pharmaceutical drug discovery. Using a combination of field research, discovery data from nine pharmaceutical firms, and data on 218 alliances involving new technologies for experimentation and testing, three causes affecting asset accumulation are identified and described. First, the difficulty of imitating a particular asset is affected by interdependencies with other assets. Second, trading of assets can be impeded by structural inertia in the core of a firm that is adopting the technology asset. And third, fully specifying all factors affecting imitation and trading ex ante is very difficult, if not nearly impossible, under conditions of rapid technological change. We propose that the complex interactions of these causes can give rise to imperfections in factor markets. Finally, implications for further research are discussed as well. Copyright © 2002 John Wiley & Sons, Ltd.
Case study: a maintenance practice used with real‐time telecommunications software
Authors: Popović Miroslav , Atlagić Branislav , Kovačević Vladimir
Published: August 2002

In this paper we present a case study of the software maintenance practice that has been successfully applied to real‐time distributed systems, which are installed and fully operational in Moscow, St. Petersburg, and other cities across Russia. In this paper we concentrate on the software maintenance process, including customer request servicing, in‐field error logging, role of information system, software deployment, and software quality policy, and especially the software quality prediction process. In this case study, the prediction process is shown to be integral and one of the most important parts of the software maintenance process. We include a software quality prediction procedure overview and an example of the actual practice. The quality of the new software update is predicted on the basis of the current update's quantity metrics data and quality data, and new update's quantity metrics data. For management, this forecast aids software maintenance efficiency, and cost reduction. For practitioners, the most useful result presented is the process for determining the value for the break point. We end this case study with five lessons learned. Copyright © 2001 John Wiley & Sons, Ltd.
Optimization schemas for parallel implementation of non‐deterministic languages and systems
Authors: Gupta Gopal , Pontelli Enrico
Published: August 2002

Naive parallel implementation of non‐deterministic systems (such as a theorem proving system) and languages (such as logic, constraint, or concurrent constraint languages) can result in poor performance. We present three optimization schemas, based onflattening of the computation tree,procrastination of overheads, andsequentialization of computationsthat can be systematically applied to parallel implementations of non‐deterministic systems/languages to reduce the parallel overhead and to obtain improved efficiency of parallel execution. The effectiveness of these schemas is illustrated by applying them to the ACE parallel logic programming system. The performance data presented show that considerable improvement in execution efficiency can be achieved. Copyright © 2001 John Wiley & Sons, Ltd.
Processes for software in safety critical systems
Authors: Benediktsson O. , Hunter R. B. , McGettrick A. D.
Published: August 2002

Two complementary standards are compared, both of which are concerned with the production of quality software. One, IEC 61508, is concerned with the safety of software intensive systems and the other, ISO/IEC TR 15504, takes a process view of software capability assessment. The standards are independent, though both standards build on ISO/IEC 12207. The paper proposes a correspondence between the safety integrity levels (SILs) of 61508 and the capability levels (CLs) of 15504, and considers the appropriateness of the 15504 reference model as a framework for assessing safety critical software processes. Empirical work from the SPICE trials and COCOMO II is used to support the arguments of the paper as well as to investigate their consequences. The development of a 15504 compatible assessment model for software in safety critical systems is proposed. Copyright © 2001 John Wiley & Sons Ltd
Rating the process attribute utilizing AHP in SPICE‐based process assessments
Authors: Jung Ho‐Won
Published: August 2002

In SPICE (Software Process Improvement and Capability dEtermination) assessments, the rating of a process attribute is determined by the aggregated achievements of associated MPs (management practices). Previous rating scale usability studies revealed that experienced assessors had difficulty distinguishing the boundaries between adjacent ratings: Fully and Largely, Largely and Partially, and Partially and Not achieved. To cope with these boundary problems, this study presents an AHP (analytic hierarchy process) approach as an objective aggregation method for the achievements of MPs. This research analyzed assessors' responses to our questions. Results indicated that the AHP approach was a systematic method and helpful in determining assessors' consensus in boundary problems. Furthermore, respondents answered that they would again use the AHP approach for tackling boundary problems for future assessments. In addition, they felt that the AHP approach could provide the assessors with confidence in the results of an assessment. While assessors responded that the AHP approach was easy to understand, some assessors had difficulty in creating an AHP comparison matrix in detail. Assessors with AHP experience expressed their support through such statements as ‘reduce the assessment effort’ and ‘provide confidence in the assessment results’. These results suggest the AHP approach could be employed as a method in solving the boundary problem in SPICE‐based process assessments. Copyright © 2001 John Wiley & Sons, Ltd.
Analysing IT ethics
Authors: Taylor M. J. , Moynihan E.
Published: August 2002

