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Surface Variables (surface + variable)
Selected AbstractsSome soft tissue characteristics at implant abutments with different surface topographyJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 1 2003A study in humans Abstract Background: If an implant with a rough surface is exposed to the oral cavity, it may accumulate greater amounts of plaque than a smooth surface, which may lead to severe problems with mucositis and peri-implantitis. The purpose of the present paper was to investigate the early inflammatory response to mucosa-penetrating abutments prepared with varying surface roughness. Methods: Nine patients had all five of their original abutments exchanged to test abutments for a 4-week period. The test abutments were prepared with five different roughnesses. The surface roughness was measured with an optical profilometer. At the end of the test period, clinical evaluation was performed; the health of the surrounding mucosa, the amount of accumulated plaque and marginal bleeding were registered. One biopsy was taken from each test abutment. Qualitative and quantitative histological evaluations were performed. Results: There was a statistically significant difference between patients regarding the amount of accumulated plaque on the abutment surfaces and inflammatory cells, but no difference between the surface modifications in relation to plaque accumulation or number of inflammatory cells. Conclusion: No relation was found between inflammatory response and abutment surface roughness after an evaluation time of 4 weeks in a human test model. Zusammenfassung Hintergrund: Wenn ein Implantat mit einer rauhen Oberfläche der Mundhöhle ausgesetzt wird, kann es zu stärkerer Plaqueakkumulation kommen als bei glatten Oberflächen, was zu ernsthaften Problemen mit Mukositis und Periimplantitis führen kann. Zielsetzung: Untersuchung der frühen Entzündungsreaktion auf durch die Schleimhaut tretende Implantatpfeiler mit unterschiedlicher Oberflächenrauhigkeit. Methoden: Bei jedem von 9 Patienten wurden alle 5 ursprünglichen Implantatpfeiler für einen Zeitraum von 4 Wochen gegen Testpfeiler ausgetauscht. Die Testpfeiler waren jeweils mit unterschiedlichen Oberflächenrauhigkeiten präpariert. Die Rauhigkeiten waren mit einem Profilometer gemessen worden. Am Ende des Untersuchungszeitraumes wurden klinische Parameter bestimmt: der Zustand der periimplantären Mukosa, die Menge der akkumulierten Plaque und marginales Bluten. An jedem Pfeiler wurde eine Biopsie entnommen, die jeweils qualitativ und quantitativ histologisch ausgewertet wurde. Ergebnisse: Es bestanden statistisch signifikante interindividuelle Unterschiede zwischen den Patienten hinsichtlich abgelagerter Plaque und Zahl der Entzündungszellen an den Implantatpfeilern, aber keine diesbezüglichen intraindividuellen Unterschiede zwischen den verschiedenen Oberflächenrauhigkeiten. Schlussfolgerung: In einem menschlichen Versuchsmodell wurden über einen Zeitraum von 4 Wochen keine Beziehungen zwischen Entzündungsreaktion und Implantatpfeileroberflächenrauhigkeit beobachtet. Résumé Origine: Lorsqu'un implant à surface rugueuse est exposé dans la cavité buccale, il peut accumuler davantage de plaque qu'une surface lisse, ce qui peut conduire à des problèmes graves associés à une mucite ou une péri-implantite. Le but de cette étude était d'examiner la réponse inflammatoire précoce aux implants pénétrant la muqueuse et ayant une rugosité de surface variable. Méthodes: Les cinq implants d'origine de chacun des neuf patients ont été remplacés par des implants expérimentaux pour une période de quatre semaines. Ces implants expérimentaux ont été conçus avec cinq rugosités différentes. La rugosité de surface a été mesurée à l'aide d'un profilomètre optique. A l'issue de la période expérimentale, une évaluation clinique a été réalisée: l'état de la muqueuse environnante, la quantité de plaque accumulée et le saignement marginal ont été relevés. Une biopsie a été prélevée sur chaque implant expérimental et des évaluations histologiques qualitatives et quantitatives ont été faites. Résultats: Il y avait une différence statistiquement significative entre les patients en ce qui concerne la quantité de plaque accumulée à la surface des implants et les cellules inflammatoires, mais aucune différence entre les modifications de surface en rapport avec l'accumulation de plaque ou le nombre de cellules inflammatoires. Conclusion: Aucune relation n'a étéétablie entre la réponse inflammatoire et la rugosité de surface des implants au bout de quatre semaines d'évaluation dans un modèle expérimental humain. Mots clés: Pilier d'implant; réponse des tissus mous; étude clinique; histologie. [source] Estimating within-field variation using a nonparametric density algorithmENVIRONMETRICS, Issue 5 2006A. Castrignanò Abstract The application of site-specific techniques