22,617 research outputs found
Study of the Outcomes and Impacts of the Global Forum on Migration and Development and Civil Society Days
In November 2011, the Global Forum on Migration and Development (GFMD) and accompanying Civil Society Days (CSD) completed their fifth year of operation, with the aim of improving migration policy coherence and enhancing the benefits of migration to sending and receiving countries, and to migrants themselves. The John D. and Catherine T. MacArthur Foundation, the largest non-governmental donor to this process, commissioned this study to retrospectively assess the outcomes and impact of the CSD and GFMD on policies, practices, issue framing, and government-civil society cooperation; and to prospectively draw lessons learned for the future of the GFMD and CSD. The evaluation took place from November 2011 through September 2012, allowing the team to observe the CSD and GFMD in Geneva, conduct an in-depth case study in Mexico, distribute online surveys to participants, conduct interviews at the UN offices in New York, and conduct key informant interviews by phone. Using a mixed method approach, combining quantitative survey data with qualitative key informant interviews and an extensive document review, the team has worked to triangulate data and strengthen the validity of findings. This study is geared towards the main stakeholders of the GFMD and CSD, including governments, civil society representatives, and donors. It is hoped that the aforementioned stakeholders will be able to utilize the findings, conclusions, and recommendations within this report to better inform their work in migration and development moving forward -- both within and outside of the GFMD and CSD processes
Semi-Automated Nasal PAP Mask Sizing using Facial Photographs
We present a semi-automated system for sizing nasal Positive Airway Pressure
(PAP) masks based upon a neural network model that was trained with facial
photographs of both PAP mask users and non-users. It demonstrated an accuracy
of 72% in correctly sizing a mask and 96% accuracy sizing to within 1 mask size
group. The semi-automated system performed comparably to sizing from manual
measurements taken from the same images which produced 89% and 100% accuracy
respectively.Comment: 4 pages, 3 figures, 4 tables, IEEE Engineering Medicine and Biology
Conference 201
Probing Pulsar Winds Using Inverse Compton Scattering
We investigate the effects of inverse Compton scattering by electrons and
positrons in the unshocked winds of rotationally-powered binary pulsars. This
process can scatter low energy target photons to produce gamma rays with
energies from MeV to TeV. The binary radio pulsars PSR B1259-63 and PSR
J0045-73 are both in close eccentric orbits around bright main sequence stars
which provide a huge density of low energy target photons. The inverse Compton
scattering process transfers momentum from the pulsar wind to the scattered
photons, and therefore provides a drag which tends to decelerate the pulsar
wind. We present detailed calculations of the dynamics of a pulsar wind which
is undergoing inverse Compton scattering, showing that the deceleration of the
wind of PSR B1259-63 due to `inverse Compton drag' is small, but that this
process may confine the wind of PSR J0045-73 before it attains pressure balance
with the outflow of its companion star. We calculate the spectra and light
curves of the resulting inverse Compton emission from PSR B1259-63 and show
that if the size of the pulsar wind nebula is comparable to the binary
separation, then the gamma-ray emission from the unshocked wind may be
detectable by atmospheric Cerenkov detectors or by the new generation of
satellite-borne gamma-ray detectors such as INTEGRAL and GLAST. This mechanism
may therefore provide a direct probe of the freely-expanding regions of pulsar
winds, previously thought to be invisible.Comment: To be published in Astroparticle Physics. 27 pages, 5 figure
A Radio--Optical Reference Frame VIII. CCD observations from KPNO and CTIO: internal calibration and first results
In this pilot investigation, precise optical positions in the FK5 system are
presented for a set of 16 compact extragalactic radio sources, which will be
part of the future radio--optical reference frame. The 0.9 m KPNO and CTIO
telescopes equipped with 2K CCD's have been used for this project. The
astrometric properties of these instruments are investigated in detail. New
techniques of using wide field CCD observations for astrometry in general are
developed. An internal precision of 5 to 31 mas in position per single exposure
is found, depending on the brightness of the object. The tie to the primary
optical reference system is established by photographic astrometry using
dedicated astrographs on both hemispheres. An accuracy of mas per
source is estimated for the multi--step reduction procedure when based on the
future Hipparcos catalog, while the FK5--based positions suffer from system
errors of 100 to 200 mas as compared to the radio positions. This work provides
