DID VIETNAM VETERANS GET SICKER IN THE 1990s? THE COMPLICATED EFFECTS OF MILITARY SERVICE ON SELF-REPORTED HEALTH

The veterans disability compensation (VDC) program, which provides a monthly stipend to disabled veterans, is the third largest American disability insurance program. Since the late 1990s, VDC growth has been driven primarily by an increase in claims from Vietnam veterans, raising concerns about costs as well as health. We use the draft lottery to study the long-term effects of Vietnam-era military service on health and work in the 2000 Census. These estimates show no significant overall effects on employment or work-related disability status, with a small effect on non-work-related disability for whites. On the other hand, estimates for white men with low earnings potential show a large negative impact on employment and a marked increase in non-work-related disability rates. The differential impact of Vietnam-era service on low-skill men cannot be explained by more combat or war-theatre exposure for the least educated, leaving the relative attractiveness of VDC for less skilled men and the work disincentives embedded in the VDC system as a likely explanation.

Did Vietnam Veterans Get Sicker in the 1990s? The Complicated Effects of Military Service on Self-Reported Health

The veterans disability compensation (VDC) program, which provides a monthly stipend to disabled veterans, is the third largest American disability insurance program. Since the late 1990s, VDC growth has been driven primarily by an increase in claims from Vietnam veterans, raising concerns about costs as well as health. We use the draft lottery to study the long-term effects of Vietnam-era military service on health and work in the 2000 Census. These estimates show no significant overall effects on employment or work-related disability status, with a small effect on non-work-related disability for whites. On the other hand, estimates for white men with low earnings potential show a large negative impact on employment and a marked increase in non-work-related disability rates. The differential impact of Vietnam-era service on low-skill men cannot be explained by more combat or wartheatre exposure for the least educated, leaving the relative attractiveness of VDC for less skilled men and the work disincentives embedded in the VDC system as a likely explanation.Public economics, social security and public pensions, health, education, welfare,labour, demographic economics

Asphaltene detection using Surface Enhanced Raman Scattering (SERS)

Peer reviewedPostprin

Supporting play exploration and early developmental intervention versus usual care to enhance development outcomes during the transition from the neonatal intensive care unit to home: a pilot randomized controlled trial

Background While therapy services may start in the Neonatal Intensive Care Unit (NICU) there is often a gap in therapy after discharge. Supporting Play Exploration and Early Development Intervention (SPEEDI) supports parents, helping them build capacity to provide developmentally supportive opportunities starting in the NICU and continuing at home. The purpose of this single blinded randomized pilot clinical trial was to evaluate the initial efficacy of SPEEDI to improve early reaching and exploratory problem solving behaviors. Methods Fourteen infants born very preterm or with neonatal brain injury were randomly assigned to SPEEDI or Usual Care. The SPEEDI group participated in 5 collaborative parent, therapist, and infant interventions sessions in the NICU (Phase 1) and 5 at home (Phase 2). Parents provided daily opportunities designed to support the infants emerging motor control and exploratory behaviors. Primary outcome measures were assessed at the end of the intervention, 1 and 3 months after the intervention ended. Reaching was assessed with the infant supported in an infant chair using four 30 s trials. The Early Problem Solving Indicator was used to evaluate the frequency of behaviors during standardized play based assessment. Effect sizes are including for secondary outcomes including the Test of Infant Motor Performance and Bayley Scales of Infant and Toddler Development. Results No group differences were found in the duration of toy contact. There was a significant group effect on (F1,8 = 4.04, p = 0.08) early exploratory problem-solving behaviors with infants in the SPEEDI group demonstrating greater exploration with effect sizes of 1.3, 0.6, and 0.9 at the end of the intervention, 1 and 3 months post-intervention. Conclusions While further research is needed, this initial efficacy study showed promising results for the ability of SPEEDI to impact early problem solving behaviors at the end of intervention and at least 3 months after the intervention is over. While reaching did not show group differences, a ceiling effect may have contributed to this finding. This single blinded pilot RCT was registered prior to subject enrollment on 5/27/14 at ClinicalTrials.Gov with number NCT02153736

Search for correlation effects in linear chains of trapped ions

We report a precise search for correlation effects in linear chains of 2 and 3 trapped Ca+ ions. Unexplained correlations in photon emission times within a linear chain of trapped ions have been reported, which, if genuine, cast doubt on the potential of an ion trap to realize quantum information processing. We observe quantum jumps from the metastable 3d 2D_{5/2} level for several hours, searching for correlations between the decay times of the different ions. We find no evidence for correlations: the number of quantum jumps with separations of less than 10 ms is consistent with statistics to within errors of 0.05%; the lifetime of the metastable level derived from the data is consistent with that derived from independent single-ion data at the level of the experimental errors 1%; and no rank correlations between the decay times were found with sensitivity to rank correlation coefficients at the level of |R| = 0.024.Comment: With changes to introduction. 5 pages, including 4 figures. Submitted to Europhys. Let

Deterministic entanglement and tomography of ion spin qubits

We have implemented a universal quantum logic gate between qubits stored in the spin state of a pair of trapped calcium 40 ions. An initial product state was driven to a maximally entangled state deterministically, with 83% fidelity. We present a general approach to quantum state tomography which achieves good robustness to experimental noise and drift, and use it to measure the spin state of the ions. We find the entanglement of formation is 0.54.Comment: 3 figures, 4 pages, footnotes fixe

Long-lived mesoscopic entanglement outside the Lamb-Dicke regime

We create entangled states of the spin and motion of a single $^{40}$Ca$^+$ ion in a linear ion trap. The motional part consists of coherent states of large separation and long coherence time. The states are created by driving the motion using counterpropagating laser beams. We theoretically study and experimentally observe the behaviour outside the Lamb-Dicke regime, where the trajectory in phase space is modified and the coherent states become squeezed. We directly observe the modification of the return time of the trajectory, and infer the squeezing. The mesoscopic entanglement is observed up to $\Delta \alpha = 5.1$ with coherence time 170 microseconds and mean phonon excitation \nbar = 16.Comment: 5 pages, 3 figures. Revised version after editor comment

Potential formulation of the dispersion relation for a uniform, magnetized plasma with stationary ions in terms of a vector phasor

The derivation of the helicon dispersion relation for a uniform plasma with stationary ions subject to a constant background magnetic field is reexamined in terms of the potential formulation of electrodynamics. Under the same conditions considered by the standard derivation, the nonlinear self-coupling between the perturbed electron flow and the potential it generates is addressed. The plane wave solution for general propagation vector is determined for all frequencies and expressed in terms of a vector phasor. The behavior of the solution as described in vacuum units depends upon the ratio of conductivity to the magnitude of the background field. Only at low conductivity and below the cyclotron frequency can significant propagation occur as determined by the ratio of skin depth to wavelength.Comment: 10 pages, 6 figures, major revision, final version, to appear in Po