bluuebunny/crossref_metadata_2025 huggingface dataset:
Parallel iterative methods for Navier–Stokes equations and application to eigenvalue computation
Authors: Graham Ivan G. , Spence Alastair , Vainikko Eero
Published: September 2003

We describe the construction of parallel iterative solvers for finite‐element approximations of the Navier–Stokes equations on unstructured grids using domain decomposition methods. The iterative method used is FGMRES, preconditioned by a parallel adaptation of a block preconditioner recently proposed by Kay et al. The parallelization is achieved by adapting the technology of our domain decomposition solver DOUG (previously used for scalar problems) to block‐systems. The iterative solver is applied to shifted linear systems that arise in eigenvalue calculations. To illustrate the performance of the solver, we compare several strategies both theoretically and practically for the calculation of the eigenvalues of large sparse non‐symmetric matrices arising in the assessment of the stability of flow past a cylinder. Copyright © 2003 John Wiley & Sons, Ltd.
Indoor microcell area prediction system using a ray‐tracing method
Authors: Imai Tetsuro , Inukai Yuichiro , Fujii Teruya
Published: September 2003

In mobile communications, such as the cordless telephone, it is important to identify the service area for situations where a base station is installed indoors. However, the mix of walls, columns, and partitions in the typical indoor environment makes it difficult to develop a precise signal propagation estimation formula. The ray‐tracing method provides a precise method for the estimation of electric field strengths. Although this method provides a relatively facile way of estimating the electric field strength by simply determining the geometric tracing between sender and receiver, an increase in the number of structural components, such as walls, columns, and partitions, results in a rapid increase in the required processing time. Therefore, the practical utilization of an area prediction system requires an increase in processing speed. This paper proposes a ray‐trace‐based algorithm that permits high‐speed processing. It also describes an indoor area prediction system, IMAP, that has been developed based on the proposed algorithm, and discusses its prediction accuracy. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(10): 60–72, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10189
Adsorption Effect on the Dynamic Response of a Biochemical Reaction in a Biofilm Reactor for Wastewater Treatment
Authors: Tsuneda S. , Inoue Y. , Auresenia J. , Hirata A.
Published: September 2003

The dynamic behavior of a completely mixed, three‐phase, fluidized bed biofilm reactor treating simulated domestic wastewater was studied with step changes in inlet concentration. It was found that the response curves showed second order characteristics, i.e., as the inlet concentration was increased, the outlet concentration also increased, reached a peak value and then decreased until it leveled to a new steady‐state value corresponding to the new inlet concentration level. Nonlinear regression analysis was performed using Monod‐type rate equations with and without an adsorption term. As a result, the theoretical curve of the kinetic model that incorporates the adsorption term has best fit to the actual response in most cases. Thus, it was concluded that the adsorption of a substrate onto the biofilm and carrier particles has a significant effect on the dynamic response in biofilm processes.
Production of Recombinant Proteins with Pichia pastoris in Integrated Processing
Authors: Cornelissen G. , Bertelsen H.‐P. , Lenz K. , Hahn B. , Schultz M. , Scheffler U. , Werner E. , Leptien H. , Krüß S. , Jansen A.‐K. , Elsholz O. , Gliem T. , Wilhelm B.‐U. , Sowa E. , Radeke H.H. , Luttman R.
Published: September 2003

Devices and methods for Integrated Bioprocessing have been developed for production of recombinant proteins with the yeast Pichia pastoris. In doing so cross flow filtration techniques for cell separation and product concentration are connected directly to high instrumented cultivation processes. These are equipped with on‐line measuring techniques for substrates and products, e.g., glycerol, methanol and pyruvate as well as recombinant proteins, e.g., the chemokines 1–8del MCP‐1 and vMIP‐II. Complex automation structures allow for process development at virtual plants which can be used as the basis for establishing and implementing fully automated real processes. Experiments for determination of reaction kinetics, optimization of productivity in high‐cell density cultures and Integrated Bioprocessing are outlined, along with detailed illustration of the realization of the methods at industrial pilot plant scale.
Study and Identification of Retention Process of Heavy Metals by Adsorption on Agricultural Byproducts
Authors: Bencheikh‐lehocine M. , Arris S. , Meniai A.‐H. , Morcellet M. , Bacquet M. , Martel B. , Mansri A.
Published: September 2003

This present study considers the adsorption of cations of heavy metals (zinc, cadmium, copper) which are frequently encountered in industrial wastewaters. The solid material used as adsorbent is nonactivated carbon obtained from a local cereal byproduct. In order to assess this material, adsorbents obtained from other agricultural byproducts, such as almond and peanuts shells, have also been tested. Adsorption isotherms have been determined and the influence of various parameters, such as the particle size, the solid‐liquid contacting time, the pH of the solution, the initial concentration, the mixing velocity, the temperature and the ratio solid mass over solution volume, have been considered. The case of simultaneous presence of metallic cations in the solution has also been considered in order to examine their affinity towards the adsorbent. An attempt to determine whether the retention of the cations is a pure adsorption or an ion exchange has also been carried out. Retention yield values exceeding 90 % have been reached with an initial concentration of 10 mg/L, a temperature of 20 °C, a particle size smaller than 0.1 mm, a mixing velocity of 600 rev/min, a ratio of 0.5 g adsorbent over 50 ml of solution and a pH varying between 3 and 6.
Geomorphic changes in a complex gully system measured from sequential digital elevation models, and implications for management
Authors: Betts Harley D. , Trustrum Noel A. , Rose Ronald C. De
Published: September 2003

