47 research outputs found
Prognostic Factors Associated with Ocriplasmin Efficacy for the Treatment of Symptomatic Vitreomacular Adhesion and Full-thickness Macular Hole: Analysis from Four Studies
Purpose: To assess the effect of patient baseline characteristics on the efficacy of ocriplasmin treatment for symptomatic vitreomacular adhesion (VMA) with full-thickness macular hole (FTMH) from phase 3/4 studies.
Methods: Patients with symptomatic VMA and FTMH at baseline and receiving ocriplasmin treatment 12
Models of the Compact Jet in GRS 1915+105
In this article, models are constructed of the compact jet in GRS 1915+105
during an epoch of optimal data capture. On April 02, 2003, the object was
observed in the hard X-ray/soft gamma ray band (INTEGRAL), hard X-ray band
(RXTE), near IR (ESO/New Technology Telescope) and the VLBA (8.3 GHz and 15
GHz). The source was in a so-called "high plateau state." The large radio flux
provides high signal to noise ratios in the radio images. Thus, one can image
the jet out to large distances ( cm). This combined with the
broadband coverage make this epoch the best suited for modeling the jet. The
parametric method developed in the papers \cite{ghi85,ghi89,ghi96,sam97} that
has been successfully utilized in the realm of extragalactic radio jets is
implemented. The basic model is one where external inverse Compton (EIC)
scattering of accretion disk photons by jet plasma provides the hard X-ray
powerlaw. Unlike AGN jets, it is found that the radio jet must be highly
stratified in the transverse direction in order to produce the observed surface
brightness distribution in the radio images. Various jet models are considered.
The jet power is ergs/sec if the hard X-ray
powerlaw luminosity is from EIC in the jet and
ergs/sec if the X-rays are emitted from the accretion disk corona. These
estimates indicate that the jet power can be as high as 60% of the total X-ray
luminosity.Comment: To appear in MNRA
Connection between the Accretion Disk and Jet in the Radio Galaxy 3C 111
We present the results of extensive multi-frequency monitoring of the radio
galaxy 3C 111 between 2004 and 2010 at X-ray (2.4--10 keV), optical (R band),
and radio (14.5, 37, and 230 GHz) wave bands, as well as multi-epoch imaging
with the Very Long Baseline Array (VLBA) at 43 GHz. Over the six years of
observation, significant dips in the X-ray light curve are followed by
ejections of bright superluminal knots in the VLBA images. This shows a clear
connection between the radiative state near the black hole, where the X-rays
are produced, and events in the jet. The X-ray continuum flux and Fe line
intensity are strongly correlated, with a time lag shorter than 90 days and
consistent with zero. This implies that the Fe line is generated within 90
light-days of the source of the X-ray continuum. The power spectral density
function of X-ray variations contains a break, with steeper slope at shorter
timescales. The break timescale of 13 (+12,-6) days is commensurate with
scaling according to the mass of the central black hole based on observations
of Seyfert galaxies and black hole X-ray binaries (BHXRBs). The data are
consistent with the standard paradigm, in which the X-rays are predominantly
produced by inverse Compton scattering of thermal optical/UV seed photons from
the accretion disk by a distribution of hot electrons --- the corona ---
situated near the disk. Most of the optical emission is generated in the
accretion disk due to reprocessing of the X-ray emission. The relationships
that we have uncovered between the accretion disk and the jet in 3C 111, as
well as in the FR I radio galaxy 3C 120 in a previous paper, support the
paradigm that active galactic nuclei and Galactic BHXRBs are fundamentally
similar, with characteristic time and size scales proportional to the mass of
the central black holeComment: Accepted for publication in ApJ. 18 pages, 17 figures, 11 tables
(full machine readable data-tables online in ApJ website
The On-Site Analysis of the Cherenkov Telescope Array
The Cherenkov Telescope Array (CTA) observatory will be one of the largest
ground-based very high-energy gamma-ray observatories. The On-Site Analysis
will be the first CTA scientific analysis of data acquired from the array of
telescopes, in both northern and southern sites. The On-Site Analysis will have
two pipelines: the Level-A pipeline (also known as Real-Time Analysis, RTA) and
the level-B one. The RTA performs data quality monitoring and must be able to
issue automated alerts on variable and transient astrophysical sources within
30 seconds from the last acquired Cherenkov event that contributes to the
alert, with a sensitivity not worse than the one achieved by the final pipeline
by more than a factor of 3. The Level-B Analysis has a better sensitivity (not
be worse than the final one by a factor of 2) and the results should be
available within 10 hours from the acquisition of the data: for this reason
this analysis could be performed at the end of an observation or next morning.
