311 research outputs found
Current Update on the Randomized Controlled Trials of Intracranial Aneurysms
Endovascular coiling has become the primary treatment modality for the treatment of intracranial ruptured aneurysms in many centers. A multicenter randomized controlled trial (RCT), ISAT study, has demonstrated that endovascular coiling of ruptured intracranial aneurysms has benefits over surgical clipping in those patients suitable for either treatment. Because RCT comparing conservative management with surgical clipping and with endovascular coiling have not been performed to date for unruptured intracranial aneurysms, the best management for unruptured aneurysm remains unclear. A RCT is ongoing to answer the question whether active treatment can improve the outcome of patients with unruptured intracranial aneurysms as compared with observation
From Commensal to Pathogen: Translocation of Enterococcus faecalis from the Midgut to the Hemocoel of Manduca sexta
A dynamic homeostasis is maintained between the host and native bacteria of the gastrointestinal tract in animals, but migration of bacteria from the gut to other organs can lead to disease or death. Enterococcus faecalis is a commensal of the gastrointestinal tract; however, Enterococcus spp. are increasingly frequent causes of nosocomial infections with a high mortality rate. We investigated the commensal-to-pathogen switch undergone by E. faecalis OG1RF in the lepidopteran model host Manduca sexta associated with its location in the host. E. faecalis persists in the harsh midgut environment of M. sexta larvae without causing apparent illness, but injection of E. faecalis directly into the larval hemocoel is followed by rapid death. Additionally, oral ingestion of E. faecalis in the presence of Bacillus thuringiensis insecticidal toxin, a pore-forming toxin that targets the midgut epithelium, induces an elevated mortality rate. We show that the loss of gut integrity due to B. thuringiensis toxin correlates with the translocation of E. faecalis from the gastrointestinal tract into the hemolymph. Upon gaining access to the hemolymph, E. faecalis induces an innate immune response, illustrated by hemocyte aggregation, in larvae prior to death. The degree of hemocyte aggregation is dependent upon the route of E. faecalis entry. Our data demonstrate the efficacy of the M. sexta larval model system in investigating E. faecalis-induced sepsis and clarifies controversies in the field regarding the events leading to larval death following B. thuringiensis toxin exposure
Radio lobes and X-ray hot spots in the microquasar S26
We have studied the structure and energetics of the powerful
microquasar/shock-ionized nebula S26 in NGC 7793, with particular focus on its
radio and X-ray properties. Using the Australia Telescope Compact Array, we
have resolved for the first time the radio lobe structure and mapped the
spectral index of the radio cocoon. The steep spectral index of the radio lobes
is consistent with optically-thin synchrotron emission; outside the lobes, the
spectral index is flatter, suggesting an additional contribution from free-free
emission, and perhaps ongoing ejections near the core. The radio core is not
detected, while the X-ray core has a 0.3-8 keV luminosity ~6 x 10^{36} erg/s.
The size of the radio cocoon matches that seen in the optical emission lines
and diffuse soft X-ray emission. The total 5.5-GHz flux of cocoon and lobes is
~2.1 mJy, which at the assumed distance of 3.9 Mpc corresponds to about 3 times
the luminosity of Cas A. The total 9.0-GHz flux is ~1.6 mJy. The X-ray hot
spots (combined 0.3-8 keV luminosity ~2 x 10^{37} erg/s) are located ~20 pc
outwards of the radio hot spots (ie, downstream along the jet direction),
consistent with a different physical origin of X-ray and radio emission
(thermal-plasma and synchrotron, respectively). The total particle energy in
the bubble is ~10^{53} erg: from the observed radio flux, we estimate that only
about a few 10^{50} erg are stored in the relativistic electrons; the rest is
in protons, nuclei and non-relativistic electrons. The X-ray-emitting component
of the gas in the hot spots contains ~10^{51} erg, and ~10^{52} erg over the
whole cocoon. We suggest that S26 provides a clue to understand how the ambient
medium is heated by the mechanical power of a black hole near its Eddington
accretion rate.Comment: Accepted by MNRAS on 2010 July 12. Twelve pages, 8 figures, size =
1.3 MB. Contact the authors for higher-res figure
CPAP, weight loss, or both for obstructive sleep apnea
BACKGROUNd: Obesity and obstructive sleep apnea tend to coexist and are associated with inflammation, insulin resistance, dyslipidemia, and high blood pressure, but their causal relation to these abnormalities is unclear.
