Improved lithology prediction in channelized reservoirs by integrating stratigraphic forward modelling: towards improved model calibration in a case study of the Holocene Rhine-Meuse fluvio-deltaic system.

Stratigraphic forward modelling (SFM) provide the means to produce geologically coherent and realistic models. In this paper, we demonstrate the possibility of matching lithological variability simulated with a basin-scale advection-diffusion SFM to a data-rich real-world setting, i.e. the Holocene Rhine-Meuse fluvio-deltaic system in the Netherlands. SFM model calibration to real-world data in general has proven non-trivial. This study focuses on a novel inversion process constrained by the top surface and the sand proportion observed at specific pseudo-wells in the study area. Goodness-of-fit expressed by a new fitness function, gives the error calculated as the average of two calibration constraints. Computational efficiency was increased significantly by implementing a new optimization process in two hierarchical steps: a) optimization in terms of sediment load and discharge, which are the most influential parameters having the largest uncertainty and b) optimization with respect to the remaining uncertain parameters, these being sediment transport parameters. The calibration process described allows for the most optimal combination of achieving acceptable levels of goodness-of-fit, feasible runtimes and multiple (non-unique) solutions to obtain synthetic stratigraphic output best matching real-world datasets. By removing model realizations which are geologically unrealistic, calibrated SFM models provide a multiscale stratigraphic framework for reconstructing static models of reservoirs which are consistent with the palaeogeographic layout, basin-fill history and external drivers (e.g. sea level, sediment supply). The static reservoir models that are matched with highest certainty therefore contain the highest geological realism and may be used to improve deep subsurface reservoir or aquifer property prediction. The new methodology was applied to the well-established Holocene Rhine-Meuse dataset which allows a rigorous testing of the optimization and the calibrated SFM allows investigation of controls of the Holocene development on the sedimentary system

Geoarchaeological and palaeontological research in the Maasvlakte 2 sand extraction zone and on the artificially created Maasvlakte 2 beach: a synthesis

Zooarchaeolog

Quality of life and salivary output in patients with head-and-neck cancer five years after radiotherapy

BACKGROUND: To describe long-term changes in time of quality of life (QOL) and the relation with parotid salivary output in patients with head-and-neck cancer treated with radiotherapy. METHODS: Forty-four patients completed the EORTC-QLQ-C30(+3) and the EORTC-QLQ-H&N35 questionnaires before treatment, 6 weeks, 6 months, 12 months, and at least 3.5 years after treatment. At the same time points, stimulated bilateral parotid flow rates were measured. RESULTS: There was a deterioration of most QOL items after radiotherapy compared with baseline, with gradual improvement during 5 years follow-up. The specific xerostomia-related items showed improvement in time, but did not return to baseline. Global QOL did not alter significantly in time, although 41% of patients complained of moderate or severe xerostomia at 5 years follow-up. Five years after radiotherapy the mean cumulated parotid flow ratio returned to baseline but 20% of patients had a flow ratio <25%. The change in time of xerostomia was significantly related with the change in flow ratio (p = 0.01). CONCLUSION: Most of the xerostomia-related QOL scores improved in time after radiotherapy without altering the global QOL, which remained high. The recovery of the dry mouth feeling was significantly correlated with the recovery in parotid flow ratio

Serum-Induced Differentiation of Glioblastoma Neurospheres Leads to Enhanced Migration/Invasion Capacity That Is Associated with Increased MMP9

Glioblastoma (GBM) is a highly infiltrative brain tumor in which cells with properties of stem cells, called glioblastoma stem cells (GSCs), have been identified. In general, the dominant view is that GSCs are responsible for the initiation, progression, invasion and recurrence of this tumor. In this study, we addressed the question whether the differentiation status of GBM cells is associated with their invasive capacity. For this, several primary GBM cell lines were used, cultured either as neurospheres known to enrich for GSCs or in medium supplemented with 10% FCS that promotes differentiation. The differentiation state of the cells was confirmed by determining the expression of stem cell and differentiation markers. The migration/invasion potential of these cells was tested using in vitro assays and intracranial mouse models. Interestingly, we found that serum-induced differentiation enhanced the invasive potential of GBM cells, which was associated with enhanced MMP9 expression. Chemical inhibition of MMP9 significantly reduced the invasive potential of differentiated cells in vitro. Furthermore, the serum-differentiated cells could revert back to an undifferentiated/stem cell state that were able to form neurospheres, although with a reduced efficiency as compared to non-differentiated counterparts. We propose a model in which activation of the differentiation program in GBM cells enhances their infiltrative potential and that depending on microenvironmental cues a significant portion of these cells are able to revert back to an undifferentiated state with enhanced tumorigenic potential. Thus, effective therapy should target both GSCs and differentiated offspring and targeting of differentiation-associated pathways may offer therapeutic opportunities to reduce invasive growth of GBM

Human presence in the central Netherlands during early MIS 6 (~170-190 Ka) : evidence from early Middle Paleolithic artefacts in ice-pushed Rhine-Meuse sediments

