bluuebunny/crossref_metadata_2025 huggingface dataset:
Reply by the author to H. N. Collins
Authors: Carlson R. L.
Published: October 2002

In our paper on P‐wave anisotropy in deep‐sea carbonates we assessed the degree of water saturation in the samples by a weighted linear regression of [Formula: see text] on Φ in the form [Formula: see text] (1) where [Formula: see text] is bulk density, [Formula: see text] is grain density, Φ is fractional porosity, and [Formula: see text] where [Formula: see text] is fluid density.
Reply by the author to E. Szaraniec
Authors: Parker R. L.
Published: October 2002

I thank Dr. Szaraniec for his comments and valuable criticism. I readily admit to being poorly informed upon the history of the resistivity sounding problem but the references provided in Dr. Szaraniec’s list amply compensate for my oversight.
Reply by the author to N. C. Steenland
Authors: Davies F. Bryan
Published: October 2002

I agree with Steenland’s general remarks on my discussion of Hammer’s paper, except for a clarification of my comment on the Nyquist topic.
Reply by the author to B. J. Evans
Authors: René R. M.
Published: October 2002

I wish to thank Dr. Evans for his comments. In the data of the subject paper, hodograms differ from particle motion for frequency components below the resonant frequency of the geophone (8 Hz) or above the corner frequency of the anti‐aliasing filter (125 Hz). The necessity of compensation for phase response depends upon the nature of the signal and purpose of the study. The method of multicomponent complex trace analysis is largely concerned with phase differences between vertical and horizontal components of motion.
Reply by the author to F. K. Levin
Authors: Thomsen Leon
Published: October 2002

Levin is correct, of course, in his evaluation of the apparent implications of the anisotropies tabulated in the subject paper. Taken at face value, they do imply that moveout velocities may differ from vertical velocities by more than a few percent. Since some subtleties are involved, however, I take this opportunity to amplify his analysis.
Response by R. Ignetik to the author's reply
Authors: Ignetik Rainer
Published: October 2002

It would be interesting to compare the two computational algorithms proposed by Raiche with Boerner and West's approach, to see which of the three is computationally fastest under similar conditions. I also note that although the semi-analytic algorithm proposed by Raiche is more elegant and may require less storage, the paper does not make it entirely clear whether we get a real reduction in computing time; reduced computational time was the motivation for the procedure in the first place.
On: “Seismic stratigraphy study of algal mound reservoirs, Patterson and Nancy fields, Paradox basin, San Juan County, Utah by T. L. Davis and G. M. Jackson (GEOPHYSICS, 53, 875–880, July 1988).
Authors: Biswas Buddhadeb
Published: October 2002

The editors are to be thanked profusely for trying to strike a balance between theoretical papers and case history papers of much interest to the profession. I would appreciate discussing the following points relating to this excellent contribution by Dr. Davis and Mr. Jackson.
Reply by author to L. B. Pedersen
Authors: Chan Kwok C.
Published: October 2002

I would like to thank Prof. Pedersen for his interest in the paper that the late Dr. Bhattacharyya and I coauthored more than a decade ago.
Reply by the author to M. Ivan
Authors: Plouff Donald
Published: October 2002

I thank M. Ivan for the suggestion to substitute an arctangent term and another term for the arccosine term in equation (3). Without verifying the mathematics, I assume that this substitution would permit faster arctangent addition for clusters of four terms, a mathematical operation that I discussed in the section entitled “Supplementary Notes.” Okabe (1979, p. 739) and M. Ivan have questioned my use of the theorem from analytic geometry, which calculates the angle between intersecting lines with given slopes.
Reply by the authors to F. K. Levin
Authors: Chen S. T.
Published: October 2002

My coauthors and I agree with the Discussion by Dr. Levin. We appreciate the valuable information of his early work and his constructive comments.
On: “Why don’t we measure seismic signatures?” by A. Ziolkowski (GEOPHYSICS, 56, 190–201, February 1991).
Authors: Jin Doo Jung
Published: October 2002

I read Ziolkowski’s paper with great interest, and in my opinion, it addresses some very important aspects of seismic deconvolution, however it contains several statements that need discussion. My discussion concerns Ziolkowski’s description and evaluation of homomorphic deconvolution, starting with the last paragraph of p. 194.
On: “Why don’t we measure seismic signatures?” by A. Ziolkowski (GEOPHYSICS, 56, 190–201, February 1991)
Authors: Jain Sudhir
Published: October 2002

In his excellent paper, Ziolkowski points to nonlinearity as a reason for the invalidity of seismic wavelets computed from sonic logs and stacked seismic traces. Many additional reasons contribute to the failure of this process in practice. These reasons are practical, having to do with imperfections of actual recordings. Some of the reasons are as follows.
Reply by the author to E. Gerald Hensel
Authors: LaFehr T. R.
Published: October 2002

