bluuebunny/crossref_metadata_2025 huggingface dataset:
Texture model regression for effective feature discrimination: Application to seismic facies visualization and interpretation
Authors: Gao Dengliang
Published: July 2004

The classical approach to feature discrimination requires extraction and classification of multiple attributes. Such an approach is expensive in terms of computational time and storage space, and the results are generally difficult to interpret. With increasing data size and dimensionality, along with demand for high performance and productivity, the effectiveness of a feature‐discrimination methodology has become a critically important issue in many areas of science. To address such an issue, I developed a texture model regression (TMR) methodology. Unlike classical attribute extraction and classification algorithms, the TMR methodology uses an interpreter‐defined texture model as a calibrating filter and regresses the model texture with the data texture at each sample location to create a regression‐gradient volume. The new approach not only dramatically reduces computational cycle time and space but also creates betters results than those obtained from classical techniques, resulting in improved feature discrimination, visualization, and interpretation.

Application of the TMR concept to reflection seismic data demonstrates its value in seismic‐facies analysis. In order to characterize reflection seismic images composed of wiggle traces with variable amplitude, frequency, and phase, I introduced two simple seismic‐texture models in this application. The first model is defined by a full cycle of a cosine function whose amplitude and frequency are the maximum amplitude and dominant frequency of wiggle traces in the interval of interest. The second model is defined by a specific reflection pattern known to be associated with a geologic feature of interest, such as gas sand in a hydrocarbon reservoir. I applied both models to a submarine turbidite system offshore West Africa and to a gas field in the deep‐water Gulf of Mexico, respectively. Based on extensive experimentation and comparative analysis, I found that the TMR process with such simple texture models creates superior results, using minimal computational resources. The result is geologically intriguing, easily interpretable, and consistent with general depositional and reservoir‐facies concepts. Such a successful application may be attributable to the sensitivity of image texture to physical texture in the Fresnel zone at an acoustic interface and therefore to lithology, depositional facies, and hydrocarbonsaturation.
Stochastic reservoir characterization using prestack seismic data
Authors: Eidsvik Jo , Avseth Per , Omre Henning , Mukerji Tapan , Mavko Gary
Published: July 2004

Reservoir characterization must be based on information from various sources. Well observations, seismic reflection times, and seismic amplitude versus offset (AVO) attributes are integrated in this study to predict the distribution of the reservoir variables, i.e., facies and fluid filling. The prediction problem is cast in a Bayesian setting. The a priori model includes spatial coupling through Markov random field assumptions and intervariable dependencies through nonlinear relations based on rock physics theory, including Gassmann's relation. The likelihood model relating observations to reservoir variables (including lithology facies and pore fluids) is based on approximations to Zoeppritz equations. The model assumptions are summarized in a Bayesian network illustrating the dependencies between the reservoir variables. The posterior model for the reservoir variables conditioned on the available observations is defined by the a priori and likelihood models. This posterior model is not analytically tractable but can be explored by Markov chain Monte Carlo (MCMC) sampling. Realizations of reservoir variables from the posterior model are used to predict the facies and fluid‐filling distribution in the reservoir. A maximum a posteriori (MAP) criterion is used in this study to predict facies and pore‐fluid distributions. The realizations are also used to present probability maps for the favorable (sand, oil) occurrence in the reservoir. Finally, the impact of seismic AVO attributes—AVO gradient, in particular—is studied.

The approach is demonstrated on real data from a turbidite sedimentary system in the North Sea. AVO attributes on the interface between reservoir and cap rock are extracted from 3D seismic AVO data. The AVO gradient is shown to be valuable in reducing the ambiguity between facies and fluids in the prediction.
Joint inversion of seismic data for acoustic impedance
Authors: Fu Li‐Yun
Published: July 2004

I propose a joint inversion scheme to integrate seismic data, well data, and geological knowledge for acoustic impedance estimation. I examine the problem of recovering acoustic impedance from band‐limited seismic data. Optimal estimation of impedance can be achieved by combined applications of model‐based and deconvolution‐based methods. I incorporate the Robinson seismic convolutional model (RSCM) into the Caianiello neural network for network mapping. The Caianiello neural network provides an efficient approach to decompose the seismic wavelet and its inverse. The joint inversion consists of four steps: (1) multistage seismic inverse wavelets (MSIW) extraction at the wells, (2) the deconvolution with MSIW for initial impedance estimation, (3) multistage seismic wavelets (MSW) extraction at the wells, and (4) the model‐based reconstruction of impedance with MSW for improving the initial impedance model. The Caianiello neural network offers two algorithms for the four‐step process: neural wavelet estimation and input signal reconstruction. The frequency‐domain implementation of the algorithms enables control of the inversion on different frequency scales and facilitates an understanding of reservoir behavior on different resolution scales. The test results show that, with well control, the joint inversion can significantly improve the spatial description of reservoirs in data sets involving complex continental deposits.
Amplitude and kinematic corrections of migrated images for nonunitary imaging operators
Authors: Guitton Antoine
Published: July 2004

