442 research outputs found
The politics of American China policy: the Clinton administration's China policy during its first term of office
This thesis examines the formulation and implementation of us policy towards China during the Clinton Administration's first term of office. Its central contention is that the Clinton Administration's China policy-making process was founded on largely on domestic political calculations, to the detriment of America's long term broad strategic interests in the People's Republic. This is exemplified by his advocacy, implementation, and eventual abandonment, of a strategy of linkage toward China. This thesis contends that President Clinton's preoccupation with domestic political calculations led to three major flaws in his Administration's China policy-making process. Firstly, it led to a failure to define a hierarchy of US priorities in China. Secondly, it led to a failure to articulate a coherent framework for US China relations to either the Chinese or domestic American audiences. Thirdly, Clinton failed to commit himself to, or provide leadership on, China policy except in the event of a political crisis. Accordingly, these flaws encouraged splits within the Administration whereby different agencies pursued their own agendas with Beijing. As a result, the Clinton Administration's China policy appeared confused, incoherent and discordant. This served to undermine both the US strategic relationship with Beijing, and domestic legitimacy for US China policy
Counselor Educators Lean-In to Walk the Talk: A Team Approach to Strengthening Faculty Multicultural Sensitivity
This session offers an innovative approach for engaging faculty in the development and deepening of their own multicultural sensitivity, for improving pedagogy, and in turn promoting second-order change within students as they engage with multicultural competencies. Broader systemic issues are also addressed given the university\u27s contextual setting as a faith-based, primarily Caucasian institution
The impact of islet mass, number of transplants, and time between transplants on graft function in a national islet transplant program
The UK islet allotransplant program is nationally funded to deliver one or two transplants over 12 months to individuals with type 1 diabetes and recurrent severe hypoglycemia. Analyses were undertaken 10 years after program inception to evaluate associations between transplanted mass; single versus two transplants; time between two transplants and graft survival (stimulated C-peptide >50 pmol/L) and function. In total, 84 islet transplant recipients were studied. Uninterrupted graft survival over 12 months was attained in 23 (68%) single and 47 (94%) (p =.002) two transplant recipients (separated by [median (IQR)] 6 (3â8) months). 64% recipients of one or two transplants with uninterrupted function at 12 months sustained graft function at 6 years. Total transplanted mass was associated with Mixed Meal Tolerance Test stimulated C-peptide at 12 months (p <.01). Despite 1.9-fold greater transplanted mass in recipients of two versus one islet infusion (12 218 [9291â15 417] vs. 6442 [5156â7639] IEQ/kg; p <.0001), stimulated C-peptide was not significantly higher. Shorter time between transplants was associated with greater insulin dose reduction at 12 months (beta â0.35; p =.02). Graft survival over the first 12 months was greater in recipients of two versus one islet transplant in the UK program, although function at 1 and 6 years was comparable. Minimizing the interval between 2 islet infusions may maximize cumulative impact on graft function
Optimized immunosuppression to prevent graft failure in renal transplant recipients with HLA antibodies (OuTSMART): a randomised controlled trial
Background:
3% of kidney transplant recipients return to dialysis annually upon allograft failure. Development of antibodies (Ab) against human leukocyte antigens (HLA) is a validated prognostic biomarker of allograft failure. We tested whether screening for HLA Ab, combined with an intervention to improve adherence and optimization of immunosuppression could prevent allograft failure.
Methods:
Prospective, open-labelled randomised biomarker-based strategy (hybrid) trial in 13 UK transplant centres [EudraCT (2012-004308-36) and ISRCTN (46157828)]. Patients were randomly allocated (1:1) to unblinded or double-blinded arms and screened every 8 months. Unblinded HLA Ab+ patients were interviewed to encourage medication adherence and had tailored optimisation of Tacrolimus, Mycophenolate mofetil and Prednisolone. The primary outcome was time to graft failure in an intention to treat analysis. The trial had 80% power to detect a hazard ratio of 0.49 in donor specific antibody (DSA)+ patients.
Findings:
From 11/9/13 to 27/10/16, 5519 were screened for eligibility and 2037 randomised (1028 to unblinded care and 1009 to double blinded care). We identified 198 with DSA and 818 with non-DSA. Development of DSA, but not non-DSA was predictive of graft failure. HRs for graft failure in unblinded DSA+ and non-DSA+ groups were 1.54 (95% CI: 0.72 to 3.30) and 0.97 (0.54â1.74) respectively, providing no evidence of an intervention effect. Non-inferiority for the overall unblinded versus blinded comparison was not demonstrated as the upper confidence limit of the HR for graft failure exceeded 1.4 (1.02, 95% CI: 0.72 to 1.44). The only secondary endpoint reduced in the unblinded arm was biopsy-proven rejection.