High‐resolution digital elevation models (DEMs) were derived from sequential aerial photography of an active ﬂuvio‐mass movement (gully) complex in New Zealand's North Island East Coast region, to measure geomorphic changes over approximately one year. The gully showed a complex behaviour, combining ﬂuvial and mass movement erosion, deposition, and reworking of materials stored in an active debris fan. During the measurement period 5200 ± 1700 m3 of material were eroded from the 8·7 ha gully complex and 670 ± 180 m3 from the 0·8 ha depositional fan, giving a total of 5870 ± 1710 m3 for the entire gully complex–fan system.

The results provide a high‐resolution description of gully behaviour over a short time period, and also demonstrate that mass movement (slumping and debris ﬂows) accounted for almost 90 per cent (4660 ± 200 m3) of the sediment generated. This erosional response is described in terms of gully evolution by comparing the gully complex to other systems in the region in various stages of development. The effect of gully evolution on geomorphic coupling between the gully complex and channel system is described, and coupling is also shown to vary with the magnitude and frequency of rainfall events.

From a land management perspective the success of strategies, such as tree planting, to mitigate against gully erosion depends on the stage of gully development – particularly on whether or not mass movement erosion has begun. In contrast to gully rehabilitation efforts elsewhere, basin‐wide afforestation in the early stages of gully incision is favoured over riparian planting, given that mass movement assisted by excessive groundwater pressure is the main process leading to uncontrollable gully expansion.

To protect land effectively against continuing gully erosion of headwater catchments and resulting downstream aggradation, it is necessary for land managers to understand the spatial and temporal variability of gully development fully so that mitigation efforts can be targeted appropriately. Copyright © 2003 John Wiley & Sons, Ltd.
Coastal conglomerates around the Hadjer el Khamis inselbergs (western Chad, central Africa): new evidence for Lake Mega‐Chad episodes
Authors: Schuster Mathieu , Duringer Philippe , Ghienne Jean‐Francois , Vignaud Patrick , Beauvilain Alain , Mackaye Hassan Taisso , Brunet Michel
Published: September 2003

This paper reports on a study dealing with the rhyolitic inselbergs of Hadjer el Khamis that formed palaeoislands during Lake Mega‐Chad events. Field observations have shown that: (1) conglomeratic patches of immature to mature clasts are preserved at the feet of the Hadjer el Khamis inselbergs; (2) in cross‐section, their proﬁle reveals a well deﬁned cliff–platform junction at a constant elevation (325 m). The monolithological clasts show all degrees of roundness, from angular cobbles to well rounded pebbles. This wide range of maturity suggests a coastal origin for these cobbles. The system was permanently fed with angular clasts, which were progressively worn by waves. Cobbles that were wave‐worked for the longest time are the best rounded. The cliff–platform junction is the result of erosion by waves, which attacked and undercut the inselberg cliffs during Lake Mega‐Chad events. Asymmetrical erosion proﬁles moreover suggest a wind regime dominated by SW to NE oriented winds. These interpretations have two implications. The elevation of the cliff–platform junction is an indication of the highest water level of Lake Mega‐Chad at 320–325 m, which is in agreement with other observations elsewhere in the basin. The SW to NE oriented winds show that monsoon‐related winds were prevalent during Lake Mega‐Chad events, suggesting the Inter‐Tropical Convergence Zone was located higher in latitude than today. Copyright © 2003 John Wiley & Sons, Ltd.
Testing etching hypothesis for the shaping of granite dome structures beneath lateritic weathering landsurfaces using ERT method
Authors: Beauvais Anicet , Ritz Michel , Parisot Jean‐Claude , Bantsimba Christian
Published: September 2003

An Erratum has been published for this article in Earth Surface Processes and Landforms 28(13) 2003, 1491.

Granite domes, boulders and knobs buried within saprolite have been detected beneath lateritic weathering landsurfaces using 2D electrical resistivity tomography (ERT). This technique provides a valuable means of mapping the bedrock topography and the regolith structures underneath landsurfaces, as it is intrinsically very sensitive to the electrical properties of superimposed pedological, hydrological and geological layers, allowing the determination of their relative geometry and spatial relationships. For instance, 2D inverse electrical resistivity models including topographic data permit the deﬁnition of lithostratigraphic cross‐sections. It shows that resistive layers, such as the more or less hardened ferruginous horizons and/or the bedrock, are generally well differentiated from poorly resistive layers, such as saprolite, including water‐saturated lenses, as has been corroborated by past and actual borehole observations. The analysis of the 2D geometrical relations between the weathering front, i.e. the bedrock topography, and the erosion surface, i.e. the landsurface topography, documents the weathering and erosion processes governing the development of the landforms and the underlying structures, thus allowing the etching hypothesis to be tested. The inﬁltration waters are diverted by bedrock protrusions, which behave as structural thresholds compartmentalizing the saprolite domain, and also the regolith water table, into distinct perched saturated subdomains. The diverted waters are thus accumulated in bedrock troughs, which behave like underground channels where the saprolite production rate may be enhanced, provided that the water drainage is efﬁcient. If the landsurface topography controls the runoff dynamics, the actual bedrock topography as depicted by ERT imaging inﬂuences the hydrodynamics beneath the landsurface. In some way, this may control the actual weathering rate and the shaping of bedrock protrusions as granite domes and knobs within thick saprolite, before their eventual future exposure. Copyright © 2003 John Wiley & Sons, Ltd.
Water and sediment outbursts from advanced Franz Josef Glacier, New Zealand
Authors: Davies Timothy R. H. , Smart Chris C. , Turnbull Jill M.
Published: September 2003