Mr. Hensel’s discussion is a positive contribution to an understanding of curvature effects. I am especially grateful to learn of Talwani’s formula, which had not only escaped my search, but also that of the several reviewers, one of whom expended some effort on the matter. Dr. Bob Bean has pointed out two additional references (Lejay, 1947; Qureshi, 1976). Although there is no way to be sure, I doubt that Sir Edward Bullard used an earth radius substantially in error. [The radius at mid‐latitudes was known to be greater than 6365 km much earlier (Dana, 1871.)] It seems more likely to me that the Cassinis tables (or the way they were used) addressed a somewhat different model, perhaps including that part of the spherical sector which is labeled as “C” in Figure A‐1 in my paper.
Response by J. M. Mendel to the reply by the author
Authors: Mendel J. M.
Published: October 2002

I thank Prof. Ziolkowski for his reply to my comments. He has correctly pointed out a flaw in my lossy convolutional model; however, he has made new statements about random quantities that are once again in error, and must be called to the attention of the reader. In this response to his reply (I hope this does not continue ad infinitum), I first focus on the latter and then make additional comments about modeling for statistical‐based deconvolution, model validation, and statistical‐based deconvolution.
Response by the author to the response by J. M. Mendel
Authors: Ziolkowski A.
Published: October 2002

I thank Prof. Mendel for his response to my reply to his discussion on my paper and I thank the Editor of Geophysics for allowing the author to have a last word.
Reply by the authors to N. L. Mohan
Authors: Roest W. R. , Verhoef J. , Pilkington M.
Published: October 2002

The purpose of our paper (Roest et al., 1992) was to present the generalization of the analytic signal (Nabighian, 1972) from two to three dimensions and illustrate its use in magnetic interpretation. The comments by Dr. Mohan can be separated into three categories.
Reply by the authors to A. Tarantola
Authors: Mittet Rune , Houlder Tom
Published: October 2002

We highly appreciate the piquant comment to our paper from Professor Tarantola. One of the first attempts to investigate systematically the sensitivity of seismic data to perturbations of different sizes was done by Jannane et al. (1989). What we found provocative in that paper was not the results, but the fact that general conclusions were drawn based on a single set of numerical experiments with only one measure of the sensitivity, the [Formula: see text] type objective function. The only reservation taken by the authors is that their results apply only to isotropic, perfectly elastic models of the earth. In general, the validity of a theory or a hypothesis cannot be demonstrated (proved) by performing numerical experiments of this type. Every (numerical) experiment supporting a theory (or a hypothesis) will strengthen the belief in it. However, only one (numerical) experiment with the opposite result can falsify a theory or a hypothesis.
Reply by author to N. Steenland
Authors: McCaffrey Robert
Published: October 2002

The authors thank Nelson Steenland for his interesting comments, which we welcome and which we feel are most constructive. As he suggests, other geophysical methods are ‘time‐proven’, but our main intention was to use a relatively new method and subsequently to bring it to the attention of a wider audience. The method has subsequently been used in a similar geological situation with, again, some success (McCaffrey et al., 1995).
Reply by the author to Pierre Valla
Authors: Das Umesh C.
Published: October 2002

I thank Pierre Valla for his interest in my paper (Das, 1995a). Transformation of controlled source electromagnetic (CSEM) measurements into apparent resistivities is carried out as an intermediate step in order to enhance interpretation. Duroux (1967; and hence Valla, 1984) derives, using asymptotic expressions (higher order terms are dropped out), apparent resistivities from CSEM measurements. Valla mentions, ‘those apparent resistivities do not have the nice asymptotic behavior’, and they can not be used as an intermediate step to estimate the layer resistivities and thicknesses in the subsurface. My aim in the paper has been not to work a ‘miracle’ but to derive a function to reflect the subsurface resistivity distributions of the layered earth structures directly. The calculations on a few models indicate that such a function can be derived which yields an unambiguous apparent resistivity. The apparent resistivity curves are similarly useful in interpretation as the direct current and magnetotelluric apparent resistivity curves. Inclusion of Duroux’s work would have given the readers a chance to appreciate my definition.
Seismic array theorem and rapid calculation of acquisition footprint noise
Authors: Schuster Gerard T. , Liu Zhaojun
Published: October 2002

The acquisition footprint noise in migrated sections partly consists of migration artifacts associated with a discrete recording geometry. Such noise can corrupt the interpretation of seismic sections for stratigraphic variations, AVO signatures, and enhanced oil recovery operations. We show that the point scatterer response of the far‐field Kirchhoff migration operator, which reveals acquisition footprint noise, is proportional to the stretched Fourier transform of the source and geophone sampling function. Using the array theorem developed by optical and electrical engineers, this Fourier transform for an orthogonal recording geometry can be calculated quickly by a product of 1‐D analytical functions. Thus, the acquisition footprint noise in migrated sections can be calculated efficiently for different recording arrays. By rapid trial and error or by an optimization method, the survey planner can use this theorem to help design a better recording geometry.
Seismic sequence analysis and attribute extraction using quadratic time‐frequency representations
Authors: Steeghs Philippe , Drijkoningen Guy
Published: October 2002

