166 research outputs found
CMB Polarization Systematics, Cosmological Birefringence and the Gravitational Waves Background
Cosmic Microwave Background experiments must achieve very accurate
calibration of their polarization reference frame to avoid biasing the
cosmological parameters. In particular, a wrong or inaccurate calibration might
mimic the presence of a gravitational wave background, or a signal from
cosmological birefringence, a phenomenon characteristic of several
non-standard, symmetry breaking theories of electrodynamics that allow for
\textit{in vacuo} rotation if the polarization direction of the photon.
Noteworthly, several authors have claimed that the BOOMERanG 2003 (B2K)
published polarized power spectra of the CMB may hint at cosmological
birefringence. Such analyses, however, do not take into account the reported
calibration uncertainties of the BOOMERanG focal plane. We develop a formalism
to include this effect and apply it to the BOOMERanG dataset, finding a
cosmological rotation angle . We also
investigate the expected performances of future space borne experiment, finding
that an overall miscalibration larger then for Planck and
for EPIC, if not properly taken into account, will produce a bias on the
constraints on the cosmological parameters and could misleadingly suggest the
presence of a GW background.Comment: 10 pages, 3 figure
The first confirmed superoutburst of the dwarf nova GALEX J215818.5+241924
In 2011 October an optical transient was reported in Pegasus as a possible
nova. The object had an ultraviolet counterpart, GALEX J215818.5+241924. In
this paper we present follow-up photometry of the object which revealed the
presence of superhumps, with peak-to-peak amplitude of up to 0.22 magnitudes,
diagnostic of it being a member of the SU UMa family of dwarf novae. The
outburst amplitude was 4.6 magnitudes and it lasted at least 10 days, with a
maximum brightness of magnitude 14.3. We determined the mean superhump period
from our first 5 nights of observations as Psh = 0.06728(21) d. However
analysis of the O-C residuals showed a dramatic evolution in Psh during the
outburst. During the first part of the plateau phase the period increased with
dPsh/dt = +2.67(15) x 10-4. There was then an abrupt change following which the
period decreased with dPsh/dt = -2.08(9)x 10-4. We found a signal in the power
spectrum of the photometry which we tentatively interpret as the orbital signal
with Porb = 0.06606(35) d. Thus the superhump period excess was epsilon =
0.020(8), such value being consistent with other SU UMa systems of similar
orbital period.Comment: Accepted for publication in the Journal of the British Astronomical
Association. 10 pages, 3 figures. arXiv admin note: text overlap with
arXiv:1005.5378. Have corrected outburst amplitude, reworded the first 2
sentences of the Abstract for clarity and solved some typo
On the Electrical and Optical Features of the Plasma Coagulation Controller Low Temperature Atmospheric Plasma Jet
We report on the electrical and optical characterization of the Plasma Coagulation Controller (PCC) device, a low temperature atmospheric plasma source for biomedical applications. This device, designed for the study of plasma-induced blood coagulation, has been developed to operate flexibly in several operational conditions, since it is possible to vary the applied voltage V p and the pulse repetition rate f in a quite wide range ( V p range: 2–12 kV, f range: 1–40 kHz). Emission spectroscopy measurements were conducted by varying the line of sight along the axis of helium and neon plasma plumes. The increase of the Reactive Oxygen and Nitrogen Species (RONS) has been observed, as one moves from inside the gas pipe to the outside, as a consequence of the gas mixture with the surrounding air. Furthermore, high-speed photographs of the plasma jet were taken, showing that the plasma is not uniformly distributed in a continuous volumetric region, the plasma being concentrated in localized structures called Pulsed Atmospheric-pressure Plasma Streams (PAPS). The propagation velocities of these objects have been examined, noting that they are not related to the propagation of ion sound waves. Rather, we provide indications that the streamer propagation speed is proportional to the electron drift velocity
Long-Term Follow-Up In Paroxysmal Atrial Fibrillation Patients With Documented Isolated Trigger
AimsSupraventricular tachycardias may trigger atrial fibrillation (AF). The aim of the study was to evaluate the prevalence of supraventricular tachycardia (SVT) inducibility in patients referred for AF ablation and to evaluate the effects of SVT ablation on AF recurrences.Methods and results249 patients (mean age: 54 ± 14 years) referred for paroxysmal AF ablation were studied. In all patients, only AF relapses had been documented in the clinical history. 47 patients (19%; mean age: 42 ± 11 years) had inducible SVT during the electrophysiological study and underwent an ablation targeted only at SVT suppression. Ablation was successful in all 47 patients. The ablative procedures were: 11 slow-pathway ablations for atrioventricular nodal re-entrant tachycardia; 6 concealed accessory pathway ablations for atrioventricular re-entrant tachycardia; 17 focal ectopic atrial tachycardia ablations; 13 with only one arrhythmogenic pulmonary vein. No recurrences of SVT were observed during the follow-up (32 ± 18 months). 4 patients (8.5%) showed recurrence of at least one episode of AF. Patients with inducible SVT had less structural heart disease and were younger than those without inducible SVT.ConclusionA significant proportion of candidates for AF ablation are inducible for an SVT. SVT ablation showed a preventive effect on AF recurrences. Those patients should be selected for simpler ablation procedures tailored only to the triggering arrhythmia suppression
