Effects of chemical releases by the STS-3 Orbiter on the ionosphere

The Plasma Diagnostics Package, flown aboard STS-3 as part of the first Shuttle payload (OSS-1), recorded the effects of various chemical releases from the Orbiter. Changes in the plasma environment was observed during flash evaporator system releases, water dumps and maneuvering thruster operations. During flash evaporator operations, broadband Orbiter-generated electrostatic noise was enhanced and plasma density irregularities were observed to increase by 3 to 30 times with a spectrum which rose steeply and peaked below 6 Hz. In the case of water dumps, background electrostatic noise was enhanced at frequencies below about 3 kHz and suppressed at frequencies above 2 kHz. Thruster activity also stimulated electrostatic noise with a spectrum which peaked at approximately 0.5 kHz. In addition, ions with energies up to 1 keV were seen during some thruster events

Simulation study of the interaction between large-amplitude HF radio waves and the ionosphere

The time evolution of a large-amplitude electromagnetic (EM) wave injected vertically into the overhead ionosphere is studied numerically. The EM wave has a carrier frequency of 5 MHz and is modulated as a Gaussian pulse with a width of approximately 0.1 milliseconds and a vacuum amplitude of 1.5 V/m at 50 km. This is a fair representation of a modulated radio wave transmitted from a typical high-power HF broadcast station on the ground. The pulse is propagated through the neutral atmosphere to the critical points of the ionosphere, where the L-O and R-X modes are reflected, and back to the neutral atmosphere. We observe mode conversion of the L-O mode to electrostatic waves, as well as harmonic generation at the turning points of both the R-X and L-O modes, where their amplitudes rise to several times the original ones. The study has relevance for ionospheric interaction experiments in combination with ground-based and satellite or rocket observations.Comment: 6 pages, 7 figure

Beyond spinal manipulation: should Medicare expand coverage for chiropractic services? A review and commentary on the challenges for policy makers

Objectives: Private insurance plans typically reimburse doctors of chiropractic for a range of clinical services, but Medicare reimbursements are restricted to spinal manipulation procedures. Medicare pays for evaluations performed by medical and osteopathic physicians, nurse practitioners, physician assistants, podiatrists, physical therapists, and occupational therapists; however, it does not reimburse the same services provided by chiropractic physicians. Advocates for expanded coverage of chiropractic services under Medicare cite clinical effectiveness and patient satisfaction, whereas critics point to unnecessary services, inadequate clinical documentation, and projected cost increases. To further inform this debate, the purpose of this commentary is to address the following questions: (1) What are the barriers to expand coverage for chiropractic services? (2) What could potentially be done to address these issues? (3) Is there a rationale for Centers for Medicare and Medicaid Services to expand coverage for chiropractic services? Methods: A literature search was conducted of Google and PubMed for peer-reviewed articles and US government reports relevant to the provision of chiropractic care under Medicare. We reviewed relevant articles and reports to identify key issues concerning the expansion of coverage for chiropractic under Medicare, including identification of barriers and rationale for expanded coverage. Results: The literature search yielded 29 peer-reviewed articles and 7 federal government reports. Our review of these documents revealed 3 key barriers to full coverage of chiropractic services under Medicare: inadequate documentation of chiropractic claims, possible provision of unnecessary preventive care services, and the uncertain costs of expanded coverage. Our recommendations to address these barriers include the following: individual chiropractic physicians, as well as state and national chiropractic organizations, should continue to strengthen efforts to improve claims and documentation practices; and additional rigorous efficacy/effectiveness research and clinical studies for chiropractic services need to be performed. Research of chiropractic services should target the triple aim of high-quality care, affordability, and improved health. Conclusions: The barriers that were identified in this study can be addressed. To overcome these barriers, the chiropractic profession and individual physicians must assume responsibility for correcting deficiencies in compliance and documentation; further research needs to be done to evaluate chiropractic services; and effectiveness of extended episodes of preventive chiropractic care should be rigorously evaluated. Centers for Medicare and Medicaid Services policies related to chiropractic reimbursement should be reexamined using the same standards applicable to other health care providers. The integration of chiropractic physicians as fully engaged Medicare providers has the potential to enhance the capacity of the Medicare workforce to care for the growing population. We recommend that Medicare policy makers consider limited expansion of Medicare coverage to include, at a minimum, reimbursement for evaluation and management services by chiropractic physicians

Experimental determination of the complete spin structure for anti-proton + proton -> anti-\Lambda + \Lambda at anti-proton beam momentum of 1.637 GeV/c

The reaction anti-proton + proton -> anti-\Lambda + \Lambda -> anti-proton + \pi^+ + proton + \pi^- has been measured with high statistics at anti-proton beam momentum of 1.637 GeV/c. The use of a transversely-polarized frozen-spin target combined with the self-analyzing property of \Lambda/anti-\Lambda decay allows access to unprecedented information on the spin structure of the interaction. The most general spin-scattering matrix can be written in terms of eleven real parameters for each bin of scattering angle, each of these parameters is determined with reasonable precision. From these results all conceivable spin-correlations are determined with inherent self-consistency. Good agreement is found with the few previously existing measurements of spin observables in anti-proton + proton -> anti-\Lambda + \Lambda near this energy. Existing theoretical models do not give good predictions for those spin-observables that had not been previously measured.Comment: To be published in Phys. Rev. C. Tables of results (i.e. Ref. 24) are available at http://www-meg.phys.cmu.edu/~bquinn/ps185_pub/results.tab 24 pages, 16 figure