The variation of frequency content of a seismic trace with time carries information about the properties of the subsurface reflectivity sequence. As a result, analysis of the data in terms of the local frequency content can provide a worthwhile addition to the standard procedures that are used in seismo‐stratigraphic interpretation. The theory of quadratic time‐frequency representations provides a solid foundation for local frequency analysis of seismic data and seismic attribute extraction. Two applications of the quadratic time‐frequency representations are demonstrated: seismic sequence analysis and seismic attribute extraction. The joint time‐frequency representation of a seismic reflection pattern is often much more easily interpreted in terms of subsurface stratification than the time‐or frequency‐domain description alone. We show how the time‐frequency representation can be used to delineate seismic sequences on the basis of the time‐frequency characteristics of the signal. There exists a close relation between complex‐trace attribute analysis and quadratic time‐frequency representations. In the time‐frequency approach, the seismic attributes are characteristics of the local spectrum. Extraction of the attributes from the time‐frequency representation of the seismic trace leads to considerable improvement of the signal‐to‐noise ratio of the attributes. Furthermore, the classic set of seismic attributes of instantaneous amplitude, phase, and frequency can be easily extended with other parameters describing the local spectrum, such as instantaneous bandwidth, skewness, and kurtosis.
On hitting times for compound Poisson dams with exponential jumps and linear release rate
Authors: Kella Offer , Stadje Wolfgang
Published: October 2002

For a compound Poisson dam with exponential jumps and linear release rate (shot-noise process), we compute the Laplace-Stieltjes transform (LST) and the mean of the hitting time of some positive level given that the process starts from some given positive level. The solution for the LST is in terms of confluent hypergeometric functions of the first and second kinds (Kummer functions).
Energy of a string driven by a two-parameter Gaussian noise white in time
Authors: Belinskiy Boris P. , Caithamer Peter
Published: October 2002

In this paper we consider the stochastic wave equation in one spatial dimension driven by a two-parameter Gaussian noise which is white in time and has general spatial covariance. We give conditions on the spatial covariance of the driving noise sufficient for the string to have finite expected energy and calculate this energy as a function of time. We show that these same conditions on the spatial covariance of the driving noise are also sufficient to guarantee that the energy of the string has a version which is continuous almost surely.
Distribution-free confidence intervals for measurement of effective bandwidth
Authors: Györfi László , Rácz András , Duffy Ken , Lewis John T. , Toomey Fergal
Published: October 2002

Hoeffding's inequality can be used in conjunction with the declared parameters of a traffic source, such as its peak rate, to obtain confidence intervals for measurements of the traffic's effective bandwidth. We describe a variety of interval-estimation procedures based on this idea, designed to provide differing degrees of robustness against non-stationarity. We also discuss how to compute confidence intervals for the effective bandwidth of an aggregate of traffic sources.
Hypothesis testing and Skorokhod stochastic integration
Authors: Privault Nicolas
Published: October 2002

We define a class of anticipative flows on Poisson space and compute its Radon-Nikodym derivative. This result is applied to statistical testing in an anticipative queueing problem.
An unexpected connection between branching processes and optimal stopping
Authors: Assaf David , Goldstein Larry , Samuel-Cahn Ester
Published: October 2002

A curious connection exists between the theory of optimal stopping for independent random variables, and branching processes. In particular, for the branching process Zn with offspring distribution Y, there exists a random variable X such that the probability P(Zn = 0) of extinction of the nth generation in the branching process equals the value obtained by optimally stopping the sequence X1,…, Xn, where these variables are i.i.d. distributed as X. Generalizations to the inhomogeneous and infinite horizon cases are also considered. This correspondence furnishes a simple ‘stopping rule’ method for computing various characteristics of branching processes, including rates of convergence of the nth generation's extinction probability to the eventual extinction probability, for the supercritical, critical and subcritical Galton-Watson process. Examples, bounds, further generalizations and a connection to classical prophet inequalities are presented. Throughout, the aim is to show how this unexpected connection can be used to translate methods from one area of applied probability to another, rather than to provide the most general results.
Open-loop routeing to M parallel servers with no buffers
Authors: Altman Eitan , Bhulai Sandjai , Gaujal Bruno , Hordijk Arie
Published: October 2002

In this paper we study the assignment of packets to M parallel heterogeneous servers with no buffers. The controller does not have knowledge on the state of the servers and bases all decisions on the number of time slots ago that packets have been sent to the different servers. The objective of the controller is to minimize the expected average cost. We consider a general stationary arrival process, with no independence assumptions. We show that the problem can be transformed into a Markov Decision Process (MDP). We further show under quite general conditions on cost functions that only a finite number of states have to be considered in this MDP, which then implies the optimality of periodic policies. For the case of two servers we obtain a more detailed structure of the cost and optimal policies. In particular we show that the average cost function is multimodular, and we obtain expressions for the cost for MMPP and MAP processes. Finally we present an application to optimal robot scheduling for Web search engines.
Dynamics of large uncontrolled loss networks
Authors: Zachary Stan
Published: October 2002

This paper studies the connection between the dynamical and equilibrium behaviour of large uncontrolled loss networks. We consider the behaviour of the number of calls of each type in the network, and show that, under the limiting regime of Kelly (1986), all trajectories of the limiting dynamics converge to a single fixed point, which is necessarily that on which the limiting stationary distribution is concentrated. The approach uses Lyapunov techniques and involves the evolution of the transition rates of a stationary Markov process in such a way that it tends to reversibility.
On the dependence structure and bounds of correlated parallel queues and their applications to synchronized stochastic systems
Authors: Li Haijun , Xu Susan H.
Published: October 2002

This paper studies the dependence structure and bounds of several basic prototypical parallel queueing systems with correlated arrival processes to different queues. The marked feature of our systems is that each queue viewed alone is a standard single-server queuing system extensively studied in the literature, but those queues are statistically dependent due to correlated arrival streams. The major difficulty in analysing those systems is that the presence of correlation makes the explicit computation of a joint performance measure either intractable or computationally intensive. In addition, it is not well understood how and in what sense arrival correlation will improve or deteriorate a system performance measure.

