243 research outputs found
Networks : On the relation of bi- and multivariate measures
Date of Acceptance: 28/04/2015 Acknowledgement The article processing charge was funded by the German Research Foundation (DFG) and the Albert Ludwigs University Freiburg in the funding programme Open Access PublishingPeer reviewedPublisher PD
Assessing the strength of directed influences among neural signals : An approach to noisy data
Acknowledgements This work was supported by the German Science Foundation (Ti315/4-2), the German Federal Ministry of Education and Research (BMBF grant 01GQ0420), and the Excellence Initiative of the German Federal and State Governments. B.S. is indebted to the Kosterlitz Centre for the financial support of this research project.Peer reviewedPreprin
Distinguishing Direct from Indirect Interactions in Oscillatory Networks with Multiple Time Scales
Peer reviewedPublisher PD
General practitioners' approaches to prostate-specific antigen testing in the north-east of the Netherlands
BACKGROUND: There is wide variation in clinical practice for the early detection of prostate cancer, not least because of the ongoing debate about the benefits of prostate-specific antigen (PSA) testing. In this study, we aimed to assess the approaches, attitudes, and knowledge of general practitioners (GPs) regarding PSA testing in primary care in the Netherlands, particularly regarding recommendations for prostate cancer. METHODS: Questionnaire surveys were sent to 179 GPs in the north-east of the Netherlands, of which 65 (36%) were completed and returned. We also surveyed 23 GPs attending a postgraduate train-the-trainer day (100%). In addition to demographic data and practice characteristics, the 31-item questionnaire covered the attitudes, clinical practice, adherence to PSA screening recommendations, and knowledge concerning the recommendations for prostate cancer early detection. Statistical analysis was limited to the descriptive level. RESULTS: Most GPs (95%; n = 82) stated that they had at least read the Dutch GP guideline, but just half (50%; n = 43) also stated that they knew the content. Almost half (46%; n = 39) stated they would offer detailed counseling before ordering a PSA test to an asymptomatic man requesting a test. Overall, prostate cancer screening was reported to be of minor importance compared to other types of cancer screening. CONCLUSIONS: Clinical PSA testing in primary care in this region of the Netherlands seems generally to be consistent with the relevant guideline for Dutch GPs that is restrictive to PSA testing. The next step will be to further evaluate the effects of the several PSA testing strategies
PG 1211+143: probing high frequency lags in a high mass AGN
We present the timing analysis of the four archived XMM-Newton observations
of PG 1211+143. The source is well-known for its spectral complexity,
comprising a strong soft-excess and different absorption systems. Soft energy
band (0.3-0.7 keV) lags are detected over all the four observations, in the
frequency range \nu \lsim 6 \times 10^{-4} Hz, where hard lags, similar to
those observed in black hole X-ray binaries, are usually detected in smaller
mass AGN. The lag magnitude is energy-dependent, showing two distinct trends
apparently connectable to the two flux levels at which the source is observed.
The results are discussed in the context of disk- and/or corona-reprocessing
scenarios, and of disk wind models. Similarities with the high-frequency
negative lag of 1H 0707-495 are highlighted, and, if confirmed, they would
support the hypothesis that the lag in PG 1211+143 represents the signature of
the same underlying mechanism, whose temporal characteristics scale with the
mass of the central object.Comment: 6 pages, 6 figures, accepted for publication in MNRAS Letter
Discovery of a relation between black hole mass and soft X-ray time lags in active galactic nuclei
We carried out a systematic analysis of time lags between X-ray energy bands
in a large sample (32 sources) of unabsorbed, radio quiet active galactic
nuclei (AGN), observed by XMM-Newton. The analysis of X-ray lags (up to the
highest/shortest frequencies/time-scales), is performed in the
Fourier-frequency domain, between energy bands where the soft excess (soft
band) and the primary power law (hard band) dominate the emission. We report a
total of 15 out of 32 sources displaying a high frequency soft lag in their
light curves. All 15 are at a significance level exceeding 97 per cent and 11
are at a level exceeding 99 per cent. Of these soft lags, 7 have not been
previously reported in the literature, thus this work significantly increases
the number of known sources with a soft/negative lag. The characteristic
time-scales of the soft/negative lag are relatively short (with typical
frequencies and amplitudes of \nu\sim 0.07-4 \times 10^{-3} Hz and \tau\sim
10-600 s, respectively), and show a highly significant (\gsim 4\sigma)
correlation with the black hole mass. The measured correlations indicate that
soft lags are systematically shifted to lower frequencies and higher absolute
amplitudes as the mass of the source increases. To first approximation, all the
