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Useful Indications (useful + indication)
Selected AbstractsNumerical modelling of regional faults in land subsidence prediction above gas/oil reservoirsINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 6 2008Massimiliano Ferronato Abstract The stress variation induced by gas/oil production may activate pre-existing regional faults. This may enhance the expected land subsidence due to the generation of mechanically weak points close to the producing field. A class of elasto-plastic interface elements (IE), specifically designed to address the mechanical behaviour of faults over a regional scale, is integrated into a finite element (FE) geomechanical model and used to investigate the role exerted by active faults in anthropogenic land subsidence. The importance of regional faults depends on a variety of factors including depth of the depleted reservoir, fault number, orientation and size, geomechanical properties of porous medium, pore pressure drawdown induced by fluid production, etc. With the aid of some representative examples, a useful indication is provided as to where and how fault activation may influence both magnitude and extent of the land subsidence bowl above producing gas/oil reservoirs, pointing to a generally limited impact on the ground surface. The simulation of a real faulted gas reservoir in a complex 3-D setting shows that the proposed IE can be simply and efficiently incorporated into a FE geomechanical model, thus improving the quality of the stress and displacement prediction. Copyright © 2007 John Wiley & Sons, Ltd. [source] RESPONSE OF GLUTAMINE SYNTHETASE GENE TRANSCRIPTION AND ENZYME ACTIVITY TO EXTERNAL NITROGEN SOURCES IN THE DIATOM SKELETONEMA COSTATUM (BACILLARIOPHYCEAE),JOURNAL OF PHYCOLOGY, Issue 1 2005Misaki Takabayashi To understand the enhanced ability of marine diatoms to assimilate nitrogen (N), we measured changes in the transcript abundance and enzyme activity of glutamine synthetase (GS), one of the key enzymes that link carbon (C) and N metabolism, in the common diatom Skeletonema costatum (Greville) Cleve. Transcript abundance of glnII (the gene that encodes the GSII isoenzyme), measured by quantitative reverse transcriptase-PCR, and total GS activity increased 2 to 3.5 times above background in the cells taking up nitrate (NO3,) but not the cells taking up ammonium (NH4+). A background level of glnII mRNA was maintained at a steady level up to 15 days of N starvation before decreasing to below detection after 21 days. These results confirm that transcription of glnII is induced to assimilate NH4+ derived from reduction of NO3,. Because of this role of GSII in diatoms assimilating NH4+ derived from NO3, reduction rather than from the environmental NH4+, quantification of glnII mRNA promises to be a useful indication of new production by phytoplankton. [source] Inviscid, laminar and turbulent opposed flowsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 11 2004Ersel Korusoy Abstract This paper attempts to reproduce numerically previous experimental findings with opposed flows and extends their range to quantify the effects of upstream pipes and nozzles with inviscid, laminar and turbulent flows. The choice of conservation equations, boundary conditions, algorithms for their solution, the degree of grid dependence, numerical diffusion and the validity of numerical approximations are justified with supporting calculations where necessary. The results of all calculations on the stagnation plane show maximum strain rates close to the annular exit from the nozzles and pipes for lower separations and it can be expected that corresponding reacting flows will tend to extinguish in this region with the extinction moving towards the axis. With laminar flows, the maximum strain rate increased with Reynolds number and the maximum values were generally greater than with inviscid flows and smaller than with turbulent flows. With large separations, the strain rates varied less and this explains some results with reacting flows where the extinction appeared to begin on the axis. The turbulent-flow calculations allowed comparison of three common variants of a two-equation first-moment closure. They provided reasonable and useful indications of strain rates but none correctly represented the rms of velocity fluctuations on the axis and close to the stagnation plane. As expected, those designed to deal with this problem produced results in better agreement with experiment but were still imperfect. Copyright © 2004 John Wiley & Sons, Ltd. [source] The Effect of Reminiscence Group Work on Life Satisfaction, Self-Esteem and Mood of Ageing People with Intellectual DisabilitiesJOURNAL OF APPLIED RESEARCH IN INTELLECTUAL DISABILITIES, Issue 1 2009Joris Van Puyenbroeck Background, This study evaluates the effects of reminiscence group work on the subjective well-being of ageing people with intellectual disabilities. Methods, The content of the successive group work sessions was manipulated as follows: a control-phase with three ,current topics' sessions, an experimental phase with six ,reminiscence' sessions and finally three ,current topics' sessions. Life satisfaction, perceived self-competence and mood were measured by questionnaires, filled in by the participants and direct support