247 research outputs found
Description of a mathematical model and computer simulation of separation of the nose cap from the solid rocket booster
A system of equations which models the motion of the Solid Rocket Booster Nose Cap upon separation is described. The computer program which utilizes these equations to generate nose cap trajectories is described in detail. Application of the program to simulate a rocket sled test of the nose cap separation is discussed and the results of the applications are presented. With the information given a user should be able to exercise the computer program with a minimum of effort
Using Molecules to Measure Nuclear Spin-Dependent Parity Violation
Nuclear spin-dependent parity violation arises from weak interactions between
electrons and nucleons, and from nuclear anapole moments. We outline a method
to measure such effects, using a Stark-interference technique to determine the
mixing between opposite-parity rotational/hyperfine levels of ground-state
molecules. The technique is applicable to nuclei over a wide range of atomic
number, in diatomic species that are theoretically tractable for
interpretation. This should provide data on anapole moments of many nuclei, and
on previously unmeasured neutral weak couplings
Measuring the impact of ambulatory red blood cell transfusion on home functional status: study protocol for a pilot randomized controlled trial
SPIRIT 2013: SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) Checklist for clinical trial protocols. (DOCX 65Â kb
Orbit image analysis machine learning software can be used for the histological quantification of acute ischemic stroke blood clots
Our aim was to assess the utility of a novel machine learning software (Orbit Image Analysis) in the histological quantification of acute ischemic stroke (AIS) clots. We analyzed 50 AIS blood clots retrieved using mechanical thrombectomy procedures. Following HandE staining, quantification of clot components was performed by two different methods: a pathologist using a reference standard method (Adobe Photoshop CC) and an experienced researcher using Orbit Image Analysis. Following quantification, the clots were categorized into 3 types: RBC dominant (\u3e/=60% RBCs), Mixed and Fibrin dominant ( \u3e /=60% Fibrin). Correlations between clot composition and Hounsfield Units density on Computed Tomography (CT) were assessed. There was a significant correlation between the components of clots as quantified by the Orbit Image Analysis algorithm and the reference standard approach (rho = 0.944**, p \u3c 0.001, n = 150). A significant relationship was found between clot composition (RBC-Rich, Mixed, Fibrin-Rich) and the presence of a Hyperdense artery sign using the algorithmic method (X2(2) = 6.712, p = 0.035*) but not using the reference standard method (X2(2) = 3.924, p = 0.141). Orbit Image Analysis machine learning software can be used for the histological quantification of AIS clots, reproducibly generating composition analyses similar to current reference standard methods
First results from the JWST Early Release Science Program Q3D: Benchmark Comparison of Optical and Mid-IR Tracers of a Dusty, Ionized Red Quasar Wind at z=0.435
The [OIII] 5007 A emission line is the most common tracer of warm, ionized
outflows in active galactic nuclei across cosmic time. JWST newly allows us to
use mid-infrared spectral features at both high spatial and spectral resolution
to probe these same winds. Here we present a comparison of ground-based,
seeing-limited [OIII] and space-based, diffraction-limited [SIV] 10.51 micron
maps of the powerful, kpc-scale outflow in the Type 1 red quasar SDSS
J110648.32+480712.3. The JWST data are from the Mid-InfraRed Instrument (MIRI).
