bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of chiral reactions: the structural detection of new hydrogenated isocinchona alkaloids from mixtures without isolation using electrospray ionization tandem mass spectrometry
Authors: Bartók Mihály , Kele Zoltán , Sutyinszki Mária , Bucsi Imre , Felföldi Károly
Published: May 2004

The reaction mixture for the hydrogenation of ethyl pyruvate on Pt‐alumina catalyst modified with isocinchona alkaloids (α‐ICN (I) and β‐ICN (II)) was studied by electrospray ionization tandem mass spectrometry (ESI‐MS/MS). It was established that part of the chiral modifiers themselves are converted into ions of m/z 299, 305 and 309 in the course of chiral hydrogenation. The experimental data allowed the determination of the probable structure of the ions mentioned. According to ESI‐MS/MS spectra the structure of the new cinchona alkaloids was assumed: tetrahydro‐isocinchonines (III–VI), decahydro‐isocinchonines (VII, VIII) and hydrogenated compounds of VII and VIII by scission of their CN and CO bonds (IX/1, IX/2, X). Fragmentation pathways are proposed for these new compounds. Copyright © 2004 John Wiley & Sons, Ltd.
Rapid screening of plasma volume expanders in urine using matrix‐assisted laser desorption/ionisation time‐of‐flight mass spectrometry
Authors: Gallego Ricardo Gutiérrez , Segura Jordi
Published: May 2004

The use of plasma volume expanders, especially those based on chemically modified polysaccharides such as hydroxyethyl starch, has found its way from the medical field to the athletic community in the everlasting drive for performance enhancement. As such, plasma volume expanders have been placed on the list of banned substances by the International Olympic Committee, and in turn require accurate and sensitive analytical tools for their detection in complex biological matrices. Here we present a relatively straightforward method for the detection of polysaccharide‐based plasma volume expanders (PVE) in urine, based on the carefully controlled partial acid hydrolysis of urine (20 μL) in a total volume of 500 μL 4 M trifluoroacetic acid. Following the incubation (30 min at 100°C) an aliquot of the hydrolysate is dried, re‐suspended in the analytical matrix (e.g. 2,5‐dihydroxybenzoic acid) and examined by matrix‐assisted laser desorption/ionisation time‐of‐flight mass spectrometry (MALDI‐TOFMS). The obtained mass spectrometric profile reveals a high number of characteristic peaks in the mass range between 500 and 3000 Da, a region that in urine samples devoid of PVE appears relatively clean, and thus allows the unambiguous identification of the presence of such PVE. This approach is fast (the mass profile can be obtained within 90 min), highly sensitive (the effective sample amount on the MALDI target is equivalent to 100 nL urine), needs little sample handling (four steps), requires no derivatisation and is devoid of interference from other biomolecules. The approach has been worked‐out for hydroxy ethyl starch but can be applied to other polymer‐derived plasma expanders such as dextran and probably the newly developed acetyl starch. Copyright © 2004 John Wiley & Sons, Ltd.
A voronoi diagram‐visibility graph‐potential field compound algorithm for robot path planning
Authors: Masehian Ellips , Amin‐Naseri M. R.
Published: May 2004

Numerous methods have been developed to solve the motion planning problem, among which the Voronoi diagram, visibility graph, and potential fields are well‐known techniques. In this paper, a new path planning algorithm is presented where these three methods are integrated for the first time in a single architecture. After constructing the generalized Voronoi diagram of C‐space, we introduce a novel procedure for its abstraction, producing apruned generalized Voronoi diagram. A broad freeway net is then developed through a new α‐MID(maximal inscribed discs) concept. A potential function is assigned to the net to form an obstacle‐free network of valleys. Afterwards we take advantage of a bidirectional search, where the visibility graph and potential field modules execute alternately from both start and goal configurations. Asteepest descent mildest ascentsearch technique is used for local planning and avoiding local minima. The algorithm provides a parametric tradeoff between safest and shortest paths and generally yields shorter paths than the Voronoi and potential field methods, and faster than the visibility graph. It also performs well in complicated environments. © 2004 Wiley Periodicals, Inc.
Three‐dimensional map building for mobile robot navigation environments using a self‐organizing neural network
Authors: Kim Min Young , Cho Hyungsuck
Published: May 2004

In recent years, mobile robots have been required to become more and more autonomous in such a way that they are able to sense and recognize the three‐dimensional space in which they live or work. In this paper, we deal with such an environment map building problem from three‐dimensional sensing data for mobile robot navigation. In particular, the problem to be dealt with is how to extract and model obstacles which are not represented on the map but exist in the real environment, so that the map can be newly updated using the modeled obstacle information. To achieve this, we propose a three‐dimensional map building method, which is based on a self‐organizing neural network technique called “growing neural gas network.” Using the obstacle data acquired from the 3D data acquisition process of an active laser range finder, learning of the neural network is performed to generate a graphical structure that reflects the topology of the input space. For evaluation of the proposed method, a series of simulations and experiments are performed to build 3D maps of some given environments surrounding the robot. The usefulness and robustness of the proposed method are investigated and discussed in detail. © 2004 Wiley Periodicals, Inc.
Kinematic optimal design of a paramill: A multi‐SP device
Authors: Lee Jun‐Ho , Hong Keum‐Shik
Published: May 2004