Obtaining migrated images with meaningful amplitudes is a challenging problem when the migration operator is not unitary. One possible solution to this problem is iterative inversion. However, inversion is an expensive process that can be rather difficult to apply, especially with 3D data. In this paper, I propose estimating migrated images similar to the least‐squares inverse images by approximating the inverse Hessian, thus avoiding the need for iterative inversion. The inverse Hessian is approximated with a bank of nonstationary matching filters. These filters are not exact impulse responses and are limited in their ability to mimic the full effects of least‐squares inversion. Tests on two data sets show that this filtering approach gives results similar to iterative least‐squares inversion at a lower cost. This technique is flexible enough to be applied to images migrated from zero‐offset or angle‐domain common‐image‐point gathers.
Design of one‐way wavefield extrapolation operators, using smooth functions in WLSQ optimization
Authors: Thorbecke Jan W , Wapenaar Kees , Swinnen Gerd
Published: July 2004

Many depth migration methods use one‐way frequency–space depth extrapolation methods. These methods are generally considered to be expensive, so it is important to find the most efficient way of implementing them. This usually means making spatial convolution operators that are as short as possible. Applying the extrapolation operators in a recursive way, using small depth steps, also demands that the operators do not amplify the wavefield at every depth step.

Weighted least squares is an appropriate method to use for designing extrapolation operators that are accurate and efficient and that remain stable in a recursive algorithm. The extrapolated wavefields calculated with these operators are comparable with the extrapolation results obtained with other known operator design techniques as the Remez exchange method and nonlinear optimization. In this paper, the weighted least‐squares technique is refined by using different model functions. By smoothing the phase and amplitude transition at the evanescent cutoff, we can stabilize the resulting operators.

The accuracy of the operators is shown in zero‐offset migration impulse responses in 2D and 3D media. The Sigsbee2A data set is used to illustrate the quality of the extrapolation operators in prestack depth migration in a complex medium.
Slowness‐weighted diffraction stack for migrating wide‐angle seismic data in laterally varying media
Authors: Van Avendonk Harm J. A.
Published: July 2004

Wide‐angle prestack depth migration is an important tool for studying the nature of reflecting boundaries in the earth's crust. The slowness‐weighted diffraction stack (SWDS) method has been used to incorporate both two‐way traveltime constraints and slowness information in the migration. For this purpose, traveltimes and apparent slownesses of reflected arrivals must be calculated in the image space. Earlier applications of SWDS required a 1D or gently varying seismic velocity structure to obtain these quantities by ray tracing in the image space. I show that the apparent slownesses can also be derived directly from one‐way traveltime maps using Fermat's principle. The SDWS is applied to an existing onshore–offshore wide‐angle data set, and the example shows that the method can be used to image detailed reflectivity structure at great depths.
The isochron ray in seismic modeling and imaging
Authors: Iversen Einar
Published: July 2004

The isochron, the name given to a surface of equal two‐way time, has a profound position in seismic imaging. In this paper, I introduce a framework for construction of isochrons for a given velocity model. The basic idea is to let trajectories called isochron rays be associated with iso chrons in an way analogous to the association of conventional rays with wavefronts. In the context of prestack depth migration, an isochron ray based on conventional ray theory represents a simultaneous downward continuation from both source and receiver. The isochron ray is a generalization of the normal ray for poststack map migration. I have organized the process with systems of ordinary differential equations appearing on two levels. The upper level is model‐independent, and the lower level consists of conventional one‐way ray tracing. An advantage of the new method is that interpolation in a ray domain using isochron rays is able to treat triplications (multiarrivals) accurately, as opposed to interpolation in the depth domain based on one‐way traveltime tables. Another nice property is that the Beylkin determinant, an important correction factor in amplitude‐preserving seismic imaging, is closely related to the geometric spreading of isochron rays. For these reasons, the isochron ray has the potential to become a core part of future implementations of prestack depth migration. In addition, isochron rays can be applied in many contexts of forward and inverse seismic modeling, e.g., generation of Fresnel volumes, map migration of prestack traveltime events, and generation of a depth‐domain–based cost function for velocity model updating.
Matrix propagator method for layered porous media: Analytical expressions and stability criteria
Authors: Jocker Jeroen , Smeulders David , Drijkoningen Guy , van der Lee Caroline , Kalfsbeek Alina
Published: July 2004

We fully expand the Thomson‐Haskell propagator matrix method to obtain closed‐form analytical expressions for the reflectivity and transmittivity of a horizontally stratified poroelastic Biot‐type medium that is bounded from above and below by fluid half‐spaces. Stable and unstable regions of the propagator matrix method are determined by means of comparison with the inherently stable reflectivity method. It was found that the stability is mainly determined by the imaginary part of the vertical wavenumber of the Biot slowwave.
High‐resolution seismic traveltime tomography incorporating static corrections applied to a till‐covered bedrock environment
Authors: Bergman Björn , Tryggvason Ari , Juhlin Christopher
Published: July 2004

