Exploring the connection between radio and GeV-TeV gamma-ray emission in the 1FHL and 2FHL AGN samples

The Fermi Large Area Telescope (LAT) revealed that blazars, representing the most extreme radio-loud active galactic nuclei (AGN) population, dominate the census of the gamma-ray sky, and a significant correlation was found between radio and gamma-ray emission in the 0.1-100 GeV energy range. However, the possible connection between radio and very high energy (VHE, E>0.1 TeV) emission still remains elusive, owing to the lack of a homogeneous coverage of the VHE sky. The main goal of this work is to quantify and assess the significance of a possible connection between the radio emission on parsec scale measured by the very long baseline interferometry (VLBI) and GeV-TeV gamma-ray emission in blazars, which is a central issue for understanding the blazar physics and the emission processes. We investigate the radio VLBI and high energy gamma-ray emission by using two large and unbiased AGN samples extracted from the first and second Fermi-LAT catalogs of hard gamma-ray sources detected above 10 GeV (1FHL) and 50 GeV (2FHL). For comparison, we perform the same correlation analysis by using the 0.1-300 GeV gamma-ray energy flux provided by the third Fermi-LAT source catalog. We find that the correlation strength and significance depend on the gamma-ray energy range with a different behavior among the blazar sub-classes. Overall, the radio and gamma-ray emission above 10 GeV turns out to be uncorrelated for the full samples and for all of the blazar sub-classes with the exception of high synchrotron peaked (HSP) objects, which show a strong and significant correlation. On the contrary, when 0.1-300 GeV gamma-ray energies are considered, a strong and significant correlation is found for the full blazar sample as well as for all of the blazar sub-classes. We interpret and explain this correlation behavior within the framework of the blazar spectral energy distribution properties.Comment: 8 pages, 6 figures, 3 tables. Accepted for publication in Astronomy and Astrophysic

On the radio and GeV-TeV gamma-ray emission connection in Fermi blazars

The Fermi-LAT revealed that the census of the gamma-ray sky is dominated by blazars. Looking for a possible connection between radio and gamma-ray emission is a central issue for understanding the blazar physics, and various works were dedicated to this topic. However, while a strong and significant correlation was found between radio and gamma-ray emission in the 0.1-100 GeV energy range, the connection between radio and very high energy (VHE, E>0.1 TeV) emission is still elusive. The main reason is the lack of a homogeneous VHE sky coverage, due to the operational mode of the imaging atmospheric Cherenkov telescopes. With the present work we aim to quantify and assess the significance of the possible connection between high-resolution radio emission, on milliarcsecond scale, and GeV-TeV gamma-ray emission in blazars. For achieving our goal we extract two large and unbiased blazar samples from the 1FHL and 2FHL Fermi catalogs, above 10 GeV and 50 GeV, respectively. To investigate how the correlation evolves as the gamma-ray energy increases, we perform the same analysis by using the 0.1-300 GeV 3FGL gamma-ray energy fluxes. When we consider the 0.1-300 GeV gamma-ray energy range, we find a strong and significant correlation for all of the blazar sub-classes. Conversely, when we consider the gamma-ray emission above 10 GeV the correlation with the radio emission vanishes, with the exception of the blazar sub-class of high synchrotron peaked objects.Comment: 6 pages, 2 figures, 1 table. For the proceedings of the 7th International Fermi Symposiu

The connection between radio and high energy emission in black hole powered systems in the SKA era

Strong evidence exists for a highly significant correlation between the radio flux density and gamma-ray energy flux in blazars revealed by Fermi. However, there are central issues that need to be clarified in this field: what are the counterparts of the about 30% of gamma-ray sources that are as yet unidentified? Are they just blazars in disguise or they are something more exotic, possibly associated with dark matter? How would they fit in the radio-gamma ray connection studied so far? With their superb sensitivity, SKA1-MID and SKA1-SUR will help to resolve all of these questions. Even more, while the radio-MeV/GeV connection has been firmly established, a radio-VHE connection has been entirely elusive so far. The advent of CTA in the next few years and the expected CTA-SKA1 synergy will offer the chance to explore this connection, even more intriguing as it involves the opposite ends of the electromagnetic spectrum and the acceleration of particles up to the highest energies. We are already preparing to address these questions by exploiting data from the various SKA pathfinders and precursors. We have obtained 18 cm European VLBI Network observations of E>10 GeV sources, with a detection rate of 83%. Moreover, we are cross correlating the Fermi catalogs with the MWA commissioning survey: when faint gamma-ray sources are considered, pure positional coincidence is not significant enough for selecting counterparts and we need an additional physical criterion to pinpoint the right object. It can be radio spectral index, variability, polarization, or compactness, needing high angular resolution in SKA1-MID; timing studies can also reveal pulsars, which are often found from dedicated searches of unidentified gamma-ray sources. SKA will be the ideal instrument for investigating these characteristics in conjunction with CTA. (abridged)Comment: 12 pages, to be published in the proceedings of "Advancing Astrophysics with the Square Kilometre Array", PoS(AASKA14)15