In this paper, a manipulability analysis of a new parallel‐type rolling mill, named “paramill,” in its conceptual design stage is investigated. The paramill considered uses two Stewart platforms (SPs) in opposite directions for the generation of 6 degree‐of‐freedom motions of individual work‐rolls. The objective of this new approach is to pursue an integrated control of the strip thickness, strip shape, pair‐crossing angle, uniform wear of the rolls, and tension of the strip. The forward/inverse kinematics problems are formulated. Two main kinematic parameters, the size of the base and the acute angle made by two neighboring joints for a given size of the work‐roll, have been determined in the way that the force and moment transmission from the actuators to the work‐rolls is maximized. © 2004 Wiley Periodicals, Inc.
GLU♮ embedded in C++: a marriage between multidimensional and object‐oriented programming
Authors: Papaspyrou Nikolaos S. , Kassios Ioannis T.
Published: May 2004

The embedding of a small but expressive language of multidimensional functional programming in a well known and widely used language of object‐oriented programming leads to the combination of two radically different programming models. In this paper, we formally define the syntax and semantics of GLU♮, which can be thought of as the multidimensional core of Lucid and GLU, and we describe its implementation as a language embedded in C++. With the aid of a few examples, we argue that the marriage of the two programming models is not only compatible and natural, but also that it produces a new and interesting hybrid language. Copyright © 2004 John Wiley & Sons, Ltd.
Bela H. Banathy: a short story of my life
Authors: Jenlink Patrick M.
Published: May 2004

This article reflects an autobiographical account of Bela H. Banathy's life, providing a recorded history of his accomplishments, personally and professionally. Importantly, Bela's story provides insight into his early life and the historicity of his origins as a systems and design scientist. Copyright © 2004 John Wiley & Sons, Ltd.
The well‐being of social systems
Authors: Jenks C. Lynn
Published: May 2004

The emphasis is on social systems that are intentionally created to accomplish one or more purposes and, by design, size, and/or intention, are highly vulnerable to their membership. Such systems tend to prosper and evolve in desirable directions as long as they measure up to certain criteria. At the most basic and immediate level, such systems need to achieve their purposes, effectively perform their appointed tasks, and satisfy their stakeholders. Effectiveness reports try to focus on criteria such as these. But, limiting measures to these, though publicly desirable, present only part of the system picture. Ignored are the implications of the presence of certain system characteristics that have a profound effect on the system's evolution and well‐being. This paper explores a more comprehensive set of variables believed to be useful for both the immediate and longer‐range time frame. Copyright © 2004 John Wiley & Sons, Ltd.
Designingwith: a homeopoietic ethic for organizational change
Authors: Rowland Gordon
Published: May 2004

Banathy (1996) states that it is ethical to designwithothers rather thanforthem. In this essay I explore the distinction from the perspective of complexity science and adopt the view, at least metaphorically, that human individuals and groups are complex creative systems, which under some conditions will self‐organize. I argue that such phenomena are not truly autopoietic, but subject to the influence of their systemic environment, which in human terms may include respectful, caring others. Creatingwithcan be called homeopoietic action and is a primary ethic for evolutionary guidance in many contexts and at many levels. The focus here is on change in organizations. Copyright © 2004 John Wiley & Sons, Ltd.
The empty chair: uncertain futures and systemic dichotomies
Authors: Chroust Gerhard
Published: May 2004

One of the outstanding characteristics of Bela H. Banathy was his deep concern for designing better systems for future generations. In plenary meetings often an empty chair reminded us of our responsibility to the coming generations in designing the systems for a world to come. Systems designers often have a problem in making basic a priori assumptions about system choices without having sufficient information. We describe so‐called systemic dichotomies: design decisions that have to choose between basic conflict pairs (like immediate or delayed enactment, optimistic versus pessimistic approaches). For each class we give several examples, mostly from software engineering. In concluding we show that certain of these dichotomies also have a meaning in social systems. This paper could be a starting point for the next generation of system scientists, for a closer investigation of such dichotomic dimensions, a study of their properties and a research into the interdependence of various such dichotomies. Copyright © 2004 John Wiley & Sons, Ltd.
Designing a transnational indigenous leaders interaction in the context of globalization: a Wisdom of the People Forum
Authors: Christakis Alexander N. , Harris LaDonna
Published: May 2004

Forty Indigenous leaders from the Americas and New Zealand and several non‐Indigenous participants sitting in the traditional Comanche Tribe circle began the forum by sharing their ‘medicine’—inner strength or personal power. They evoked in various ways a common deep spirituality based on a respect for the earth, ancestors, family, and peaceful coexistence. The purpose of the forum was to create, through true dialogue, a shared understanding of the barriers that will need to be addressed in the enhancement of liberating transnational interactions among emerging Indigenous leaders in the context of globalization. Finding patterns of effective interactions was the primary task of the forum participants. The fact that the participants are searching for ‘patterns of meaning’ implies that what they strive for is to integrate the intangible of traditional core cultural values into a contemporary reality. In the forum, the group identified effective, practical means that embody Indigeneity. Copyright © 2004 John Wiley & Sons, Ltd.
Bela H. Banathy: the legacy of a design conversation
Authors: Nelson Harold G.
Published: May 2004

