Density-Dependent Response of an Ultracold Plasma to Few-Cycle Radio-Frequency Pulses

Ultracold neutral plasmas exhibit a density-dependent resonant response to applied radio-frequency (RF) fields in the frequency range of several MHz to hundreds of MHz for achievable densities. We have conducted measurements where short bursts of RF were applied to these plasmas, with pulse durations as short as two cycles. We still observed a density-dependent resonant response to these short pulses. However, the too rapid timescale of the response, the dependence of the response on the sign of the driving field, the response as the number of pulses was increased, and the difference in plasma response to radial and axially applied RF fields are inconsistent with the plasma response being due to local resonant heating of electrons in the plasma. Instead, our results are consistent with rapid energy transfer from collective motion of the entire electron cloud to electrons in high-energy orbits. In addition to providing a potentially more robust way to measure ultracold neutral plasma densities, these measurements demonstrate the importance of collective motion in the energy transport in these systems.Comment: 5 pages, 4 figure

Light Assisted Collisional Loss in a 85/87^{85/87}Rb Ultracold Optical Trap

We have studied hetero- and homonuclear excited state/ground state collisions by loading both $^{85}$Rb and $^{87}$Rb into a far off resonant trap (FORT). Because of the relatively weak confinement of the FORT, we expect the hyperfine structure of the different isotopes to play a crucial role in the collision rates. This dependence on hyperfine structure allows us to measure collisions associated with long range interatomic potentials of different structure: such as long and short ranged; or such as purely attractive, purely repulsive, or mixed attractive and repulsive. We observe significantly different loss rates for different excited state potentials. Additionally, we observe that some collisional channels' loss rates are saturated at our operating intensities (~15 mW/cm$^{2}$). These losses are important limitations in loading dual isotope optical traps.Comment: about 8 pages, 5 figure

Exploring the Role of Contextual Integrity in Electronic Medical Record (EMR) System Workaround Decisions: An Information Security and Privacy Perspective

Many healthcare providers in the US are seeking increased efficiency and effectiveness by rapidly adopting information technology (IT) solutions such as electronic medical record (EMR) systems. Legislation such as the Health Information Technology for Economic and Clinical Health Act (HITECH), which codified the adoption and “meaningful use” of electronic records in the US, has further spurred the industry-wide adoption of EMR. However, despite what are often large investments in EMR, studies indicate that the healthcare industry maintains a culture of system workarounds. Though perhaps not uncommon, the creation of informal workflows among healthcare workers is problematic for assuring information security and patient privacy, particularly when involving decisions of information management (e.g., information storage, retrieval, and/or transmission). Drawing on the framework of contextual integrity, we assert that one can often explain workarounds involving information transmissions in terms of trade-offs informed by context-specific informational norms. We surveyed healthcare workers and analyzed their willingness to engage in a series of EMR workaround scenarios. Our results indicate that contextual integrity provides a useful framework for understanding information transmission and workaround decisions in the health sector. Armed with these findings, managers and system designers should be better able to anticipate healthcare workers’ information transmission principles (e.g., privacy norms) and workaround patterns (e.g., usage norms). We present our findings and discuss their significance for research and practice

Type I Interferons Regulate Cytolytic Activity of Memory CD8+ T Cells in the Lung Airways during Respiratory Virus Challenge

SummaryMemory CD8+ T cells in the lung airways provide protection from secondary respiratory virus challenge by limiting early viral replication. Here, we demonstrate that although airway-resident memory CD8+ T cells were poorly cytolytic, memory CD8+ T cells recruited to the airways early during a recall response showed markedly enhanced cytolytic ability. This enhanced lytic activity did not require cognate antigen stimulation, but rather was dependent on STAT1 transcription factor signaling through the interferon-α receptor (Ifnar1), resulting in the antigen-independent expression of granzyme B protein in both murine and human virus-specific T cells. Signaling through Ifnar1 was required for the enhanced lytic activity and control of early viral replication by memory CD8+ T cells in the lung airways. These findings demonstrate that innate inflammatory signals act directly on memory T cells, enabling them to rapidly destroy infected host cells once they enter infected tissues

The disutility of commuting? The effect of gender and local labour markets

Commuting is an extremely important modern phenomenon characterised by the spatial interaction of housing and labour markets. The average commuter in the UK spends nearly an hour a day travelling to and from employment. Standard economic theory postulates that commuting is a choice behaviour undertaken when compensated through either lower rents or greater amenities in the housing market or through greater wages in the labour market. By exploiting exogenous shocks to commuting time, this paper investigates the impact on wellbeing of increased commuting. Ceteris paribus, exogenous increases in commuting time are expected to lower wellbeing. We find this holds for women but not men. This phenomenon can be explained, in part, by the different labour markets in which women operate. Where local labour markets are thin, women report significantly lower wellbeing when faced with an increased commute. This does not hold for tight local labour markets. Further our findings reveal that it is full-time working women in the managerial and professional tier of the occupational hierarchy who are most affected

Characterization of the near-Earth Asteroid 2002NY40

In August 2002, the near-Earth asteroid 2002 NY40, made its closest approach to the Earth. This provided an opportunity to study a near-Earth asteroid with a variety of instruments. Several of the telescopes at the Maui Space Surveillance System were trained at the asteroid and collected adaptive optics images, photometry and spectroscopy. Analysis of the imagery reveals the asteroid is triangular shaped with significant self-shadowing. The photometry reveals a 20-hour period and the spectroscopy shows that the asteroid is a Q-type