The Franz Josef Glacier, Westland, New Zealand, has a history of catastrophic sediment‐laden outburst ﬂoods associated with extreme rainfall events when the glacier toe is advanced over its own sediments. Consideration of these events and inspection of recent sediment deposits suggest that there are three distinct modes of outburst. The ﬁrst is associated with fans fed by overﬂow along the glacier margin. As the glacier has advanced across its own foreﬁeld gravels, it is inferred that the primary drainage conduit has developed a reach of negative slope. In high ﬂows massive boulders can block the conduit, trapping lesser clasts. The resulting backup of water causes overﬂows through marginal moulins, producing the fan type of deposit.

The second type of outburst deposits massive imbricated boulders at a greater or lesser distance from the glacier portal. In this case, pressure buildup drives the blockage out of the portal where the boulders deposit. Smaller materials are generally carried away.

The third type consists of very shallow ﬂows, and produces massive gravel deposits of uncertain provenance. In this condition, the excess pressure in the conduit results in slight uplift of the glacier and widespread discharge of water and sediment below the glacier snout; gravels and smaller sediments are laid down in a massive deposit across the foreﬁeld.

The massive, boulder‐veneered deposit from the December 1995 outburst is interpreted in the light of the above mechanisms as a hyperconcentrated ﬂow deposit from hydraulic jacking, overlain by boulders emplaced by a subsequent conduit outburst. A possible association of outbursts with the present advanced position of the glacier is suggested. Copyright © 2003 John Wiley & Sons, Ltd.
The design of post‐mining landscapes using geomorphic principles
Authors: Hancock G. R. , Loch R. J. , Willgoose G. R.
Published: September 2003

Nature can provide analogues for post‐mining landscapes in terms of landscape stability and also in terms of the rehabilitated structure ‘blending in’ with the surrounding undisturbed landscape. In soil‐mantled landscapes, hillslopes typically have a characteristic proﬁle that has a convex upper hillslope proﬁle with a concave proﬁle lower down the slope. In this paper hillslope characteristic form is derived using the area–slope relationship from pre‐mining topography at two sites in Western Australia. Using this relationship, concave hillslope proﬁles are constructed and compared to linear hillslopes in terms of sediment loss using the SIBERIA erosion model. It is found that concave hillslopes can reduce sediment loss by up to ﬁve times that of linear slopes. Concave slopes can therefore provide an alternative method for the construction of post‐mining landscapes. An understanding of landscape geomorphological properties and the use of erosion models can greatly assist in the design of post‐mining landscapes. Copyright © 2003 John Wiley & Sons, Ltd.
Simulation and measurement of surface shear stress over isolated and closely spaced transverse dunes in a wind tunnel
Authors: Walker Ian J. , Nickling William G.
Published: September 2003

Topographic interactions generate multidirectional and unsteady airﬂow that limits the application of velocity proﬁle approaches for estimating sediment transport over dunes. Results are presented from a series of wind tunnel simulations using Irwin‐type surface‐mounted pressure sensors to measure shear stress variability directly at the surface over both isolated and closely spaced sharp‐crested model dunes. Findings complement existing theories on secondary airﬂow effects on stoss transport dynamics and provide new information on the inﬂuence of lee‐side airﬂow patterns on dune morphodynamics.

For all speeds investigated, turbulent unsteadiness at the dune toe indicates a greater, more variable surface shear, despite a signiﬁcant drop in time‐averaged measurements of streamwise shear stress at this location. This effect is believed sufﬁcient to inhibit sediment deposition at the toe and may be responsible for documented intermittency in sand transport in the toe region. On the stoss slope, streamline compression and ﬂow acceleration cause an increase in ﬂow steadiness and shear stress to a maximum at the crest that is double that at the toe of the isolated dune and 60–70 per cent greater than at ﬂow reattachment on the lower stoss of closely spaced dunes. Streamwise ﬂow accelerations, rather than turbulence, have greater inﬂuence on stress generation on the stoss and this effect increases with stoss slope distance and with incident wind speed. Reversed ﬂow within the separation cell generates signiﬁcant surface shear (30–40 per cent of maximum values) for both spacings. This supports ﬁeld studies that suggest reversed ﬂow is competent enough to return sediment to the dune directly or in a deﬂected direction. High variability in shear at reattachment indicates impact of a turbulent shear layer that, despite low values of time‐averaged streamwise stress in this region, would inhibit sediment accumulation. Downwind of reattachment, shear stress and ﬂow steadiness increase within 6 h (h = dune height) of reattachment and approach upwind values by 25 h. A distance of at least 30 h is suggested for full boundary layer recovery, which is comparable to ﬂuvial estimates.