Prophylactic salpingectomy in premenopausal low-risk women for ovarian cancer: Primum non nocere

Abstract Objective The objective of this study is to compare ovarian function and surgical outcomes between patients affected by benign uterine pathologies submitted to total laparoscopic hysterectomy (TLH) plus salpingectomy and women in which standard TLH with adnexal preservation was performed. Methods We retrospectively compared data of 79 patients who underwent TLH plus bilateral salpingectomy (group A), with those of 79 women treated by standard TLH without adnexectomy (sTLH) (group B). Ovarian reserve modification, expressed as the difference between 3months post-operative and pre-operative values of Anti-Mullerian Hormone (AMH), Follicle Stimulating Hormone (FSH), Antral Follicle Count (AFC), mean ovarian diameters and Peak Systolic Velocity (PSV), was recorded for each patient. For each surgical procedure, operative time, variation of hemoglobin level (ΔHb), postoperative hospital stay, postoperative return to normal activity, and complication rate were recorded as secondary outcomes. Results According to our post-hoc analysis , this equivalence study resulted to have a statistical power of 96.8%. Significant difference was not observed between groups with respect to ΔAMH ( p = 0.35 ), ΔFSH ( p = 0.15 ), ΔAFC ( p = 0.09 ), Δ mean ovarian diameters ( p = 0.57 ) and ΔPSV ( p = 0.61 ). In addition, secondary outcomes such as operative time ( p = 0.79 ), ΔHb ( p = 0.41 ), postoperative hospital stay ( p = 0.16 ), postoperative return to normal activity ( p = 0.11 ) and complication rate also did not show any significant difference. Conclusions The addition of bilateral salpingectomy to TLH for prevention of ovarian cancer in women who do not carry a BRCA1/2 mutations do not show negative effects on the ovarian function. In addition, no perioperative complications are related to the salpingectomy step in TLH

Parsec scale polarization properties of the TeV blazar Markarian 421

In this work we present a polarization analysis at radio frequencies of Markarian 421, one of the closest (z=0.03) TeV blazars. The observations were obtained, both in total and in polarized intensity, with the Very Long Baseline Array (VLBA) at 15, 24, and 43 GHz throughout 2011, with one observation per month (for a total of twelve epochs). We investigate the magnetic field topology and the polarization structure on parsec scale and their evolution with time. We detect polarized emission both in the core and in the jet region, and it varies with frequency, location and time. In the core region we measure a mean fractional polarization of about 1-2%, with a peak of about 4% in March at 43 GHz; the polarization angle is almost stable at 43 GHz, but it shows significant variability in the range 114-173 deg at 15 GHz. In the jet region the polarization properties show a more stable behavior; the fractional polarization is about 16% and the polarization angle is nearly perpendicular to the jet axis. The higher EVPA variability observed at 15 GHz is due both to a variable Faraday rotation effect and to opacity. The residual variability observed in the intrinsic polarization angle, together with the low degree of polarization in the core region, could be explained with the presence of a blend of variable cross-polarized subcomponents within the beam.Comment: 6 pages, 4 figures, proceedings of the 12th European VLBI Network Symposium and Users Meeting (7-10 October 2014, Cagliari, Italy

