Retained Herrick Plug.

A 79-year-old female with a history of keratoconjunctivitis sicca presented with several years of epiphora of both eyes. Thirteen years earlier, intracanalicular Herrick lacrimal plugs (Lacrimedics, Eastsound, WA, USA) had been placed in both eyes to treat her dry eye syndrome. After 13 years the patient felt the epiphora was intolerable and underwent endoscopic dacryocystorhinostomy (DCR) of the left, then the right side. Intraoperatively, during the right endoscopic DCR, a Herrick lacrimal plug was found in the common canaliculus into the lacrimal sac. Postoperatively, the patient did well with improved epiphora. The Herrick plug is designed to be intracanalicular, and this case illustrates that the plug can migrate and be retained for many years. Collared punctal plugs have a lower risk of this type of complication

Signaling pathways in osteogenesis and osteoclastogenesis: Lessons from cranial sutures and applications to regenerative medicine.

One of the simplest models for examining the interplay between bone formation and resorption is the junction between the cranial bones. Although only roughly a quarter of patients diagnosed with craniosynostosis have been linked to known genetic disturbances, the molecular mechanisms elucidated from these studies have provided basic knowledge of bone homeostasis. This work has translated to methods and advances in bone tissue engineering. In this review, we examine the current knowledge of cranial suture biology derived from human craniosynostosis syndromes and discuss its application to regenerative medicine

Characterization of polycrystalline silicon films grown by LPCVD of silane

Deposition of polycrystalline silicon by thermolysis of silane, SiH₄, is a common technique for creating polysilicon films for a variety of applications. The deposition temperature and pressure greatly influence parameters relating to growth rate and film quality. These characteristics include film crystallinity and resulting grain orientation that determine the optical and electrical properties of the films and their suitability for particular applications. An empirical approach was taken to characterize the growth process and resulting film quality. Polycrystalline silicon films were grown to map a region of temperatures and pressures in the range of 575°C to 700°C and 200 mTorr to 500 mTorr. Deposition rate increased with increasing pressure, and was a strong function of temperature, increasing quickly then diminishing due to silane depletion. The crystallinity of films increased with temperature and decreased with pressure, exhibiting regions of rapid transition between amorphous and crystalline phases. X-ray diffraction was used to determine grain orientation and size. The \u3c220\u3e grains showed preferential growth while \u3c111\u3e and \u3c311\u3e grains were completely inhibited at low temperatures. Band gap energy decreased with increasing temperature and crystallinity. Resistivity of as-deposited, intrinsic films was very high. However, planar source phosphorus diffusion and annealing reduced resistivity to as low as 2.5·10⁻³ [Omega]·m

Multi-Agent Communication and Collaboration

Degree: Master of Science in Engineering Department: EngineeringMulti-Agent Systems are becoming a popular paradigm for many engineering applications. However, there is still much research to be performed in this fast growing field. In this thesis, the effect of learning in multi-agent systems on communication and collaboration between agents is investigated. This research focuses on agents learning local cooperative behaviour from a centralised agent, as well as using learning to reduce the amount of communication between agents that use negotiation to achieve their goals. A simple test problem is formulated in MATLAB. The effect of learning is clearly seen to reduce the amount of communication between agents by up to 50%, while still maintaining cooperative behaviour. The agents are also demonstrated to learn to a large degree cooperative local behaviour from a central system

Fibronectin Contributes To Notochord Intercalation In The Invertebrate Chordate, Ciona Intestinalis

Background: Genomic analysis has upended chordate phylogeny, placing the tunicates as the sister group to the vertebrates. This taxonomic rearrangement raises questions about the emergence of a tunicate/vertebrate ancestor. Results: Characterization of developmental genes uniquely shared by tunicates and vertebrates is one promising approach for deciphering developmental shifts underlying acquisition of novel, ancestral traits. The matrix glycoprotein Fibronectin (FN) has long been considered a vertebrate-specific gene, playing a major instructive role in vertebrate embryonic development. However, the recent computational prediction of an orthologous “vertebrate-like” Fn gene in the genome of a tunicate, Ciona savignyi, challenges this viewpoint suggesting that Fn may have arisen in the shared tunicate/vertebrate ancestor. Here we verify the presence of a tunicate Fn ortholog. Transgenic reporter analysis was used to characterize a Ciona Fn enhancer driving expression in the notochord. Targeted knockdown in the notochord lineage indicates that FN is required for proper convergent extension. Conclusions: These findings suggest that acquisition of Fn was associated with altered notochord morphogenesis in the vertebrate/tunicate ancestor

Rethinking Sampled-Data Control for Unmanned Aircraft Systems

Unmanned aircraft systems are expected to provide both increasingly varied functionalities and outstanding application performances, utilizing the available resources. In this paper, we explore the recent advances and challenges at the intersection of real-time computing and control and show how rethinking sampling strategies can improve performance and resource utilization. We showcase a novel design framework, cyber-physical co-regulation, which can efficiently link together computational and physical characteristics of the system, increasing robust performance and avoiding pitfalls of event-triggered sampling strategies. A comparison experiment of different sampling and control strategies was conducted and analyzed. We demonstrate that co-regulation has resource savings similar to event-triggered sampling, but maintains the robustness of traditional fixed-periodic sampling forming a compelling alternative to traditional vehicle control design

Torque-Displacement Binding Tester

Inadvertent release of a ski binding occurs when the ski binding releases the skier under non-injurious loading conditions and has been known to cause loss of control leading to severe upper body injury and death. Work required to release the ski boot from the ski binding is a parameter that influences the tendency for inadvertent release. The project utilized Suh’s Axiomatic method for the design of a device that measures work to release through the simultaneous measurements of torque and displacement. The optical mouse is tested and recommended as a low cost displacement sensor