The objective of this paper is to provide a better understanding of the dependence structure of correlated queueing systems and to derive computable bounds for the statistics of a joint performance measure. In this paper, we obtain conditions on arrival processes under which a performance measure in two systems can be compared, in the sense of orthant and supermodular orders, among different queues and over different arrival times. Such strong comparison results enable us to study both spatial dependence (dependence among different queues) and temporal dependence (dependence over different time instances) for a joint performance measure. Further, we derive a variety of upper and lower bounds for the statistics of a stationary joint performance measure. Finally, we apply our results to synchronized queueing systems, using the ideas combined from the theory of orthant and supermodular dependence orders and majorization with respect to weighted trees (Xu and Li (2000)). Our results reveal how a performance measure can be affected, favourably or adversely, by different types of dependencies.
Some new results on stochastic comparisons of parallel systems
Authors: Khaledi Baha-Eldin , Kochar Subhash
Published: October 2002

Let X1,…,Xn be independent exponential random variables with Xi having hazard rate . Let Y1,…,Yn be a random sample of size n from an exponential distribution with common hazard rate ̃λ = (∏i=1nλi)1/n, the geometric mean of the λis. Let Xn:n = max{X1,…,Xn}. It is shown that Xn:n is greater than Yn:n according to dispersive as well as hazard rate orderings. These results lead to a lower bound for the variance of Xn:n and an upper bound on the hazard rate function of Xn:n in terms of . These bounds are sharper than those obtained by Dykstra et al. ((1997), J. Statist. Plann. Inference65, 203–211), which are in terms of the arithmetic mean of the λis. Furthermore, let X1*,…,Xn∗ be another set of independent exponential random variables with Xi∗ having hazard rate λi∗, i = 1,…,n. It is proved that if (logλ1,…,logλn) weakly majorizes (logλ1∗,…,logλn∗, then Xn:n is stochastically greater than Xn:n∗.
On the severity of M/M/∞ congested episodes
Authors: Preater J.
Published: October 2002

The Laplace transform is obtained for the joint length and height of an M/M/∞ queue excursion above occupancy level C.
Convergence in distribution of the multi-dimensional Kohonen algorithm
Authors: Sadeghi Ali A.
Published: October 2002

Here we consider the Kohonen algorithm with a constant learning rate as a Markov process evolving in a topological space. Despite the fact that the algorithm is not weak Feller, we show that it is a T-chain, regardless of the dimensionalities of both data space and network and the special shape of the neighborhood function. In addition for the practically important case of the multi-dimensional setting, it is shown that the chain is irreducible and aperiodic. We show that these imply the validity of Doeblin's condition, which in turn ensures the convergence in distribution of the process to an invariant probability measure with a geometric rate. Furthermore, it is shown that the process is positive Harris recurrent, which enables us to use statistical devices to measure the centrality and variability of the invariant probability measure. Our results cover a wide class of neighborhood functions.
Average optimal policies in a controlled queueing system with dual admission control
Authors: Lewis Mark E.
Published: October 2002

We consider a controlled M/M/1 queueing system where customers may be subject to two potential rejections. The first occurs upon arrival and is dependent on the number of customers in the queue and the service rate of the customer currently in service. The second, which may or may not occur, occurs immediately prior to the customer receiving service. That is, after each service completion the customer in the front of the queue is assessed and the service rate of that customer is revealed. If the second decision-maker recommends rejection, the customer is denied service with a fixed probability. We show the existence of long-run average optimal monotone switching-curve policies. Further, we show that the average reward is increasing in the probability that the second decision-maker's recommendation of rejection is honored. Applications include call centers with delayed classifications and manufacturing systems when the server is responsible for multiple tasks.
Modulation of growth and radiochemosensitivity of human malignant glioma cells by acidosis
Authors: Reichert Manuela , Steinbach Joachim P. , Supra Petra , Weller Michael
Published: October 2002

BACKGROUND

Glioblastoma commonly is characterized by hypoxia and acidosis and the histologic features of tissue necrosis and neovascularization. Current approaches of adjuvant radiochemotherapy for patients with glioblastoma have only a modest impact on the natural course of this disease.

METHODS

The authors examined the effects of acidosis on growth and response to irradiation and chemotherapy in cultured human malignant glioma cells.

