The connection between the radio jet and the gamma-ray emission in the radio galaxy 3C 120

We present the analysis of the radio jet evolution of the radio galaxy 3C 120 during a period of prolonged gamma-ray activity detected by the Fermi satellite between December 2012 and October 2014. We find a clear connection between the gamma-ray and radio emission, such that every period of gamma-ray activity is accompanied by the flaring of the mm-VLBI core and subsequent ejection of a new superluminal component. However, not all ejections of components are associated with gamma-ray events detectable by Fermi. Clear gamma-ray detections are obtained only when components are moving in a direction closer to our line of sight.This suggests that the observed gamma-ray emission depends not only on the interaction of moving components with the mm-VLBI core, but also on their orientation with respect to the observer. Timing of the gamma-ray detections and ejection of superluminal components locate the gamma-ray production to within almost 0.13 pc from the mm-VLBI core, which was previously estimated to lie about 0.24 pc from the central black hole. This corresponds to about twice the estimated extension of the broad line region, limiting the external photon field and therefore suggesting synchrotron self Compton as the most probable mechanism for the production of the gamma-ray emission. Alternatively, the interaction of components with the jet sheath can provide the necessary photon field to produced the observed gamma-rays by Compton scattering.Comment: Already accepted for publication in The Astrophysical Journa

Evaluation of a CTA-based convolutional neural network for infarct volume prediction in anterior cerebral circulation ischaemic stroke

Background Computed tomography angiography (CTA) imaging is needed in current guideline-based stroke diagnosis, and infarct core size is one factor in guiding treatment decisions. We studied the efficacy of a convolutional neural network (CNN) in final infarct volume prediction from CTA and compared the results to a CT perfusion (CTP)-based commercially available software (RAPID, iSchemaView). Methods We retrospectively selected 83 consecutive stroke cases treated with thrombolytic therapy or receiving supportive care that presented to Helsinki University Hospital between January 2018 and July 2019. We compared CNN-derived ischaemic lesion volumes to final infarct volumes that were manually segmented from follow-up CT and to CTP-RAPID ischaemic core volumes. Results An overall correlation of r = 0.83 was found between CNN outputs and final infarct volumes. The strongest correlation was found in a subgroup of patients that presented more than 9 h of symptom onset (r = 0.90). A good correlation was found between the CNN outputs and CTP-RAPID ischaemic core volumes (r = 0.89) and the CNN was able to classify patients for thrombolytic therapy or supportive care with a 1.00 sensitivity and 0.94 specificity. Conclusions A CTA-based CNN software can provide good infarct core volume estimates as observed in follow-up imaging studies. CNN-derived infarct volumes had a good correlation to CTP-RAPID ischaemic core volumes.Peer reviewe

As a Matter of Factions: The Budgetary Implications of Shifting Factional Control in Japan’s LDP

For 38 years, the Liberal Democratic Party (LDP) maintained single-party control over the Japanese government. This lack of partisan turnover in government has frustrated attempts to explain Japanese government policy changes using political variables. In this paper, we look for intraparty changes that may have led to changes in Japanese budgetary policy. Using a simple model of agenda-setting, we hypothesize that changes in which intraparty factions “control” the LDP affect the party’s decisions over spending priorities systematically. This runs contrary to the received wisdom in the voluminous literature on LDP factions, which asserts that factions, whatever their raison d’être, do not exhibit different policy preferences. We find that strong correlations do exist between which factions comprise the agenda-setting party “mainstream” and how the government allocates spending across pork-barrel and public goods items

