William Arbuthnot Lane (1856-1943): Surgical Innovator and His Theory of Autointoxication.

William Arbuthnot Lane contributed to the advancement of many fields of orthopedics, otolaryngology, and general surgery. He is credited for his no-touch technique and the invention of long-handled instruments, some of which are still in use today, to minimize tissue handling. He is most well known for his hypothesis that slowing of gastric contents could cause a variety of ailments and this became known as Lane\u27s disease. Although his surgical treatment of Lane\u27s disease is now defunct, it advanced the surgical technique in colorectal surgery. It seems likely that some of Lane\u27s autointoxication patients would be classified today as patients with colonic inertia, diverticulitis, colonic volvulus, and megacolon or, which are all treated with colectomy. Lane was a pioneer in multiple fields and a true general surgeon. He advanced colorectal surgery immensely and propelled the field of surgery into a new era

Quantifying the Reversible Association of Thermosensitive Nanoparticles

Under many conditions, biomolecules and nanoparticles associate by means of attractive bonds, due to hydrophobic attraction. Extracting the microscopic association or dissociation rates from experimental data is complicated by the dissociation events and by the sensitivity of the binding force to temperature (T). Here we introduce a theoretical model that combined with light-scattering experiments allows us to quantify these rates and the reversible binding energy as a function of T. We apply this method to the reversible aggregation of thermoresponsive polystyrene/poly(N-isopropylacrylamide) core-shell nanoparticles, as a model system for biomolecules. We find that the binding energy changes sharply with T, and relate this remarkable switchable behavior to the hydrophobic-hydrophilic transition of the thermosensitive nanoparticles

Allosteric activation of the nitric oxide receptor soluble guanylate cyclase mapped by cryo-electron microscopy.

Soluble guanylate cyclase (sGC) is the primary receptor for nitric oxide (NO) in mammalian nitric oxide signaling. We determined structures of full-length Manduca sexta sGC in both inactive and active states using cryo-electron microscopy. NO and the sGC-specific stimulator YC-1 induce a 71° rotation of the heme-binding β H-NOX and PAS domains. Repositioning of the β H-NOX domain leads to a straightening of the coiled-coil domains, which, in turn, use the motion to move the catalytic domains into an active conformation. YC-1 binds directly between the β H-NOX domain and the two CC domains. The structural elongation of the particle observed in cryo-EM was corroborated in solution using small angle X-ray scattering (SAXS). These structures delineate the endpoints of the allosteric transition responsible for the major cyclic GMP-dependent physiological effects of NO

Syndemics and the PrEP Cascade: Results from a Sample of Young Latino Men Who Have Sex with Men.

Young Latino men who have sex with men (MSM) are a highly vulnerable population for HIV infection. Pre-exposure prophylaxis (PrEP) is a novel biomedical HIV prevention tool that may aid in reducing the disparity in HIV incidence among Latino MSM. However, PrEP use is disproportionally low among Latino MSM and, therefore, identifying barriers along the PrEP continuum of care (the "PrEP cascade") would provide insight into how to best deploy PrEP interventions. Syndemics theory is a prominent framework employed in HIV prevention; however, to date, no known studies have applied this theory to PrEP. Thus, the aim of the current study was to explore the association between syndemics and the PrEP cascade, including the degree to which psychosocial and structural syndemic constructs are related to the PrEP cascade. Participants were 151 young Latino MSM (M age = 24 years; SD = 3) residing in San Diego, California, who completed a battery of online self-report measures. Results indicated high levels of syndemic indicators and varying levels of engagement across the PrEP cascade. As syndemic indicators increased, the odds of engagement across the PrEP cascade were significantly lowered. Psychosocial and structural syndemic factors accounted for unique variance in the PrEP cascade. Results highlight the need for combination interventions that address both psychosocial and structural barriers to PrEP use and persistence among young Latino MSM

Stabilizing Highly Dynamic Locomotion in Planar Bipedal Robots with Dimension Reducing Control.