This paper is a reflection on the influence of Bela H. Banathy's scholarship and leadership in the field of social systems design. In particular, the focus of this paper is on the development of a model of systems design inquiry and a model of systems design communication. The seminal ideas for the models were first explored at the annual Asilomar Conversations hosted by the International Systems Institute (ISI), a non‐profit organization founded by Prof. Banathy. The models are representative of the legacy of an ongoing design conversation with Prof. Banathy concerning the integration of human values into a systems science approach to the challenge of securing improvement in the human condition. Copyright © 2004 John Wiley & Sons, Ltd.
Reflections on the role of dialogue in education and community building
Authors: Hammond Debora
Published: May 2004

This paper documents a decade of thinking and practice inspired by Bela H. Banathy and his work on collaborative systems design. I first met Bela in 1994 at the annual conference of the International Society for the Systems Sciences (ISSS), where he invited me to discuss my recently launched dissertation project on the history and social implications of general systems theory. In my research on the founders of ISSS, I was particularly inspired by Kenneth Boulding's emphasis on the critical role of dialogue in decision making. I am currently a faculty member in Hutchins School of Liberal Studies at Sonoma State University, which offers an interdisciplinary seminar‐based program, embodying the spirit of both Boulding's and Banathy's work. It has provided an excellent laboratory for practicing the art of interdisciplinary dialogue, which extends into the larger community in a variety of ways. In this paper, I offer examples of dialogue and design in action, inspired and enriched through my acquaintance with Bela. Copyright © 2004 John Wiley & Sons, Ltd.
Search‐based software test data generation: a survey
Authors: McMinn Phil
Published: May 2004

The use of metaheuristic search techniques for the automatic generation of test data has been a burgeoning interest for many researchers in recent years. Previous attempts to automate the test generation process have been limited, having been constrained by the size and complexity of software, and the basic fact that, in general, test data generation is an undecidable problem. Metaheuristic search techniques offer much promise in regard to these problems. Metaheuristic search techniques are high‐level frameworks, which utilize heuristics to seek solutions for combinatorial problems at a reasonable computational cost. To date, metaheuristic search techniques have been applied to automate test data generation for structural and functional testing; the testing of grey‐box properties, for example safety constraints; and also non‐functional properties, such as worst‐case execution time. This paper surveys some of the work undertaken in this field, discussing possible new future directions of research for each of its different individual areas. Copyright © 2004 John Wiley & Sons, Ltd.
Prenatal cocaine exposure decreases nigrostriatal dopamine release in vitro: Effects of age and sex
Authors: Glatt Stephen J. , Trksak George H. , Cohen Ori S. , Simeone Benjamin P. , Jackson Denise
Published: May 2004

The present study examined the effects of prenatal cocaine (PCOC) exposure, age, sex, and estrous phase on the functional development of nigrostriatal dopamine (DA) neurons. Striatal tissue was obtained from prepubescent and adult rats of both sexes after bidaily exposure to saline (1 ml/kg) or cocaine (20 mg/kg/ml saline) from embryonic days 15–21. Tissue levels, basal release, and electrically evoked (1 or 8 Hz) overflow of endogenous DA and its metabolite, 3,4‐dihydroxyphenylacetic acid (DOPAC), as well as their efflux in response to superfusion with the DA transport blocker, nomifensine (10 μM), were measured from superfused striatal slices. Generally, these measures were highest in tissue from males and adults. Tissue DA and DOPAC levels and the rate of DA turnover were unaffected by PCOC exposure. Slices from PCOC‐exposed juvenile and adult male rats exhibited significantly reduced basal and electrically evoked DA release at both stimulation intensities, in conjunction with higher levels of presynaptic DA reuptake. Female rats were largely spared from the effects of PCOC exposure, and measures did not vary with estrous phase. These findings demonstrate that the effects of PCOC exposure on various parameters of nigrostriatal DA neuronal function are not uniform across age, sex, or phases of the estrous cycle. These novel alterations in nigrostriatal DA transmission are in need of independent replication, but they may have profound implications for behavioral activities regulated by these neurons and, thus, may provide a basis for sex‐selective effects of PCOC in exposed humans. Possible mechanisms of deleterious effects of PCOC exposure in select groups are discussed. Synapse 53:74–89, 2004. © 2004 Wiley‐Liss, Inc.
Isoflurane induces dopamine transporter trafficking into the cell cytoplasm
Authors: Byas‐Smith Michael G. , Li Juan , Szlam Fania , Eaton Douglas C. , Votaw John R. , Denson Donald D.
Published: May 2004