METHODS: We randomly assigned 181 patients with obesity, moderate-to-severe obstructive sleep apnea, and serum levels of C-reactive protein (CRP) greater than 1.0 mg per liter to receive treatment with continuous positive airway pressure (CPAP), a weight-loss intervention, or CPAP plus a weight-loss intervention for 24 weeks. We assessed the incremental effect of the combined interventions over each one alone on the CRP level (the primary end point), insulin sensitivity, lipid levels, and blood pressure.
RESULTS: Among the 146 participants for whom there were follow-up data, those assigned to weight loss only and those assigned to the combined interventions had reductions in CRP levels, insulin resistance, and serum triglyceride levels. None of these changes were observed in the group receiving CPAP alone. Blood pressure was reduced in all three groups. No significant incremental effect on CRP levels was found for the combined interventions as compared with either weight loss or CPAP alone. Reductions in insulin resistance and serum triglyceride levels were greater in the combined-intervention group than in the group receiving CPAP only, but there were no significant differences in these values between the combined-intervention group and the weight-loss group. In per-protocol analyses, which included 90 participants who met prespecified criteria for adherence, the combined interventions resulted in a larger reduction in systolic blood pressure and mean arterial pressure than did either CPAP or weight loss alone.
CONCLUSIONS: In adults with obesity and obstructive sleep apnea, CPAP combined with a weight-loss intervention did not reduce CRP levels more than either intervention alone. In secondary analyses, weight loss provided an incremental reduction in insulin resistance and serum triglyceride levels when combined with CPAP. In addition, adherence to a regimen of weight loss and CPAP may result in incremental reductions in blood pressure as compared with either intervention alone. (Funded by the National Heart, Lung, and Blood Institute; ClinicalTrials.gov number, NCT0371293 .)
Reference Array and Design Consideration for the next-generation Event Horizon Telescope
We describe the process to design, architect, and implement a transformative
enhancement of the Event Horizon Telescope (ngEHT). This program - the
next-generation Event Horizon Telescope (ngEHT) - will form a networked global
array of radio dishes capable of making high-fidelity real-time movies of
supermassive black holes (SMBH) and their emanating jets. This builds upon the
EHT principally by deploying additional modest-diameter dishes to optimized
geographic locations to enhance the current global mm/submm wavelength Very
Long Baseline Interferometric (VLBI) array, which has, to date, utilized mostly
pre-existing radio telescopes. The ngEHT program further focuses on observing
at three frequencies simultaneously for increased sensitivity and Fourier
spatial frequency coverage. Here, the concept, science goals, design
considerations, station siting and instrument prototyping are discussed, and a
preliminary reference array to be implemented in phases is described.Comment: Submitted to the journal Galaxie
Chatpal Chatbot dialogue data set
The scripts used in the ChatPal chatbot are freely available as an output from the ChatPal project. The datasets contain the chatbot utterances in English, Swedish, Finnish and Scottish Gaelic. Any replies collected from users through the ChatPal chatbot are not included in these data. Datasets are available in csv format and contain Unicode character encodings (UTF-8). Disclaimer: The datasets are open access, should be used appropriately and can be repurposed. However, the ChatPal project team are not responsible for how you chose to use the data or repurpose the content
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Jet-Launching Structure Resolved Near the Supermassive Black Hole in M87
Approximately 10% of active galactic nuclei exhibit relativistic jets, which are powered by the accretion of matter onto supermassive black holes. Although the measured width profiles of such jets on large scales agree with theories of magnetic collimation, the predicted structure on accretion disk scales at the jet launch point has not been detected. We report radio interferometry observations, at a wavelength of 1.3 millimeters, of the elliptical galaxy M87 that spatially resolve the base of the jet in this source. The derived size of 5.5 ± 0.4 Schwarzschild radii is significantly smaller than the innermost edge of a retrograde accretion disk, suggesting that the M87 jet is powered by an accretion disk in a prograde orbit around a spinning black hole
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