239 research outputs found

    The Macy Study: A Framework for Consensus

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153659/1/jddj002203372008722suppltb04486x.pd

    U.S. State‐Supported Dental Schools: Financial Projections and Implications

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153620/1/jddj002203372006703tb04080x.pd

    U.S. State‐Supported Dental Schools: Financial Projections and Implications

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    This article examines the impact of financial trends in state‐supported dental schools on full‐time clinical faculty; the diversity of dental students and their career choices; investments in physical facilities; and the place of dentistry in research universities. The findings of our study are the following: the number of students per full‐time clinical faculty member increased; the three schools with the lowest revenue increases lost a third of their full‐time clinical faculty; more students are from wealthier families; most schools are not able to adequately invest in their physical plant; and more than half of schools have substantial NIH‐funded research programs. If current trends continue, the term “crisis” will describe the situation faced by most dental schools. Now is the time to build the political consensus needed to develop new and more effective strategies to educate the next generation of American dentists and to keep dental education primarily based in research universities. The future of the dental profession and the oral health of the American people depend on it.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153587/1/jddj002203372008722suppltb04487x.pd

    A weak lensing analysis of the PLCK G100.2-30.4 cluster

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    We present a mass estimate of the Planck-discovered cluster PLCK G100.2-30.4, derived from a weak lensing analysis of deep SUBARU griz images. We perform a careful selection of the background galaxies using the multi-band imaging data, and undertake the weak lensing analysis on the deep (1hr) r-band image. The shape measurement is based on the KSB algorithm; we adopt the PSFex software to model the Point Spread Function (PSF) across the field and correct for this in the shape measurement. The weak lensing analysis is validated through extensive image simulations. We compare the resulting weak lensing mass profile and total mass estimate to those obtained from our re-analysis of XMM-Newton observations, derived under the hypothesis of hydrostatic equilibrium. The total integrated mass profiles are in remarkably good agreement, agreeing within 1σ\sigma across their common radial range. A mass M500∌7×1014M⊙M_{500} \sim 7 \times 10^{14} M_\odot is derived for the cluster from our weak lensing analysis. Comparing this value to that obtained from our reanalysis of XMM-Newton data, we obtain a bias factor of (1-b) = 0.8 ±\pm 0.1. This is compatible within 1σ\sigma with the value of (1-b) obtained by Planck Collaboration XXIV from their calibration of the bias factor using newly-available weak lensing reconstructed masses.Comment: 11 pages, 12 figures, accepted for publication on Astronomy & Astrophysics; updates in affiliation

    Deep-underground search for the decay of 180m-Ta with an ultra-low-background HPGe detector

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    180m^{180m}Ta is the longest-lived metastable state presently known. Its decay has not been observed yet. In this work, we report a new result on the decay of 180m^{180m}Ta obtained with a 2015.122015.12-g tantalum sample measured for 527.7527.7 d with an ultra-low background HPGe detector in the STELLA laboratory of the Laboratori Nazionali del Gran Sasso, in Italy. Before the measurement, the sample has been stored deep-underground for ten years, resulting in subdominant background contributions from cosmogenically activated 182^{182}Ta. We observe no signal in the regions of interest and set half-life limits on the process for the two channels EC and ÎČ−\beta^-: T1/2, EC>1.6×1018T_{1/2,~\mathrm{EC}} > 1.6 \times 10^{18} yr and T1/2, ÎČ−>1.1×1018T_{1/2,~\beta^-} > 1.1\times 10^{18} yr (9090% C. I.), respectively. We also set the limit on the Îł\gamma de-excitation / IC channel: T1/2, IC>4.1×1015T_{1/2,~\mathrm{IC}} > 4.1 \times 10^{15} yr (9090% C. I.). These are, as of now, the most stringent bounds on the decay of 180m^{180m}Ta worldwide.Comment: 8 pages, 7 figures, 4 table

    The synergistic effect of chlorotoxin-mApoE in boosting drug-loaded liposomes across the BBB

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    We designed liposomes dually functionalized with ApoE-derived peptide (mApoE) and chlorotoxin (ClTx) to improve their blood-brain barrier (BBB) crossing. Our results demonstrated the synergistic activity of ClTx-mApoE in boosting doxorubicin-loaded liposomes across the BBB, keeping the anti-tumour activity of the drug loaded: mApoE acts promoting cellular uptake, while ClTx promotes exocytosis of liposomes