For a systems analyst there can be many ethical questions related to the activities of systems analysis and systems design. In this paper we examine the ethical problems that can arise for a systems analyst, discuss potential sources of ethical guidance for systems analysts, and outline a framework for analysing ethical issues in information technology projects. A case study is examined in a large insurance company which demonstrates how analysis of ethical issues can be embedded in a proprietary methodology such as SSADM. Copyright © 2001 John Wiley & Sons, Ltd.
Nipple aspiration in diagnosis of breast cancer
Authors: Shao Zhi‐Ming , Nguyen Mai
Published: August 2002

It has been shown that early detection of breast cancer saves lives. Mammography and physical examination are currently the most commonly utilized screening methods for breast cancer. Research is being carried out to optimize these screening methods, as well as to develop new techniques. This review summarizes the findings of the research focusing on the diagnostic techniques involving the breast ductal system to date. These tests include nipple fluid cytology, nipple fluid tumor markers, ductogram, and ductoscopy. Semin. Surg. Oncol. 20:175–180, 2001. © 2001 Wiley‐Liss, Inc.
Sentinel lymph node—why study it: Implications of the B‐32 study
Authors: Harlow Seth P. , Krag David N.
Published: August 2002

Surgical removal of the regional lymph nodes by a level I and level II axillary dissection remains the standard of care for patients with surgically resectable breast cancer. Axillary dissection provides accurate pathologic staging and excellent regional disease control, and likely provides a small benefit in patient survival. Axillary dissection, however, is associated with significant patient morbidity. Sentinel lymph node (SLN) biopsy procedures have been found to provide very accurate pathologic staging when compared to axillary dissection; however, their effect on regional disease control and patient survival is not yet known. The National Cancer Institute (NCI) has sponsored a Phase III prospective, randomized clinical trial (the B‐32 trial) through the National Adjuvant Breast and Bowel Project (NSABP), to compare results of patients treated with SLN biopsy alone vs. SLN biopsy with completion axillary node dissection in patients with clinically node‐negative breast cancer. Results of this trial will provide evidence of the safety of SLN biopsy procedures in the management of patients with breast cancer. Semin. Surg. Oncol. 20:224–229, 2001. © 2001 Wiley‐Liss, Inc.
CAD Tools for System‐Level Modeling and Implementation
Authors: Flynn Michael J. , Hung Patrick
Published: August 2002

Designing a silicon chip is an increasingly complicated process. MICHAEL J FLYNN and PATRICK HUNG discuss the implications. Copyright © 2002 John Wiley & Sons, Ltd.
Altered dendritic spine density in animal models of depression and in response to antidepressant treatment
Authors: Norrholm Seth D. , Ouimet Charles C.
Published: August 2002

Olfactory bulbectomy, neonatal clomipramine administration, and maternal deprivation have been employed as animal models of depression. Each model is unique with respect to the experimental manipulations required to produce “depressive” signs, expression and duration of these signs, and response to antidepressant treatments. Dendritic spines represent a possible anatomical substrate for the enduring changes seen with depression and we have previously shown that chronic antidepressant drug exposure alters the density of hippocampal dendritic spines in an enduring fashion. The purpose of the present study was to determine whether persistent alteration of hippocampal spine density is a common element in each of these different models of depression and whether such alterations could be reversed with chronic antidepressant treatment. The results show that olfactory bulbectomy reduced spine density in CA1, CA3, and dentate gyrus compared to sham‐operated controls. Chronic treatment with amitriptyline, a tricyclic antidepressant, reversed the bulbectomy‐ induced reduction in dendritic spine density in CA1, CA3, and dentate gyrus, whereas treatment with mianserin, an atypical antidepressant, reversed this reduction only in dentate gyrus. On the other hand, neither neonatal clomipramine administration nor maternal deprivation affected hippocampal dendritic spine density. Repeated neonatal handling, however, as a control or as part of the maternal deprivation procedure, elevated spine density in dentate gyrus. These data suggest that long‐lasting alterations in hippocampal dendritic spine density contribute to the neural mechanism underlying the olfactory bulbectomy model of depression, but not the neonatal clomipramine or maternal deprivation models. Synapse 42:151–163, 2001. © 2001 Wiley‐Liss, Inc.
Topology of ionotropic glutamate receptors in brains of heterozygous and homozygous weaver mutant mice
Authors: Reader Tomás A. , Sénécal Jacques
Published: August 2002