RESULTS

The authors found that mild acidosis (pH 7.0) inhibited the growth of cell lines that retained wild type p53 activity but did not inhibit the growth of cell lines that were devoid of p53 function. Transfer of a dominant‐negative p53 gene into p53 wild type cells failed to override the acidosis‐conferred growth arrest, suggesting that loss of p53 activity per se does not mediate escape from acidosis‐induced growth inhibition. Moderate acidosis (pH 6.6) inhibited the growth of all cell lines. Acidosis‐mediated growth arrest was not associated with a specific type of cell cycle arrest, e.g., in G0/G1 or G2/M phase. Acidosis did not result in consistent changes in radiosensitivity; however, it enhanced the cytotoxic effects of lomustine but conferred protection from topotecan, vincristine, teniposide, and cisplatin cytotoxicity. Lomustine exhibited enhanced stability at low pH, providing a putative mechanism for the enhanced cytotoxic effects of lomustine in acidotic conditions. Decreased sensitivity to the other drugs did not result from altered multidrug resistance drug transport activity.

CONCLUSIONS

Taken together, the current results suggest that tissue acidosis may be an important determinant of glioma cell responses to adjuvant radiochemotherapy. The superior activity of nitrosoureas, such as lomustine, compared with other agents in patients with glioblastoma may result in part from prolonged drug stability in an acidotic microenvironment. Cancer 2002;95:1113–9. © 2002 American Cancer Society.

DOI 10.1002/cncr.10767
Immunomodulatory effects of high‐dose and low‐dose interferon α2b in patients with high‐risk resected melanoma
Authors: Kirkwood John M. , Richards Thomas , Zarour Hassane M. , Sosman Jeffrey , Ernstoff Marc , Whiteside Theresa L. , Ibrahim Joseph , Blum Ronald , Wieand Samuel , Mascari Ruth
Published: October 2002

BACKGROUND

The clinical antitumor activity of recombinant interferon α2b (IFNα2b) has been well documented in patients with advanced and high‐risk melanoma; however, its mechanism of action remains conjectural. Trial E2690 evaluated the immunomodulatory effects of IFNα2b in vivo during treatment at high doses (the HDI arm; n = 51 patients) and at low doses (the LDI arm; n = 54 patients) in relation to standard observation (OBS; n = 43 patients).

METHODS

This study evaluated peripheral blood lymphocytes (PBLs) for phenotypic markers and cytotoxic functions at 1 month, 3 months, and 12 months in the HDI arm, the LDI arm, and the OBS arm and examined correlations between changes observed in PBLs or in tumors with regard to treatment dosage and disease outcome. Tumor biopsy samples were studied for response to IFNα2b at a range of concentrations in vitro.

RESULTS

Baseline blood phenotypic and functional assays did not predict disease outcome; however, modulation of these immunologic assays by IFNα2b treatment was observed and was associated with IFNα2b dosage. Tumor cell class II major histocompatibility antigen expression (human leukocyte/lymphocyte antigen DR) and adhesion molecule expression (ICAM‐1) were modulated by exposure to IFNα2b in a dose dependent manner. Blood natural killer (NK) cell function, T‐cell function, and subset distribution were modulated early by patients in the HDI arm and later by patients in the LDI arm. None of the variables tested in these studies predicted recurrence free survival. The numbers of patients studied were smaller than may be needed to detect potentially clinically significant changes.

CONCLUSIONS

These data demonstrate changes in immunologic parameters associated with IFNα2b treatment and dosage that may account for some of the differences in the clinical efficacy of this modality. The current results also suggest the need for further study of newer molecular intermediates of IFNα2b and T‐cell response to specific antigens of melanoma. Cancer 2002;95:1101–12. © 2002 American Cancer Society.

DOI 10.1002/cncr.10775
Thirteen‐year, long‐term efficacy of interferon 2α and interleukin 2‐based home therapy in patients with advanced renal cell carcinoma
Authors: Atzpodien Jens , Hoffmann Reinhard , Franzke Marcus , Stief Christian , Wandert Thomas , Reitz Martina
Published: October 2002

BACKGROUND

The goal of the current report was to demonstrate the long‐term efficacy of outpatient subcutaneous (sc) interferon α (IFN‐α) and sc interleukin 2 (IL‐2)‐based combination regimens in patients with metastatic renal cell carcinoma.

METHODS

In three consecutive clinical trials, 443 patients received combined sc IFN‐α and sc IL‐2 (n = 97 patients); combined sc IFN‐α, sc IL‐2, and intravenous (iv) 5‐fluorouracil (5‐FU) (n = 260 patients); or combined sc IFN‐α, sc IL‐2, and iv 5‐FU with oral 13cis‐retinoic acid (n = 86 patients).

RESULTS

The median overall survival was 21+ months. The 2‐year, 5‐year, and 13‐year survival rates were calculated at 45.26%, 15.96%, and 8.96%, respectively. The median time to disease progression was 6 months. The 2‐year, 5‐year, and 13‐year progression free survival rates were 17.84%, 9.54%, and 9.20%, respectively.

CONCLUSIONS

The current data suggest that combined outpatient sc IFN‐α and sc IL‐2, according to the Atzpodien regimen, achieves long‐term survival benefits in a subset of patients with metastatic renal cell carcinoma, both with and without 13‐cis‐retinoic acid and/or 5‐fluorouracil. Cancer 2002;95:1045–50. © 2002 American Cancer Society.