and technologies in precision farming requires subdividing a field into a generally small number of contiguous homogeneous zones. The proposed algorithm of clustering is based on nonparametric density estimate, where a cluster is defined as a region surrounding a local maximum of the probability density function. Soil samples were collected in a 2-ha field of the experimental farm of the Agricultural Research Institute, located in Foggia (Southern Italy) and some of the most production-affecting soil properties were interpolated by using the geostatistical techniques of kriging and cokriging. The application of the clustering approach to the (co)kriged surface variables produced the subdivision of the field into five distinct classes. The proposed algorithm proves quite promising in identifying spatially contiguous zones, which are more homogeneous in soil properties than the whole-field. Its great advantage consists in giving an additional description of the residual variation within the class and such a piece of information is very useful in precision farming as a basis for the variable-rate application of agronomic inputs. Copyright © 2005 John Wiley & Sons, Ltd. [source] Crayfish as geomorphic agents and ecosystem engineers: effect of a biomass gradient on baseflow and flood-induced transport of gravel and sand in experimental streamsFRESHWATER BIOLOGY, Issue 1 2003B. Statzner SUMMARY 1.,Using experimental streams, we studied the impact of the crayfish Orconectes limosus on (i) the transport of gravel and sand at baseflow; (ii) the sediment surface (bedform, particle consolidation, proportion of sand, algal and gravel cover); and (iii) the critical shear stress (,C) causing incipient gravel and sand motion during simulated floods. We examined (i) and (ii) in experimental outdoor flumes that replicated riffle-pool sequences and (iii) in a larger laboratory flume, in which we exposed sediments retrieved from the outdoor flumes to a progressively increasing discharge. 2.,Habitat changes induced by crayfish, such as bedform alterations in riffles (downstream displacement of riffle heads) and the increase of gravel on sand dunes in pools, had major impacts on the spatial and temporal patterns of the baseflow transport of gravel and sand. 3.,In addition to their impact on bedform in riffles and on gravel cover in pools, crayfish prevented the physical consolidation of particles in riffles and reduced the algal cover and the proportion of sand in the surface layer in both riffles and pools. These crayfish impacts on sediment surface variables had complex, interacting effects on the mobilisation of gravel and sand during subsequent flood simulations. For sand, crayfish progressively decreased the ,C (i.e. the sum of bedform drag and skin friction) by about 50% along the entire biomass gradient in pools, whereas the presence of crayfish abruptly decreased the ,C by about 75% in riffles. For gravel, the discharge causing motion in riffles produced a shear stress (in terms of skin friction) on an even bedform that was about 75% lower in all flumes with crayfish compared with the flumes without crayfish. Crayfish had no impact on ,C for gravel in pools. 4.,Scaling-up these experimental results to real streams suggests that crayfish could affect the patch dynamics of major sediment transport events and habitat suitability for other organisms that, at larger spatial scales, could increase the overall spatio-temporal habitat diversity and thus the overall structural and functional biodiversity of lotic communities. [source] The influences of the Southern and North Atlantic Oscillations on climatic surface variables in TurkeyHYDROLOGICAL PROCESSES, Issue 6 2005M. Ça, atay Karabörk Abstract In this study, Turkish climatic variables (precipitation, stream flow and maximum and minimum temperatures) were first analysed in association with both the Southern Oscillation (SO) and the North Atlantic Oscillation (NAO). The relationships between Turkish maximum and minimum monthly temperatures and the extreme phases of the SO (El Niño and La Niña events) were examined. The results of this analysis showed that relationships between Turkish monthly maximum temperatures and El Niño and La Niña contain some complexity still to be identified, because both events produce a signal indicating a correspondence with cold anomalies in the aggregate composites. A relationship between turkish minimum temperatures and El Niño was detected in western Anatolia, whereas there was no significant and consistent signal associated with La Niña. Moreover a series of cross-correlation analyses was carried out to demonstrate the teleconnections between the climatic variables and both the NAO and SO. The NAO during winter was found to influence precipitation and stream-flow patterns. In contrast temperature patterns appeared to be less sensitive to the NAO. Furthermore, lag-correlation