A major obstacle in tomographic inversion is near‐surface velocity variations. Such shallow velocity variations need to be known and correctly accounted for to obtain images of deeper structures with high resolution and quality. Bedrock cover in many areas consists of unconsolidated sediments and glacial till. To handle the problems associated with this cover, we present a tomographic method that solves for the 3D velocity structure and receiver static corrections simultaneously. We test the method on first‐arrival picks from deep seismic reflection data acquired in the mid‐ late to 1980s in the Siljan Ring area, central Sweden. To use this data set successfully, one needs to handle a number of problems, including time‐varying, near‐surface velocities from data recorded in winter and summer, several sources and receivers within each inversion cell, varying thickness of the cover layer in each inversion cell, and complex 3D geology. Simultaneous inversion for static corrections and velocity produces a much better image than standard tomography without statics. The velocity model from the simultaneous inversion is superior to the velocity model produced using refraction statics obtained from standard reflection seismic processing prior to inversion. Best results using the simultaneous inversion are obtained when the initial top velocity layer is set to the near‐surface bedrock velocity rather than the velocity of the cover. The resulting static calculations may, in the future, be compared to refraction static corrections in standard reflection seismic processing. The preferred final model shows a good correlation with the mapped geology and the airborne magneticmap.
Intelligent multimedia communication for enhanced medical e-collaboration in back pain treatment
Authors: Ghinea George , Magoulas George D. , Frank Andrew O.
Published: July 2004

Remote, multimedia-based, collaboration in back pain treatment is an option which only recently has come to the attention of clinicians and IT providers. The take-up of such applications will inevitably depend on their ability to produce an acceptable level of service over congested and unreliable public networks. However, although the problem of multimedia application-level performance is closely linked to both the user perspective of the experience as well as to the service provided by the underlying network, it is rarely studied from an integrated viewpoint. To alleviate this problem, we propose an intelligent mechanism that integrates user-related requirements with the more technical characterization of quality of service, obtaining a priority order of low-level quality of service parameters, which would ensure that user-centred quality of perception is maintained at an optimum level. We show how our framework is capable of suggesting appropriately tailored transmission protocols, by incorporating user requirements in the remote delivery of e-health solutions.
Intelligent alarms integrated in a multi-agent architecture for diabetes management
Authors: Hernando M. Elena , García Gema , Gómez Enrique J. , del Pozo Francisco
Published: July 2004

This paper describes the development of an intelligent agent that interprets blood glucose monitoring data received by a telemedicine-based diabetes management service. The agent generates automatic alarms when some deviations in the patient status are detected. The agent combines different methods to produce data summaries and automatic alarms based on statistics, rule-based techniques and model-based techniques. The rule-based analysis allows the detection of severe abnormalities using different time scales depending on the quality of the received information. The model-based analysis uses a physiological qualitative model implemented with a causal probabilistic network that detects deviations in the ‘insulin effectiveness’ along days. The KM (Knowledge Management) agent was tested with data from 11 patients with diabetes that used a telemedicine service during 1 year. The KM agent detected anomalous situations in the 100% of the cases where a therapy modification was decided by the healthcare professional; the agent detected abnormal data in 37% of transmissions, being able to decrease professionals’ workload due to telemedicine. The advantages of an automatic response integrated in a telemedicine service are that it focuses doctors’ and patients’ attention on abnormal data and gives instantaneous feedback to patients reinforcing the education and the motivation aspects of the therapy.
A web-based diabetes management system
Authors: Roudsari Abdul , Zhao Nengquan , Carson Ewart
Published: July 2004

Effective management of diabetes mellitus requires the processing and interpretation of blood glucose, insulin and other lifestyle data. This paper presents a web-based diabetes management system (DiabNet), developed to provide instant access to the electronic diabetes database and real-time information for healthcare professionals in order to facilitate their decision-making. DiabNet offers innovative online diabetes management involving online appointment and consultation. It integrates portable glucometer, handheld computer, mobile phone and Internet access as a combined telecommunication and mobile computing solution for diabetes management. Active Server Pages (ASP) embedded with advanced ActiveX controls and VBScript were programmed to allow remote data upload, retrieval and interpretation. This intelligent system can be personalized to the needs of the individual patient, incorporating appropriate historic trends in blood glucose data and with the potential for including an adaptive capability. Internet-based learning features, together with a video teleconferencing component make the DiabNet website an informative platform for teleconsultation. Security steps have also been taken to protect sensitive patient information and the authentication of registered user.
Optical dating studies of mud-dominated alluvium and buried hearth-like features from Red River Valley, southern Manitoba, Canada
Authors: Lian Olav B. , Brooks Gregory R.
Published: July 2004

Optical dating studies of samples of late-Holocene mud-dominated alluvium, and heated alluvium in features interpreted to be hearths, collected from the banks of the Red River, southern Manitoba, Canada, were undertaken to assess the viability of these deposits as chronometers for floodplain evolution. Optical dating was done by utilizing the violet luminescence emitted during infrared excitation of the potassium feldspar in the fine-silt polymineral fraction. The alluvial samples, dated by radiocarbon to be about 1 ka old, yielded maximum limiting optical ages between about 1 and 5 ka, indicating that optical dating of such samples may provide useful chronological information in cases where material suitable for radiocarbon dating is lacking, or in cases where a radiocarbon chronology needs support. Furthermore, the surprisingly low residual optical ages from sediments of this type indicate that there is a high proability that sediments representing similar mud-dominated alluvial environments in the Pleistocene record will yield ages with adequate precision and accuracy. Bulk sediment extracted from the centre of a buried hearth yielded an optical age (1.4 ± 0.2 ka) that was broadly consistent with its associated calibrated radiocarbon age (0.23-1.05 ka), but good agreement (0.79 ± 0.09 ka) was achieved when small fragments of hard-baked mud (ñ0.5 g) extracted from within the feature were optically dated separately; hard-baked fragments from two other hearths yielded similar results. Optical dating of sediments from hearths formed in mud-dominated alluvial sediments thus represents a viable method for obtaining a useful chronology in circumstances where organic material suitable for radiocarbon dating is absent.
Holocene sea-ice variations in Greenland: onshore evidence
Authors: Bennike Ole
Published: July 2004

