Construction of silicon nanocolumns with the scanning tunneling microscope

Voltage pulses to a scanning tunneling microscope (STM) are used to construct silicon columns of 30–100 Å diameter and up to 200 Å height on a silicon surface and on the end of a tungsten probe. These nanocolumns have excellent conductivity and longevity, and they provide an exceptional new ability to measure the shapes of nanostructures with a STM. This construction methodology and these slender yet robust columns provide a basis for nanoscale physics, lithography, and technology

Operational and Technical Updates to the Object Reentry Survival Analysis Tool

The Object Reentry Survival Analysis Tool (ORSAT) has been used in the NASA Orbital Debris Program Office for over 25 years to estimate risk due to uncontrolled reentry of spacecraft and rocket bodies. Development over the last 3 years has included: a major change to the treatment of carbon fiber- and glass fiber-reinforced plastics (CFRP and GFRP, respectively); an updated atmospheric model; a new model for computing casualty area around an impacting debris object; and a newly-implemented scheme to determine the breakup altitude of a reentry object. Software also was written to automatically perform parameter sweeps in ORSAT to allow for uncertainty quantification and sensitivity analysis for components with borderline demisability. These updates have improved the speed and fidelity of the reentry analysis performed using ORSAT, and have allowed for improved engineering understanding by estimating the uncertainty for each components survivability. A statistical model for initial conditions captures the latitude bias in population density, a large improvement over the previous inclination-based latitude-averaged models. A sample spacecraft has been analyzed with standard techniques using ORSAT 6.2.1 and again using all the updated models; we will demonstrate the variation in the total debris casualty area and overall expectation of casualty

Concurrent Validation of the Affective Scale of the Diagnostic Assessment for the Severely Handicapped (DASH) Scale

Sixty-nine severely and profoundly retarded clients in a residential setting, each of whom could ambulate without staff assistance, were administered the Diagnostic Assessment for the Severely Handicapped (DASH) Scale. Three groups of 23 were selected based on previous psychiatric diagnosis and matched for social age. The group with no psychiatric diagnosis served as the nominal control. The second group contained a mix of non-affective psychiatric diagnoses. The third group contained clients with a diagnosis of bipolar disorder. A one-way analysis of variance was conducted. The data demonstrated the DASH effectively discriminated clients with bipolar disorder from those without psychiatric as well as from non-affective psychiatric disorders. The implications of these findings were discussed, and areas for future study were suggested

Advantages of a Polycentric Approach to Climate Change Policy

Lack of progress in global climate negotiations has led scholars to reconsider polycentric approaches to climate policy. Several examples of subglobal mechanisms to reduce greenhouse-gas emissions have been touted, but it remains unclear why they might achieve better climate outcomes than global negotiations alone. Decades of work conducted by researchers associated with the Vincent and Elinor Ostrom Workshop in Political Theory and Policy Analysis at Indiana University have emphasized two chief advantages of polycentric approaches over monocentric ones: they provide more opportunities for experimentation and learning to improve policies over time, and they increase communications and interactions — formal and informal, bilateral and multilateral — among parties to help build the mutual trust needed for increased cooperation. A wealth of theoretical, empirical and experimental evidence supports the polycentric approach

Impaired M3 and enhanced M2 muscarinic receptor contractile function in a streptozotocin model of mouse diabetic urinary bladder

We investigated the contractile roles of M2 and M3 muscarinic receptors in urinary bladder from streptozotocin-treated mice. Wild-type and M2 muscarinic receptor knockout (M2 KO) mice were given a single injection of vehicle or streptozotocin (125 mg kg−1) 2–24 weeks prior to bladder assays. The effect of forskolin on contractions elicited to the muscarinic agonist, oxotremorine-M, was measured in isolated urinary bladder (intact or denuded of urothelium). Denuded urinary bladder from vehicle-treated wild-type and M2 KO mice exhibited similar contractile responses to oxotremorine-M, when contraction was normalized relative to that elicited by KCl (50 mM). Eight to 9 weeks after streptozotocin treatment, the EC50 value of oxotremorine-M increased 3.1-fold in urinary bladder from the M2 KO mouse (N = 5) compared to wild type (N = 6; P < 0.001). Analogous changes were observed in intact bladder. In denuded urinary bladder from vehicle-treated mice, forskolin (5 µM) caused a much greater inhibition of contraction in M2 KO bladder compared to wild type. Following streptozotocin treatment, this forskolin effect increased 1.6-fold (P = 0.032). At the 20- to 24-week time point, the forskolin effect increased 1.7-fold for denuded as well as intact bladders (P = 0.036, 0.01, respectively). Although streptozotocin treatment inhibits M3 receptor-mediated contraction in denuded urinary bladder, muscarinic contractile function is maintained in wild-type bladder by enhanced M2 contractile function. M2 receptor activation opposes forskolin-induced relaxation of the urinary bladder, and this M2 function is enhanced following streptozotocin treatment

Terror, War, and the Economy in George W. Bush’s Approval Ratings: The Importance of Salience in Presidential Approval

George W. Bush\u27s presidency provides a fertile ground to further develop the standard model of presidential approval. In contrast to the vast presidential approval literature, early studies of Bush conclude economic conditions had no effect once the war in Iraq began. Rather than require a fundamental rethinking of presidential approval theories, we argue that approval models must take into account issue salience. When a factor is salient, it has a stronger effect. During the Bush presidency, with considerable over-time variation in the salience of the economy, terrorism, and the war in Iraq, each, in turn, powerfully affected Bush\u27s approval

CBLAST-Low 2001 pilot study mooring deployment cruise and data report ; FV Nobska, June 4 to August 17, 2001

During the summer of 2001, several moorings and cruises were used as part of the CBLAST-Low (Coupled Boundary Layer Air-Sea Transfer under low wind conditions) pilot experiment in the North Atlantic, south of Martha’s Vineyard Island, MA, USA. Six subsurface tide gauges were deployed around the study site for a period of approximately 3 months during the summer of 2001. Further, two surface buoys equipped with meteorological instrumentation and subsurface arrays that measured temperature, conductivity and velocity were deployed during the months of July and August 2001. For a short intensive operating period during July 2001, a newly manufactured three-dimensional mooring designed to sample three-dimensional properties of the upper ocean was deployed for a period of 6 days. During the Intensive Operating Period (IOP) along-shelf and across-shelf conductivity-temperature-depth (CTD) sections were completed as well as a drifting array designed to passively collect data from the upper water column released for approximately 24 hours. This report describes the instrumentation and type of moorings deployed by the Woods Hole Oceanographic Institution Upper Ocean Processes (WHOI UOP) group as well as data return and quality from the CBLAST-Low 2001 pilot study. This is summarized in graphical and tabular form in this report.Funding provided by the Office of Naval Research under Contract No. N00014-01-1-0029 and from the Secretary of the Navy / CNO Chair Grant No. N00014-99-1-0090