DOI 10.1002/cncr.10783
Role of ultrasound‐guided fine‐needle aspiration of indeterminate and suspicious axillary lymph nodes in the initial staging of breast carcinoma
Authors: Krishnamurthy Savitri , Sneige Nour , Bedi Deepak G. , Edieken Beth S. , Fornage Bruno D. , Kuerer Henry M. , Singletary S. Eva , Hunt Kelly K.
Published: October 2002

BACKGROUND

Ultrasound (US) is more sensitive than physical examination alone in determining axillary lymph node involvement during preliminary staging of breast carcinoma. Due to occasional overlap of sonographic features of benign and indeterminate lymph nodes, fine‐needle aspiration (FNA) of sonographically indeterminate/suspicious lymph nodes can provide a more definitive diagnosis than US alone. This study was undertaken to determine the diagnostic accuracy of US‐guided FNA of indeterminate/suspicious/metastatic‐appearing axillary lymph nodes during the initial staging of breast carcinoma.

METHODS

The cytology of 103 cases of US‐guided FNA of nonpalpable indeterminate/suspicious/metastatic‐appearing lymph nodes was compared with the final histopathologic status of the entire axilla after axillary dissection. The final axillary lymph node status was categorized as either negative when all lymph nodes were negative for metastasis or positive when there was evidence of metastasis in one or more lymph nodes. The sensitivity, specificity, diagnostic accuracy, and false‐negative rate of US‐guided FNA of nonpalpable axillary lymph nodes in the preliminary staging process were calculated.

RESULTS

In 51 of 103 cases (49.5%), the US‐guided FNA and histopathology were both positive for metastasis. In 24 of 103 cases (23.3%), both were negative. The apparent false‐positive FNA in 16 (15.5%) cases was explained by the complete response of the metastatic lymph nodes to neoadjuvant chemotherapy in the interval between FNA and axillary dissection. In 12 cases (11.6%), US‐guided FNA was negative, but metastasis was seen in histologic sections. All cases with three or more lymph nodes with metastatic disease and 93% of those with metastatic deposit measuring more than 0.5 mm were detected by US‐guided FNA. The probability of detecting lymph nodes with smaller metastatic deposit measuring less than 0.5 cm was 44%. The overall sensitivity of US‐guided FNA was 86.4%, the specificity was 100%, the diagnostic accuracy was 79.0%, the positive predictive value was 100%, and the negative predictive value was 67%.

CONCLUSIONS

US‐guided FNA of nonpalpable indeterminate and suspicious axillary lymph nodes is a simple, minimally invasive, and reliable technique for the initial determination of axillary lymph node status in breast carcinoma. The common causes of discrepancy between the initial and final axillary lymph node status include failure to visualize all lymph nodes during US examination, small‐sized metastases, and preoperative neoadjuvant chemotherapy. Cancer 2002;95:982–8. © 2002 American Cancer Society.

DOI 10.1002/cncr.10786
Salvage combination chemotherapy with 5‐fluorouracil and actinomycin D for patients with refractory, high‐risk gestational trophoblastic tumors
Authors: Matsui Hideo , Suzuka Kiyomi , Iitsuka Yoshinori , Yamazawa Koji , Tanaka Naotake , Mitsuhashi Akira , Seki Katsuyoshi , Sekiya Souei
Published: October 2002

BACKGROUND

The objective of this study was to evaluate the efficacy and toxicity of a high‐dose 5‐fluorouracil and actinomycin D regimen (the FA regimen) as salvage chemotherapy for patients with high‐risk gestational trophoblastic tumors (GTTs).

METHODS

From 1985 to 1997, 10 patients with refractory, high‐risk GTTs were treated with the FA regimen at Chiba University Hospital. Of those 10 patients, 7 patients developed drug resistance to methotrexate, etoposide, and actinomycin D combination chemotherapy (the MEA regimen); 1 patient developed recurrent disease after receiving the MEA regimen; and 2 patients developed recurrent disease after receiving combination chemotherapy with etoposide, methotrexate, and actinomycin D alternating with cyclophosphamide and vincristine (the EMA/CO regimen). The hematologic toxicity of the FA regimen was graded at every chemotherapy course.

RESULTS

With the FA regimen, the survival rate was 80.0% (8 of 10 patients) for a mean follow‐up of 10 years. Two patients died due to multidrug resistance, and two patients subsequently developed recurrent disease. The two patients with recurrent disease were successfully salvaged again with the MEA regimen. The toxicity of the FA regimen was evaluated in 78 cycles. Myelosuppression seemed to be the dose‐limiting toxicity, and the incidences of World Health Organization Grade 4 leukocytopenia and thrombocytopenia were 6.4% and 3.8%, respectively, of 78 cycles.

CONCLUSIONS

Although etoposide‐containing chemotherapy is currently the most effective and well‐tolerated regimen for patients with high‐risk GTTs, 20–30% of patients develop resistance to etoposide‐containing regimens. Salvage combination chemotherapy with FA is effective for these patients with refractory disease, and the toxicity is predictable and manageable. Cancer 2002;95:1051–4. © 2002 American Cancer Society.