The oldest dated driftwood log from northern Greenland is c. 9300 cal. years old, which is about 2000 years younger than the beginning of the last deglaciation and 2000 years younger than the oldest driftwood on Svalbard. Driftwood entry to northern Greenland was rare until 7400 cal. years BP, indicating more severe summer sea-ice conditions than at present. More open water than at present probably characterized the period between 6800 and 5500 cal. years BP, during which time driftwood stranded on the beaches of Nioghalvfjerdsfjorden that is now covered by a floating glacier. In central East Greeland, the occurrence of the extralimital species Mytilus edulis in the time interval from c. 8500 to 6000 cal. years BP indicates more open water than at present, and in northwest Greenland studies of dinoflagellate cysts in a marine core indicate warmer surface waters, and hence less sea ice than at present from 7300 to 3700 cal. years BP.
Seventeenth-century uplift in eastern Hokkaido, Japan
Authors: Atwater Brian F. , Furukawa Ryuta , Hemphill-Haley Eileen , Ikeda Yasutaka , Kashima Kaoru , Kawase Kumiko , Kelsey Harvey M. , Moore Andrew L. , Nanayama Futoshi , Nishimura Yuichi , Odagiri Satoko , Ota Yoko , Park Sun-Cheon , Satake Kenji , Sawai Yuki , Shimokawa Koichi
Published: July 2004

Shores of eastern Hokkaido rose by perhaps I m a few centuries ago. The uplifted area extended at least 50km along the southern Kuril Trench. It included the estuaries Akkeshi-ko and Hichirippu, on the Pacific coast, and Furen-ko and Onneto, which open to the Okhotsk Sea. At each estuary, intertidal and subtidal flats rose with respect to tide level; wetland plants colonized the emerging land; and peaty wetland deposits thereby covered mud and sand of the former flats. Previous work at Akkeshi-ko and Onneto showed that such emergence occurred at least three times in the past 3000 years. Volcanic-ash layers date the youngest emergence to the seventeenth century AD. New evidence from Akkeshi-ko, Hichirippu and Furen-ko clarifies the age and amount of this youngest emergence. Much of it probably dates from the century's middle decades. Some of the newly emerged land remained above high tides into the middle of the eighteenth century or later. The emergence in the last half of the seventeenth century probably exceeded 0.5 m (inferred from stratigraphy and diatom palaeoecology) without far exceeding I m (estimated by comparing seventeenth-and eighteenth-century descriptions of Akkeshi-ko). The stratigraphy and palaeoecology of the emergence are better explained by tectonic uplift than by bay-mouth blockage, tidal-flat accretion or sea-level fall. Eastern Hokkaido needs occasional uplift, moreover, to help reconcile its raised marine terraces with its chronic twentieth-century subsidence. Because it took place above forearc mantle, eastern Hokkaido's seventeenth-century uplift probably lacks analogy with coseismic uplift that occurs above typical plate-boundary ruptures at subduction zones.
Past monsoon rainfall variations in peninsular India recorded in a 331-year-old speleothem
Authors: Yadava M. G. , Ramesh R. , Pant G. B.
Published: July 2004

An actively growing stalagmite collected from a cave located in the hills of the Western Ghats in the Uttar Kannada District of Karnataka, India, has been studied for stable isotope ratios of oxygen and carbon, width of growth layers and grey-level changes. Distinct carbonate layers, alternate coarse and compact, are seen in cross-section. Each couplet of compact and coarse layer is found to represent a single year. A total of 331 such couplets has been counted, indicating that the stalagmite started growing in AD 1666 and continued until it was sampled. Stable isotope ratios of oxygen (δ18O) and carbon (δ13C) show variations ranging from-13.6 to-7.9%° and from-2.7 to 1.6%°, respectively. We have reconstructed past rainfall changes of the cave site using the‘amount effect’ in &δ18O of rain. Speleothemδ18O and instrumental rainfall data from the associated climate subdivision show a significant correlation (r =-0.62, decadal average). Several sharp spikes of enrichment and depletion in 18O are indicative of the past deficiency and excess in rainfall. Most of the severe drought years recorded independently by meteorological observations are found registered in the stalagmite layers. During the 331-year-period, rainfall was highest at Añ 1666 and lowest around AD 1900. The stalagmite-generated past rainfall record can serve as a reasonable proxy for testing monsoon models.
Identification and palaeoenvironmental significance of late-Quaternary ermine (Mustela erminea) in the central Columbia Basin, Washington, northwestern USA
Authors: Lee Lyman R.
Published: July 2004