workers. Results, A quasi-experimental pre-test,post-test design (n = 41) did not detect any changes in life satisfaction and perceived self-competence. For mood, a quasi-experimental ABA-design (n = 41) did not yield an experimental treatment effect, but a significant increase in scores was observed over time. Personality characteristics ,extraversion' and ,emotional stability', but not memory specificity were found to be significant covariates for the mood scores. Conclusion, Although the study's design did not allow us to confirm the effect of reminiscence group work, the analysis nonetheless revealed some useful indications for further research. Also, interviews conducted before and after the programme resulted in positive appraisals of the programme as a worthwhile and meaningful activity for ageing people with intellectual disability. [source] A robust benchmark for the h- and g-indexesJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 6 2010Giovanni Abramo The use of Hirsch's h-index as a joint proxy of the impact and productivity of a scientist's research work continues to gain ground, accompanied by the efforts of bibliometrists to resolve some of its critical issues through the application of a number of more or less sophisticated variants. However, the literature does not reveal any appreciable attempt to overcome the objective problems of measuring h-indexes on a large scale for purposes of comparative evaluation. Scientists may succeed in calculating their own h-indexes but, being unable to compare them to those of their peers, they are unable to obtain truly useful indications of their individual research performance. This study proposes to overcome this gap, measuring the h- and Egghe's g-indexes of all Italian university researchers in the hard sciences over a 5-year window. Descriptive statistics are provided concerning all of the 165 subject fields examined, offering robust benchmarks for those who wish to compare their individual performance to those of their colleagues in the same subject field. [source] Prospective comparison of [18F]fluorodeoxyglucose positron emission tomography with conventional assessment by computed tomography scans and serum tumor markers for the evaluation of residual masses in patients with nonseminomatous germ cell carcinomaCANCER, Issue 9 2002Christian Kollmannsberger M.D. Abstract BACKGROUND To assess the ability of [18F]fluorodeoxyglucose (F-18 FDG) positron emission tomography (PET) to predict the viability of residual masses after chemotherapy in patients with metastatic nonseminomatous germ cell tumors (GCT), PET results were compared in a blinded analysis with computed tomography (CT) scans and serum tumor marker changes (TUM) as established methods of assessment. METHODS Independent reviewers who were blinded to each other's results evaluated the PET results and corresponding CT scan and TUM results in 85 residual lesions from 45 patients. All patients were treated within prospective clinical trials and received primary/salvage, high-dose chemotherapy with autologous blood stem cell support for primary poor prognosis disease or recurrent disease. PET results were assessed both visually and by quantifying glucose uptake (standardized uptake values). Results were validated either by histologic examination of a resected mass and/or biopsy (n = 28 lesions) or by a 6-month clinical follow-up after evaluation (n = 57 lesions). RESULTS F-18 FDG PET showed increased tracer uptake in 32 of 85 residual lesions, with 29 true positive (TP) lesions and three false positive (FP) lesions. Fifty-three lesions were classified by PET as negative (no viable GCT), 33 lesions were classified by PET as true negative (TN), and 20 lesions were classified by PET as false negative (FN). In the blinded reading of the corresponding CT scan and TUM results, 38 residual lesions were assessed correctly as containing viable carcinoma and/or teratoma. Forty-six lesions were classified as nonsuspicious by CT scan/TUM (33 TN lesions and 14 falsely classified lesions). PET correctly predicted the presence of viable carcinoma in 5 of these 14 and the absence of viable carcinoma in 3 of these 14 lesions. Resulting sensitivities and specificities for the prediction of residual mass viability were as follows: PET, 59% sensitivity and 92% specificity; radiologic monitoring, 55% sensitivity and 86% specificity; and TUM, 42% sensitivity and 100% specificity. The positive and negative predictive values for PET were 91% and 62%, respectively. The diagnostic efficacy of PET did not improve when patients with teratomatous elements in the primary tumor were excluded from the analysis. In patients with multiple residual masses, a uniformly increased residual F-18 FDG uptake in all lesions was a strong predictor for the presence of viable carcinoma. CONCLUSIONS F-18 FDG PET imaging performed in conjunction with conventional staging methods offers additional information for the prediction of residual mass histology in patients with nonseminomatous GCT. A positive PET is highly predictive for the presence of viable carcinoma. Other useful indications for a PET examination include patients with multiple residual masses and patients with marker negative disease. Cancer 2002;94:2353,62. © 2002 American Cancer Society. DOI 10.1002/cncr.10494 [source] | |||||||||||||