Electroweak and Flavour Structure of a Warped Extra Dimension with Custodial Protection

We present the electroweak and flavour structure of a model with a warped extra dimension and the bulk gauge group SU(3) x SU(2)_L x SU(2)_R x P_LR x U(1)_X. The presence of SU(2)_R implies an unbroken custodial symmetry in the Higgs system allowing to eliminate large contributions to the T parameter, whereas the P_LR symmetry and the enlarged fermion representations provide a custodial symmetry for flavour diagonal and flavour changing couplings of the SM Z boson to left-handed down-type quarks. We diagonalise analytically the mass matrices of charged and neutral gauge bosons including the first KK modes. We present the mass matrices for quarks including heavy KK modes and discuss the neutral and charged currents involving light and heavy fields. We give the corresponding complete set of Feynman rules in the unitary gauge.Comment: 74 pages, 2 figures. clarifying comments and references added, version to be published in JHE

Charming CP Violation and Dipole Operators from RS Flavor Anarchy

Recently the LHCb collaboration reported evidence for direct CP violation in charm decays. The value is sufficiently large that either substantially enhanced Standard Model contributions or non-Standard Model physics is required to explain it. In the latter case only a limited number of possibilities would be consistent with other existing flavor-changing constraints. We show that warped extra dimensional models that explain the quark spectrum through flavor anarchy can naturally give rise to contributions of the size required to explain the the LHCb result. The D meson asymmetry arises through a sizable CP-violating contribution to a chromomagnetic dipole operator. This happens naturally without introducing inconsistencies with existing constraints in the up quark sector. We discuss some subtleties in the loop calculation that are similar to those in Higgs to \gamma\gamma. Loop-induced dipole operators in warped scenarios and their composite analogs exhibit non-trivial dependence on the Higgs profile, with the contributions monotonically decreasing when the Higgs is pushed away from the IR brane. We show that the size of the dipole operator quickly saturates as the Higgs profile approaches the IR brane, implying small dependence on the precise details of the Higgs profile when it is quasi IR localized. We also explain why the calculation of the coefficient of the lowest dimension 5D operator is guaranteed to be finite. This is true not only in the charm sector but also with other radiative processes such as electric dipole moments, b to s\gamma, \epsilon'/\epsilon_K and \mu\ to e\gamma. We furthermore discuss the interpretation of this contribution within the framework of partial compositeness in four dimensions and highlight some qualitative differences between the generic result of composite models and that obtained for dynamics that reproduces the warped scenario.Comment: 14 page

Polarized nuclear target based on parahydrogen induced polarization

We discuss a novel concept of a polarized nuclear target for accelerator fixed-target scattering experiments, which is based on parahydrogen induced polarization (PHIP). One may be able to reach a 33% free-proton polarization in the ethane molecule. The potential advantages of such a target include operation at zero magnetic field, fast ($\sim$100 Hz) polarization reversal, and operation with large intensity of an electron beam.Comment: 16 pages, 2 figure

The helicity amplitudes A1/2_{1/2} and A3/2_{3/2} for the D13(1520)_{13}(1520) resonance obtained from the γ⃗p⃗→pπ0\vec{\gamma} \vec{p} \to p \pi^0 reaction}

The helicity dependence of the $\vec{\gamma} \vec{p} \to p \pi^0$ reaction has been measured for the first time in the photon energy range from 550 to 790 MeV. The experiment, performed at the Mainz microtron MAMI, used a 4$\pi$-detector system, a circularly polarized, tagged photon beam, and a longitudinally polarized frozen-spin target. These data are predominantly sensitive to the $D_{13}(1520)$ resonance and are used to determine its parameters.Comment: 5 pages, 4 figure

Geographical location influences the composition of the gut microbiota in wild house mice (Mus musculus domesticus) at a fine spatial scale.

The composition of the mammalian gut microbiota can be influenced by a multitude of environmental variables such as diet and infections. Studies investigating the effect of these variables on gut microbiota composition often sample across multiple separate populations and habitat types. In this study we explore how variation in the gut microbiota of the house mouse (Mus musculus domesticus) on the Isle of May, a small island off the east coast of Scotland, is associated with environmental and biological factors. Our study focuses on the effects of environmental variables, specifically trapping location and surrounding vegetation, as well as the host variables sex, age, body weight and endoparasite infection, on the gut microbiota composition across a fine spatial scale in a freely interbreeding population. We found that differences in gut microbiota composition were significantly associated with the trapping location of the host, even across this small spatial scale. Sex of the host showed a weak association with microbiota composition. Whilst sex and location could be identified as playing an important role in the compositional variation of the gut microbiota, 75% of the variation remains unexplained. Whereas other rodent studies have found associations between gut microbiota composition and age of the host or parasite infections, the present study could not clearly establish these associations. We conclude that fine spatial scales are important when considering gut microbiota composition and investigating differences among individuals