Previous investigations have shown that the binding of a selective hydrophilic positron emission tomography radiotracer for the dopamine transporter (DAT) (2β‐carbomethoxy‐3β‐(4‐chlorophenyl)‐8‐(2‐(18)F‐fluoroethyl)nortropane) decreased in monkey striatum during deep isoflurane anesthesia. Immunohistochemistry experiments suggested but did not prove that isoflurane induced a decrease in cell surface DAT. The present investigation was undertaken to demonstrate quantitatively the isoflurane‐induced internalization of DAT using a rapid and relatively uncomplicated biochemical technique in human embryonic kidney (HEK‐293) cells stably expressing the human DAT (h‐DAT) protein. Biotinylation followed by Western blot analysis was used to determine the extent of change in cell surface expression of the DAT under control conditions and in the presence of a clinically relevant concentration of isoflurane. Isoflurane treatment for 30 min resulted in a highly significant decrease in the amount of h‐DAT on the cell surface (21 ± 15% of control; P < 0.01) (mean ± SD; n = 4). These data are consistent with the hypothesis that isoflurane results in internalization of DAT from the cell membrane and further validate our qualitative results reported previously. In addition, the current results confirm the hypothesis that biotinylation can be used to quantitate the extent of disappearance of DAT from the cell surface making dose–response studies and comparisons of DAT internalization with other general anesthetics practical. Synapse 53:68–73, 2004. © 2004 Wiley‐Liss, Inc.
σ‐1 Receptors potentiate epidermal growth factor signaling towards neuritogenesis in PC12 cells: Potential relation to lipid raft reconstitution
Authors: Takebayashi Minoru , Hayashi Teruo , Su Tsung‐Ping
Published: May 2004

We previously demonstrated that overexpression of σ‐1 receptors (σ‐1R) potentiated neurite sprouting caused by nerve growth factor in PC12 cells (Takebayashi et al. 2002 J Pharmacol Exp Ther 202:1227–1237). In this study we examined if σ‐1R may be involved in the action of epidermal growth factor (EGF). EGF is conventionally recognized as a mitogenic factor that stimulates only the proliferation of various types of cells, including PC12 cells. We found here that in σ‐1 receptor‐overexpressing PC12 cells (σ‐1R OE cells), EGF markedly stimulates neuritogenesis without affecting cellular proliferation. EGF receptors (EGFR) are largely reduced in lipid rafts and are enriched in non‐raft regions in σ‐1R OE cells. The enrichment of EGFR in the non‐raft region is correlated with enhanced downstream signaling of EGFR including the phosphorylation of both EGFR and extracellular signal‐regulated kinases (ERKs). Destruction of cholesterol‐containing rafts by treating cells with methyl‐β‐cyclodextrin also causes a reduction of EGFR in lipid rafts, a concomitant increase in the phosphorylation of both EGFR and ERK, and an increase in the EGF‐induced neurite sprouting in wildtype cells. Furthermore, while overexpression of σ‐1R increases the level of lipid raft‐associated cholesterol, the overexpression alters the levels of gangliosides in lipid rafts: GM1 and GM2 are decreased, whereas GD1a is increased. We conclude that σ‐1R cause the remodeling of lipid rafts, at least by increasing the level of lipid raft‐associated cholesterol and by altering the levels of certain critical lipid raft‐forming gangliosides. σ‐1R may thus play an important role in directing EGF signaling towards neuritogenesis, perhaps by shifting EGFR from the lipid raft into non‐raft regions. Synapse 53:90–103, 2004. Published 2004 Wiley‐Liss, Inc.
Regional distribution of SK3 mRNA‐containing neurons in the adult and adolescent rat ventral midbrain and their relationship to dopamine‐containing cells
Authors: Sarpal Deepak , Koenig James I. , Adelman John P. , Brady Dana , Prendeville Lucy Clerkin , Shepard Paul D.
Published: May 2004

SK3 small conductance, calcium‐activated potassium channels play an important role in regulating the activity of mesencephalic dopamine (DA) neurons. In the present series of experiments, in situ hybridization techniques were used to compare SK3 and tyrosine hydroxylase (TH) mRNA expression throughout the rostrocaudal extent of the ventral midbrain in juvenile and adult rats. SK3 mRNA was found exclusively in areas that also contained large numbers of DA neurons including the substantia nigra (SN), the ventral tegmental area, and related cell groups (VTA‐A10). An anteroposterior and mediolateral gradient in SK3 mRNA hybridization was apparent in the VTA‐A10 but not in the SN. Younger rats appeared to possess higher levels and less regional variation in TH and SK3 transcripts. These results are consistent with previous studies reporting differential expression of SK3 protein within the midbrain and suggest that variations in SK3 channel distribution could contribute to differences in dopamine‐related functions in the rat. Synapse 53:104–113, 2004. © 2004 Wiley‐Liss, Inc.
Optimal control of MDOF structures with controlled stiffness dampers
Authors: Ribakov Y. , Dancygier A. N.
Published: May 2004

The structure and application of supplemental controlled stiffness dampers are discussed. The instantaneous and the polynomial active control theories are used to obtain the control forces at each time step during an occurring earthquake. The efficiency of these control strategies in a structure with the controlled stiffness dampers is compared. Control of the damping forces is enabled due to the mechanical structure of the damper, which is described in the paper. This device can be efficiently used as a structural damper because the forces developed in it are independent of the structure's displacements or velocities. The efficiency of the damper is demonstrated in a numerical simulation of a seven‐story building. The simulation shows that the behavior of a structure with the active controlled stiffness dampers was significantly improved compared to that of an uncontrolled structure, and of a passive controlled viscous damped structure, subjected to the same earthquakes. Copyright © 2003 John Wiley & Sons, Ltd.
Reconnaissance and preliminary assessment of a damaged high‐rise building near Ground Zero
Authors: Warn Gordon , Berman Jeffrey , Whittaker Andrew , Bruneau Michel
Published: May 2004