a contribution to the international effort to link the Hipparcos instrumental
coordinate system to the quasi--inertial VLBI radio reference frame. Precise
radio and optical astrometry of a large sample of compact extragalactic sources
will also contribute to the astrophysics of these objects by comparing the
respective centers of emission at the optical and radio wavelengths.Comment: AAS v.4 LaTeX, 2 parts on 1 file (main text + deluxetable), accepted
by AJ, Dec.95, fig. with reprint
RNAseq analysis of fast skeletal muscle in restriction-fed transgenic coho salmon (Oncorhynchus kisutch) : an experimental model uncoupling the growth hormone and nutritional signals regulating growth
Background Coho salmon (Oncorhynchus kisutch) transgenic for growth hormone (Gh) express Gh in multiple tissues which results in increased appetite and continuous high growth with satiation feeding. Restricting Gh-transgenics to the same lower ration (TR) as wild-type fish (WT) results in similar growth, but with the recruitment of fewer, larger diameter, muscle skeletal fibres to reach a given body size. In order to better understand the genetic mechanisms behind these different patterns of muscle growth and to investigate how the decoupling of Gh and nutritional signals affects gene regulation we used RNA-seq to compare the fast skeletal muscle transcriptome in TR and WT coho salmon. Results Illumina sequencing of individually barcoded libraries from 6 WT and 6 TR coho salmon yielded 704,550,985 paired end reads which were used to construct 323,115 contigs containing 19,093 unique genes of which >10,000 contained >90 % of the coding sequence. Transcripts coding for 31 genes required for myoblast fusion were identified with 22 significantly downregulated in TR relative to WT fish, including 10 (vaspa, cdh15, graf1, crk, crkl, dock1, trio, plekho1a, cdc42a and dock5) associated with signaling through the cell surface protein cadherin. Nineteen out of 44 (43 %) translation initiation factors and 14 of 47 (30 %) protein chaperones were upregulated in TR relative to WT fish. Conclusions TR coho salmon showed increased growth hormone transcripts and gene expression associated with protein synthesis and folding than WT fish even though net rates of protein accretion were similar. The uncoupling of Gh and amino acid signals likely results in additional costs of transcription associated with protein turnover in TR fish. The predicted reduction in the ionic costs of homeostasis in TR fish associated with increased fibre size were shown to involve multiple pathways regulating myotube fusion, particularly cadherin signaling.Publisher PDFPeer reviewe
Direct observation of a Fermi liquid-like normal state in an iron-pnictide superconductor
There are two prerequisites for understanding high-temperature (high-T)
superconductivity: identifying the pairing interaction and a correct
description of the normal state from which superconductivity emerges. The
nature of the normal state of iron-pnictide superconductors, and the role
played by correlations arising from partially screened interactions, are still
under debate. Here we show that the normal state of carefully annealed
electron-doped BaFeCoAs at low temperatures has all the
hallmark properties of a local Fermi liquid, with a more incoherent state
emerging at elevated temperatures, an identification made possible using
bulk-sensitive optical spectroscopy with high frequency and temperature
resolution. The frequency dependent scattering rate extracted from the optical
conductivity deviates from the expected scaling
with
1.47 rather than = 2, indicative of the presence of residual elastic
resonant scattering. Excellent agreement between the experimental results and
theoretical modeling allows us to extract the characteristic Fermi liquid scale
1700 K. Our results show that the electron-doped iron-pnictides
should be regarded as weakly correlated Fermi liquids with a weak mass
enhancement resulting from residual electron-electron scattering from thermally
excited quasi-particles.Comment: 6+9pages, 3+9 figures To be published in Scientific Report
Inverse Compton Emission of TeV Gamma Rays from PSR B1259-63
We derive light curves for the hard gamma-ray emission, at energies up to
several TeV, expected from the unique pulsar/Be-star binary system PSR
B1259-63. This is the only known system in our galaxy in which a radio pulsar
is orbiting a main sequence star. We show that inverse Compton emission from
the electrons and positrons in the shocked pulsar wind, scattering target
photons from the Be star, produces a flux of hard gamma-rays that should be
above the sensitivity threshold of present day atmospheric Cerenkov detectors.
Furthermore, we predict that the flux of hard gamma-rays produced via this
mechanism has a characteristic variation with orbital phase that should be
observable, and which is not expected from any other mechanism.Comment: To be published in Astroparticle Physics. 24 pages, 8 figure
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