212 research outputs found
A method of assessing the quality of pharmaceutical market and industry reports as a source to study access to medicines
This repository item contains a single issue of the Health and Development Discussion Papers, an informal working paper series that began publishing in 2002 by the Boston University Center for Global Health and Development. It is intended to help the Center and individual authors to disseminate work that is being prepared for journal publication or that is not appropriate for journal publication but might still have value to readers.Market and industry reports can be useful in studying access to medicines from a pharmaceutical market perspective. However, many market and industry reports lack some or much of the information required to conduct analyses to study access to medicines and are often not transparent in their data sources and research methodologies. The instrument developed in this study, titled the Pharmaceutical Market and Industry Report Assessment Tool (PIRAT), assesses the quality of pharmaceutical market and industry reports, specifically focusing on the needs of public health researchers, and includes criteria describing the content and quality of the market reports. The assessment tool generates an unweighted score indicating the relative strengths and weaknesses of reports
Identification of key parameters controlling demographically structured vegetation dynamics in a land surface model: CLM4.5(FATES)
Vegetation plays an important role in regulating global carbon cycles and is a key component of the Earth system models (ESMs) that aim to project Earth\u27s future climate. In the last decade, the vegetation component within ESMs has witnessed great progress from simple âbig-leafâ approaches to demographically structured approaches, which have a better representation of plant size, canopy structure, and disturbances. These demographically structured vegetation models typically have a large number of input parameters, and sensitivity analysis is needed to quantify the impact of each parameter on the model outputs for a better understanding of model behavior. In this study, we conducted a comprehensive sensitivity analysis to diagnose the Community Land Model coupled to the Functionally Assembled Terrestrial Simulator, or CLM4.5(FATES). Specifically, we quantified the first- and second-order sensitivities of the model parameters to outputs that represent simulated growth and mortality as well as carbon fluxes and stocks for a tropical site with an extent of 1Ă1â. While the photosynthetic capacity parameter (Vc,max25) is found to be important for simulated carbon stocks and fluxes, we also show the importance of carbon storage and allometry parameters, which determine survival and growth strategies within the model. The parameter sensitivity changes with different sizes of trees and climate conditions. The results of this study highlight the importance of understanding the dynamics of the next generation of demographically enabled vegetation models within ESMs to improve model parameterization and structure for better model fidelity
Survivin expression in in situ and invasive breast cancer relates to COX-2 expression and DCIS recurrence
In lung cancer cyclooxygenase-2 (COX-2) expression has been reported to stabilise survivin, an inhibitor of apoptosis (IAP) which prevents cell death by blocking activated caspases. COX-2 expression limits the ubiquitination of survivin, protecting it from degradation. To determine if COX-2 expression in breast cancer showed an association with survivin expression, we assessed the levels of each protein in ductal carcinoma in situ (DCIS) and invasive breast cancer (IBC); relating expression patterns to recurrence of DCIS after surgery. Patterns of COX-2 and survivin expression were determined by intensity-graded immunohistochemistry of the primary tumours. Patients with DCIS (n=161) which had either recurred (n=47) or shown no evidence of recurrence (n=114) 5 years following primary surgery were studied. These were compared to 58 cases of IBC. Survivin was expressed in the cytoplasm of 59% of DCIS and 17% of IBC. High levels of both cytoplasmic survivin and COX-2 expression significantly correlated to DCIS recurrence. COX-2 expression was present in 72% of DCIS, and levels of expression positively correlated with cytoplasmic survivin expression in DCIS and invasive disease. The majority of DCIS that recurred expressed both proteins (69%) vs 39% nonrecurrent. Recurrence was not seen in DCIS lacking both proteins at 5 years (P=0.001). Expression of the IAP survivin is increased in DCIS and correlates closely with COX-2 expression. Increased expression of IAP, (leading to reduced apoptosis) may explain the effect of COX-2 in increasing recurrence of DCIS after surgical treatment
Modern optical astronomy: technology and impact of interferometry
The present `state of the art' and the path to future progress in high
spatial resolution imaging interferometry is reviewed. The review begins with a
treatment of the fundamentals of stellar optical interferometry, the origin,
properties, optical effects of turbulence in the Earth's atmosphere, the
passive methods that are applied on a single telescope to overcome atmospheric
image degradation such as speckle interferometry, and various other techniques.
These topics include differential speckle interferometry, speckle spectroscopy
and polarimetry, phase diversity, wavefront shearing interferometry,
phase-closure methods, dark speckle imaging, as well as the limitations imposed
by the detectors on the performance of speckle imaging. A brief account is
given of the technological innovation of adaptive-optics (AO) to compensate
such atmospheric effects on the image in real time. A major advancement
involves the transition from single-aperture to the dilute-aperture
interferometry using multiple telescopes. Therefore, the review deals with
recent developments involving ground-based, and space-based optical arrays.