The Irwin sensor used in this study provides a reliable means to measure skin friction force responsible for sand transport and its robust, simple, and cost‐effective design shows promise for validating these ﬁndings in natural dune settings. Copyright © 2003 John Wiley & Sons, Ltd.
Geomorphological and historical data in assessing landslide hazard
Authors: Carrara Alberto , Crosta Giovanni , Frattini Paolo
Published: September 2003

Traditionally, earth scientists assess landslide occurrence on the basis of geomorphological investigations carried out through aerial photograph interpretation and ﬁeldwork. Conversely, local administrators primarily evaluate the impact of natural catastrophes, such as landsliding, on the basis of historical records and data. Owing to the substantial difference in the structure and spatial density of these two types of information, it is difﬁcult to compare them directly and few investigators have attempted this.

We compared landslide information derived from geomorphological mapping and historical data in a pilot area (the Staffora river basin, northern Italy). To do this we generated two multivariate statistical models where the dependent variable was either the mapped landslide deposits (geomorphological model), or the historical sites affected by landslide‐induced damage (historical model). By quantitatively comparing these two model maps, we demonstrate that the geomorphological model performs better in terms of percentage of terrain units correctly predicted as stable or unstable. The historical model underestimates landslide hazard mainly where human structures are lacking. However, it highlights slopes where landslide movements take place with a high frequency at the temporal scale of human life. Hence, the joint use of these two models may facilitate the knowledge of the overall instability conditions of a given region and the identiﬁcation of the landslides that are most frequently reactivated. Copyright © 2003 John Wiley & Sons, Ltd.
A two‐mean reverting‐factor model of the term structure of interest rates
Authors: Moreno Manuel
Published: September 2003

This article presents a two‐factor model of the term structure of interest rates. It is assumed that default‐free discount bond
prices are determined by the time to maturity and two factors, the long‐term interest rate, and the spread (i.e., the difference)
between the short‐term (instantaneous) risk‐free rate of interest and the long‐term rate. Assuming that both factors
follow a joint Ornstein‐Uhlenbeck process, a general bond pricing equation is derived. Closed‐form expressions for prices of bonds and
interest rate derivatives are obtained. The analytical formula for derivatives is applied to price European options on discount bonds and more
complex types of options. Finally, empirical evidence of the model's performance in comparison with an alternative two‐factor
(Vasicek‐CIR) model is presented. The findings show that both models exhibit a similar behavior for the shortest maturities.
However, importantly, the results demonstrate that modeling the volatility in the long‐term rate process can help to fit the observed data,
and can improve the prediction of the future movements in medium‐ and long‐term interest rates. So it is not so clear which is the best
model to be used. © 2003 Wiley Periodicals, Inc. Jrl Fut Mark 23: 1075–1105, 2003
The design and pricing of fixed‐ and moving‐window contracts: An application of Asian‐Basket option pricing methods to the hog‐finishing sector
Authors: Shao Renyuan , Roe Brian
Published: September 2003

Asian‐Basket‐type moving‐window contracts are an increasingly used risk‐management tool in the North American hog
sector. The moving‐window contract is decomposed into a portfolio of a long Asian‐Basket put and a short Asian‐Basket call
option. A projected break‐even price is used to determine the floor price, and then Monte Carlo simulation methods are used to price both a
moving‐ and a fixed‐window contract. These methods provide unbiased pricing of fixed‐ and moving‐window
hog‐finishing contracts of 1‐year duration. © 2003 Wiley Periodicals, Inc. Jrl Fut Mark 23:1047–1073, 2003
Asymmetric covariance in spot‐futures markets
Authors: Meneu Vicente , Torró Hipòlit
Published: September 2003

This article studies how the spot‐futures conditional covariance matrix responds to positive and negative innovations. The main results of
the article are achieved by obtaining the Volatility Impulse Response Function (VIRF) for asymmetric multivariate GARCH structures, extending
Lin (1997) findings for symmetric GARCH models. This theoretical result is general and can be applied to analyze covariance dynamics in any
financial system. After testing how multivariate GARCH models clean up volatility asymmetries, the Asymmetric VIRF is computed for the Spanish stock
index IBEX‐35 and its futures contract. The empirical results indicate that the spot‐futures variance system is more sensitive to
negative than positive shocks, and that spot volatility shocks have much more impact on futures volatility than vice versa. Additionally, evidence is
obtained showing that optimal hedge ratios are insensitive to the well‐known asymmetric volatility behavior in stock markets. © 2003 Wiley
Periodicals, Inc. Jrl Fut Mark 23:1019–1046, 2003
Radiation therapy for angiosarcoma
Authors: Ward Jon R. , Feigenberg Steven J. , Mendenhall Nancy Price , Marcus Robert B. , Mendenhall William M.
Published: September 2003

Background.

Between 1964 and 1998, 19 patients with histologically proven angiosarcoma were treated with curative intent with radiation therapy.

Methods.

Median follow‐up was 37 months (range, 8–234 months).

Results.