On the nature of an ejection event in the jet of 3C111

We present a possible scenario for the ejection of a superluminal component in the jet of the Broad Line Radio Galaxy 3C111 in early 1996. VLBI observations at 15 GHz discovered the presence of two jet features on scales smaller than one parsec. The first component evolves downstream, whereas the second one fades out after 1 parsec. We propose the injection of a perturbation of dense material followed by a decrease in the injection rate of material in the jet as a plausible explanation. This scenario is supported by 1D relativistic hydrodynamics and emission simulations. The perturbation is modeled as an increase in the jet density, without modifying the original Lorentz factor in the initial conditions. We show that an increase of the Lorentz factor in the material of the perturbation fails to reproduce the observed evolution of this flare. We are able to estimate the lifetime of the ejection event in 3C111 to be 36\pm7 days.Comment: Accepted for publication in Astronomy & Astrophysics Letter

Physical parameters of a relativistic jet at very high redshift: the case of the blazar J1430+4204

Context. The high-redshift (z = 4.72) blazar J1430+4204 produced a major radio outburst in 2005. Such outbursts are usually associated with the emergence of a new component in the inner radio jet. Aims. We searched for possible changes in the radio structure on milli-arcsecond angular scales, to determine physical parameters that characterise the relativistic jet ejected from the centre of this source. Methods. We analysed 15-GHz radio interferometric images obtained with the Very Long Baseline Array (VLBA) before and after the peak of the outburst. Results. We did not identify any significant new jet component over a period of 569 days. We estimated the Doppler factor, the Lorentz factor, and the apparent transverse speed of a putative jet component using three different methods. The likely small jet angle to the line of sight and our values of the apparent transverse speed are consistent with not detecting a new jet feature.Comment: (6 pages, 4 figures) accepted for publication in Astronomy and Astrophysic

Multiwavelength observations of the blazar BL Lacertae: a new fast TeV γ-ray flare

Proceedings of the 35th International Cosmic Ray Conference (ICRC 2017), Busan (South Korea). Published in Proceeding of Science.Observations of fast TeV γ-ray flares from blazars reveal the extreme compactness of emitting regions in blazar jets. Combined with very-long-baseline radio interferometry measurements, they probe the structure and emission mechanism of the jet. We report on a fast TeV γ-ray flare from BL Lacertae observed by VERITAS, with a rise time of about 2.3 hours and a decay time of about 36 minutes. The peak flux at >200 GeV measured with the 4-minute binned light curve is (4.2±0.6)×10−6photonsm−2s−1, or ∼180% the Crab Nebula flux. Variability in GeV γ-ray, X-ray, and optical flux, as well as in optical and radio polarization was observed around the time of the TeV γ-ray flare. A possible superluminal knot was identified in the VLBA observations at 43 GHz. The flare constrains the size of the emitting region, and is consistent with several theoretical models with stationary shocks

Longitudinal perspective on cryptocurrency trading and increased gambling problems : a 3 wave national survey study

Objectives: Cryptocurrency trading has gained popularity over the last few years. Trading is facilitated by online platforms that enable 24/7 trading. Cryptocurrency trading is potentially attractive to gamblers, and it may increase their gambling problems. Furthermore, cryptocurrency trading might be a particularly harmful activity for those gambling offshore. We investigated whether cryptocurrency trading predicts excessive gambling over time. We also analyzed how cryptocurrency trading combined with offshore gambling is associated with excessive gambling. Study design: This was a population-based longitudinal survey study. Methods: We surveyed a sample of Finnish people aged 18–75 years (N = 1022, 51.27% male) at three time points in 6-month intervals: April 2021 (T1), October to November 2021 (T2), and April to May 2022 (T3). Of the original T1 respondents, 66.80% took part in T2 and T3. Outcome measure was excessive gambling using the Problem Gambling Severity Index, and the predictor was cryptocurrency trading. We adjusted models for onshore and offshore gambling online, excessive gaming (Internet Gaming Disorder Test), excessive internet use (Compulsive Internet Use Scale), excessive alcohol use (Alcohol Use Disorders Identification Test), and sociodemographic background factors. We used multilevel regression models to investigate within-person and between-person effects. Results: Cryptocurrency trading has increased in popularity over time. Within-person changes in cryptocurrency trading predicted increased excessive gambling. Excessive gambling was also generally more common among cryptocurrency traders. The full model that was adjusted for the number of confounding factors showed that cryptocurrency trading had a within-person effect on excessive gambling. Of the confounding factors, offshore online gambling, excessive gaming, and excessive internet use had within-person effects on excessive gambling. Offshore and onshore online gamblers and excessive gamers showed more excessive gambling than others. Those participants who were both cryptocurrency traders and offshore gamblers showed significantly higher rate of excessive gambling than others. Conclusions: Cryptocurrency trading is a risky activity and associated with a higher rate of excessive gambling over time. Such activity is especially risky among offshore online gamblers, who could view cryptocurrency trading as another form of gambling or as a way to make money for gambling. Policymakers and counselors should be aware of the risks of cryptocurrency trading.publishedVersionPeer reviewe