In the field of robotic locomotion, the method of hybrid zero dynamics (HZD) proposed by Westervelt, Grizzle, and Koditschek provided a new solution to the canonical problem of stabilizing walking in planar bipeds. Original walking experiments on the French biped RABBIT were very successful, with gaits that were robust to external disturbances and to parameter mismatch. Initial running experiments on RABBIT were cut short before a stable gait could be achieved, but helped to identify performance limiting aspects of both the physical hardware of RABBIT and the method of hybrid zero dynamics. To improve upon RABBIT, a new robot called MABEL was designed and constructed in collaboration between the University of Michigan and Carnegie Mellon University. In light of experiments on RABBIT and in preparation for experiments on MABEL, this thesis provides a theoretical foundation that extends the method of hybrid zero dynamics to address walking in a class of robots with series compliance. Extensive new design tools address two main performance limiting aspects of previous HZD controllers: the dependence on non-Lipschitz finite time convergence and the lack of a constructive procedure for achieving impact invariance when outputs have relative degree greater than two. An analytically rigorous set of solutions - an arbitrarily smooth stabilizing controller and a constructive parameter update scheme - is derived using the method of Poincare sections. Additional contributions of this thesis include the development of sample-based virtual constraints, analysis of walking on a slope, and identification of dynamic singularities that can arise from poorly chosen virtual constraints.Ph.D.Electrical Engineering: SystemsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/58477/1/morrisbj_1.pd

System Identification and Control of Valkyrie through SVA--Based Regressor Computation

This paper demonstrates simultaneous identification and control of the humanoid robot, Valkyrie, utilizing Spatial Vector Algebra (SVA). In particular, the inertia, Coriolis-centrifugal and gravity terms for the dynamics of a robot are computed using spatial inertia tensors. With the assumption that the link lengths or the distance between the joint axes are accurately known, it will be shown that inertial properties of a robot can be directly evaluated from the inertia tensor. An algorithm is proposed to evaluate the regressor, yielding a run time of O(n^2). The efficiency of this algorithm yields a means for online system identification via the SVA--based regressor and, as a byproduct, a method for accurate model-based control. Experimental validation of the proposed method is provided through its implementation in three case studies: offline identification of a double pendulum and a 4-DOF robotic leg, and online identification and control of a 4-DOF robotic arm

The Northwest Tropical Atlantic Station (NTAS) : NTAS-14 mooring turnaround cruise report

The Northwest Tropical Atlantic Station (NTAS) was established to address the need for accurate air-sea flux estimates and upper ocean measurements in a region with strong sea surface temperature anomalies and the likelihood of significant local air-sea interaction on interannual to decadal timescales. The approach is to maintain a surface mooring outfitted for meteorological and oceanographic measurements at a site near 15°N, 51°W by successive mooring turnarounds. These observations are used to investigate air-sea interaction processes related to climate variability. The NTAS Ocean Reference Station (ORS NTAS) is supported by the National Oceanic and Atmospheric Administration’s (NOAA) Climate Observation Program. This report documents recovery of the NTAS-13 mooring and deployment of the NTAS-14 mooring at the same site. Both moorings used Surlyn foam buoys as the surface element. These buoys were outfitted with two Air-Sea Interaction Meteorology (ASIMET) systems. Each system measures, records, and transmits via Argos satellite the surface meteorological variables necessary to compute air-sea fluxes of heat, moisture and momentum. The upper 160 m of the mooring line were outfitted with oceanographic sensors for the measurement of temperature, salinity and velocity. The mooring turnaround was done by the Upper Ocean Processes Group of the Woods Hole Oceanographic Institution (WHOI), onboard R/V Endeavor, Cruise EN549. The cruise took place between December 5 and 21 December 2014. The NTAS-14 mooring was deployed on December 13, and immediately followed by a 36-hour intercomparison period during which data from the buoy, telemetered through Argos satellite system, and the ship’s meteorological and oceanographic data were monitored. The NTAS-13 buoy had parted on September 23 and was recovered on October 28 while drifting freely near Martinique. The rest of the mooring, which had fallen to the seafloor was recovered during EN549, on December 17. This report describes these operations, as well as other work done on the cruise and some of the pre-cruise buoy preparations. Other operations during EN549 consisted in the recovery and deployment of Pressure Inverted Echo Sounders (PIES) and the acoustic download of data from PIES and subsurface moorings that are part of the Meridional Overturning Variability Experiment (MOVE) array. MOVE is designed to monitor the integrated deep meridional flow in the tropical North Atlantic. Two Argo floats were also deployed during the cruise on behalf of the Argo group at WHOI.Funding was provided by the National Oceanic and Atmospheric Administration under Grant No. NA14OAR4320158