Distinguishing late-quaternary remains of long-tailed weasel (Mustela frenata) from those of ermine (M. erininea) usually depends on size as the former species tends to be larger than the latter. Clinal variation and character displacement among these two taxa make comparative data taken from modern specimens of similar location to prehistoric holocene-age specimens mandatory for valid identifications. Taxonomically diagnostic criteria for modern long-tailed weasels and ermines in eastern Washington indcate that the smallest remains of Mustela represent ermines, mid-size remains cannot be identified to spcies, and the largest remains represent long-tailed weasel. Re-evaluation of small late-Quaternary Mvustela specimens originally identified as ermine suggests that all but two of them cannot be assigned to species. The original identification of one of the remaining specimens as ermine is confirmed. The latto middlHolocene age of the confirmed ermine specimen corresponds to a period of cooler and moister climates, and this accounts for its recovery from modern warm-dry areas in eastern Washington where ermine do not occur today.
Assessing the dendrochronological potential of Pinus occidentalis Swartz in the Cordillera Central of the Dominican Republic
Authors: Speer James H. , Orvis Kenneth H. , Grissino-Mayer Henri D. , Kennedy Lisa M. , Horn Sally P.
Published: July 2004

Opportunities for dendrochronology in the tropics are rare because few locations experience sesonality strong enough to induce annual (or even dependably cyclic) ring formation in trees. Consequently, any such opportunities that exist are valuable and identifying them is worth investing time and effort. West Indian pine (Pinus occidentalis Swartz) is endemic to the island of Hispaniola (l9°N, 71°W). It has prviously been shown not to produce useful rings in low-elevation (<2000 m) stands. We investigated its potential in small (4-11 tree) sample sets from four sites between 2000m and 3000m where seasonality of temperature and precipitation is more pronounced. Primary growth rings were distinct at all sites. False rings, diffuse rings, pinching rings and micro-rings were also present, and their number varied considerably by site. Quality of ring formation appeared to increase with both moisture stress (elevation, exposure, edaphic factors) and cold stress (elevation, exposure, cold-air drainage). We were able to cross-date saples (average interseries correlation= 0.44; average mean sensitivity= 0.44) from nine trees at the higheselevation site, and that chronology correlated significantly (r=–0.45, P<0.001) with monthly and sesonal maximum temperatures from a nearby meteorological station. This finding suggests a centuries-long reconstruction of temperature may be possible for this subtropical location. We conclude that, with careful site and tree selection, oversampling to allow exclusion of problematic specimens and greater use of coplete cross-sections rather than cores, P. occidentalis may allow dendrochronological reconstruction of climate, fire history and other environmental processes that operate on the island of Hispaniola.
Late-Holocene inland dune activity in the UK: a case study from Breckland, East Anglia
Authors: Bateman Mark D. , Godby Steven P.
Published: July 2004

Inland dunefields found in Breckland, East Anglia, UK, have previously been correlated with the widespread late-Devensian coversands of the region and a seventeenth-century‘sandflood’ which is known to have inundated the village of Santon Downham. A programme of optically stimulated luminescence and radiocarbon dating undertaken on the dunes at Wangford Warren and Santon Downham reveals that episodic aeolian activity has taken place during the last 7000 years. Five sand depositional phases on Breckland dunes are identified: c. 6500, c. 1600-1100, c. 500, c. 400-335 and c. 200-30 years before present. Between c. 2120 and 1840 years ago and within the period 1100-300 years ago quiescent periods allowed the development of fen peat and soils. Local controlling factors on aeolian activity in Breckland appear to be related to anthropogenic activities and livestock (sheep and rabbits) reducing vegetation cover, and decreased precipitation and sea levels which led to lowering of water tables. Breckland aeolian activity, when compared to the national and subcontinental Holocene aeolian activity record, shows a high level of concordance. The underlying forcing factor for late-Holocene dune activity in the UK and elsewhere in Europe appears to be climatic instability in the North Atlantic, associated with both the‘Little Ice Age’ and previous similar events which led to increased storminess, climatic variability and lower temperatures.
A Holocene lacustrine rock platform around Storavatnet, Osterøy, western Norway
Authors: Aarseth Inge , Fossen Haakon
Published: July 2004

A recently discovered lacustrine rock platform at low altitude exists along a 1Okm2 lake on the Osterøy Island near Bergen, western Norway. The lake was converted to a reservoir in 1920 and therefore is subject to frequent changes in level above and below the previous natural level of 151.5 m a.s.l. The rock platform, up to 20 m wide, is developed in strongly foliated metamorphic Proterozoic and Palaeozoic berock. Overhanging notches and small caves are developed along bedrock fractures in some places along the platform, which typically tilts 5 to 10 degrees towards the lake and is veneered with angular debris from the cliffs. The study area was deglaciated at the Pleistocene/Holocene transition 10 000 14C yr BP, and the tilting of the glacial rebound was complete about 6000 14C yr BP. The west-coast climate in Norway duing the latter part of the Holocene, with high precipitation and frequent freeze-thaw cycles during winter, resulted in highly fluctuating lake levels. These conditions are consistent with the conclusion that the plaform was formed by frost weathering. Mass movement from the steep slopes, together with ice-push duing ice breakup, was responsible for transportation of the debris. Because the platform around the lake is essentially at the same level, it must have been formed between the mid-Holocene and AD 1920.
Soil erosion in small catchments of the Quercy region (southwester France) during the Holocene
Authors: Bertran Pascal
Published: July 2004