The latency (in particular for the RTA) and the sensitivity requirements are
challenging because of the large data rate, a few GByte/s. The remote
connection to the CTA candidate site with a rather limited network bandwidth
makes the issue of the exported data size extremely critical and prevents any
kind of processing in real-time of the data outside the site of the telescopes.
For these reasons the analysis will be performed on-site with infrastructures
co-located with the telescopes, with limited electrical power availability and
with a reduced possibility of human intervention. This means, for example, that
the on-site hardware infrastructure should have low-power consumption. A
substantial effort towards the optimization of high-throughput computing
service is envisioned to provide hardware and software solutions with
high-throughput, low-power consumption at a low-cost.Comment: In Proceedings of the 34th International Cosmic Ray Conference
(ICRC2015), The Hague, The Netherlands. All CTA contributions at
arXiv:1508.0589
Vaccine candidates derived from a novel infectious cDNA clone of an American genotype dengue virus type 2
BACKGROUND: A dengue virus type 2 (DEN-2 Tonga/74) isolated from a 1974 epidemic was characterized by mild illness and belongs to the American genotype of DEN-2 viruses. To prepare a vaccine candidate, a previously described 30 nucleotide deletion (Î30) in the 3' untranslated region of DEN-4 has been engineered into the DEN-2 isolate. METHODS: A full-length cDNA clone was generated from the DEN-2 virus and used to produce recombinant DEN-2 (rDEN-2) and rDEN2Î30. Viruses were evaluated for replication in SCID mice transplanted with human hepatoma cells (SCID-HuH-7 mice), in mosquitoes, and in rhesus monkeys. Neutralizing antibody induction and protective efficacy were also assessed in rhesus monkeys. RESULTS: The rDEN2Î30 virus was ten-fold reduced in replication in SCID-HuH-7 mice when compared to the parent virus. The rDEN-2 viruses were not infectious for Aedes mosquitoes, but both readily infected Toxorynchites mosquitoes. In rhesus monkeys, rDEN2Î30 appeared to be slightly attenuated when compared to the parent virus as measured by duration and peak of viremia and neutralizing antibody induction. A derivative of rDEN2Î30, designated rDEN2Î30-4995, was generated by incorporation of a point mutation previously identified in the NS3 gene of DEN-4 and was found to be more attenuated than rDEN2Î30 in SCID-HuH-7 mice. CONCLUSIONS: The rDEN2Î30 and rDEN2Î30-4995 viruses can be considered for evaluation in humans and for inclusion in a tetravalent dengue vaccine
Multiwavelength Observations of A0620-00 in Quiescence
[Abridged.] We present multiwavelength observations of the black hole binary
system, A0620-00. Using the Cosmic Origins Spectrograph on the Hubble Space
Telescope, we have obtained the first FUV spectrum of A0620-00. The observed
spectrum is flat in the FUV and very faint (with continuum fluxes \simeq 1e -
17 ergs/cm^2/s/A). We compiled the dereddened, broadband spectral energy
distribution of A0620-00 and compared it to previous SEDs as well as
theoretical models. The SEDs show that the source varies at all wavelengths for
which we have multiple samples. Contrary to previous observations, the
optical-UV spectrum does not continue to drop to shorter wavelengths, but
instead shows a recovery and an increasingly blue spectrum in the FUV. We
created an optical-UV spectrum of A0620-00 with the donor star contribution
removed. The non-stellar spectrum peaks at \simeq3000 {\deg}A. The peak can be
fit with a T=10,000 K blackbody with a small emitting area, probably
originating in the hot spot where the accretion stream impacts the outer disk.