The actuarial 5‐year absolute survival and local control rates were 51% and 50%, respectively. Of 12 patients who relapsed, 8 had isolated local recurrence as the first site of treatment failure, 2 had local (1 patient) or regional recurrence in conjunction with distant metastases, and 2 had distant metastases alone. Two of four patients who underwent further therapy for recurrent disease were successfully salvaged.

Conclusions.

Only the location of the primary tumor was a predictor of local control and absolute survival at 5 years. Angiosarcomas located on the scalp imply a dismal prognosis compared with those in other locations with the predominant pattern of failure being local recurrence. Patients should be treated aggressively with surgical resection and preoperative or postoperative radiation therapy. © 2003 Wiley Periodicals, Inc. Head Neck 25: 873–878, 2003
Assessment of parathyroid autotransplantation for preservation of parathyroid function after total thyroidectomy
Authors: El‐Sharaky Magdy I. , Kahalil Mohamed R. , Sharaky Ola , Sakr Mahmoud F. , Fadaly Geylan A. , El‐Hammadi Habashi A. , Moussa Mohamed M.
Published: September 2003

Background.

Hypoparathyroidism with permanent hypocalcemia is a well‐recognized complication after thyroid surgery.

Aim.

This study was conducted to assess the role of immediate parathyroid autotransplantation in the preservation of parathyroid function after total thyroidectomy.

Patients and Methods.

Twenty‐eight patients had autotransplantation of parathyroid glands resected or devascularized during total thyroidectomy. Data were collected prospectively regarding demographics, indication for surgery, operative procedure, pathologic diagnosis, number of glands transplanted, and subsequent course. Thyroid nodules were evaluated by ultrasonography, radionuclide scanning, and/or fine‐needle aspiration cytology. All patients had serum ionized calcium, phosphorus, and intact parathyroid hormone (PTH) levels measured preoperatively and monitored regularly postoperatively for a period of 14 weeks and again at 6 months after operation. Patients were categorized into three groups according to the number of glands transplanted: one (group 1, n = 6), two (group 2, n = 14), or three glands (group 3, n = 8). In three other volunteers, one parathyroid gland was transplanted in the brachioradialis and subjected to electron microscopy 1, 2, and 4 weeks after transplantation.

Results.

Total thyroidectomy was performed for malignant disease in 16 patients (57.1%) and for benign disease in 12 (42.9%) patients. All patients reverted to asymptomatic normocalcemia without the need for any medications within 4 to 14 weeks. Normal levels of serum markers were regained slower when one gland was transplanted compared with two or three glands (P < .01). Electron microscopic examination showed evidence of ischemic degeneration in the transplanted tissues 1 week postoperatively. Regeneration started by the second week and coincided with normalization of PTH levels. Optimum resting and nearly normal status of parathyroid tissue was achieved by the fourth week.

Conclusions.

This study showed that active PTH production coincides with regeneration of parathyroid cells and that autotransplantation of at least two resected or devascularized glands during total thyroidectomy nearly eliminates permanent postoperative hypoparathyroidism, thus improving the safety of total thyroidectomy performed for malignant or benign disease. © 2003 Wiley Periodicals, Inc. Head and Neck 25: 799–807, 2003
Comorbid condition as a prognostic factor for complications in major surgery of the oral cavity and oropharynx with microvascular soft tissue reconstruction
Authors: Borggreven Pepijn A. , Kuik Dirk J. , Quak Jasper J. , de Bree Remco , Snow Gordon B. , Leemans C. René
Published: September 2003

Background.

Identification of factors, especially comorbidity, that affect the incidence and severity of complications in head and neck cancer patients.

Methods.

One hundred patients with an oral/oropharynx carcinoma undergoing composite resection and microvascular soft tissue transfer were analyzed. Patient data and tumor and treatment factors were recorded. Comorbidity was graded by an Adult Comorbidity Evaluation 27 (ACE‐27) test. Postoperative complications were scored according to their severity.

Results.

Comorbidity score ACE‐27 grade 2 or higher was present in 47% of patients, whereas 33% had a clinically important complication develop. A comorbidity score of ACE‐27 grade ≥2 was a strong predictor for complications (p < .001). There were no other predictors for postoperative complications.

Conclusions.

Comorbidity is of great importance for prediction of postoperative complications in head and neck cancer patients, especially an ACE‐27 grade ≥2. It may be concluded from these results that prevention of complications should focus on comorbidities. © 2003 Wiley Periodicals, Inc. Head and Neck 25: 808–815, 2003
Papillary thyroid cancer: High inter‐(simple sequence repeat) genomic instability in a typically indolent cancer
Authors: Wiseman Sam M. , Loree Thom R. , Rigual Nestor R. , Hicks Wesley L. , Winston Janet S. , Swede Helen , Bartos Jeremy D. , Anderson Garth R. , Stoler Daniel L.
Published: September 2003

Objectives.

The object of this study is to measure genomic instability in papillary thyroid cancer and correlate these measurements with known clinical prognosticators such as patient age, tumor size, histologic subtype, and three commonly used thyroid risk assessment indices. A secondary objective of this study was to use the measurements of genomic instability to estimate the number of mutational events present in the papillary thyroid cancer genome.

Methods.

Inter‐simple sequence repeat polymerase chain reaction (ISSR‐PCR) is a rapid and reproducible technique for quantitation of genomic instability, or the degree of genome alteration, in solid tumors. This includes quantitation of amplifications, deletions, translocations, and insertions. Twenty‐eight papillary carcinomas were evaluated by ISSR‐PCR.

