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S U M M A R YThe reliability of information obtained from surface seismic measurements is an important factor to be considered before one attempts to depth migrate or invert seismic data. The uniqueness of the retrieved model can only be achieved if the observed seismic data contain information on all the wavelengths of the Earth structure.In this study we investigated the sensitivity of model parameters obtainable from elastic multi-offset seismic data. We perturbed a background model, which was defined in terms of longitudinal and shear velocities and density, with quasi-sinusoidal perturbations. The reference and perturbed synthetic seismograms were calculated in the intercept time and slowness (7-p) domain. The seismic waveform misfit between these two synthetic seismograms computed in a least-squares sense was used as a quantitative measure of the sensitivity of model parameters. We found that middlewavelength variations of model parameters are sensitive to critical-angle seismic data. This was further confirmed by using a 1-D waveform inversion. These results suggest that all wavelengths of model parameters can be retrieved from waveform analysis of seismic reflection/refraction data: the long wavelengths from traveltime data and the short to medium wavelengths from waveform analysis. The non-uniqueness associated with the information gap for middle wavelengths, as previously proposed for seismic reflection data, can therefore be avoided.

ObjectiveEvaluate the esthetic perception and attractiveness of the smile with regard to the buccal corridor in different facial types by brachyfacial, mesofacial and dolichofacial individuals.Material and MethodsThe image of a smiling individual with a mesofacial type of face was changed to create three different facial types with five different buccal corridors (2%, 10%, 15%, 22% and 28%). To achieve this effect, a photo editing software was used (Adobe Photoshop, Adobe Systems Inc, San Francisco, CA, EUA). The images were submitted to evaluators with brachyfacial, mesofacial and dolichofacial types of faces, who evaluated the degree of esthetic perception and attractiveness by means of a visual analog scale measuring 70 mm. The differences between evaluators were verified by the Mann-Whitney test. All statistics were performed with a confidence level of 95%.ResultsBrachyfacial individuals perceived mesofacial and dolichofacial types of faces with buccal corridor of 2% as more attractive. Mesofacial individuals perceived mesofacial and dolichofacial types of faces with buccal corridor of 2%, 10% and 15% as more attractive. Dolichofacial individuals perceived the mesofacial type of face with buccal corridor of 2% as more attractive. Evaluators of the female sex generally attributed higher scores than the male evaluators.ConclusionTo achieve an enhanced esthetic smile it is necessary to observe the patient's facial type. The preference for narrow buccal corridors is an esthetic characteristic preferred by men and women, and wide buccal corridors are less attractive.

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A sequence stratigraphic study of the Cenomanian-early Turonian Mishrif Formation has been carried out in the SW of the United Arabian Emirates (UAE) in order to understand the evolution of the reservoir distribution and occurrence of potential stratigraphic and diagenetic traps in the UAE. The study has used an integrated reservoir approach that includes regional geology, seismic stratigraphy together with well data. The use of the core data and logs has allowed identification of facies changes, key stratigraphic surfaces and a number of a few feet thick dense intervals that show a relatively high lateral correlatibility, which appear to be below the seismic resolution. The use of seismic attributes together with the well calibration has been crucial to define seismic facies and their lateral and vertical distribution. Results from this study allowed recognition of several smaller scale 3rd order cycles, which are comprised in a larger 2nd order genetic sequence. Each small-scale cycle is bounded by a sequence boundary overlain by a flooding event made up of a thin dense interval which shows an increase in argillaceous content and locally chert. These sequences are characterised by an eastward progradation from muddy inner ramp facies passing upwards to rudist-rich patch reef/mixed skeletal shoal complexes developed in an inner to mid-ramp depositional setting. This latter setting appears to be best developed in the uppermost large-scale sequence, below the regional unconformity that separates the Mishrif from Ruwaydha and Tuwayil formations. Highly porous facies appear to decrease seismic velocity. The integrated approach presented here captures the variety in depositional environments, architecture, geometry and reservoir heterogeneity, which results in higher likehood to identify stratigraphic and diagenetic traps. Furthermore, the recognition of seismic characteristics of the Mishrif reservoir may be used as a tool to predict the distribution and evolution of units that create velocity variations in the Mishrif Formation and which affect the structural definition of deeper reservoirs as the Shuaiba Formation.