DOI 10.1002/cncr.10790
Outbreak of jaundice and hemorrhagic fever in the Southeast of Brazil in 2001: Detection and molecular characterization of yellow fever virus
Authors: de Filippis A.M.B. , Nogueira R.M.R. , Schatzmayr H.G. , Tavares D.S. , Jabor A.V. , Diniz S.C.M. , Oliveira J.C. , Moreira E. , Miagostovich M.P. , Costa E.V. , Galler R.
Published: October 2002

Between January and March 2001, an outbreak of jaundice and hemorrhagic fever occurred in the state of Minas Gerais, Southeast region of Brazil, in which a mortality rate of 53% was reported. Seroconversion, virus isolation, histopathological and immunohistochemical findings, and reverse transcription‐polymerase chain reaction (RT‐PCR) identified yellow fever virus (YFV) as the etiological agent responsible for the outbreak. Partial nucleotide sequence analysis from a fragment of the YFV genome spanning parts of nonstructural (NS) 5 gene and 3′ noncoding region (3′ UTR) showed that the YFV involved in this outbreak belongs to South American genotype I and differs from the Brazilian virus identified in 1996. J. Med. Virol. 68:620–627, 2002. © 2002 Wiley‐Liss, Inc.
Genetic diversity of echovirus 30 during a meningitis outbreak, demonstrated by direct molecular typing from cerebrospinal fluid
Authors: Bailly Jean‐Luc , Brosson Damien , Archimbaud Christine , Chambon Martine , Henquell Cécile , Peigue‐Lafeuille Hélène
Published: October 2002

Echovirus 30 is one of the enterovirus serotypes isolated most frequently in meningitis cases. The genetic diversity of echovirus 30 was investigated in patients hospitalised during an outbreak in 2000 in Clermont‐Ferrand, France. A nested reverse transcription‐PCR (RT‐PCR) assay was developed for qualitative analysis of the echovirus 30 VP1 encoding sequence directly from cerebrospinal fluid. The viral sequences obtained for 22 patients were compared with those of virus isolates obtained from nine patients with echovirus 30 meningitis admitted to hospital in 1996–1997 and with echovirus 30 sequences from international databases. In 2000, meningitis cases were caused by two virus variants (C3 and C4) distinct genetically from the other two variants (C1 and C2) identified during the period 1996–1997. A detailed phylogenetic analysis established that the C1, C2, and C3 variants had close relatives among viruses previously identified in other geographical areas. The C4 variant had not been described earlier. The genomic differences observed between the four echovirus 30 variants arose at synonymous sites indicating that the viruses shared similar antigenic sites in the VP1 encoding sequence. Overall, these observations suggest wide circulation of different echovirus 30 variants and periodic importation of new viruses. The apparent displacement observed between virus variants did not result from a selective advantage caused by antigenic variation. J. Med. Virol. 68:558–567, 2002. © 2002 Wiley‐Liss, Inc.
Convergence of finite element approximations of large eddy motion
Authors: Iliescu Traian , John Volker , Layton William J.
Published: October 2002

Fluid motion in many applications occurs at higher Reynolds numbers. In these applications dealing with turbulent flow is thus inescapable. One promising approach to the simulation of the motion of the large structures in turbulent flow is large eddy simulation in which equations describing the motion of local spatial averages of the fluid velocity are solved numerically. This report considers “numerical errors” in LES. Specifically, for one family of space filtered flow models, we show convergence of the finite element approximation of the model and give an estimate of the error. © 2002 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 18: 689–710, 2002; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/num.10027.
On the finite‐differences schemes for the numerical solution of two dimensional Schrödinger equation
Authors: Subaşi Murat
Published: October 2002

In this study three different finite‐differences schemes are presented for numerical solution of two‐dimensional Schrödinger equation. The finite difference schemes developed for this purpose are based on the (1, 5) fully explicit scheme, and the (5, 5) Noye‐Hayman fully implicit technique, and the (3, 3) Peaceman and Rachford alternating direction implicit (ADI) formula. These schemes are second order accurate. The results of numerical experiments are presented, and CPU times needed for this problem are reported. © 2002 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 18: 752–758, 2002; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/num.10029.
On the subdomain‐Galerkin/least squares method for 2‐ and 3‐D mixed elliptic problems with reaction terms
Authors: Yang Suh‐Yuh
Published: October 2002

In this article we apply the subdomain‐Galerkin/least squares method, which is first proposed by Chang and Gunzburger for first‐order elliptic systems without reaction terms in the plane, to solve second‐order non‐selfadjoint elliptic problems in two‐ and three‐dimensional bounded domains with triangular or tetrahedral regular triangulations. This method can be viewed as a combination of a direct cell vertex finite volume discretization step and an algebraic least‐squares minimization step in which the pressure is approximated by piecewise linear elements and the flux by the lowest order Raviart‐Thomas space. This combined approach has the advantages of both finite volume and least‐squares methods. Among other things, the combined method is not subject to the Ladyzhenskaya‐Babus̆ka‐Brezzi condition, and the resulting linear system is symmetric and positive definite. An optimal error estimate in the H1(Ω) × H(div; Ω) norm is derived. An equivalent residual‐type a posteriori error estimator is also given. © 2002 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 18: 738–751, 2002; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/num.10030.
Teachers implementing writing‐to‐learn strategies in junior secondary science: A case study
Authors: Hand Brian , Prain Vaughan
Published: October 2002