Results.

Evaluation of 28 papillary carcinomas by ISSR‐PCR demonstrated a wide range of genomic instability. Of the panel of clinicopathologic factors examined, only patient age was significantly associated with genomic instability. The mean genomic instability index value was greatest in the youngest age group, which was significantly different from the median value measured in the oldest age group (3.7, 2.5, respectively, p = .05). The mean value in the intermediate age group fell between the younger and older groups (3.1). By use of ISSR‐PCR, we have calculated 15,000 individual genomic events as having occurred in each papillary tumor cell.

Conclusions.

Despite its generally indolent biologic behavior, papillary thyroid cancer exhibits a high degree of genomic instability comparable to that seen in colorectal cancer. These results suggest that elevated genomic instability, as measured by ISSR‐PCR, may not be sufficient to enable thyroid tumor progression to less indolent disease and that this process is severely constrained by some additional essential factor such as the differentiated state of the tissue or the need to bring into play an additional form of genomic destabilization. © 2003 Wiley Periodicals, Inc. Head and Neck 25: 825–832, 2003
Who merits a neck dissection after definitive chemoradiotherapy for N2–N3 squamous cell head and neck cancer?
Authors: McHam Scott A. , Adelstein David J. , Rybicki Lisa A. , Lavertu Pierre , Esclamado Ramon M. , Wood Benjamin G. , Strome Marshall , Carroll Marjorie A.
Published: September 2003

Background.

The role of neck dissection (ND) after definitive chemoradiotherapy for squamous cell head and neck cancer is incompletely defined. We retrospectively reviewed 109 patients with N2–N3 disease treated with chemoradiotherapy to identify predictors of a clinical complete response in the neck (CCR‐neck), pathologic complete response after ND (PCR‐neck), and regional failure.

Method.

All patients were given 4‐day continuous infusions of 5‐fluorouracil (1000 mg/m2/d) and cisplatin (20 mg/m2/d) during the first and fourth weeks of either once daily (n = 68) or twice daily (n = 41) radiation therapy. ND was considered for all patients after completion of chemoradiotherapy and was performed in 32 of the 65 patients achieving a CCR‐neck after chemoradiotherapy and in all 44 patients with residual clinical evidence of neck disease. CCR‐neck, PCR‐neck, and regional failure were then correlated with potential predictors, including T, N, largest lymph node size (<3 cm, ≥3 cm), primary tumor site, and radiation fractionation schedule.

Results.

Achievement of a CCR‐neck was predicted by N, N2 vs N3 (53 of 80 vs 12 of 29, p = .019) and by largest lymph node size, <3 cm vs ≥3 cm (19 of 25 vs 46 of 84, p = .06). Achievement of a PCR‐neck could not be predicted by any clinical parameter. Regional failure occurred both in patients undergoing ND and those not dissected (5 of 76 vs 4 of 33, p = .33) and proved more likely only in the ND patients with residual positive pathology compared with those achieving a PCR‐neck (5 of 25 vs 0 of 51, p < .001). Primary site was not a useful predictor of CCR‐neck, PCR‐neck, or regional failure. Most importantly, CCR‐neck (vs <CCR‐neck) did not predict either a PCR‐neck (24 of 32 vs 27 of 44, p = .21) or regional failure (5 of 65 vs 4 of 44, p = .80).

Conclusions.

After chemoradiotherapy, clinical parameters do not identify those patients with residual neck node disease or those at risk for regional failure, suggesting that ND be considered for all N2–N3 patients. © 2003 Wiley Periodicals, Inc. Head and Neck 25: 791–798, 2003
Videofiberoptic examination of the pharyngoesophageal segment and esophagus in patients after total laryngectomy
Authors: Chu Pen‐Yuan , Guo Yuan‐Ching , Tai Shyh‐Kuan , Hwang Jui‐Ling , Tsai Tung‐Lung , Chang Shyue‐Yih
Published: September 2003

Background.

Posttreatment follow‐up in patients with squamous cell carcinoma of the head and neck is critical because of the high risk of recurrence or a new primary tumor. However, in patients who have undergone total laryngectomy, evaluation of the pharyngoesophageal segment (PES) and esophagus is difficult.

Methods.

Sixty patients who had undergone total laryngectomy received a videofiberoptic examination of the PES and esophagus at the OPD office during follow‐up.

Results.

Satisfactory examination was achieved in 56 (93%) of the patients. Each procedure was completed within 15 minutes. Although only 11 (18%) of the patients were symptomatic at follow‐up, 19 patients (34%) had significant findings, including one local recurrence and two secondary esophageal cancers. Patients were asymptomatic in all three cases.

Conclusions.

Videofiberoptic examination is a simple, effective, and relatively noninvasive method that can be performed in the OPD office to evaluate the PES and esophagus in patients after total laryngectomy. © 2003 Wiley Periodicals, Inc. Head Neck 25: 858–863, 2003
Applicability of lymphoscintigraphy with sentinel node biopsy to eccrine carcinoma of the head and neck
Authors: Chang Amy S. , Busam Klaus , Kraus Dennis H.
Published: September 2003

Background.

