Exceptional surgeries in 3-manifolds

Myers shows that every compact, connected, orientable 3--manifold with no 2--sphere boundary components contains a hyperbolic knot. We use work of Ikeda with an observation of Adams-Reid to show that every 3--manifold subject to the above conditions contains a hyperbolic knot which admits a non-trivial non-hyperbolic surgery, a toroidal surgery in particular. We conclude with a question and a conjecture about reducible surgeries.Mathematic

Poincare homology sphere, lens space surgeries, and some knots with tunnel number two

We exhibit an infinite family of knots in the Poincare homology sphere with tunnel number 2 that have a lens space surgery. Notably, these knots are not doubly primitive and provide counterexamples to a few conjectures. Additionally, we update (and correct) our earlier work on Hedden’s almost-simple knots. In the appendix, it is shown that a hyperbolic knot in the Poincare homology sphere with a lens space surgery has either no symmetries or just a single strong involution.Mathematic

Concepts of Sliding and Lifting Tissue Movement in Flap Reconstruction

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94457/1/j.1524-4725.2000.09172.x.pd

An Interdisciplinary Approach to the Management of Basal Cell Carcinoma of the Head and Neck

At the University of Michigan the dermatologic surgeon works closely with the head and neck surgeon in resecting extensive cutaneous malignancies that could benefit from the combined skills of both surgical specialists. Mohs surgery offers complete microscopic controlled resection of the cutaneous portion of skin cancers. Tumors extending deeply from the skin into underlying bone and soft tissue are resected with the assistance of the head and neck surgeon familiar with the anatomy and trained in the protection of the vital structures of the head and neck. It is evident that patients with large or aggressive basal cell carcinomas will best be served when this interdisciplinary approach has become commonplace.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72612/1/j.1524-4725.1987.tb00917.x.pd

Jointly primitive knots and surgeries between lens spaces

This paper describes a Dehn surgery approach to generating asymmetric hyperbolic manifolds with two distinct lens space fillings. Such manifolds were first identified in work of Dunfield-Hoffman-Licata as the result of a computer search of the SnapPy census, but the current work establishes a topological framework for constructing vastly many more such examples. We introduce the notion of a ``jointly primitive'' presentation of a knot and show that a refined version of this condition ``longitudinally jointly primitive'' is equivalent to being surgery dual to a (1,2)--knot in a lens space. This generalizes Berge's equivalence between having a doubly primitive presentation and being surgery dual to a (1,1)--knot in a lens space. Through surgery descriptions on a seven-component link in S3, we provide several explicit multi-parameter infinite families of knots in lens spaces with longitudinal jointly primitive presentations and observe among them all the examples previously seen in Dunfield-Hoffman-Licata.Mathematic

GIANT CHLOROPLAST 1 Is Essential for Correct Plastid Division in Arabidopsis

AbstractPlastids are vital plant organelles involved in many essential biological processes [1, 2]. Plastids are not created de novo but divide by binary fission mediated by nuclear-encoded proteins of both prokaryotic and eukaryotic origin [3–7]. Although several plastid division proteins have been identified in plants [8–17], limited information exists regarding possible division control mechanisms. Here, we describe the identification of GIANT CHLOROPLAST 1 (GC1), a new nuclear-encoded protein essential for correct plastid division in Arabidopsis. GC1 is plastid-localized and is anchored to the stromal surface of the chloroplast inner envelope by a C-terminal amphipathic helix. In Arabidopsis, GC1 deficiency results in mesophyll cells harbouring one to two giant chloroplasts, whilst GC1 overexpression has no effect on division. GC1 can form homodimers but does not show any interaction with the Arabidopsis plastid division proteins AtFtsZ1-1, AtFtsZ2-1, AtMinD1, or AtMinE1. Analysis reveals that GC1-deficient giant chloroplasts contain densely packed wild-type-like thylakoid membranes and that GC1-deficient leaves exhibit lower rates of CO2 assimilation compared to wild-type. Although GC1 shows similarity to a putative cyanobacterial SulA cell division inhibitor, our findings suggest that GC1 does not act as a plastid division inhibitor but, rather, as a positive factor at an early stage of the division process