In weaver mice, mutation of a G‐protein inwardly rectifying K+ channel leads to a cerebellar developmental anomaly characterized by granule and Purkinje cell loss and, in addition, degeneration of dopaminergic neurons. To evaluate other deficits, ionotropic glutamate receptors sensitive to N‐methyl‐D‐aspartate (NMDA), amino‐3‐hydroxy‐5‐methylisoxazole‐4‐propionic acid (AMPA), and kainic acid (KA) were examined by autoradiography with [3H]MK‐801, [3H]AMPA, and [3H]KA. These surveys were carried out in selected areas of cerebral cortex, hippocampus and related limbic regions, basal ganglia, thalamus, hypothalamus, brainstem, and cerebellum from heterozygous (wv/+) and homozygous (wv/wv) weaver mutants, and compared to wild‐type (+/+) mice. In wv/+ and wv/wv mutants, NMDA receptor levels were lower in cortical areas, septum, hippocampus, subiculum, neostriatum, nucleus accumbens, superior colliculus, and in the cerebellar granular layer. Densities of KA receptors were lower in cortical areas, hippocampus, limbic system structures, neostriatum, nucleus accumbens, thalamus and hypothalamus, superior and inferior colliculi, and cerebellar cortex of wv/wv mutants. Levels of AMPA receptors in the weaver were higher than in +/+ mice, particularly in somatosensory and piriform cortices and periaqueductal gray of wv/+, and in somatosensory cortex, CA1 field of Ammon's horn and cerebellar granular layer of wv/wv. Abnormal developmental signals, aberrant cellular responses, or a distorted balance between neurotransmitter interactions may underlie such widespread and reciprocal glutamate receptor alterations, while in the case of cerebellar cortex, NMDA receptors are lacking due to a massive disappearance of cerebellar granule cells and some loss of Purkinje neurons. Synapse 42:213–233, 2001. © 2001 Wiley‐Liss, Inc.
Age‐related changes in regional activation during working memory in young adults: An fMRI study
Authors: Adler Caleb M. , Holland Scott K. , Enseleit Stephen , Strakowski Stephen M.
Published: August 2002

Several lines of evidence suggest that working memory diminishes with advancing age, with concomitant functional changes in associated neuronal activation in frontal cortical regions and hippocampi. No studies to date, however, have investigated age‐related changes in neuronal activation in these regions during performance of a working memory task in younger subjects without working memory deficits. In this study, we utilized fMRI to examine changes in brain activation with increasing age in specific regions‐of‐interest. Eleven healthy subjects performed a “two‐back” working memory task and a matched “zero‐back” attention task during fMRI. There was no association between age and performance on either task. Left hippocampal activation significantly correlated with age (P = 0.01) and right hippocampal activation showed an association with age (P = 0.09). This study demonstrates that increasing age is associated with increased activation of hippocampus even in young patients without evidence of working memory deficits and suggests that functional changes may precede overt evidence of working memory deficits. Synapse 42:252–257, 2001. © 2001 Wiley‐Liss, Inc.
Capability Maturity Model® Integration (CMMISM): A view from the sponsors
Authors: Rassa Robert C. , Garber Vitalij , Etter Delores
Published: August 2002

The Capability Maturity Model® Integration (CMMISM) Project is a joint Industry—Government—Software Engineering Institute collaborative effort to develop an enterprise‐wide process improvement product suite based on existing capability models and methods. The Project is sponsored by the Office of the Under Secretary of Defense as well as by the National Defense Industrial Association Systems Engineering Committee. The first completed CMMISM product suite was released to the public for adoption in December 2000. This paper will describe the origins and rationale for the CMMISM Project, providing significant and detailed background information as well as a snapshot of current status and future plans. It will highlight some of the documented benefits of Capability Maturity Models, with specific focus on software engineering since this is the discipline where the greatest savings have been documented as a result of implementation of process improvement in engineering development. The paper will describe the CMMISM product suite components, and delineats some of the anticipated benefits from CMMISM adoption. Finally, the paper will discuss the CMMISM Version 1.1 update. © 2002 John Wiley & Sons, Inc. Syst Eng 5: 3–6, 2002; DOI 10.1002/sys.10011
A portrait of a CMMISM level 4 effort
Authors: Hollenbach Craig , Smith Doug
Published: August 2002

