Fearless: Anastasia Maisel

Working to create a meaningful, respectful, and community-minded Day of Service in honor of Gettysburg College student Emily Silverstein ’11, and continually involved in different farming and food initiatives in the Gettysburg area to promote food justice and environmentally friendly farming practices, Anastasia Maisel ’14 fearlessly gives her time, energy, and passion to promoting social justice on and off campus. [excerpt

Channel noise effects on neural synchronization

Synchronization in neural networks is strongly tied to the implementation of cognitive processes, but abnormal neuronal synchronization has been linked to a number of brain disorders such as epilepsy and schizophrenia. Here we examine the effects of channel noise on the synchronization of small Hodgkin-Huxley neuronal networks. The principal feature of a Hodgkin-Huxley neuron is the existence of protein channels that transition between open and closed states with voltage dependent rate constants. The Hodgkin-Huxley model assumes infinitely many channels, so fluctuations in the number of open channels do not affect the voltage. However, real neurons have finitely many channels which lead to fluctuations in the membrane voltage and modify the timing of the spikes, which may in turn lead to large changes in the degree of synchronization. We demonstrate that under mild conditions, neurons in the network reach a steady state synchronization level that depends only on the number of neurons in the network. The channel noise only affects the time it takes to reach the steady state synchronization level.Comment: 7 Figure

Preliminary investigation of an electrical network model for ultrasonic scattering

The behavior of acoustic attenuation in a solid is related to the electrical transmission line model where the electrical shunt conductance, which is frequency dependent, represents the loss due to the scattering sites in the solid. Results indicate that the absolute value of attenuation at a given frequency depends on both the normalized mean square deviation of the density and bulk modulus of the scattering sites from the ambient medium and the spatial scattering correlation function. Besides establishing the absolute value of attenuation, the spatial correlation function determines the attenuation profile as a function of frequency

Do we need another heart failure biomarker. focus on soluble suppression of tumorigenicity 2 (sST2)

If sST2 indeed turns into the HbA1c of heart failure, its value should increase exponentially in our management of patients with heart failure. Serial sST2 levels should allow us to titrate therapy and monitor the clinical state of the patient. In addition, since sST2 is such a strong marker of the risk of death, it would not be surprising to see a level be used to make decisions when patients are on the cusp of such therapies as ICD, CRT, CardioMems implantation and even left ventricular assist devices. A discussion about the use of biomarkers would not be complete without mentioning the issue of surrogates for determining the therapy effectiveness of some of the newer heart failure drugs. Novartis’s EntrestoVR , the brand name for its recently CE marked and FDA approved ARNI1 drug (previously known as LCZ696) and Servier’s ivabradine drug CorlanorVR (marketed by Amgen in the USA), also CE marked and FDA approved, while offering exciting potential benefits to heart failure patients—even being hailed ‘game-changer’ drugs by some—raises the thorny issue of cost vs. benefit. These new drugs are several times the cost of the generics that have become the mainstay of heart failure treatment, i.e. ACE inhibitors, angiotensin receptor blocker (ARBs), beta-blockers, etc. Pushback is therefore expected from payers. Because sST2 changes rapidly with the underlying condition of the patient, is not affected by normal confounding factors, and has a single cut point, it may be ideally suited to help clinicians determine if these newer mediations are effective for each patient, are improving quality of life, and whether dosing needs to be titrated or changed. The new reality of heart failure care is that while more treatment options have opened up, which can literally be a lifesaver for millions of patients, the burden on healthcare systems has skyrocketed. Biomarkers, and particularly sST2, could offer physicians and payers a way to bring treatment down to an individual patient level, providing

Interest Rate Changes and Commercial Bank Revenues and Costs

This paper estimates statistical cost. and revenue curves for a cross-section of banks in the years 1962-75. The primary data cover reported accounting or book rates of return. Approximations are also made to estimate economic or total returns. These approximations take into account changes in capital values during the year as a result of movements in interest rates measured by market yields of government securities of the proper duration. Book rates of return and costs adjust towards each other so that marginal rates received or paid for different activities tend to equalize. On the other hand, the rates of adjustment are slow. While movements in the cost of demand and time deposits correlate well with changes in market rates, not all of the advantages of interest rate ceilings are given up to depositors. Movements in interest rates cause sharp fluctuations in total returns. These movements are sharp enough so that in several years economic losses occurred rather than reported book profits. Furthermore, over this period the net economic returns of classes of assets were poorly correlated with their risks (their variance of returns).