Erosion rates in two small catchments of the Quercy region (southwestern France) calculated from colluvial deposits trapped in karstic depressions show a progressive increase during the Holocene. Rates lower than 0.2 t.ha-1.yr-1 have been found for the period that covers the beginning of the Holocene to the early Iron Age. The soils buried in the depressions testify to the permanence of a forest cover until the late Neolithic, and to its replacement by a herbaceous vegetation during protohistorical times probably as a consequence of forest clearance and increased grazing by cattle. After the early Iron Age, erosion increased significantly and the mean rate reached 0.8 t.ha-1.yr-1 before Mediaeval times. The associated coarse-grained, crudely stratified colluvium is thought to reflect ploughing of the surrounding fields. Erosion rate increased up to c. 1.3t.ha-1.yr-1 during Mediaeval and modem times.
A case of systemic lupus erythematosus with giant hepatic cavernous hemangioma
Authors: Maeshima E , Minami Y , Sato M , Matsuda K , Uchiyama K , Goda M , Ueda H , Kida Y , Mune M
Published: July 2004

A 39-year old woman with antiphospholipid antibody positive systemic lupus erythematosus (SLE) was admitted to our department because of high fever, liver dysfunction and high level of C-reactive protein. At hospitalization, there was no anemia or jaundice. A tumor was palpable in the epigastric region, and there was tenderness in this region, but no muscular defense. There were no findings which indicated disease activity of SLE. The result of abdominal ultrasonography showed that there was a giant tumor, which occupied the majority of the left lobule of the liver, and a nonuniform ultrasound image was observed inside the tumor. The result of dynamic computed tomography (CT) showed peripheral globular enhancement, and enhancement then extended to the tumor center with time. Consequently, the patient was diagnosed with multiple hepatic hemangiomas. After admission, anemia rapidly deteriorated, and platelet count tended to decline. Therefore, intratumor hemorrhage was suspected, and emergent angiography was performed. For hemostatic purposes, transcatheter arterial embolization (TAE) and extended left hepatic lobectomy were performed. In patients with autoimmune diseases such as SLE and antiphospholipid syndromes, when thrombocytopenia is observed, care should be paid to identifying its cause, considering thrombocytopenia may be induced by hemangioma, although these cases are extremely rare.
Pulmonary hypertension in systemic lupus
Authors: Johnson S R , Gladman D D , Urowitz M B , Ibañez D , Granton J T
Published: July 2004

Pulmonary arterial hypertension (PAH) has devastating consequences in the rheumatic diseases; however, the prevalence in lupus is not well delineated. We searched the University of Toronto lupus database to ascertain the first echocardiogram ordered at their physician’s discretion between 1995 and 2002. We reviewed the echocardiogram reports for right ventricular systolic pressure (RVSP), valvular disease, and atrial and ventricular function. The PAH was defined as RVSP ≥40 mmHg. Patients were divided into three groups: RVSP ≥40 mmHg, RVSP 1/4 30-39 mmHg and RVSP, 30 mmHg. We analysed potential associations between presence of PAH and lupus including disease activity, organ involvement and anticardiolipin antibodies, both at the time of and any time prior to echocardiography. In total, 129 patients underwent echocardiography. Nine patients’ echocardiogramswere not obtainable, and three patients were excluded from analysis, as their visit was more than six months from the date of echocardiography. Sixteen patients (14%) had RVSP ≥40 mmHg, 43 (37%) patients had RVSP of 30-39, and 60 (51%) patients had RVSP, 30 mmHg. There was no statistical difference in disease activity, organ involvement or serology among all three groups. In conclusion, the prevalence of PAH (RVSP ≥40 mmHg) on first echocardiogram ordered at physician discretion in our cohort was 14%. An RVSP of 30-39 mmHg was found in 37% of patients. Although abnormal, the clinical significance of this finding is unknown. Disease activity, organ involvement and anti-cardiolipin antibodies were not associated with PAH. Further research is needed to identify the mechanism, response to immunosuppression and impact on quality of life in these patients.
Peptides from antibodies to DNA elicit cytokine release from peripheral blood mononuclear cells of patients with systemic lupus erythematosus: relation of cytokine pattern to disease duration
Authors: Kalsi J K , Grossman J , Kim J , Sieling P , Gjertson D W , Reed E F , Ebling F M , Linker-Israeli M , Hahn B H
Published: July 2004