There is a significant amount of confusion over the quantitative and statistical nature of SW − CMM®‡ Level 4 within the assessment and improvement communities. Past SEI surveys of Level 4 and 5 companies have found a lack of consensus on what constitutes the necessary characteristics for Level 4. While the CMMISM model is an attempt to rectify this situation, experience with the CMMISM is limited. This article describes what a CMMISM Level 4 effort looks like by describing Northrop Grumman Information Technology's quantitative management program. Even though Northrop Grumman Information Technology has not been evaluated against the CMMISM, the authors have verified with the CMMISM model team that their processes meet the intent of the CMMISM model. This paper provides actual objectives, measures, results, and baselines that show how the specific goals and practices of the CMMISM Level 4 process areas can be implemented. The article provides a picture of how quantitative measures can be derived from business objectives, tracked at the project level using statistical process control, and meaningfully analyzed at the organizational level. © 2002 Wiley Periodicals, Inc. Syst Eng 5: 52–61, 2002; DOI 10.1002/sys.10012
Operator interface system using a plant object‐oriented model
Authors: Gabbar Hossam A. , Shimada Yukiyasu , Suzuki Kazuhiko
Published: August 2002

Recent researches in the area of plant modeling in concurrent engineering proposed a mechanism to represent the plant lifecycle in a central model on the basis of unified modeling language (UML). UML models are intelligent and informative, where they include useful information about plant objects. In this article, we are studying the utilization of such model as a part of the operator interface system. The focus will be on how to represent plant design model in an easy and useful manner along with operational models in a window within the operator interface system. The proposed plant model is translated into static and dynamic web pages so that the operator can use normal Internet browsers to navigate through the model. The proposed plant model includes information about plant structure, behavior, and function. Such information is essential for an operator to make the correct decision in normal and abnormal situations. System architecture of the proposed solution is illustrated. A reactor unit from a PVC batch plant is used as a case study to elucidate the utilization of the proposed solution. © 2001 John Wiley & Sons, Inc. Syst Eng 4: 179–189, 2001
Empirical hysteretic energy with strength, strength and drift, and SCWB designs using steel moment‐resisting frames
Authors: Choi Byong Jeong , Shen Jay
Published: August 2002

This paper represents the hysteretic energy performance of twelve steel moment‐resisting frames intentionally designed by three different design procedures. The three types of design procedure were: (1) strength controlled design; (2) strength and drift controlled design; and (3) strong‐column/weak‐beam controlled design. The energy performances of the so‐designed frames were discussed in view of the effects of strength variations, stiffness variations, and plastic mechanism variations, on the hysteretic energy input and its distribution in multiple storey frames. An empirical mean hysteretic energy formula has been proposed based on this study. Copyright © 2001 John Wiley & Sons, Ltd.
Life‐cycle cost analysis of supplemental damping
Authors: King S. A. , Jain A. , Hart G. C.
Published: August 2002

This paper illustrates a method for assessing the economic effects of supplemental damping in a building design (new or rehabilitation scheme) over a given time period of interest. The method involves simulation of life‐cycle costs and benefits (in terms of avoided loss) attributable to earthquake hazard over a user‐defined time period. At each time step, the capacity of the building is a function of the capacity and earthquake performance at the previous time step. The method allows for the user to specify the threshold for capacity updating, as well as the level of damage at which repairs will be made (i.e. losses will actually be incurred). The simulation method is illustrated through a case study of a high‐rise steel moment frame building located in a region of high seismicity. The effects of adding supplemental damping to the building are investigated for several time periods. Time periods of 5, 15, 30, 50 and 100 years are used, and, for each time period, damping ratios of 5%, 10%, 20% and 30% of critical are used. The results can be used to help determine whether it is beneficial or not to incur the extra cost associated with adding supplemental damping in the building design. For example, for a 30‐year time period, the results show that it would be beneficial to use supplemental damping devices to increase the damping to 10% if the added cost is less than US$4·9 million, to 20% if the added cost is less than US$8·3 million, and to 30% if the added cost is less than US$10 million. Similarly, if an additional US$3·25 million is spent to increase the damping in the building to 20%, the results show that it would take approximately 15 years to recover the additional cost in terms of expected loss reduction. The paper also discusses the limitations associated with these results. Copyright © 2001 John Wiley & Sons, Ltd.
Embryolethality induced by metronidazole (MTZ) in Rattus norvegicus
Authors: Mudry M.D. , Martínez‐Flores I. , Palermo A.M. , Carballo M.A. , Egozcue J. , Caldés M. García
Published: August 2002