An MCEER research team, sponsored by the National Science Foundation, visited Ground Zero twice in the two weeks following the attacks of September 11, 2001, to collect perishable data related to the collapse of the two 110‐story towers and collateral damage to buildings and infrastructure surrounding the World Trade Center complex. The visit on September 23 involved a walk‐through of one high‐rise building that was badly damaged by large pieces of debris that were ejected from World Trade Center Tower 2 as it collapsed. This paper presents information from the building‐interior reconnaissance on September 23 and the subsequent analysis of a building frame with properties similar to those of the damaged building. Linear and non‐linear analyses were undertaken. Such analyses showed that the use of rigid beam‐to‐column connections in the building frame enabled gravity loads in the frame above the segment of the building that partially collapsed to be transferred to adjacent undamaged vertical components. Copyright © 2003 John Wiley & Sons, Ltd.
Energy‐based design of structures using modified force analogy method
Authors: Wong Kevin K. F. , Wang Yi
Published: May 2004

Energy due to earthquake excitations is used to evaluate the performance of a structure. This energy is derived analytically based on the force analogy method, which uses only initial stiffness with changing displacement to accurately capture the inelastic material behaviour. However, numerical calculation using the classical force analogy method considers mass matrices that are invertible, and therefore it is not appropriate for use in analysing real structures where rotational mass moment of inertia is generally ignored. In this research, derivation of the force analogy method is modified to analyse real moment‐resisting frames using static condensation. Using this modified force analogy method in the condensed form significantly reduces the size of the structural problem because a large number of rotational degrees of freedom can be condensed. Numerical simulation is then performed to analyse the dynamic response of a six‐storey moment‐resisting frame and the concept of performance‐based design is used to improve the structural performance in terms of energy dissipation ‘demand’ at each plastic hinge. Results show that the amount of total plastic energy dissipation remains about the same for structures with similar frequency contents. This is significant because it shows that understanding the flow of energy in the structure is important in improving structural performance under earthquake excitations. Copyright © 2003 John Wiley & Sons, Ltd.
Analysis and behaviour of transfer plate–shear wall systems in tall buildings
Authors: Kuang J. S. , Zhang Zhijun
Published: May 2004

The current practice of design for a transfer plate–shear wall system in tall buildings does not generally include the interaction effect of the transfer plate and the supported shear walls on the structural behaviour of the system. As a result, it may lead to an unreasonable design for the internal forces of structural members and the corresponding steel reinforcement detailing. In this paper, analysis and structural behaviour of transfer plates supporting in‐plane loaded shear walls are presented, where emphasis is placed on the interaction between the transfer plate and the supported shear walls. The interaction effect is shown to cause significant stress redistributions both in the transfer plate and in the shear walls within an interactive zone. Parameters that influence significantly the structural behaviour and force transfer mechanism, such as the span–depth ratio of the transfer plate, the stiffness and locations of the shear walls, and the stiffness of support columns, are also highlighted. The paper is expected to provide not only a better understanding of the interactive characteristic of transfer plate–shear wall systems, but also a useful reference for the design of transfer plates supporting in‐plane loaded shear walls in tall buildings. Copyright © 2003 John Wiley & Sons, Ltd.
Multi‐layered energy absorber frames for tall buildings under high‐speed impact
Authors: Horr A. M. , Safi M.
Published: May 2004

Based on the advanced fractional derivative damping theory for vibration of large systems and the flexible surface‐to‐surface advanced contact theory, a new design strategy has been presented to deal with the high‐speed impact of flying objects into tall buildings. Using a multi‐layered frame system with external energy absorber frame and a new individual grid‐stiffened flooring system (IGSF), a new system has been design to resist the initial impact force and the progressive collapse phenomena. The system can also guide the heat waves caused by the explosion using a special frame system. These characteristics of the new design method have been shown graphically using a full documented numerical example, which highlights the efficiency of the new multi‐layered frame system under high‐speed impact. The advanced flexible surface‐to‐surface contact theory is used to model the actual initial impact force and the advanced fractional derivative damping theory is used to obtained the energy absorption characteristics of large‐scale dampers used in the external frame system. The purpose of this paper is to present a new design method, which improves the resulting dynamic responses of a tall building induced by a high‐speed impact of a flying object. Copyright © 2003 John Wiley & Sons, Ltd.
Impact of Circulating Free Tumor Cells in the Peripheral Blood of Colorectal Cancer Patients during Laparoscopic Surgery
Authors: Chen Wei‐Shone , Chung Ming‐yi , Liu Jin‐Hwang , Liu Jacqueline Ming , Lin Jen‐Kou
Published: May 2004