Eccrine carcinoma of the head and neck has the propensity to metastasize both to regional and distant sites. When associated with nodal metastasis, there is a high incidence of distant spread of disease, ultimately being associated with the death of the patient. Management of the patient with clinically negative nodes remains controversial. Although elective nodal dissection has been performed, the impact of this intervention remains indeterminate. This case series serves as a feasibility study for use of the technique of lymphoscintigraphy with sentinel node biopsy for eccrine carcinoma arising in the head and neck.

Methods.

Two patients with eccrine carcinoma underwent sentinel node biopsy by way of the standard, three‐part technique using lymphoscintigraphy, 1% isosulfan blue dye, and intraoperative use of the gamma probe.

Results.

In each of these cases, the lymphoscintigram successfully identified sentinel lymph nodes. Intraoperative findings were significant for confirmation of sentinel nodes with the presence of blue dye in the lymph node. In one case, frozen section identified a positive sentinel lymph node, and the patient underwent definitive nodal dissection and postoperative radiotherapy. In the second case, immunohistochemistry as part of final pathology identified a single microscopic foci of metastatic eccrine carcinoma, for which the patient elected to receive definitive radiation therapy.

Conclusions.

This report documents the efficacy of lymphoscintigraphy with sentinel lymph node biopsy in identifying microscopic metastasis eccrine carcinoma in primary lesions arising in the head and neck. © 2003 Wiley Periodicals, Inc. Head and Neck 25: 879–882, 2003
Quality of life in patients with oropharynx carcinomas: Assessment after accelerated radiotherapy with or without chemotherapy versus radical surgery and postoperative radiotherapy
Authors: Allal Abdelkarim S. , Nicoucar Kevin , Mach Nicolas , Dulguerov Pavel
Published: September 2003

Background.

In oropharyngeal carcinomas, it is assumed that the effectiveness of the different treatment approaches is roughly equivalent, whereas the functional outcome after radical radiotherapy (RT) is superior to that associated with primary surgery. The aim of this study is to assess quality of life (QoL) outcomes of patients after two treatment strategies: radical surgery with postoperative RT and accelerated concomitant boost RT with or without chemotherapy.

Methods.

Sixty patients who were disease free at least 1 year after treatment of oropharynx carcinoma were studied. Forty had been treated with radical RT (median tumor dose, 69.9 Gy in 5.5 weeks), and 20 had been treated with primary surgery and postoperative monofractionated RT (median dose, 60.2 Gy). Seven of the former patients received chemotherapy concomitantly with, and one before, RT. Functional outcome was assessed by the subjective Performance Status Scale for Head and Neck cancer (PSSHN) and the general QoL by the European Organization for Research and Treatment of Cancer Core QoL questionnaire (EORTC QLQ‐C30). The unpaired t test was used to assess for significant differences between means.

Results.

By use of the PSSHN module, scores were generally higher in the RT group, with a significant difference in the speech subscale (p = .005), a trend for a significant difference for the eating in public subscale (p = .08), and an insignificant difference for the normalcy of diet subscale (p = .25). When analyzed by tumor stage, no significant differences were observed for T1–2 tumors, whereas for patients with T3–4 tumors highly significant differences favoring the RT group became evident for all three subscales. Although no significant differences were observed using the EORTC QLQ C‐30 functional scales, patients treated with primary surgery reported significantly more dyspnea (28 vs 12, p = .04) and appetite loss (30 vs 13, p = .05). In patients with T3–4 tumors, trends toward better scores favoring the RT group were observed for physical, role, emotional, and social functions, as well as a significantly better score for pain symptoms.

Conclusions.

Although for early stages no clear advantage in QoL outcome was noted for the RT group compared with the surgery group, for advanced‐stage disease an advantage favoring radical RT seemed apparent. For those patients, if an equivalency between the two treatment strategies could be assumed regarding oncologic results, then nonsurgical treatment should be considered the preferred option. © 2003 Wiley Periodicals, Inc. Head and Neck 25: 833–840, 2003
The prevalence and significance of clinically unsuspected neoplasms in cervical lymph nodes
Authors: Ansari‐Lari M. Ali , Westra William H.
Published: September 2003

Background.

Histopathologic scrutiny of surgical pathology specimens can uncover unexpected but important pathologic processes that might not (yet) be clinically apparent. We suspect that cervical lymph nodes removed from patients with known cancers of the head and neck might occasionally harbor clinically unsuspected neoplasms.

Methods.

We reviewed the pathology reports of all patients who had undergone cervical lymph node dissections at our institution between 1984 and 2001 to determine the prevalence of occult metastatic thyroid cancer and other clinically unsuspected tumors. The medical records were reviewed to obtain follow‐up information when histologic examination disclosed some significant finding that was unsuspected on clinical grounds.

Results.

Of the 1337 patients who underwent cervical lymphadenectomy during the 17‐year period, 27 (2.0%) had at least one lymph node harboring an unanticipated finding that raised the concern of a clinically unsuspected neoplasm. Sixteen (1.2%) of these patients had conclusive histologic evidence of an unexpected neoplasm, including 6 patients (0.4%) with malignant lymphomas (low‐grade B cell, n = 5; high‐grade B cell, n = 1) and 10 patients (0.7%) with metastatic papillary thyroid carcinomas. An additional 11 patients (0.8%) had lymph nodes harboring “benign” thyroid inclusions or psammoma bodies. Four of these 11 patients underwent thyroidectomy, but thyroid cancer was not detected in the ipsilateral thyroid. Only one patient died as a consequence of the incidentally discovered neoplasm.