Measurement of the time-temperature dependent dynamic mechanical properties of boron/aluminum composites

A flexural vibration test and associated equipment were developed to accurately measure the low strain dynamic modulus and damping of composite materials from -200 C to over 500 C. The basic test method involves the forced vibration of composite bars at their resonant free-free flexural modes in a high vacuum cryostat furnace. The accuracy of these expressions and the flexural test was verified by dynamic moduli and damping capacity measurements on 50 fiber volume percent boron/aluminum (B/Al) composites vibrating near 2000 Hz. The phase results were summarized to permit predictions of the B/Al dynamic behavior as a function of frequency, temperature, and fiber volume fraction

High temperature dynamic modulus and damping of aluminum and titanium matrix composites

Dynamic modulus and damping capacity property data were measured from 20 to over 500 C for unidirectional B/Al (1100), B/Al (6061), B/SiC/Al (6061), Al2O3/Al, SiC/Ti-6Al-4V, and SiC/Ti composites. The measurements were made under vacuum by the forced vibration of composite bars at free-free flexural resonance near 2000 Hz and at amplitudes below 0.000001. Whereas little variation was observed in the dynamic moduli of specimens with approximately the same fiber content (50 percent), the damping of B/Al composites was found at all temperatures to be significantly greater than the damping of the Al2O3/Al and SiC/Ti composites. For those few situations where slight deviations from theory were observed, the dynamic data were examined for information concerning microstructural changes induced by composite fabrication and thermal treatment. The 270 C damping peak observed in B/Al (6061) composites after heat treatment above 460 C appears to be the result of a change in the 6061 aluminum alloy microstructure induced by interaction with the boron fibers. The growth characteristics of the damping peak suggest its possible value for monitoring fiber strength degration caused by excess thermal treatment during B/Al (6061) fabrication and use

Advanced Communications Technology Satellite (ACTS). Phase 1: Industrial/academic experimenters

This report presents the work done at Arizona State University under the ACTS Experimenters Program. The main thrust of the Program was to develop experiments to test, evaluate, and prove the commercial worthiness of the ACTS satellite which is scheduled for launch in 1993. To accomplish this goal, meetings were held with various governmental, industrial, and academic units to discuss the ACTS satellite and its technology and possible experiments that would generate industrial interest and support for ASU's efforts. Several local industries generated several experiments of their own. The investigators submitted several experiments of educational, medical, commercial, and technical value and interest. The disposition of these experimental proposals is discussed in this report

“Un bacio”—ancora? Un altro “bacio”!

It is difficult to credit the usual explanation that the mere fact of the “bacio” theme’s recapitulation in act 4 of Verdi’s Otello accounts for its powerful effect. Even the irony of dramatic circumstances radically altered from those it accompanied when introduced in act 1 seems insufficient to explain the complex impact of the theme’s return. If, however, its recurrence represents the culmination of musical processes at work throughout the opera, then the effect is understandable. This paper uses a Schenkerian approach to demonstrate that such processes, in the form of motivic transformations and musical-verbal associations, are in fact under way from the very beginning though sometimes hidden below the surface

Aerodynamic characteristics of two-dimensional wing configurations at angles of attack near -90 deg

Wind tunnel tests were conducted to determine the drag of two-dimensional wing sections operating in a near-vertical flow condition. Various leading- and trialing-edge configurations, including plain flaps of 25, 30, and 35% chord were tested at angles of attack from -75 to -105 deg. Reynolds numbers examined ranged from approximately 0.6 x 10 to the 6th power to 1.4 x 10 to the 6th power. The data were obtained using a wind tunnel force and moment balance system and arrays of chordwise pressure orifices. The results showed that significant reductions in drag, beyond what would be expected by virtue of the decreased frontal area, were obtainable with geometries that delayed flow separation. Rapid changes in drag with angle of attack were noted for many configurations. The results, however, were fairly insensitive to Reynolds number variations. Drag values computed from the pressure data generally agreed with the force data within 2%