MOJAVE: monitoring of jets in active galactic nuclei with VLBA experiments. V. Multi-epoch VLBA images

We present images from a long-term program (MOJAVE: Monitoring of Jets in active galactic nuclei (AGNs) with VLBA Experiments) to survey the structure and evolution of parsec-scale jet phenomena associated with bright radio-loud active galaxies in the northern sky. The observations consist of 2424 15 GHz Very Long Baseline Array (VLBA) images of a complete flux-density-limited sample of 135 AGNs above declination –20°, spanning the period 1994 August to 2007 September. These data were acquired as part of the MOJAVE and 2 cm Survey programs, and from the VLBA archive. The sample-selection criteria are based on multi-epoch parsec-scale (VLBA) flux density, and heavily favor highly variable and compact blazars. The sample includes nearly all the most prominent blazars in the northern sky, and is well suited for statistical analysis and comparison with studies at other wavelengths. Our multi-epoch and stacked-epoch images show 94% of the sample to have apparent one-sided jet morphologies, most likely due to the effects of relativistic beaming. Of the remaining sources, five have two-sided parsec-scale jets, and three are effectively unresolved by the VLBA at 15 GHz, with essentially all of the flux density contained within a few tenths of a milliarcsecond

Small Is Beautiful: Why Profundaplasty Should Not Be Forgotten

Background: Surgical profundaplasty (SP)is used mainly as an adjunct to endovascular management of peripheral vascular disease (PAD) today. Results from earlier series of profundaplasty alone have been controversial, especially regarding its hemodynamic effect. The question is: Can profundaplasty alone still be useful? Our aim was to evaluate its role in the modern management of vascular patients. Methods: This was a retrospective outcome study. A consecutive series of 97 patients (106 legs) from January 2000 through December 2003 were included. In 55 (52%) legs, the superficial femoral artery was occluded. These patients were included in the current analysis. Of these patients 14 (25%) were female. Mean age was 71 ((11) years. Nineteen (35%) were diabetic. The indication for operation was claudication in 29 (53%), critical leg ischemia (CLI) in 26 (47%), either with rest pain in 17 (31%), or ulcer/gangrene in 9 (16%). Endarterectomy with patch angioplasty with bovine pericardium was performed in all cases. Mean follow-up was 33(14 months. Mean preoperative ankle brachial index (ABI) was 0.6. Sustained clinical efficacy was defined as upward shift of 1 or greater on the Rutherford scale without repeat target limb revascularization (TLR) or amputation. Mortality, morbidity, need for TLR, or amputation were separate endpoints. Results: Postoperatively, ABI was significantly improved (mean=0.7), in 24 (44%) by more than 0.15. At three years, cumulative clinical success rate was 80%. Overall, patients with claudication had a better outcome than those with CLI (p=0.04). Two (4%) major amputations and 2 (4%) minor ones were performed, all in patients with CLI. None of the 9 (16%) ulcers healed. Conclusion: Profundaplasty is still a valuable option for patients with femoral PAD and claudication without tissue loss. It is a straightforward procedure that combines good efficacy with low complication rates. Further endovascular treatment may be facilitated. It is not useful for patients with the combination of critical ischemia and tissue los