sources in the sample are consistent with having similar mass-scaled lag
properties. These results strongly suggest the existence of a mass-scaling law
for the soft/negative lag, that holds for AGN spanning a large range of masses
(about 2.5 orders of magnitude), thus supporting the idea that soft lags
originate in the innermost regions of AGN and are powerful tools for testing
their physics and geometry.Comment: 12 pages, 6 figures. Revised version, accepted for publication in
MNRA
Impact of the SARS-CoV-2 pandemic on the survival of patients with high-grade glioma and best practice recommendations
X-ray Reverberation close to the black hole in RE J1034+396
In previous work, we discussed the detection of reverberation delays in the
NLS1 1H0707-495. The delays originate close to the black hole. Here, we show
that RE J1034+396 shows very similar lag properties. At low frequencies (< 1
\times 10-4 Hz), the time lag between energy bands increases with energy
separation, similar to that commonly seen in Galactic black holes and other
AGN. At higher frequencies (~ 3.5 \times 10-4 Hz), the soft (< 1 keV) and hard
(> 3 keV) bands lag behind the intermediate band (1-3 keV). The simplest
interpretation is that the intermediate band is dominated by the direct
power-law continuum, while the soft and hard bands are dominated by the
relativistically-smeared reflected emission. The low frequency delays are
present in both available observations. The high frequency lags are only seen
in one observation. In the observation where high frequency reverberation
delays are observed, the spectrum contains a power-law component and there is a
QPO in the light curve. In the other observation, no power-law component is
required and no QPO is seen. The lags originate a few gravitational radii from
the black hole, and the QPO is associated with the power-law emitting corona.Comment: Accepted for publication in MNRA
Influence of bacterial lectins on some reactions of nonspecific immunity in sarcoma 37 transplanted mice
The aim of this paper is to study preventive effect of cytotoxic lectin from Bacillus subtilis B-7025 on the tumor growth and nonspecific immunity in sarcoma 37 transplanted mice
Effect of Early Surgery vs Endoscopy-First Approach on Pain in Patients With Chronic Pancreatitis The ESCAPE Randomized Clinical Trial:The ESCAPE Randomized Clinical Trial
IMPORTANCE For patients with painful chronic pancreatitis, surgical treatment is postponed until medical and endoscopic treatment have failed. Observational studies have suggested that earlier surgery could mitigate disease progression, providing better pain control and preserving pancreatic function. OBJECTIVE To determine whether early surgery is more effective than the endoscopy-first approach in terms of clinical outcomes. DESIGN, SETTING, AND PARTICIPANTS The ESCAPE trial was an unblinded, multicenter, randomized clinical superiority trial involving 30 Dutch hospitals participating in the Dutch Pancreatitis Study Group. From April 2011 until September 2016, a total of 88 patients with chronic pancreatitis, a dilated main pancreatic duct, and who only recently started using prescribed opioids for severe pain (strong opioids for INTERVENTIONS There were 44 patients randomized to the early surgery group who underwent pancreatic drainage surgery within 6 weeks after randomization and 44 patients randomized to the endoscopy-first approach group who underwent medical treatment, endoscopy including lithotripsy if needed, and surgery if needed. MAIN OUTCOMES AND MEASURES The primary outcome was pain, measured on the Izbicki pain score and integrated over 18 months (range, 0-100 [increasing score indicates more pain severity]). Secondary outcomes were pain relief at the end of follow-up; number of interventions, complications, hospital admissions; pancreatic function; quality of life (measured on the 36-Item Short Form Health Survey [SF-36]); and mortality. RESULTS Among 88 patients who were randomized (mean age, 52 years; 21 (24%) women), 85 (97%) completed the trial. During 18 months of follow-up, patients in the early surgery group had a lower Izbicki pain score than patients in the group randomized to receive the endoscopy-first approach group (37 vs 49; between-group difference, -12 points [95% CI, -22 to -2]; P = .02). Complete or partial pain relief at end of follow-up was achieved in 23 of 40 patients (58%) in the early surgery vs 16 of 41 (39%)in the endoscopy-first approach group (P = .10). The total number of interventions was lower in the early surgery group (median, 1 vs 3; P <.001). Treatment complications (27% vs 25%), mortality (0% vs 0%), hospital admissions, pancreatic function, and quality of life were not significantly different between early surgery and the endoscopy-first approach. CONCLUSIONS AND RELEVANCE Among patients with chronic pancreatitis, early surgery compared with an endoscopy-first approach resulted in lower pain scores when integrated over 18 months. However, further research is needed to assess persistence of differences over time and to replicate the study findings
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