Emphasis is placed on the problems specific to delay-lines, beam recombination,
polarization, dispersion, fringe-tracking, bootstrapping, coherencing and
cophasing, and recovery of the visibility functions. The role of AO in
enhancing visibilities is also discussed. The applications of interferometry,
such as imaging, astrometry, and nulling are described. The mathematical
intricacies of the various `post-detection' image-processing techniques are
examined critically. The review concludes with a discussion of the
astrophysical importance and the perspectives of interferometry.Comment: 65 pages LaTeX file including 23 figures. Reviews of Modern Physics,
2002, to appear in April issu
Cosmological parameters from SDSS and WMAP
We measure cosmological parameters using the three-dimensional power spectrum
P(k) from over 200,000 galaxies in the Sloan Digital Sky Survey (SDSS) in
combination with WMAP and other data. Our results are consistent with a
``vanilla'' flat adiabatic Lambda-CDM model without tilt (n=1), running tilt,
tensor modes or massive neutrinos. Adding SDSS information more than halves the
WMAP-only error bars on some parameters, tightening 1 sigma constraints on the
Hubble parameter from h~0.74+0.18-0.07 to h~0.70+0.04-0.03, on the matter
density from Omega_m~0.25+/-0.10 to Omega_m~0.30+/-0.04 (1 sigma) and on
neutrino masses from <11 eV to <0.6 eV (95%). SDSS helps even more when
dropping prior assumptions about curvature, neutrinos, tensor modes and the
equation of state. Our results are in substantial agreement with the joint
analysis of WMAP and the 2dF Galaxy Redshift Survey, which is an impressive
consistency check with independent redshift survey data and analysis
techniques. In this paper, we place particular emphasis on clarifying the
physical origin of the constraints, i.e., what we do and do not know when using
different data sets and prior assumptions. For instance, dropping the
assumption that space is perfectly flat, the WMAP-only constraint on the
measured age of the Universe tightens from t0~16.3+2.3-1.8 Gyr to
t0~14.1+1.0-0.9 Gyr by adding SDSS and SN Ia data. Including tensors, running
tilt, neutrino mass and equation of state in the list of free parameters, many
constraints are still quite weak, but future cosmological measurements from
SDSS and other sources should allow these to be substantially tightened.Comment: Minor revisions to match accepted PRD version. SDSS data and ppt
figures available at http://www.hep.upenn.edu/~max/sdsspars.htm
LSST Science Book, Version 2.0
A survey that can cover the sky in optical bands over wide fields to faint
magnitudes with a fast cadence will enable many of the exciting science
opportunities of the next decade. The Large Synoptic Survey Telescope (LSST)
will have an effective aperture of 6.7 meters and an imaging camera with field
of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over
20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with
fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a
total point-source depth of r~27.5. The LSST Science Book describes the basic
parameters of the LSST hardware, software, and observing plans. The book
discusses educational and outreach opportunities, then goes on to describe a
broad range of science that LSST will revolutionize: mapping the inner and
outer Solar System, stellar populations in the Milky Way and nearby galaxies,
the structure of the Milky Way disk and halo and other objects in the Local
Volume, transient and variable objects both at low and high redshift, and the
properties of normal and active galaxies at low and high redshift. It then
turns to far-field cosmological topics, exploring properties of supernovae to
z~1, strong and weak lensing, the large-scale distribution of galaxies and
baryon oscillations, and how these different probes may be combined to
constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at
http://www.lsst.org/lsst/sciboo
Quantifying uncertainties in primordial nucleosynthesis without Monte Carlo simulations
We present a simple method for determining the (correlated) uncertainties of
the light element abundances expected from big bang nucleosynthesis, which
avoids the need for lengthy Monte Carlo simulations. Our approach helps to
clarify the role of the different nuclear reactions contributing to a
particular elemental abundance and makes it easy to implement
energy-independent changes in the measured reaction rates. As an application,
we demonstrate how this method simplifies the statistical estimation of the
nucleon-to-photon ratio through comparison of the standard BBN predictions with
the observationally inferred abundances.Comment: 22 pages (RevTeX) incl. 8 figures (epsf); Changes: Figs. 5 & 6
combined + typo in Footnote 1 corrected + several stylistic changes; to
appear in Phys. Rev.
Potential for comparative public opinion research in public administration
The public administration and public services have always taken a
marginal place in the political scientistsâ behavioural research.
Public administration students on the other hand tend to focus on
political and administrative elites and institutions, and largely
ignored citizens in comparative research. In this article we make a
plea for international comparative research on citizensâ attitudes
towards the public administration from an interdisciplinary
perspective. Available international survey material is discussed, and
main trends in empirical practice and theoretical approaches are
outlined, especially those with a potential impact on public sector
reform
Recommended from our members
Vulnerability of Amazon forests to storm-driven tree mortality
Tree mortality is a key driver of forest community composition and carbon dynamics. Strong winds associated with severe convective storms are dominant natural drivers of tree mortality in the Amazon. Why forests vary with respect to their vulnerability to wind events and how the predicted increase in storm events might affect forest ecosystems within the Amazon are not well understood. We found that windthrows are common in the Amazon region extending from northwest (Peru, Colombia, Venezuela, and west Brazil) to central Brazil, with the highest occurrence of windthrows in the northwest Amazon. More frequent winds, produced by more frequent severe convective systems, in combination with well-known processes that limit the anchoring of trees in the soil, help to explain the higher vulnerability of the northwest Amazon forests to winds. Projected increases in the frequency and intensity of convective storms in the Amazon have the potential to increase wind-related tree mortality. A forest demographic model calibrated for the northwestern and the central Amazon showed that northwestern forests are more resilient to increased wind-related tree mortality than forests in the central Amazon. Our study emphasizes the importance of including wind-related tree mortality in model simulations for reliable predictions of the future of tropical forests and their effects on the Earth' system
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