However, one or more components in addition to the blackbody are needed to fit
the FUV upturn and the red optical fluxes in the optical-UV spectrum. By
comparing the mass accretion rate determined from the hot spot luminosity to
the mean accretion rate inferred from the outburst history, we find that the
latter is an order of magnitude smaller than the former, indicating that
\sim90% of the accreted mass must be lost from the system if the predictions of
the disk instability model and the estimated interoutburst interval are
correct. The mass accretion rate at the hot spot is 10^5 the accretion rate at
the black hole inferred from the X-ray luminosity. To reconcile these requires
that outflows carry away virtually all of the accreted mass, a very low rate of
mass transfer from the outer cold disk into the inner hot region, and/or
radiatively inefficient accretion.Comment: ApJ, accepte
Transformative sensemaking: Development in Whose Image? Keyan Tomaselli and the semiotics of visual representation
The defining and distinguishing feature of homo sapiens is its ability to make sense of the world, i.e. to use its intellect to understand and change both itself and the world of which it is an integral part. It is against this backdrop that this essay reviews Tomaselli's 1996 text, Appropriating Images: The Semiotics of Visual Representation/ by summarizing his key perspectives, clarifying his major operational concepts and citing particular portions from his work in support of specific perspectives on sense-making. Subsequently, this essay employs his techniques of sense-making to interrogate the notion of "development". This exercise examines and confirms two interrelated hypotheses: first, a semiotic analysis of the privileged notion of "development" demonstrates its metaphysical/ ideological, and thus limiting, nature especially vis-a-vis the marginalized, excluded, and the collective other, the so-called Developing Countries. Second, the interrogative nature of semiotics allows for an alternative reading and application of human potential or skills in the quest of a more humane social and global order, highlighting thereby the transformative implications of a reflexive epistemology.Web of Scienc
Franchises lost and gained: post-coloniality and the development of womenâs rights in Canada
The Canadian constitution is to some extent characterised by its focus on equality, and in particular gender equality. This development of womenâs rights in Canada and the greater engagement of women as political actors is often presented as a steady linear process, moving forwards from post-enlightenment modernity. This article seeks to disturb this âdiscourse of the continuous,â by using an analysis of the pre-confederation history of suffrage in Canada to both refute a simplistic linear view of womenâs rights development and to argue for recognition of the Indigenous contribution to the history of womenâs rights in Canada.
The gain of franchise and suffrage movements in Canada in the late nineteenth and early twentieth century are, rightly, the focus of considerable study (Pauker 2015), This article takes an alternative perspective. Instead, it examines the exercise of earlier franchises in pre-confederation Canada. In particular it analyses why franchise was exercised more widely in Lower Canada and relates this to the context of the removal of franchises from women prior to confederation
The JWST Galactic Center Survey -- A White Paper
The inner hundred parsecs of the Milky Way hosts the nearest supermassive
black hole, largest reservoir of dense gas, greatest stellar density, hundreds
of massive main and post main sequence stars, and the highest volume density of
supernovae in the Galaxy. As the nearest environment in which it is possible to
simultaneously observe many of the extreme processes shaping the Universe, it
is one of the most well-studied regions in astrophysics. Due to its proximity,
we can study the center of our Galaxy on scales down to a few hundred AU, a
hundred times better than in similar Local Group galaxies and thousands of
times better than in the nearest active galaxies. The Galactic Center (GC) is
therefore of outstanding astrophysical interest. However, in spite of intense
observational work over the past decades, there are still fundamental things
unknown about the GC. JWST has the unique capability to provide us with the
necessary, game-changing data. In this White Paper, we advocate for a JWST
NIRCam survey that aims at solving central questions, that we have identified
as a community: i) the 3D structure and kinematics of gas and stars; ii)
ancient star formation and its relation with the overall history of the Milky
Way, as well as recent star formation and its implications for the overall
energetics of our galaxy's nucleus; and iii) the (non-)universality of star
formation and the stellar initial mass function. We advocate for a large-area,
multi-epoch, multi-wavelength NIRCam survey of the inner 100\,pc of the Galaxy
in the form of a Treasury GO JWST Large Program that is open to the community.
We describe how this survey will derive the physical and kinematic properties
of ~10,000,000 stars, how this will solve the key unknowns and provide a
valuable resource for the community with long-lasting legacy value.Comment: This White Paper will be updated when required (e.g. new authors
joining, editing of content). Most recent update: 24 Oct 202