results indicated a prediction potential for both precipitation and stream-flow variables in connection with the NAO. Simultaneous and time-lag correlations between the climatic variables and the SO index, in general, indicated weaker relationships in comparison with those for the NAO. These analyses also showed that the influences of the SO on Turkish temperature data are negligible. The outcomes were presented in conjunction with an explanation regarding physical mechanisms behind the implied teleconnections. Copyright © 2004 John Wiley & Sons, Ltd. [source] Three-dimensional variational assimilation of Special Sensor Microwave/Imager data into a mesoscale weather-prediction model: A case studyTHE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 626 2007C. Faccani Abstract Assimilation of data from the Special Sensor Microwave/Imager (SSM/I) is performed in order to improve the forecast of a heavy-precipitation case (IOP2b, 20,21 September 1999) of the Mesoscale Alpine Programme 1999. The three-dimensional variational data assimilation technique of the MM5 model is used. Either brightness temperatures or precipitable water and surface wind speed are assimilated. The sensitivity of the model to SSM/I data is also tested by selectively excluding SSM/I frequencies and changing the size of the thinning box. All the experiments are performed using the European Center for Medium range Weather Forecasting (ECMWF) analysis on pressure level. The new initial conditions show considerable underestimation of the surface wind component V, and, even more, of the surface water vapour mixing ratio. This last error is partially corrected by assimilation of precipitable water alone, although these data produce a large increase in the mean error of the other surface variables (U, V and T). However, the forecast with this new set of initial conditions shows a good agreement (high correlation coefficient) with the rain gauge observations for the 1 h accumulated precipitation 3 h after the initial time. With a doubled box size, there is low sensitivity to the density of the observations used. In this case, the effect of the SSM/I data is slight, and the rainfall pattern produced is comparable to that obtained without any data assimilation. The model performance is also degraded if the 22 GHz brightness temperatures are removed from the assimilated measurements: the correlation coefficient for the precipitation is lower than in the case where all the frequencies are assimilated, and it decreases over time. In general, the use of precipitable water and surface wind speed affects the early stages (3 h) of the rainfall forecast, reducing the model spin-up. Brightness temperatures affect the forecast at a longer range (10 h). Copyright © 2007 Royal Meteorological Society [source] Efficacy of olopatadine HCI 0.1%, ketotifen fumarate 0.025%, epinastine HCI 0.05%, emedastine 0.05% and fluorometholone acetate 0.1% ophthalmic solutions for seasonal allergic conjunctivitis: a placebo-controlled environmental trialACTA OPHTHALMOLOGICA, Issue 5 2009Mehmet Borazan Abstract. Purpose:, We aimed to compare the clinical efficacy and ocular surface variables of olopatadine, ketotifen fumarate, epinastine, emedastine and fluorometholone acetate ophthalmic solutions in preventing the signs and symptoms of seasonal allergic conjunctivitis (SAC). Methods:, This was a prospective, randomized, double-blinded and placebo-controlled study. A total of 100 patients with SAC were randomly assigned to one of five groups, in which they were administered olopatadine, ketotifen fumarate, epinastine, emedastine or fluorometholone acetate, instilled twice daily for 2 weeks. One eye of each patient was treated with the study drug and the other was treated with a placebo. Signs and symptoms of allergic conjunctivitis (itching, redness, tearing, chemosis and eyelid swelling) were scored on a 4-point scale. Each symptom was assessed at baseline and then again after 1 and 2 weeks of treatment. Ocular surface variables were assessed by conjunctival impression cytology. Results:, At weeks 1 and 2, all antiallergic agents were significantly more effective than placebo in alleviating itching, redness, tearing, chemosis and eyelid swelling. Fluorometholone acetate was significantly less effective than the other agents in reducing itching and redness at all control visits. Ocular surface findings by impression cytology improved significantly after all treatments compared with placebo. Conclusions:, In patients with SAC, olopatadine, ketotifen, epinastine and emedastine are more efficacious than fluorometholone acetate in preventing itching and redness. All the antiallergic agents gave similar results in terms of reducing tearing, chemosis and eyelid swelling. Our data showed that impression cytology parameters improved after treatment with antiallergic agents in patients with SAC. [source] | ||||||||||