Part of the gravelly deposits of a combined Rhine-Meuse river of Middle Pleistocene age in the central Netherlands contains early Middle Palaeolithic artefacts. Although not in their original position, a significant part of these artefacts is hardly abraded, indicating limited fluvial transport. The artefacts have mainly been made from fluvial flint gravel boulders, originating from the Meuse catchment. Thus far, inferences for the age of the artefacts are based on the stratigraphic context and floral and faunal remains, which suggest a MIS 7 age. In this paper, OSL dating carried-out in the framework of a research aimed at the paleogeographical reconstruction of the Rhine-Meuse fluvial system in the central Netherlands and a review of published data are used to provide absolute age constraints for the artefact-bearing deposits. It is argued that the deposits were formed during the glacial phase directly preceding the Drenthe substage of the late Saalian (early MIS 6), and that at least a part of the artefacts has approximately the same age

The Dutch Rhine-Meuse delta in 3D: A validation of model results

The Geological Survey of the Netherlands aims at building a 3D geological property model of the upper 30 meters of the Dutch subsurface. This model, called GeoTOP, provides a basis for answering subsurface related questions on, amongst others, sand and gravel resources. Modelling is carried out per province using a core-database containing several hundreds of thousands of core-descriptions, the majority of which reach down to around 10 to 15m, and a context of geological maps. This study focuses on the model of the province of Zuid-Holland where major cities like Rotterdam and The Hague are situated and the Rivers Rhine and Meuse enter the North Sea. A stepwise procedure consisting of automated database queries, 2D modelling of stratigraphic surfaces and 3D property modelling, resulted in a model of 50 million volume cells, each measuring 100 by 100 meters in horizontal directions and 0.5 meters in the vertical direction, every cell having estimates of lithology (sand, clay, peat) and sand-grain size class data. Running simulations, using the Sequential Indicator Simulation algorithm, resulted in information on the probabilities of the aforementioned properties. In the study presented here we focussed on two subjects. First we compared the above described GeoTOP model with two "quick and dirty" models constructed several years ago. The most important and visible difference between those models is the geological framework model used, which has more detail in GeoTOP. By comparing the two, we show the effect of detailed modelling on the cumulative exploitable reserves of aggregates. Secondly we show the effect of data density on GeoTOP modelling results. Using GeoTOP of Zuid-Holland gives us a opportunity to study the effect on the results of the amount of data used. We have therefore carried out a validation using subsequently less borehole information to estimate properties on a constant validation set. Organisations: Golder Magyarorszag ZRt.; Mecsekerc Zrt.; MO

The validation of a social functioning questionnaire in an African postconflict context

This study evaluated the reliability and criterion validity of the Byumba Social Functioning Questionnaire (BSFQ), an instrument to measure social functioning in Rwanda. The instrument was locally composed in concordance with a well-described method for culture-specific and sex-specific function assessment. Respondents in a Northern Province of Rwanda (N = 393) were assessed with the BSFQ and a 19-item scale (SF-19) drawn from the Medical Outcomes Study 36-Item Short-Form (SF-36). The BSFQ's internal consistency was just acceptable for women but poor for men, while the SF-19 had good to excellent internal consisteny. BSFQ total scores showed a strong floor effect, while the SF-19 showed more variation in total score distribution. The BSFQ did not perform as well as we expected, and appears not to be suitable for measuring social functioning in the study context. This outcome seems to reflect the conceptualization of social functioning used in constructing the BSFQ. Implications for the development of culture-specific measures of functional status are discusse

Early Pleistocene Tiglian sites in the Netherlands: A revised view on the significance for quaternary stratigraphy

The Tiglian-A, B and C form the main subdivision of the Early Pleistocene Tiglian Stage in Northwest European chronostratigraphy since the 1960's. We re-evaluated the sedimentary context and new and legacy pollen assemblages of the classic type localities of these Tiglian pollen zones in the Dutch-German border area and Roer-Valley-Graben. Following recalculation of new upland pollen sums, we found that the three-fold subdivision of the Tiglian Stage is too simplistic and lacks a sound stratigraphic basis. The Tiglian-A is only found locally and cannot be positively identified in the RVG. The Tiglian-B in the Tegelen-Maalbeek area is not unique since similar occurrences are present at other depths in the RVG. Sedimentary and pollen analysis suggests Tiglian-C as defined in the Tegelen-Maalbeek type area could have been deposited in a very short amount of time, although this does contradict mammal data. The T-B/C cycle preserved in the type area likely represent a single example of multiple similar Early Pleistocene climate cycles. The sediments of the so-called cool or cold phase of pollen zone T-C 4c in the stratotype of the Tiglian C substage are interpreted as having formed during the onset of crevassing and therefore its significance as a regional climate indicator is discussed. We conclude that the extrapolation of the Tiglian pollen zones into chronostratigraphical substages is questioned and it is concluded that the chronostratigraphical subdivision of the Early Pleistocene, based on palynological characteristics and palaeobotanical analyses, requires reconsideration based on independent dating and land-sea record integration