Conclusions.

To the degree that our study population is reflective of the adult population at large, at least 1% of adults harbor malignant neoplasms in their cervical lymph nodes. Although this statistic seems alarmingly high, most of these neoplasms are indolent and do not undergo unrelenting progression to clinically overt malignancies. © 2003 Wiley Periodicals, Inc. Head and Neck 25: 841–847, 2003
Prognostic significance of tumor angiogenesis, Ki 67, p53 oncoprotein, epidermal growth factor receptor and HER2 receptor protein expression in undifferentiated nasopharyngeal carcinoma—a prospective study
Authors: Ma Brigette B. Y. , Poon Terence C. W. , To K. F. , Zee Benny , Mo Frankie K. F. , Chan Charles M. L. , Ho Stephen , Teo Peter M. L. , Johnson Phillip J. , Chan Anthony T. C.
Published: September 2003

Background.

This study prospectively examines the prognostic role of p53 oncoprotein (p53), Ki67‐antigen (Ki67), tumor angiogenesis (MVD), epidermal growth factor receptor (EGFR), and HER2 receptor protein (HER2) expression in Chinese with undifferentiated nasopharyngeal carcinoma (NPC).

Methods.

Seventy‐eight Chinese were recruited from October 1995 to July 1997 at the Prince of Wales Hospital, Hong Kong. Pretreatment immunohistochemical preparations of the primary tumor were made, and clinical data were collected prospectively until October 30, 2000. The markers were correlated with overall survival (OS), disease‐free survival (DFS), time to progression (TTP), and UICC stage.

Results.

On univariate analysis, EGFR expression correlated with poorer OS (p = .0001), DFS (p = .01), shorter TTP (p = .0001), and advanced T stage (p = .036). Strong EGFR expression, when compared with weak or moderate, was associated with poorer OS (p = .04) and shorter TTP in a subgroup of patients with UICC stage III–IV disease. HER2 expression was associated with advanced UICC stage (p = .006). The presence of p53 expression correlated with poorer DFS (p = .01) and a trend toward shorter TTP (p = .06). No correlation was found with Ki67‐antigen or MVD. On multivariate analysis, only EGFR expression was significantly linked to shorter OS and TTP.

Conclusions.

EGFR expression in undifferentiated NPC is associated with a poor clinical outcome. A prognostic role of p53 and HER2 expression is suggestive but not consistently defined in this study. The relatively high prevalence of positive staining for EGFR supports the use of molecular targeted therapy in this disease. © 2003 Wiley Periodicals, Inc. Head and Neck 25: 864–872, 2003
Control rooms' design in industrial facilities
Authors: Meshkati Najmedin
Published: September 2003

A technological system's overall performance, which is an aggregate of its safety, reliability, and efficiency indicators, is a function of its control room operators' performance. Operators' performance is also strongly determined and moderated by the design of the control room. Moreover, today's complex industrial facilities require operators to continually adapt to new and unforeseen changes in technological system and environmental demands. There is no clear‐cut distinction between system design and operation since the operator will have to match system properties to changing demands and operating conditions. Thus, this continuous process needs a cohesive and integrated framework for information gathering from the interfaces, analysis according to operators' task demand, and decision making within the organizational and regulatory contexts of the technological system. Therefore, there is a need to approach human factors in a more global and systematic manner, which includes integration of display systems design, task demands, and with operators' information processing behavior. © 2003 Wiley Periodicals, Inc. Hum Factors Man 13: 269–277, 2003.
Errors in technological systems
Authors: Duffey R.B. , Saull J.W.
Published: September 2003

Massive data and experience exist on the rates and causes of errors and accidents in modern industrial and technological society. We have examined the available human record, and have shown the existence of learning curves, and that there is an attainable and discernible minimum or asymptotic lower bound for error rates. The major common contributor is human error, including in the operation, design, manufacturing, procedures, training, maintenance, management, and safety methodologies adopted for technological systems.

To analyze error and accident rates in many diverse industries and activities, we used a combined empirical and theoretical approach. We examine the national and international reported error, incident and fatal accident rates for multiple modern technologies, including shipping losses, industrial injuries, automobile fatalities, aircraft events and fatal crashes, chemical industry accidents, train derailments and accidents, medical errors, nuclear events, and mining accidents. We selected national and worldwide data sets for time spans of up to ∼200 years, covering many millions of errors in diverse technologies. We developed and adopted a new approach using the accumulated experience; thus, we show that all the data follow universal learning curves.

The vast amounts of data collected and analyzed exhibit trends consistent with the existence of a minimum error rate, and follow failure rate theory. There are potential and key practical impacts for the management of technological systems, the regulatory practices for complex technological processes, the assignment of liability and blame, the assessment of risk, and for the reporting and prediction of errors and accident rates. The results are of fundamental importance to society as we adopt, manage, and use modern technology. © 2003 Wiley Periodicals, Inc. Hum Factors Man 13: 279–291, 2003.