Peptides from VH regions of antibodies to DNA drive immune responses in systemic lupus erythematosus (SLE). We studied peptide-induced cytokine release by peripheral blood mononuclear cells (PBMC) of patients, the influence of peptide concentration, disease characteristics and HLA-D haplotypes. Cells secreting cytokines (IFNg, IL-2, IL-4 and IL-10) were measured by ELISPOT in PBMC from 31 patients with SLE and 20 matched healthy controls in response to seven peptides (A-G) from the CDR1/FR2 to CDR2/FR3 VH regions of human anti-DNA MAbs. Disease activity was assessed by SELENA-SLEDAI. HLA-DR and -DQ alleles were determined by molecular typing techniques. PBMC from significantly higher proportions of SLE patients than controls responded to VH peptides by generating IFNg and IL-10. Type of cytokines released in response to at least one peptide (D) depended on antigen concentration. Cytokine release was not associated with clinical features of SLE except for disease duration. A shift occurred from IFNg, IL-4 and IL-10 production in early disease to IL-4 and IL-10 in late disease (suggesting increasing TH2-like responses over time). Three peptides (B, D, G) were more stimulatory in the SLE patients than controls. Although none of the peptides was restricted by any particular MHC class II allele, among responders there was increased prevalence of HLA-DQB1 0201 and/or DRB1 0301, alleles known to predispose to SLE. Thus, responses to some VH peptides are more frequent in SLE and vary with disease duration. Increased responses in individuals with HLA class II genotypes that predispose to SLE suggest that peptide presentation by those molecules permits brisker peripheral blood cell responses to autoantibody peptides, thus increasing risk for disease.
Lupus pneumonitis or severe acute respiratory syndrome?
Authors: Mok C C , Ying K Y
Published: July 2004

Severe acute respiratory syndrome (SARS) is a serious respiratory illness caused by a novel human coronavirus. The disease is highly infectious and carries significant mortality and morbidity. There was a major outbreak of SARS in Guangdong, Taiwan, Beijing, Hong Kong and Toronto between March and June 2003. Common presenting features of SARS are high fever, chills, rigor, malaise, nonproductive cough, lymphopenia and pulmonary infiltrates, followed by rapidly progressive respiratory failure in some cases. We describe two patients with systemic lupus erythematosus (SLE) who presented with fever, systemic upset and pulmonary infiltrates between April and June, 2003. One patient was confirmed to have coronavirus pneumonia while the other had active SLE with lung involvement. Our cases illustrate the difficult diagnostic dilemma in the evaluation of febrile SLE patients during the SARS epidemic.
Headaches in patients with systemic lupus erythematosus: a comparative study
Authors: Whitelaw D A , Hugo F , Spangenberg J J , Rickman R
Published: July 2004

The incidence and nature of headaches in 85 systemic lupus erythematosus (SLE) patients attending an outpatient clinic were studied and compared to those experienced by 61 nurses. The two groups were similar in age, sex and ethnicity. Test-retest assessment of reliability gave both groups 95% confidence limits of 0.09-0.21. Thirty-two (38%) patients developed migrainous headaches and nine (10%) stress headaches with the onset of lupus. In the control group, four (6%) developed migraine and 40 (66%) developed stress headaches on commencing work. We could not document any association of headaches with flares of systemic disease, the ACA syndrome, Raynaud’s phenomenon or increased SLEDAI score. We conclude that migrainous headaches are more common in lupus patients than healthy controls, but in an outpatient setting are not statistically associated with flares of systemic disease.
Reduced erythrocyte complement receptor type 1 in systemic lupus erythematosus is related to a disease activity index and not to the presence or severity of renal disease
Authors: de Carvalho Lins C E , Crott L S Pereira , Teixeira J E , Barbosa J E
Published: July 2004

The present study investigated the expression of the complement receptor type 1 (CR1) on the membrane of erythrocytes (CR1/E) of patients with systemic lupus erythematosus (SLE) by flow cytometry. We found a significant reduction in CR1/E numbers in SLE patients (n 1/4 52), compared to controls (512 + 171 and 689 + 146, respectively, P 1/4 0.0001). Reduction was more pronounced in active disease patients. The mean CR1/E number observed in patients with inactive disease was 546 + 163 CR1/E, while active SLE patients presented a mean of 385 + 133 CR1/E(P 1/4 0.001). Patients with SLE with similar activity indexes tend to have similar CR1/E numbers, irrespective of disease severity. We also observed a trend to CR1/E reduction in severe nephritis patients. A small group of SLE patients with chronic renal failure and inactive disease showed CR1/E numbers nearly identical to controls (689 + 146 versus 686 + 123, respectively, P 1/4 0.95). This was the only group of SLE patients with normal CR1/E numbers. These results confirm the CR1/E reduction in SLE patients as previously described, and also suggest that this reduction is related to disease activity and not to disease severity.
Health care and burden of illness in systemic lupus erythematosus compared to rheumatoid arthritis: results from the national database of the German Collaborative Arthritis Centres
Authors: Zink A , Fischer-Betz R , Thiele K , Listing J , Huscher D , Gromnica-Ihle E , Specker C , Schneider M ,   German Collaborative Arthritis Centres
Published: July 2004

