Particle Removal Rates by the Mud Shrimp \u3cem\u3eUpogebia pugettensis\u3c/em\u3e, its Burrow, and a Commensal Clam: Effects on Estuarine Phytoplankton Abundance

The burrowing shrimp Upogebia pugettensis is an abundant intertidal invertebrate of Pacific Northwest, USA bays and estuaries where it lives commensally with the bivalve Cryptomya californica. Suspension-feeding activities by the shrimp and by its commensal clam, as well as particle settlement within the burrow, represent 3 different components that could remove phytoplankton from water drawn into shrimp burrows. These 3 components together comprise what we call the ‘U. pugettensis shrimp-burrow complex’. In laboratory experiments, we measured particle removal by each of these components. Our results indicated that U. pugettensis itself is responsible for filtering the majority of phytoplankton removed by the U. pugettensis shrimp-burrow complex at phytoplankton concentrations of 0.12 mg C l-1, with filtration by C. californica becoming increasingly important at phytoplankton concentrations of 0.48 mg C 1-1. Particle settlement in the burrow and adhesion to the burrow wall may also be responsible for removal of substantial proportions of phytoplankton. Using results from both laboratory and field experiments, we developed a population filtration model to examine the potential impacts of U. pugettensis shrimp-burrow complexes on phytoplankton in the Yaquina estuary, Newport, Oregon, USA. We showed that U. pugettensis shrimp-burrow complexes in this estuary may be capable of daily filtering the entire body of overlying water. We also examined the potential for food competition between U. pugettensis and other suspension feeders that are found in shrimp habitats, represented in this study by the Pacific oyster Crassostrea gigas. Comparison of retention efficiencies of shrimp and oysters indicated that they are both capable of utilizing phytoplankton-sized particles with similar efficiencies and, therefore, may compete for food when phytoplankton abundance is growth-limiting

Posterior sternoclavicular dislocations: a brief review and technique for closed management of a rare but serious injury

Posterior sternoclavicular dislocations are rare but serious injuries. The proximity of the medial clavicle to the vital structures of the mediastinum warrants caution with management of the injury. Radiographs are the initial imaging test, though computed tomography and magnetic resonance imaging are essential for diagnosis and preoperative planning. This paper presents an efficient diagnostic approach and effective technique of closed reduction of posterior sternoclavicular dislocations with a brief review of open and closed reduction procedures

The global percutaneous shuttling technique tip for arthroscopic rotator cuff repair

Most arthroscopic rotator cuff repairs utilize suture passing devices placed through arthro- scopic cannulas. These devices are limited by the size of the passing device where the suture is passed through the tendon. An alternative technique has been used in the senior author’s practice for the past ten years, where sutures are placed through the rotator cuff tendon using percutaneous passing devices. This technique, dubbed the global percutaneous shuttling technique of rotator cuff repair, affords the placement of sutures from nearly any angle and location in the shoulder, and has the potential advantage of larger suture bites through the tendon edge. These advantages may increase the area of tendon available to compress to the rotator cuff footprint and improve tendon healing and outcomes. The aim of this study is to describe the global percutaneous shuttling (GPS) technique and report our results using this method. The GPS technique can be used for any full thickness rotator cuff tear and is particularly useful for massive cuff tears with poor tissue quality. We recently followed up 22 patients with an average follow up of 32 months to validate its usefulness. American Shoulder and Elbow Surgeons scores improved significantly from 37 preoperatively to 90 postoperatively (P<0.0001). This data supports the use of the GPS technique for arthroscopic rotator cuff repair. Further biomechanical studies are currently being performed to assess the improvements in tendon footprint area with this technique