Despite widespread use of laparoscopic surgery for colorectal operations, its application for curative resection of colorectal cancer is still controversial. One of the major concerns is the impact of the laparoscopic procedure on dissemination of tumor cells. The main purpose of this study was to investigate the impact of laparoscopic surgery on circulating tumor cells in colorectal cancer patients. Quantitation of circulating free tumor cells (FTCs) was performed preoperatively, during the operation, and 14 days later by means of real‐time quantitative reverse transcriptase‐polymerase chain reaction (RT‐PCR) targeting guanylyl cyclase C (GCC) mRNA in 42 colorectal cancer patients undergoing laparoscopic resections. Despite an increasing trend of FTC detection in patients with advancing stage, there is no significant difference in the preoperative FTC level by disease stage. No elevation in FTC level was found during the laparoscopic procedure in most patients compared with their preoperative FTC value. Patients with a persistently high FTC load [per nucleated blood cells (NBCs)] (> 102 FTCs/106 NBCs) 2 weeks postoperatively portends a poor prognosis regarding disease recurrence and tumor‐related mortality when compared to those with an undetectable or low FTC load (≤ 102 FTCs/106 NBCs). We concluded that the laparoscopic procedure itself had no significantly deleterious effect on circulating FTCs and that the detection of FTCs by real‐time qRT‐PCR might be of clinical importance during the postoperative follow‐up for colorectal cancer patients.
Using large‐scale climate indices in climate change ecology studies
Authors: Forchhammer Mads C. , Post Eric
Published: May 2004

Recently, climate change research in ecology has embraced the use of large‐scale climate indices in long‐term, retrospective studies. In most instances, these indices are related to large‐scale teleconnection and atmospheric patterns of which over a dozen have been identified. Although most of these relate to different geographical areas, many are related and interact. Consequently, even the simple task of selecting one to use in ecological research has become complicated, despite our ability to disentangle the results from analyses involving large‐scale climate indices. Leaning upon recent reviews of the definition and functioning of large‐scale climate indices, as well as reviews on the relationship between these and concomitant changes in ecological variables, we focus here on the usefulness of large‐scale climate indices in different aspects of climate change ecology. By providing a general framework for using climate indices, we illustrate the potential advantages of their utility by integrating three case histories focusing on two groups of evolutionarily distinct organisms: birds and mammals.
Critical evaluation of p53 as a prognostic marker in ovarian cancer
Authors: Hall Jacqueline , Paul Jim , Brown Robert
Published: May 2004

The tumour suppressor gene encoding p53 has been shown from experimental studies to have a crucial role in how cells respond to DNA damage. p53 has important functions in apoptosis, cell-cycle arrest and DNA repair, largely mediated by its activity on gene transcription. However, despite this wealth of in vitro data, its role in how tumours respond to DNA damage induced by chemotherapeutic drugs remains controversial. In this review, we highlight some of the problems surrounding design and analysis of studies of p53 as a prognostic marker of clinical outcome, using ovarian cancer as an example. We aim to build on the knowledge of the published literature in ovarian cancer to identify criteria for clinical studies that should give a more definitive estimate of the role of p53 in clinical drug resistance. A search of three public databases using keywords combined with Boolean operators identified 64 clinical publications investigating the relationship of p53 to clinical outcome following chemotherapy in ovarian cancer. Although 43% of 215 published analyses from the 64 papers reported a significant correlation between p53 status and a clinical endpoint relevant to chemoresistance, only six analyses fulfil minimum criteria and none of these finds a statistically significant correlation of p53 with chemotherapy-resistance endpoints. The results from published clinical studies suggest a more complex role of p53 mutation in the mechanism of resistance in ovarian cancer than is suggested by in vitro studies.
The Decision to Test in Women Receiving Genetic Counseling for BRCA1 and BRCA2 Mutations
Authors: Kelly Kimberly , Leventhal Howard , Andrykowski Michael , Toppmeyer Deborah , Much Judie , Dermody James , Marvin Monica , Baran Jill , Schwalb Marvin
Published: May 2004

Functions of genetic counseling include provision of risk information and provision of support in an effort to assist with decision making. This study examines (1) the relationship among intentions to test, self‐reported provision of blood sample, and receipt of test results; (2) the impact of genetic counseling on distress specific to gene status, perceived risk of developing breast and ovarian cancer in the context having BRCA1/2 mutations (mutations predisposing to increased risk of breast–ovarian cancer), and perceived risk factors for breast cancer; and (3) the clinical profile of those receiving/not receiving results. Intentions to test for BRCA1/2 mutations, self‐reported provision of blood sample immediately after counseling, and receipt of test results were statistically different but highly correlated, and intentions to test increased from pre‐ to postcounseling. A repeated measures ANOVA found distress specific to gene status and perceived risk factors decreased from pre‐ to postcounseling. Further, two clinical profiles of consultands emerged: (1) those receiving results with change in intentions to test having lower levels of distress and (2) those not receiving results and those receiving results with no change in intentions to test with higher levels of distress. Our findings are consistent with the function of genetic counseling—to provide information and support to those with familial cancer, as well as to assist in decision making. The provision of support is important as distress specific to gene status may impede flexible decision making about genetic testing.
Low‐velocity damaged structure of the San Andreas Fault at Parkfield from fault zone trapped waves
Authors: Li Yong‐Gang , Vidale John E. , Cochran Elizabeth S.
Published: May 2004