Lurasidone in adolescents and adults with schizophrenia: from clinical trials to real-world clinical practice
Introduction: Lurasidone is an atypical antipsychotic agent approved in the European Union for the treatment of schizophrenia in adults and adolescents (13-17 years). Clinical trials have shown a generally favorable balance between efficacy and tolerability. Areas covered: This paper provides a review and commentary regarding the use of lurasidone in adults and adolescents with schizophrenia. The available information about efficacy, tolerability, dosing, and switching is analyzed, highlighting the strategies that may be most useful in real-world clinical practice. Virtual case studies, designed based on the authors' clinical experience with real-world patients, are provided. Expert opinion: Lurasidone is efficacious in adolescents and adults in a wide range of symptoms of schizophrenia. Choosing the right dose for each patient and combining lurasidone with other medications is key to treatment success. Lurasidone has proven effective both in adolescents and adults in treating the acute phase of schizophrenia and reducing the risk of relapse. It has shown a relatively favorable tolerability profile, with minimal effects on metabolic parameters and prolactin levels
Primary Tumor Resection for Metastatic Colorectal, Gastric and Pancreatic Cancer Patients: In Search of Scientific Evidence to Inform Clinical Practice
The management of the primary tumor in metastatic colorectal, gastric and pancreatic cancer patients may be challenging. Indeed, primary tumor progression could be associated with severe symptoms, compromising the quality of life and the feasibility of effective systemic therapy, and might result in life-threatening complications. While retrospective series have suggested that surgery on the primary tumor may confer a survival advantage even in asymptomatic patients, randomized trials seem not to definitively support this hypothesis. We discuss the evidence for and against primary tumor resection for patients with metastatic gastrointestinal (colorectal, gastric and pancreatic) cancers treated with systemic therapies and put in context the pros and cons of the onco-surgical approach in the time of precision oncology. We also evaluate current ongoing trials on this topic, anticipating how these will influence both research and everyday practice
Images of the Early Universe from the BOOMERanG experiment
The CMB is the fundamental tool to study the properties of the early universe and of the
universe at large scales. In the framework of the Hot Big Bang model, when we look to
the CMB we look back in time to the end of the plasma era, at a redshift ~ 1000, when
the universe was ~ 50000 times younger, ~ 1000 times hotter and ~ 10^9 times denser
than today. The image of the CMB can be used to study the physical processes there, to
infer what happened before, and also to study the background geometry of our Universe
â„“-space spectroscopy of the Cosmic Microwave Background with the BOOMERanG experiment
The BOOMERanG experiment has recently produced detailed maps of the Cosmic Microwave Background, where sub-horizon structures are resolved with good signal to noise ratio. A power spectrum (spherical harmonics) analysis of the maps detects three peaks, at multipoles â„“ = (213_(-13)^(+10)),(541_(-32)^(+20))(845_(-25)^(+12)). In this paper we discuss the data analysis and the implications of these results for cosmology
Location of primary tumor and benefit from anti-epidermal growth factorreceptor monoclonalantibodies in patients with RAS and BRAF wild-typemetastatic colorectal cancer
Introduction. Right- and left-sided colorectal cancers (CRCs) differ in clinical and molecular characteristics. Some retrospective analyses suggested that patients with right-sided tumors derive less benefit from anti-epidermal growth factor receptor (EGFR) antibodies; however, molecular selection in those studies was not extensive. Patients and Methods. Patients with RAS and BRAF wild-type metastatic CRC (mCRC) who were treated with single-agent anti-EGFRs or with cetuximab-irinotecan (if refractory to previous irinotecan) were included in the study. Differences in outcome between patients with right- and left-sided tumors were investigated. Results. Of 75 patients, 14 and 61 had right- and left-sided tumors, respectively. None of the right-sided tumors responded according to RECIST, compared with 24 left-sided tumors (overall response rate: 0% vs. 41%; p 5 .0032), and only 2 patients with right-sided tumors (15%) versus 47 patients with left-sided tumors (80%) achieved disease control (p, .0001). The median duration of progression-free survival was 2.3 and 6.6 months in patients with right-sided and left-sided tumors, respectively (hazard ratio: 3.97;95%confidence interval: 2.09–7.53; p,.0001). Conclusion. Patients with right-sided RAS and BRAF wild-type mCRC seemed to derive no benefit from single-agent anti- EGFRs
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