A parsec-scale wobbling jet in the high-synchrotron peaked blazar PG 1553+113

Context. The detection of quasi-periodic variability in active galactic nuclei in general, and in blazars in particular, is key to our understanding of the origin and nature of these objects as well as their cosmological evolution. PG 1553+113 is the first blazar showing an approximately two-year quasi-periodic pattern in its γ-ray light curve, which is also revealed at optical frequencies. Aims: Such quasi-periodicity might have a geometrical origin, possibly related to the precessing nature of the jet, or could be intrinsic to the source and related to pulsational accretion flow instabilities. In this work we investigate and characterise the high-resolution radio emission properties of PG 1553+113 on parsec scales in order to differentiate between these different physical scenarios. Methods: We monitored the source with the very long baseline array (VLBA) at 15, 24, and 43 GHz during an entire cycle of γ-ray activity in the period 2015-2017, with a cadence of about 2 months, both in total and polarised intensity. We constrained the jet position angle across the different observing epochs by investigating the total intensity ridge lines. Results: We find a core-dominated source with a limb-brightened jet structure extending for ∼1.5 mas in the northeast direction whose position angle varies in time in the range ∼40°-60°. No clear periodic pattern can be recognized in the VLBA light curves during 2015-2017 or in the 15 GHz Owens Valley Radio Observatory light curve during the period 2008-2018. The core region polarisation percentage varies in the range ∼1-4%, and the polarisation angle varies from being roughly parallel to roughly transverse to the jet axis. We estimate a rotation measure value in the core region of ∼-1.0 ± 0.4 × 104 rad m-2. The brightness temperature (TB) is found to decrease as the frequency increases with an intrinsic value of ∼1.5 × 1010 K and the estimated Doppler factor is ∼1.4. Conclusions: Although the jet wobbling motion indicates that geometrical effects can produce an enhanced emission through the Doppler boosting modulation, additional mechanisms are required in order to account for the quasi-periodic variability patterns observed in γ rays. The intrinsic TB value indicates that the total energy in the core region is dominated by the magnetic field

A real-life study of daratumumab-bortezomib-dexamethasone (D-VD) in lenalidomide exposed/refractory multiple myeloma patients: a report from the Triveneto Myeloma Working Group

Treatment of lenalidomide refractory (Len-R) multiple myeloma (MM) patients still represents an unmet clinical need. In the last years, daratumumab-bortezomib-dexamethasone (D-VD) combination was extensively used in this setting, even though only a small fraction of Len-R patients was included in the pivotal trial. This real-life study aimed to evaluate the efficacy and safety of the D-VD regimen in a cohort that exclusively enrolled Len exposed or refractory MM patients. The study cohort included 57 patients affected by relapsed/refractory MM. All patients were previously exposed to Len, with 77.2% being refractory. The overall response rate (ORR) was 79.6% with 43% of cases obtaining at least a very good partial response (VGPR). The D-VD regimen showed a favorable safety profile, with low frequency of grade 3–4 adverse events, except for thrombocytopenia observed in 21.4% of patients. With a median follow-up of 13 months, median progression-free survival (PFS) was 17 months. No significant PFS differences were observed according to age, ISS, LDH levels, type of relapse, and high-risk FISH. Len exposed patients displayed a PFS advantage as compared to Len refractory patients (29 vs 16 months, p = 0.2876). Similarly, patients treated after Len maintenance showed a better outcome as compared to patients who had received a full-dose Len treatment (23 vs 13 months, p = 0.1728). In conclusion, our real-world data on D-VD combination showed remarkable efficacy in Len-R patients, placing this regimen as one of the standards of care to be properly taken into account in this MM setting

A Methodological Review of the Articles Publishes in Georgia Educational Researcher from 2003-2010

Methodological reviews, reviews that concentrate on research methods rather than research outcomes, have been used in a variety of fields to improve research practice, inform debate, and identify islands of practice. In this article, we report on the results of a methodological review of all of the articles published in Georgia Educational Researcher from 2003-2010. We examined the methodological characteristics, authorial characteristics, and methodological quality of those articles using quantitative content analysis. The major findings were that (a) the proportions of the type and traditions of articles published in Georgia Educational Researcher were similar to the proportions in education research articles in general, (b) case study research and correlational research were most prominent, (c) a few universities accounted for most of the articles published, (d) male and female authors’ articles were published in equitable proportions, and (e) there were no statistically significant differences in methodological quality between genders, university affiliations, types of research, or years of publication. We end with a few suggestions for improving the quality of qualitative research articles in the Georgia Educational Researcher