We used dense linear seismic arrays across and along the San Andreas Fault (SAF) at Parkfield, California to record fault zone trapped waves generated by explosions and microearthquakes in 2002. Prominent trapped waves appeared at stations close to the SAF main fault trace while some energy was trapped in the north strand at the array site. Observations and 3‐D finite‐difference simulations of trapped waves at 2–5 Hz show evidence of a damaged core zone on the main SAF. The zone from the surface to seismogenic depths is marked by a low‐velocity waveguide ∼150 m wide, in which Q is 10–50 and shear velocities are reduced by 30–40% from wall‐rock velocities, with the greatest velocity reduction at shallow depth. We interpret that this distinct low‐velocity zone on the main SAF is a remanent of damage due to past large earthquakes on the principal fault plane at Parkfield. A less‐developed low‐velocity zone may be evident on the north strand that experienced minor breaks in the 1966 M6 event.
Fine‐scale structure of the San Andreas fault zone and location of the SAFOD target earthquakes
Authors: Thurber C. , Roecker S. , Zhang H. , Baher S. , Ellsworth W.
Published: May 2004

We present results from the tomographic analysis of seismic data from the Parkfield area using three different inversion codes. The models provide a consistent view of the complex velocity structure in the vicinity of the San Andreas, including a sharp velocity contrast across the fault. We use the inversion results to assess our confidence in the absolute location accuracy of a potential target earthquake. We derive two types of accuracy estimates, one based on a consideration of the location differences from the three inversion methods, and the other based on the absolute location accuracy of “virtual earthquakes.” Location differences are on the order of 100–200 m horizontally and up to 500 m vertically. Bounds on the absolute location errors based on the “virtual earthquake” relocations are ∼50 m horizontally and vertically. The average of our locations places the target event epicenter within about 100 m of the SAF surface trace.
Electrical resistivity structure at the SAFOD site from magnetotelluric exploration
Authors: Unsworth Martyn , Bedrosian Paul A.
Published: May 2004

The magnetotelluric dataset collected on the San Andreas Fault at Parkfield has been re‐analyzed using superior inversion algorithms that have been developed in recent years. A combination of constrained inversion, forward modeling and synthetic inversion studies are used, and show that at the SAFOD site, the low resistivity fault zone extends to a depth of 2–3 km. An extended zone of low resistivity east of the San Andreas Fault may be connected to the SAF at seismogenic depths. The connection increases along the SAF to the northwest and may be related to the transition from locked to creeping seismic behavior.
Nonlinear Alfvén waves: 1. Interactions between outgoing and ingoing waves according to an amplitude expansion
Authors: Vasquez Bernard J. , Hollweg Joseph V.
Published: May 2004

We expand the compressible magnetohydrodynamic (MHD) equations in terms of the amplitude of first‐order Alfvén waves. Incompressible MHD equations are treated as a special case. We examine the evolution of mildly oblique Alfvén waves consisting of forward and backward propagating waves so that these would correspond to the interactions of outgoing and ingoing Alfvén waves in the solar wind. We obtain the solutions of these equations through second order. We find and distinguish three types of second‐order modes which have zero frequency and are generated in association with nonsecular interactions of mildly oblique first‐order Alfvén waves. Two of these modes have wave vectors which are perpendicular to the background magnetic field. Both are associated with magnetic energy but they do not have kinetic energy.
Nonlinear Alfvén waves: 2. The influence of wave advection and finite wavelength effects
Authors: Vasquez Bernard J. , Markovskii Sergei A. , Hollweg Joseph V.
Published: May 2004

Using a hybrid code, we examine the effects of mildly oblique, low‐frequency Alfvén waves on cross‐field pressure‐balanced structures of varying scales. We show that the evolution is organized by a parameter ξ = AwcAk⊥/ω, where Aw is the relative wave amplitude, k⊥ is the characteristic wave number of a cross‐field structure, and ω is a characteristic wave frequency. This parameter is a measure of the relative displacement of the structure by the wave. When ξ ≪ 1, agreement with small‐amplitude solutions and linear wave theory is good. Waves can refract and undergo cross‐field energy transfer, which is a finite wavelength effect. When ξ is large, advection of the structure is significant and small‐amplitude solutions are not valid. The rate of wave refraction diminishes as the effective Alfvén speed gradient is diluted over a wave period by significant advection. When the structure is purely magnetic and polarized like an Alfvén wave, significant advection converts the structure into waves which have an Alfvénic character but do not always satisfy energy equipartition. Nonlinear wave interactions occur between Alfvén and gradient‐derived waves, wherein the Alfvén wave undergoes partial reflection and continued cross‐field energy transfer. When sufficiently small parallel scales are produced by advection, proton cyclotron resonant heating and damping occurs on all field lines so that both Alfvén and gradient‐derived waves undergo dissipation.
New properties of energy‐dispersed ions in the plasma sheet boundary layer observed by Cluster
Authors: Keiling A. , Rème H. , Dandouras I. , Bosqued J. M. , Sergeev V. , Sauvaud J.‐A. , Jacquey C. , Lavraud B. , Louarn P. , Moreau T. , Vallat C. , Escoubet C. P. , Parks G. K. , McCarthy M. , Möbius E. , Amata E. , Klecker B. , Korth A. , Lundin R. , Daly P. , Zong Q.‐G.
Published: May 2004