Although there is now strong support for the use of writing‐to‐learn in science, research in this field has tended to ignore the challenges facing teachers in developing new understandings and practices in relation to this use of writing. This paper reports on a 4‐year study examining teachers' concerns in implementing writing‐to‐learn strategies within science classrooms based on using a model of writing‐to‐learn. The study reports in detail on two teachers' participation in an ongoing in‐service program to develop pedagogical practices to support writing‐to‐learn strategies. The three central issues for the two teachers were assessment, planning and setup, and their changing roles as classroom teachers. © 2002 Wiley Periodicals, Inc.Sci Ed86:737–755, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/sce.10016
A study of MRP benefits and costs
Authors: Schroeder Roger G. , Anderson John C. , Tupy Sharon E. , White Edna M.
Published: October 2002

This paper describes benefits and costs of MRP systems based on a large survey of MRP users. These users report they have achieved significant improvements in inventory turnover, delivery performance, and other benefits, and that further improvements are expected when their MRP systems are fully implemented. A series of regression models are also described in the paper which explain why some companies achieve more benefits from MRP than others. The models are not only fitted to the sample data, but they obtain good predictive results on a holdout sample. These models indicate that companies should stress a broad approach to implementation; there is no one overriding factor which guarantees MRP success.
The implementation of computer based systems
Authors: Meredith Jack R.
Published: October 2002

The difficulty of implementing planned change in an organization is legend. In the last 20 years the implementation of computer based models and systems in particular has received a significant amount of attention in the form of hundreds of conference presentations, published case studies, and research reports. Yet, system implementation failures are still prevalent. p]This paper surveys the implementation literature primarily in three fields: management information systems, operations research/management science, and production‐inventory management. Common difficulties are identified and managerial proverbs, consultants' insights, statistically verified procedures, research conclusions. and other such documented wisdom for improving the chances of implementation are analyzed. p]A classification scheme is developed which divides this documented material into three diverse categories of pitfalls in implementation. These categories are then discussed from the perspective of providing managers with the information needed to analyze their own organization in terms of the likelihood of successfully implementing such computer based information systems as Material Requirements Planning (MRP).
Static vs. dynamic priority rules for check processing in multiple dispatch‐multiple branch banking
Authors: Mabert Vincent A.
Published: October 2002

This paper presents a study comparing the use of four static and two dynamic priority rules for sequencing bundled checks in the check clearing operations in a bank's back office. The six priority rules are tested in a controlled computer simulation experiment, where bank factors of check bundle size, check bundle value, transit deadlines (dispatches), and destination proportions are systematically varied over prescribed levels. The results indicate that priority rule performance, measured by reduced float, is significantly affected by bank factors. The test results indicate that the two dynamic priority rules performed statistically better than three of the four static rules tested.

The study reported here should prove useful to bank operation managers. The sequencing rules investigated here influence the level of float for a bank faced with multiple dispatches during the day. The test environments duplicated a variety of operating conditions that can be present in commercial banks. Therefore, the robustness of the tested static and dynamic rules were observed in reducing float under different conditions. Dynamic rules require recomputing priorities to reflect changes in time and create greater implementation effort to use effectively. Static rules require only one priority computation, resulting in easier implementation. This study indicates that one of the static priority rules tested provides comparable performance to the two dynamic rules.
Goal programming applied to police patrol allocation
Authors: Saladin Brooke A.
Published: October 2002

This paper describes the development of a decision‐making methodology to aid the police patrol planner in resolving the patrol allocation problem. The methodology developed provides information to assist in two major decision areas: staff sizing and vehicle requirement schedules. This research uses a queuing based simulation model to derive expected service levels for a number of different performance measures. Given these results, tradeoff curves are mapped between specified performance measures and utilization rates of patrol vehicles. With this information the patrol planner specifies limiting levels for both performance measures and other managerial constraints which, in turn, are inputted into a goal programming algorithm to determine appropriate staff sizes and vehicle requirements. The primary output provided the patrol planner is the required amount of patrol vehicle hours to allocate to each watch per day per precinct in order to satisfy a designated set of performance measure levels and managerial constraints. The methodology presented in this research was developed in conjunction with the Columbus, Ohio, Police Department with data being provided by the Research and Planning Division.
An empirical investigation of different strategies for material requirements planning
Authors: Bahl Harish C. , Ritzman Larry P.
Published: October 2002

Master production scheduling, component lot sizing, and capacity requirements planning represent three important modules of material requirements planning (MRP) systems. Coordinating these three modules has been largely dependent on managerial judgment and experience. In this research, five different strategies for integrating these modules are empirically investigated. These strategies differ mainly in the extent to which the modules are coordinated. The impact of the shop, product, component and cost characteristics is measured by varying ten experimental factors. The research findings so obtained provide several guidelines on the effectiveness of each strategy in different environmental settings.