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CONTEXT Alzheimer disease (AD) is characterized by pathological results at autopsy of amyloid plaques and tau-associated neurofibrillary tangles, but the clinical diagnosis of AD is determined on the basis of medical history, cognitive symptoms, and exclusionary criteria. The search for antemortem biomarkers is intense and has focused on cerebrospinal fluid(More)
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. ABSTRACT Midlevel ventilation, or the flux of low-entropy air into the inner(More)
This study set out to develop a land use regression model at sub-neighborhood scale (0.01-1 km) for Portland, Oregon using passive measurements of NO(2) at 77 locations. Variables used to develop the model included road and railroad density, traffic volume, and land use with buffers of 50 to 750 m surrounding each measurement site. An initial regression(More)
The Department of Earth, Atmospheric, and Planetary Sciences (EAPS) has broad intellectual horizons encompassing the solid Earth, its fluid envelopes, and its diverse neighbors throughout the solar system and beyond. The Department seeks to understand fundamental processes that define the origin, evolution, and current state of these systems and to use this(More)
The sensitivity of tropical cyclone intensity to ventilation of cooler, drier air into the inner core is examined using an axisymmetric tropical cyclone model with parameterized ventilation. Sufficiently strong ventilation induces cooling of the upper-level warm core, a shift in the secondary circulation radially outward, and a decrease in the simulated(More)
The ventilation index serves as a theoretically based metric to assess possible changes in the statistics of tropical cyclones to combined changes in vertical wind shear, midlevel entropy deficit, and potential intensity in climate models. Model output from eight Coupled Model Intercomparison Project 5 models is used to calculate the ventilation index. The(More)
  • 2013
Quantifying and reducing the uncertainty of model parameterizations using observations is evaluated for tropical cyclone (TC) intensity prediction. This is accomplished using a nonlinear inverse modeling technique that produces a joint probability density function (PDF) for a set of parameters. The dependence of estimated parameter values and associated(More)
The sensitivity of tropical cyclone spinup time to the initial entropy deficit of the troposphere is examined in an axisymmetric hurricane model. Larger initial entropy deficits correspond to less moisture above the initial lifting condensation level of a subcloud-layer parcel. The spinup time is quantified in terms of thresholds of integrated horizontal(More)
An updated climatology of Atlantic basin tropical cyclone (TC) intensity change in the presence of upper tropospheric trough forcing is presented. To control for changes in the background thermodynamic environment, a methodology that normalizes intensity change by the potential intensity of the TC is used to more narrowly focus on the effect of troughs(More)