Using multipoint measurements from the Cluster ion spectrometry instruments and the research with adaptive particle imaging detectors, we identified new properties of multiple energy‐dispersed ion structures in the plasma sheet boundary layer (PSBL). On 14 February 2001 at about 4.5 RE midnight local time, the PSBL was highly structured, showing several large‐scale dispersed ion structures, which were substructured into several (up to four) beamlets with a quasiperiodicity of 1–3 min in the spacecraft frames. The different spacecraft (SC) recorded the first dispersed ion structures at different times and on different L shells at the outer edge of the PSBL within 2 min. Three different energy dispersions were associated with the dispersed ion structures. (1) The energy dispersion of the larger‐scale structures was due to the decreasing energy of individual beamlets, covering energies from 2 to >40 keV. (2) Individual beamlets of each large‐scale structure showed themselves energy dispersion along the peak flux line with varying slopes, but in all cases these slopes were steeper compared to the dispersion associated with the large‐scale structure. (3) A third steep energy dispersion occurred at the beginning of each beamlet and covered an energy range from a few keV to >100 keV. This dispersion was associated with recurrent impulsive acceleration processes at 11–27 RE radial distance with a quasiperiodicity of 1–3 min. Moreover, most beamlets showed pitch angle dispersion. Superimposed on the dispersed ion structures were two transient ion injections, which had the same energy dispersion slope as described in item 3 (above), suggesting an association with the beamlets. The beamlets and one of the transient ion injections were recorded for different ion species: hydrogen, helium, and oxygen. Furthermore, echoes of beamlets were recorded, which makes this the first observation of bouncing ions in the PSBL. The echoes showed higher energy fluxes than the initial beamlets, indicating additional acceleration during subsequent current sheet crossings. Gradual thermalization of the initial beamlets after multiple current sheet crossings possibly led to the formation of the central plasma sheet. SC 1 and SC 3, longitudinally separated by only 100 km, recorded very different beamlet structures, which we interpret as a spatial effect; the two beamlet structures mapped into different magnetotail regions and underwent different spatiotemporal histories. Two possible scenarios are discussed to understand the spatiotemporal history of this highly structured PSBL.
Retrievals of nighttime electron density from Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) mission Global Ultraviolet Imager (GUVI) measurements
Authors: DeMajistre R. , Paxton L. J. , Morrison D. , Yee J.‐H. , Goncharenko L. P. , Christensen A. B.
Published: May 2004

In this work we will present a method for retrieving nighttime electron density profiles from OI 135.6 nm limb emissions measured by the Global Ultraviolet Imager (GUVI) aboard the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) mission spacecraft. The primary mechanism for 135.6 nm radiance in the nighttime thermosphere is recombination of O+ ions, and the volume emission rate is approximately proportional to the square of the electron density. Herein we describe a two‐step inversion method in which we first determine the volume emission rate as a function of altitude from the radiance measurements and then use the inferred volume emission rates to determine the electron density profile. There are two important factors that we have addressed in constructing the retrieval algorithms for this problem. First, the GUVI instrument was primarily designed for day side measurements. Consequently, the signal levels on the night side are very low, and our retrieval algorithms must therefore be able to function in regions where the signals are weak. Second, since we must take the square root of the volume emission rate, it must be everywhere positive in order for the electron density to be deduced. For this reason, we have imposed nonnegativity constraints (using the methods described by Menke [1989]) on what might otherwise be discrete linear retrievals of volume emission rate. After describing the retrieval method we present an error analysis and a preliminary comparison with coincident measurements by incoherent scatter radars (ISRs). In general, the retrieved electron densities from the GUVI data agree well with the ISR data, although more coincident measurements would increase our confidence in the resulting electron density profiles.
Dynamic evolution of a fault system through interactions between fault segments
Authors: Ando Ryosuke , Tada Taku , Yamashita Teruo
Published: May 2004

We simulate the dynamic evolution process of fault system geometry considering interactions between fault segments. We calculate rupture propagation using an elastodynamic boundary integral equation method (BIEM) in which the trajectory of a fault tip is dynamically self‐chosen. We consider a system of two noncoplanar fault segments: a preexisting main fault segment (fault 1) and a subsidiary one (fault 2) and, allowing the tip of fault 2 to deviate from its original plane, trace its trajectory in the step over region between the two fault segments. Our simulation results show that the final geometry of fault 2 depends on the initial configuration of the two fault segments. If the initial overlap of the two fault segments is smaller than the half length of fault 1, fault 2 coalesces with fault 1 when the step over is narrower than about 1/4–1/2 the length of the latter but is repelled from fault 1 when the step over width is larger than this threshold value. We also show that the inclination angle of fault 2 is sensitive to the rupture velocity; the inclination is larger for faster rupture propagation. Our simulation results imply that as ruptures occur repeatedly, a fault system evolves from an array of relatively small fault segments into a sequence of larger ones. Our results seem consistent with the field observations of natural fault system geometries, which are often characterized by a set of noncoplanar segments interconnected with relatively small jogs at oblique angles.