Interpretation:
Intervention to improve adherence and optimize immunosuppression does not delay failure of renal transplants after development of DSA. Whilst DSA predicts increased risk of allograft failure, novel interventions are needed before screening can be used to direct therapy
Fermi Large Area Telescope Constraints on the Gamma-ray Opacity of the Universe
The Extragalactic Background Light (EBL) includes photons with wavelengths
from ultraviolet to infrared, which are effective at attenuating gamma rays
with energy above ~10 GeV during propagation from sources at cosmological
distances. This results in a redshift- and energy-dependent attenuation of the
gamma-ray flux of extragalactic sources such as blazars and Gamma-Ray Bursts
(GRBs). The Large Area Telescope onboard Fermi detects a sample of gamma-ray
blazars with redshift up to z~3, and GRBs with redshift up to z~4.3. Using
photons above 10 GeV collected by Fermi over more than one year of observations
for these sources, we investigate the effect of gamma-ray flux attenuation by
the EBL. We place upper limits on the gamma-ray opacity of the Universe at
various energies and redshifts, and compare this with predictions from
well-known EBL models. We find that an EBL intensity in the optical-ultraviolet
wavelengths as great as predicted by the "baseline" model of Stecker et al.
(2006) can be ruled out with high confidence.Comment: 42 pages, 12 figures, accepted version (24 Aug.2010) for publication
in ApJ; Contact authors: A. Bouvier, A. Chen, S. Raino, S. Razzaque, A.
Reimer, L.C. Reye
Testbed demonstration of high-contrast coronagraph imaging in search for Earth-like exoplanets
Direct imaging of an Earth-like exoplanet requires starlight suppression with a contrast ratio on the order of 1 x 10â»Âčâ° at small angular separations of 100 milliarcseconds or less in visible light with more than 50 nm bandwidth. To our knowledge, the technology needed to achieve the contrast and stability has not been demonstrated as of January 2019. The science requirements for near future NASA missions such as James Webb Space Telescopeâs (JWST) Near Infrared Camera (NIRCam) coronagraph and Wide Field Infrared Space Telescope (WFIRST) Coronagraph Instrument (CGI) are at least 10 times short. To investigate and guide the technology to reach this capability, we built a high contrast coronagraph testbed at NASAâs Jet Propulsion Laboratory (JPL). Titled the Decadal Survey Testbed (DST), state-of-art testbed is based on the accumulated experience of JPLâs High Contrast Imaging Testbed (HCIT) team. Currently, the DST hosts a Hybrid Lyot Coronagraph (HLC) with an unobscured, circular pupil. The DST also has two deformable mirrors and is equipped with the Low Order Wavefront Sensing and Control (LOWFS/C) subsystem to sense and correct the dynamic wavefront disturbances. In this paper, we present up-to-date progress of the testbed demonstration. As of January 2019, we repeatedly obtain convergence below 4 Ă 10â»Âčâ° mean contrast with 10% broadband light centered at 550 nm in a 360 degrees dark hole with a working angle between 3 λ/D and 9 λ/D. We show the key elements used in the testbed and the performance results with associated analysis
LSST: from Science Drivers to Reference Design and Anticipated Data Products
(Abridged) We describe here the most ambitious survey currently planned in
the optical, the Large Synoptic Survey Telescope (LSST). A vast array of
science will be enabled by a single wide-deep-fast sky survey, and LSST will
have unique survey capability in the faint time domain. The LSST design is
driven by four main science themes: probing dark energy and dark matter, taking
an inventory of the Solar System, exploring the transient optical sky, and
mapping the Milky Way. LSST will be a wide-field ground-based system sited at
Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m
effective) primary mirror, a 9.6 deg field of view, and a 3.2 Gigapixel
camera. The standard observing sequence will consist of pairs of 15-second
exposures in a given field, with two such visits in each pointing in a given
night. With these repeats, the LSST system is capable of imaging about 10,000
square degrees of sky in a single filter in three nights. The typical 5
point-source depth in a single visit in will be (AB). The
project is in the construction phase and will begin regular survey operations
by 2022. The survey area will be contained within 30,000 deg with
, and will be imaged multiple times in six bands, ,
covering the wavelength range 320--1050 nm. About 90\% of the observing time
will be devoted to a deep-wide-fast survey mode which will uniformly observe a
18,000 deg region about 800 times (summed over all six bands) during the
anticipated 10 years of operations, and yield a coadded map to . The
remaining 10\% of the observing time will be allocated to projects such as a
Very Deep and Fast time domain survey. The goal is to make LSST data products,
including a relational database of about 32 trillion observations of 40 billion
objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures
available from https://www.lsst.org/overvie
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