    Impact of a revised 25^{25}Mg(p,Îł\gamma)26^{26}Al reaction rate on the operation of the Mg-Al cycle

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    Proton captures on Mg isotopes play an important role in the Mg-Al cycle active in stellar H-burning regions. In particular, low-energy nuclear resonances in the 25^{25}Mg(p,γ\gamma)26^{26}Al reaction affect the production of radioactive 26^{26}Algs^{gs} as well as the resulting Mg/Al abundance ratio. Reliable estimations of these quantities require precise measurements of the strengths of low-energy resonances. Based on a new experimental study performed at LUNA, we provide revised rates of the 25^{25}Mg(p,γ\gamma)26^{26}Algs^{gs} and the 25^{25}Mg(p,γ\gamma)26^{26}Alm^{m} reactions with corresponding uncertainties. In the temperature range 50 to 150 MK, the new recommended rate of the 26^{26}Alm^{m} production is up to 5 times higher than previously assumed. In addition, at T=100=100 MK, the revised total reaction rate is a factor of 2 higher. Note that this is the range of temperature at which the Mg-Al cycle operates in an H-burning zone. The effects of this revision are discussed. Due to the significantly larger 25^{25}Mg(p,γ\gamma)26^{26}Alm^{m} rate, the estimated production of 26^{26}Algs^{gs} in H-burning regions is less efficient than previously obtained. As a result, the new rates should imply a smaller contribution from Wolf-Rayet stars to the galactic 26^{26}Al budget. Similarly, we show that the AGB extra-mixing scenario does not appear able to explain the most extreme values of 26^{26}Al/27^{27}Al, i.e. >10−2>10^{-2}, found in some O-rich presolar grains. Finally, the substantial increase of the total reaction rate makes the hypothesis of a self-pollution by massive AGBs a more robust explanation for the Mg-Al anticorrelation observed in Globular-Cluster stars

    Ultra-sensitive in-beam gamma-ray spectroscopy for nuclear astrophysics at LUNA

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    Ultra-sensitive in-beam gamma-ray spectroscopy studies for nuclear astrophysics are performed at the LUNA (Laboratory for Underground Nuclear Astrophysics) 400 kV accelerator, deep underground in Italy's Gran Sasso laboratory. By virtue of a specially constructed passive shield, the laboratory gamma-ray background for E_\gamma < 3 MeV at LUNA has been reduced to levels comparable to those experienced in dedicated offline underground gamma-counting setups. The gamma-ray background induced by an incident alpha-beam has been studied. The data are used to evaluate the feasibility of sensitive in-beam experiments at LUNA and, by extension, at similar proposed facilities.Comment: accepted, Eur. Phys. J.

    22Ne and 23Na ejecta from intermediate-mass stars: The impact of the new LUNA rate for 22Ne(p,gamma)23Na

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    We investigate the impact of the new LUNA rate for the nuclear reaction 22^{22}Ne(p,γ)23(p,\gamma)^{23}Na on the chemical ejecta of intermediate-mass stars, with particular focus on the thermally-pulsing asymptotic giant branch (TP-AGB) stars that experience hot-bottom burning. To this aim we use the PARSEC and COLIBRI codes to compute the complete evolution, from the pre-main sequence up to the termination of the TP-AGB phase, of a set of stellar models with initial masses in the range 3.0 M⊙−6.0 M⊙3.0\,M_{\odot} - 6.0\,M_{\odot}, and metallicities Zi=0.0005Z_{\rm i}=0.0005, Zi=0.006Z_{\rm i}=0.006, and Zi=0.014Z_{\rm i} = 0.014. We find that the new LUNA measures have much reduced the nuclear uncertainties of the 22^{22}Ne and 23^{23}Na AGB ejecta, which drop from factors of ≃10\simeq 10 to only a factor of few for the lowest metallicity models. Relying on the most recent estimations for the destruction rate of 23^{23}Na, the uncertainties that still affect the 22^{22}Ne and 23^{23}Na AGB ejecta are mainly dominated by evolutionary aspects (efficiency of mass-loss, third dredge-up, convection). Finally, we discuss how the LUNA results impact on the hypothesis that invokes massive AGB stars as the main agents of the observed O-Na anti-correlation in Galactic globular clusters. We derive quantitative indications on the efficiencies of key physical processes (mass loss, third dredge-up, sodium destruction) in order to simultaneously reproduce both the Na-rich, O-poor extreme of the anti-correlation, and the observational constraints on the CNO abundance. Results for the corresponding chemical ejecta are made publicly available
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