Parasitic illnesses is increasing all over the world, especially in developing countries, and metronidazole (MTZ) is the therapeutic agent usually administered to children as well as adults at the reproductive age. In this work, we propose an evaluation of MTZ in order to analyze the potential reproductive damage in females by using Rattus norvegicus (Sprague‐Dawley) as an animal model. Adult female rats were mated after MTZ treatments, and they were sacrificed at 21 days of gestation. Different types of damage were evaluated by using mortality, phenotypic abnormalities and reproductive capacity as parameters, and were studied and scored in 70 adult specimens (450 g/bw). They were divided into five groups: a) untreated females as a control group; females treated with b) DMSO as a solvent control group or c) 500 mg/kg/bw of MTZ per day for 7 days as therapeutic dose (TD); d) a half therapeutic dose (HD); and e) a double therapeutic dose (DD). Pre‐implantation death in MTZ‐treated groups was not significantly different from controls. However, drug treatments significantly increased the frequency of post‐implantation deaths and the dominant lethals were ranged between 12.0 % and 17.8 %. Teratogenesis Carcinog. Mutagen. 21:197–205, 2001. © 2001 Wiley‐Liss, Inc.
Biarylic Biscarbazole Alkaloids: Occurrence, Stereochemistry, Synthesis, and Bioactivity
Authors: Tasler Stefan , Bringmann Gerhard
Published: August 2002

The structurally and pharmacologically intriguing but stereochemically initially disregarded small class of biarylic biscarbazole alkaloids is presented, starting with an introduction of the different structural patterns found in nature. For the construction of the biaryl bond, mainly biomimetic oxidative coupling reactions were used, as shown for the natural products bismurrayaquinone‐A, bis‐2‐hydroxy‐3‐methylcarbazole, clausenamine‐A, and murrastifoline‐F. For most of these compounds, a resolution of the respective atropo‐enantiomers succeeded either directly, by high‐performance liquid chromatography by HPLC on a chiral phase, or via atropo‐diastereomers, after derivatization with a chiral auxiliary. The absolute configurations of the pure enantiomers were assigned by comparison of experimental (CD) spectra with those quantum chemi‐cally calculated, or, for atropo‐diastereomeric derivatives, by means of ROESY investigations and X‐ray crystallography. Ullmann‐type coupling conditions were also found to be feasible for the construction of the 2,2′‐biscarbazole core, necessitating a completely regioselective 2‐bromination protocol. The first atroposelective synthesis of such a basic target structure was achieved by application of the “lactone methodology,” giving rise to an atropisomeric ratio of 85 : 15. Some of the biscarbazole alkaloids and their derivatives were found to have interesting bioactivities, and for the first time, the natural atropo‐enantiomeric ratio in the plants was determined for one of these compounds, murrastifoline‐F. ©2002 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 2:113–126, 2002: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.10014
Success in everyday physics: The role of personality and academic variables*
Authors: Norvilitis Jill M. , Reid Howard M. , Norvilitis Bret M.
Published: August 2002

Two studies examined students' intuitive physics ability and characteristics associated with physics competence. In Study 1, although many students did well on a physics quiz, more than 25% of students performed below levels predicted by chance. Better performance on the physics quiz was related to physics grades, highest level of math taken, and students' perceived scholastic competence, but was not related to a number of other hypothesized personality variables. Study 2 further explored personality and academic variables and also examined students' awareness of their own physics ability. Results indicate that the personality variables were again unrelated to ability, but narcissism may be related to subjects' estimates of knowledge. Also, academic variables and how important students think it is to understand the physical world are related to both measured and estimated physics proficiency. © 2002 Wiley Periodicals, Inc. J Res Sci Teach 39: 394–409, 2002
Design, technology, and science: Sites for learning, resistance, and social reproduction in urban schools
Authors: Seiler Gale , Tobin Kenneth , Sokolic Joseph
Published: August 2002

The teaching of science through activities that emphasize design and technology has been advocated as a vehicle for accomplishing science for all students. This study was situated in an inner7‐city neighborhood school populated mainly by African American students from life worlds characterized by poverty. The article explores the discourse and practices of students and three coteachers as a curriculum was enacted to provide opportunities for students to learn about the physics of motion through designing, building, and testing a model car. Some students participated in ways that led to their building viable model cars and interacting with one another in ways that suggest design and technological competence. However, there also was evidence of resistance from students who participated sporadically and refused to cooperate with teachers as they endeavored to structure the environment in ways that would lead to a deeper understanding of science. Analysis of in‐class interactions reveals an untapped potential for the emergence of a sciencelike discourse and diverse outcomes. Among the challenges explored in this article is a struggle for respect that permeates the students' lives on the street and bleeds into the classroom environment. Whereas teachers enacted the curriculum as if learning was the chief goal for students, it is apparent that students used the class opportunistically to maintain and earn the respect of peers. © 2001 John Wiley & Sons, Inc. J Res Sci Teach 38: 746–767, 2001