There is a close match in resolution between the datasets (0."4--0."6), in
ionization potential of the O+2 and S+3 ions (35 eV), and in line sensitivity
(1e-17 to 2e-17 erg/s/cm2/arcsec2). The [OIII] and [SIV] line shapes match in
velocity and linewidth over much of the 20 kpc outflowing nebula, and [SIV] is
the brightest line in the rest-frame 3.5--19.5 micron range, demonstrating its
usefulness as a mid-IR probe of quasar outflows. [OIII] is nevertheless
intriniscally brighter and provides better contrast with the point-source
continuum, which is strong in the mid-IR. There is a strong anticorrelation of
[OIII]/[SIV] with average velocity, which is consistent with a scenario of
differential obscuration between the approaching (blueshifted) and receding
(redshifted) sides of the flow. The dust in the wind may also obscure the
central quasar, consistent with models that attribute red quasar extinction to
dusty winds.Comment: Submitted to ApJ
Irresponsiveness of two retinoblastoma cases to conservative therapy correlates with up- regulation of hERG1 channels and of the VEGF-A pathway
<p>Abstract</p> <p>Background</p> <p>Treatment strategies for Retinoblastoma (RB), the most common primary intraocular tumor in children, have evolved over the past few decades and chemoreduction is currently the most popular treatment strategy. Despite success, systemic chemotherapeutic treatment has relevant toxicity, especially in the pediatric population. Antiangiogenic therapy has thus been proposed as a valuable alternative for pediatric malignancies, in particolar RB. Indeed, it has been shown that vessel density correlates with both local invasive growth and presence of metastases in RB, suggesting that angiogenesis could play a pivotal role for both local and systemic invasive growth in RB. We present here two cases of sporadic, bilateral RB that did not benefit from the conservative treatment and we provide evidence that the VEGF-A pathway is significantly up-regulated in both RB cases along with an over expression of hERG1 K<sup>+ </sup>channels.</p> <p>Case presentation</p> <p>Two patients showed a sporadic, bilateral RB, classified at Stage II of the Reese-Elsworth Classification. Neither of them got benefits from conservative treatment, and the two eyes were enucleated. In samples from both RB cases we studied the VEGF-A pathway: VEGF-A showed high levels in the vitreous, the <it>vegf-a, flt-1, kdr</it>, and <it>hif1-α </it>transcripts were over-expressed. Moreover, both the transcripts and proteins of the hERG1 K<sup>+ </sup>channels turned out to be up-regulated in the two RB cases compared to the non cancerous retinal tissue.</p> <p>Conclusions</p> <p>We provide evidence that the VEGF-A pathway is up-regulated in two particular aggressive cases of bilateral RB, which did not experience any benefit from conservative treatment, showing the overexpression of the <it>vegf-a</it>, <it>flt-1</it>, <it>kdr </it>and <it>hif1-α </it>transcripts and the high secretion of VEGF-A. Moreover we also show for the first time that the <it>herg1 </it>gene transcripts and protein are over expressed in RB, as occurs in several aggressive tumors. These results further stress the relevance of the VEGF-A pathway in RB and the correlation with hERG1, making aggressive and recurrent RB cases good candidates for antiangiogenesis therapies based on the targeting of VEGF-A.</p
Broad-line region in NGC 4151 monitored by two decades of reverberation mapping campaigns. I. Evolution of structure and kinematics
We report the results of long-term reverberation mapping (RM) campaigns of
the nearby active galactic nuclei (AGN) NGC 4151, spanning from 1994 to 2022,
based on archived observations of the FAST Spectrograph Publicly Archived
Programs and our new observations with the 2.3m telescope at the Wyoming
Infrared Observatory. We reduce and calibrate all the spectra in a consistent
way, and derive light curves of the broad H line and 5100\,{\AA}
continuum. Continuum light curves are also constructed using public archival
photometric data to increase sampling cadences. We subtract the host galaxy
contamination using {\it HST} imaging to correct fluxes of the calibrated light
curves. Utilizing the long-term archival photometric data, we complete the
absolute flux-calibration of the AGN continuum. We find that the H time
delays are correlated with the 5100\,{\AA} luminosities as . This is remarkably consistent with
Bentz et al. (2013)'s global size-luminosity relationship of AGNs. Moreover,
the data sets for five of the seasons allow us to obtain the velocity-resolved
delays of the H line, showing diverse structures (outflows, inflows and
disks). Combining our results with previous independent measurements, we find
the measured dynamics of the H broad-line region (BLR) are possibly
related to the long-term trend of the luminosity. There is also a possible
additional 1.86 years time lag between the variation in BLR radius and
luminosity. These results suggest that dynamical changes in the BLR may be
driven by the effects of radiation pressure.Comment: Accepted for publication in MNRAS; comments welcome
A multipoint study of a substorm occurring on 7 December, 1992, and its theoretical implications
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