Part of the Earth Sciences CommonsThis Article is brought to you for free and open access by the Earth and Atmospheric Sciences, Department of at DigitalCommons@University of Nebraska -Lincoln. It has been accepted for inclusion in Papers in the Earth and Atmospheric Sciences by an authorized administrator of DigitalCommons@University of Nebraska -Lincoln. AbstractSequence stratigraphy emphasizes facies relationships and stratal architecture within a chronological framework. Despite its wide use, sequence stratigraphy has yet to be included in any stratigraphic code or guide. This lack of standardization reflects the existence of competing approaches (or models) and confusing or even conflicting terminology. Standardization of sequence stratigraphy requires the definition of the fundamental model-independent concepts, units, bounding surfaces and workflow that outline the foundation of the method. A standardized scheme needs to be sufficiently broad to encompass all possible choices of approach, rather than being limited to a single approach or model.A sequence stratigraphic framework includes genetic units that result from the interplay of accommodation and sedimentation (i.e., forced regressive, lowstand and highstand normal regressive, and transgressive), which are bounded by "sequence stratigraphic" surfaces. Each genetic unit is defined by specific stratal stacking patterns and bounding surfaces, and consists of a tract of correlatable depositional systems (i.e., a "systems tract"). The mappability of systems tracts and sequence stratigraphic surfaces depends on depositional setting and the types of data available for analysis. It is this high degree of variability in the precise expression of sequence stratigraphic units and bounding surfaces that requires the adoption of a methodology that is sufficiently flexible that it can accommodate the range of likely expressions. The integration of outcrop, core, well-log and seismic data affords the optimal approach to the application of sequence stratigraphy. Missing insights from one set of data or another may limit the "resolution" of the sequence stratigraphic interpretation. 1 2 c a t u n e a n u e t a l . i n e a r t h -science r e v i e w s 92 (2009)

Osteoarthritis is a common complication in the elderly and is often associated with osteophyte growth on vertebral bodies. The clinical presentation of vertebral osteophytes is related to anatomical structures adjacent to the spinal column. For instance, cervical osteophytes potentially involve the pharynx and esophagus, leading to dysphagic symptoms that may be accompanied by food aspiration, vocal fold paralysis and obstructive sleep apnea. In addition to anterior cervical osteophytes, posterior and uncinate process osteophytes may form, compressing the spinal cord and vertebral artery blood supply, respectively. Cervical osteophytes have also been shown to form an accessory median atlanto-occipital joint when the relationship between the atlas, dens and basiocciput is involved. In the thorax, the esophagus is often affected by osteophytes and may result in dysphagia. Traumatic and non-traumatic thoracic aorta pseudoaneurysm formation has been attributed to sharp osteophytes lacerating the aorta, a direct complication of the relationship between the aorta anterior vertebral column. Additionally, aspiration pneumonia was reported in patients with compression of a main stem bronchus, due to mechanical compression by thoracic osteophytes. In the lumbar spinal region, the two major structures in close proximity to the spine are the inferior vena cava and abdominal aorta, both of which have been reported to be affected by osteophytes. Treatment of osteophytes is initially conservative with anti-inflammatory medications, followed by surgical removal. Increasing obesity and geriatric populations will continue to result in an array of osteoarthritic degenerative changes such as osteophyte formation.

Sequence stratigraphy emphasizes changes in stratal stacking patterns in response to varying accommodation and sediment supply through time. Certain surfaces are designated as sequence or systems tract boundaries to facilitate the construction of realistic and meaningful palaeogeographic interpretations, which, in turn, allows for the prediction of facies and lithologies away from control points. Precisely which surfaces are selected as sequence boundaries varies from one sequence stratigraphic approach to another. In practice, the selection is often a function of which surfaces are best expressed, and mapped, within the context of each case study. This high degree of variability in the expression of sequence stratigraphic units and bounding surfaces requires the adoption of a methodology that is sufficiently flexible to accommodate the wide range of possible scenarios in the rock record. We advocate a model-independent methodology that requires the identification of all sequence stratigraphic units and bounding surfaces, which can be delineated on the basis of facies relationships and stratal stacking patterns using the available data. Construction of this framework ensures the success of the method in terms of its objectives to provide a process-based understanding of the stratigraphic architecture and predict the distribution of reservoir, source-rock, and seal facies.

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Originally described over 300 years ago, the clinical scenario of intussusception remains incompletely understood. Intussusception is now one of the conditions that can be, most of the time, preoperatively diagnosed and treated with success. This article reviews the literature regarding this pathological state of the abdomen and discusses what is known regarding the presentation, diagnosis, embryology, and anatomy of intussusception.