Access to undergraduate research experiences at a large research university

The American Physical Society recently released a statement calling on all university physics departments to provide or facilitate access to research experiences for all undergraduate students. In response, we investigated the current status of access to undergraduate research at University of Colorado Boulder (CU), a large research institution where the number of undergraduate physics majors outnumber faculty by roughly ten to one. We created and administered two surveys within CU's Physics Department: one probed undergraduate students' familiarity with, and participation in, research; the other probed faculty members' experiences as research mentors to undergraduates. We describe the development of these instruments, our results, and our corresponding evidence-based recommendations for improving local access to undergraduate research experiences. Reflecting on our work, we make several connections to an institutional change framework and note how other universities and colleges might adapt our process.Comment: 4 pages, 3 figures, 1 table; Submitted to 2015 PERC Proceeding

Dynamical Realization of Macroscopic Superposition States of Cold Bosons in a Tilted Double Well

We present exact expressions for the quantum sloshing of Bose-Einstein condensates in a tilted two-well potential. Tunneling is suppressed by a small potential difference between wells, or tilt. However, tunneling resonances occur for critical values of the tilt when the barrier is high. At resonance, tunneling times on the order of 10-100 ms are possible. Furthermore, such tilted resonances lead to a dynamical scheme for creating few-body NOON-like macroscopic superposition states which are protected by the many body wavefunction against potential fluctuations.Comment: 6 pages, 5 figures, final version, only minor changes from previous arXiv versio

Rituximab with chemotherapy in children and adolescents with central nervous system and/or bone marrow-positive Burkitt lymphoma/leukaemia: a childrens oncology group report

pre-printApproximately 1 in 4 children and adolescents with de-novo mature and Burkitt lymphoma (BL) present with high-risk disease that is either mature B-cell leukaemia (bone marrow ≥ 25% blasts [BM]) and/or have central nervous system (CNS) involvement. Both the Berlin-Frankfurt- Münster (BFM) and French-American-British (FAB) international cooperative studies have unsuccessfully attempted to reduce the overall burden of chemotherapy in this high risk group of patients. In the FAB 96 study, a randomized attempt to reduce the dose of cytarabine during consolidation and eliminate three final cycles of maintenance was halted early due to inferior event-free survival (EFS) (Cairo, et al 2012, Cairo, et al concluded that reducing the infusion duration of methotrexate from 24 to 4 hours led to significantly inferior EFS in high risk (R3/R4) patients.(Woessmann, et al 2005) Subsets of children with BL, such as those with poor response to initial reduction, complex karyotypes, and those with combined BM and CNS disease, have a significantly worse prognosis (Cairo, et al 2012, Cairo, et al 2007, Poirel, et al 2009)

Generic but Expensive: Why Prices Can Remain High for Off-Patent Drugs

Brand-name prescription drugs are sold at extremely high prices in the US because patents and other market exclusivities provided by the government allow manufacturers to exclude direct competition. This period of market exclusivity was intended for pharmaceutical manufacturers to recoup costs associated with research and development of those products and make profits. The other intended outcome of this system is that the market exclusivity period for brand-name drugs should be self-limited, with competition being able to flourish after the market exclusivities end. Such competition has been most effectively supplied by generic drug manufacturers that produce Food and Drug Administration (FDA)-approved bioequivalent versions of the brand-name product. The market entry of these generic drugs—with market uptake augmented by automatic substitution of brand-name prescriptions at the pharmacy— remains the only market intervention that lowers prescription drug prices consistently and substantially. Generic manufacturers can make their drugs available at considerably lower cost because of various market advantages they have over brand-name drugs. When this process does not operate as intended, drug prices do not fall after market exclusivity expiration, or prices for generic drugs may actually increase. In this paper, we examine the variety of factors that mitigate the cost savings associated with introduction of interchangeable generic drugs, especially older, off-patent drugs. We then consider policy solutions that may help stabilize the generic drug marketplace, diminishing the frequency and impact of generic price increases

Observation of a Large Atomic Parity Violation Effect in Ytterbium

Atomic parity violation has been observed in the 6s^2 1S0 - 5d6s 3D1 408-nm forbidden transition of ytterbium. The parity-violating amplitude is found to be two orders of magnitude larger than in cesium, where the most precise experiments to date have been performed. This is in accordance with theoretical predictions and constitutes the largest atomic parity-violating amplitude yet observed. This also opens the way to future measurements of neutron skins and anapole moments by comparing parity-violating amplitudes for various isotopes and hyperfine components of the transition

The Metallicity of Pre-Galactic Globular Clusters: Observational consequences of the first stars

We explore a scenario where metal-poor globular clusters (GCs) are enriched by the first supernovae in the Universe. If the first stars in a 10^7 Msun dark halo were very massive (>180 Msun), then a pair instability supernova from a single massive star can produce sufficient iron to enrich 10^6 Msun of pristine, primordial gas to [Fe/H] ~ -2. In such a scenario, where a single massive star acts as a seed for halo GCs, the accurate abundance analysis of GC stars would allow a direct measurement of the Population III initial mass. Using the latest theoretical yields for zero metallicity stars in the mass range 140-260 Msun, we find that the metals expelled from a ~230 Msun star are consistent with [Si/Fe] and [Ca/Fe] observed in GC stars. However, no single star in this mass range can simultaneously explain all halo GC heavy-element abundance ratios, such as [V/Fe], [Ti/Fe] and [Ni/Fe]. These require a combination masses for the Population III stellar progenitors. The various observational consequences of this scenario are discussed.Comment: 5 pages, 2 figures, accepted for publication in ApJ Lette

Effect of component variations on the gate fidelity in linear optical networks

We investigate the effect of variations in beam-splitter transmissions and path-length differences in the nonlinear sign gate that is used for linear optical quantum computing. We identify two implementations of the gate and show that the sensitivity to variations in their components differs significantly between them. Therefore, circuits that require a precision implementation will generally benefit from additional circuit analysis of component variations to identify the most practical implementation. We suggest possible routes to efficient circuit analysis in terms of quantum parameter estimation