During the past 20 years, outcome studies in the rheumatic diseases have, on the one hand, given increasing evidence of the unfavourable long-term prognosis of rheumatoid arthritis (RA) and on the other hand determined continuous improvement of prognosis in systemic lupus erythematosus (SLE). The aim of the study was to investigate how this translates into the current spectrum of patients with rheumatoid arthritis (RA) or systemic lupus erythematosus (SLE) seen by rheumatologists in Germany and to compare aspects of the burden of disease, disease outcomes and treatment between these two important rheumatic diseases using a large clinical database. Current health care was analysed with data from the German rheumatological database of 10 068 patients with RA and 1248 patients with SLE seen by rheumatologists in 2001. In addition, of a total of 3546 patients with SLE and 24 969 patients with RA seen at the German Collaborative Arthritis Centres between 1994 and 2001, 3465 cases of SLE were matched by age, sex, disease duration and referral status with a corresponding RA case. There were considerable differences in treatment of patients before referral to a rheumatologist and in rheumatologic care. In 2001, patients with SLE were treated by their rheumatologists mainly with antimalarials (AM, 37%), azathioprine (29%) and nonselective NSAIDs (16%). Of them, 61% received at least one immunosuppressive drug (including AM) plus glucocorticoids. In RA, methotrexate was the predominant medication (63%), and 56% received at least one immunosuppressive drug plus glucocorticoids. Matched pairs analysis showed that SLE patients with a short disease duration were almost equally burdened by pain, functional limitations and reduced health status as RA patients. After a disease duration of .10 years, however, patients with RA showed poorer outcomes than those with SLE: RA patients reported significantly more often severe pain (30% in RA versus 17% in SLE) and poor global health status (52 versus 38%), and their disease activity as well as severity was rated higher by the rheumatologists. In conclusion, comparing large groups of RA and SLE patients we found a similar burden in early but not in late disease. Taking into account limitations as to the generalizability of the results (recruitment in rheumatologic care, cross-sectional data, underestimation of SLE-specific outcomes), the discrepancy between the high increase in disease-related negative outcomes with longer disease duration in RA but not in SLE indicates a better long-term prognosis in SLE concerning the items observed. The great disparity in treatment intensity between rheumatologists and nonrheumatologists shows that the involvement of a specialist is needed equally in both diseases.
Outcome of patients with systemic lupus erythematosus in intensive care unit
Authors: Alzeer A H , Al-Arfaj A , Basha S J , Alballa S , Al-Wakeel J , Al-Arfaj H , Al-Sugair S , Al-Mugeiren S , Al-Shamairi M , Bamgboye E A
Published: July 2004

The objective of the study was to identify the causes, outcome and prognosis of severe illness in patients with systemic lupus erythematosus (SLE) requiring intensive care unit (ICU) care in a University Hospital over a five-year period. The design was a cohort study. Forty-eight SLE patients requiring ICU management over a five-year period (January 1997-December 2001) were studied prospectively. Of 48 patients, 14 (29.2%) died, predominantly with multiorgan dysfunction syndrome (MODS). Patients whose APACHE II score was equal to or greater than 20 had higher mortality than those with APACHE score below 20 (60 versus 7.1%; and P, 0.01). All the 18 patients whose health status rated as ‘good’ survived, while 46.7% of 30 patients whose health rated as ‘poor’ died (P, 0.01). Patients who had thrombocytopenia associated with sepsis and/or disseminated intravascular coagulopathy (DIC) had the highest mortality (75%, five-year survival). In conclusion, SLE patients admitted to the ICU had a lower mortality rate than some of the previous reports. Patients with SLE with high APACHE score, ≥20, poor health status, thrombocytopenia and multiorgan dysfunction syndrome had poor prognosis in the ICU.
The Ethics of Self
Authors: Haegert Sandra
Published: July 2004

This article attempts to elucidate the ethical meaning behind the words ‘the ethics of self’ and ‘an ethical self’, particularly in the light of Noddings’ ‘ethical self’, in order to show the relevance of these terms to the practice of ethical caring. It examines the relationship that Noddings believes exists between one’s actual self and the vision one has of one’s ideal self. I attempt to draw out a meaning derived from the texts in which this concept has been captured, while at the same time juxtaposing the concept ‘ethic of care’ from my own research, together with the meaning given by philosophers Peta Bowden, Iris Murdoch and Simone Weil, who have written on the subject, albeit indirectly in some instances. A participant in a colleague’s research on care and patient satisfaction used similar expressions, and gave the impetus for this article.
A Qualitative Analysis of Ethical Problems Experienced by Physicians and Nurses in Intensive Care Units in Turkey
Authors: Çobanoğlu Nesrin , Algıer Lale
Published: July 2004

In this qualitative study, we aimed to identify and compare the ethical problems perceived by physicians and nurses in intensive care units at Baskent University hospitals in Turkey. A total of 21 physicians and 22 nurses were asked to describe ethical problems that they frequently encounter in their practice. The data were analyzed using an interactive model. The core problem for both physicians and nurses was end-of-life decisions (first level). In this category, physicians were most frequently concerned with euthanasia while nurses were more concerned with do-not-resuscitate orders (second level). At the third level, we saw that almost all of the participants’ responses related to negative perceptions about euthanasia. Communication and hierarchical problems were the second most reported main category. Nurses were more likely to cite problems with hierarchy than physicians. At the third level, a large percentage of nurses described communication problems with authority and hierarchical problems with physicians. In the same category, physicians were most often concerned with communication problems with patients’ relatives. The ethical problems were reported at different frequencies by physicians and nurses. We asked the participants about ethical decision-making styles. The results show that nurses and physicians do not follow a systematic pattern of ethical decision making.