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Quasiperiodic eruptions (QPEs) are high-amplitude, soft X-ray bursts recurring every few hours, associated with supermassive black holes. Many interpretations for QPEs were proposed since their recent discovery in 2019, including extreme mass ratio inspirals and accretion disk instabilities. But, as of today, their nature still remains debated. We perform the first high-resolution X-ray spectral study of a QPE source using the Reflection Grating Spectrometers' gratings on board XMM-Newton, leveraging nearly 2 Ms of exposure on GSN 069, the first discovered source of this class. We resolve several absorption and emission lines including a strong line pair near the N vii rest-frame energy, resembling the P-Cygni profile. We apply photoionization spectral models and identify the absorption lines as an outflow blueshifted by 1700−2900 km s−1, with a column density of about 1022 cm−2 and an ionization parameter log(ξ /erg cm s−1) of 3.9−4.6. The emission lines are instead redshifted by up to 2900 km s−1, and likely originate from the same outflow that imprints the absorption features, and covers the full 4π sky from the point of view of GSN 069. The column density and ionization are comparable to the outflows detected in some tidal disruption events, but this outflow is significantly faster and has a strong emission component. The outflow is more highly ionized when the system is in the phase during which QPEs are present, and from the limits, we derive on its location, we conclude that the outflow is connected to the recent complex, transient activity of GSN 069, which began around 2010.

In the past two decades, high-amplitude electromagnetic outbursts have been detected from dormant galaxies and often attributed to the tidal disruption of a star by the central black hole 1 , 2 . X-ray emission from the Seyfert 2 galaxy GSN 069 (2MASX J01190869-3411305) at a redshift of z  = 0.018 was first detected in July 2010 and implies an X-ray brightening by a factor of more than 240 over ROSAT observations performed 16 years earlier 3 , 4 . The emission has smoothly decayed over time since 2010, possibly indicating a long-lived tidal disruption event 5 . The X-ray spectrum is ultra-soft and can be described by accretion disk emission with luminosity proportional to the fourth power of the disk temperature during long-term evolution. Here we report observations of quasi-periodic X-ray eruptions from the nucleus of GSN 069 over the course of 54 days, from December 2018 onwards. During these eruptions, the X-ray count rate increases by up to two orders of magnitude with an event duration of just over an hour and a recurrence time of about nine hours. These eruptions are associated with fast spectral transitions between a cold and a warm phase in the accretion flow around a low-mass black hole (of approximately 4 × 10 5  solar masses) with peak X-ray luminosity of about 5 × 10 42  erg per second. The warm phase has kT (where T is the temperature and k is the Boltzmann constant) of about 120 electronvolts, reminiscent of the typical soft-X-ray excess, an almost universal thermal-like feature in the X-ray spectra of luminous active nuclei 6 – 8 . If the observed properties are not unique to GSN 069, and assuming standard scaling of timescales with black hole mass and accretion properties, typical active galactic nuclei with higher-mass black holes can be expected to exhibit high-amplitude optical to X-ray variability on timescales as short as months or years 9 . Galaxy GSN 069 has unprecedented eruptions of X-ray light every nine hours, which indicate fast transitions between cold and warm states and may shed light on black hole accretion.

Past X-ray observations of the nearby Seyfert 2 MCG-03-58-007 revealed the presence of a powerful and highly variable disk wind, where two possible phases outflowing with v out1/c ∼ −0.07 and v out2/c ∼ −0.2 were observed. Multi-epoch X-ray observations, covering the period from 2010 to 2018, showed that the lower-velocity component is persistent, as it was detected in all the observations, while the faster phase outflowing with v out2/c ∼ −0.2 appeared to be more sporadic. Here we present the analysis of a new monitoring campaign of MCG-03-58-007 performed in 2019 May–June and consisting of four simultaneous XMM-Newton and NuSTAR observations. We confirm that the disk wind in MCG-03-58-007 is persistent, as it is detected in all the observations, and powerful, having a kinetic power that ranges between 0.5% and 10% of the Eddington luminosity. The highly ionized wind (log(ξ/erg cm s−1) ∼ 5) is variable in both the opacity and, remarkably in its velocity. This is the first time where we have observed a substantial variability of the outflowing velocity in a disk wind, which dropped from v out/c ∼ −0.2 (as measured in the first three observations) to v out/c ∼ −0.074 in just 16 days. We conclude that such a dramatic and fast variability of the outflowing velocity could be due to the acceleration of the wind, as recently proposed by Mizumoto et al. Here, the faster wind, seen in the first three observations, is already accelerated to v out/c ∼ −0.2, while in the last observation our line of sight intercepts only the slower, pre-accelerated streamline.

We present O − C (“observed minus calculated”) timing analysis of the quasiperiodic eruption (QPE) source eRO-QPE2 with a multimission X-ray campaign including 32 observed eruptions spanning a month (i.e., 325 cycles). For disk instability models, the O − C is consistent with a damped random walk of the recurrence, albeit with highly uncertain parameters. For models with an underlying orbital clock, we infer a period of P ∼ 2.24 hr and two hierarchical superperiodic modulations with periods of ∼4.4 days (∼47 P) and ≈95 days (≈1000 P). We found no negative period derivative, with ∣Ṗ∣≲2×10−6 s s−1 at 3σ. This limits gravitational-wave decay disfavoring high-eccentricity white dwarfs and high-mass/eccentricity intermediate-mass black holes. For disk-collision models, where the Ṗ from gas drag and the QPE integrated energy bound the local disk density, a main-sequence star is disfavored as extreme mass-ratio inspiral (EMRI) secondary unless debris streams are present. The correlated odd/even O − C disfavors both disk crossings per orbit being observed. Interpreting the data with one observed event per orbit, the short modulation is consistent with apsidal precession for a ∼ 140 Rg, e ≈ 0.1, and MBH ≈ 1.5 × 105 M⊙. The longer modulation (much less constrained) is inconsistent with EMRI nodal precession, and disk precession is allowed in a limited parameter volume, while a hierarchical triple with an outer black hole at ∼0.4 mpc and mass ∼(0.1–1) × MBH is viable. However, more robust EMRI trajectory models yield no reliable solution, possibly due to narrow likelihood peaks in a high-dimensional space with sparse data.

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Instagram and WhatsApp are two social media and networking services introduced in 2010. They are currently subsidiaries of Facebook, Inc., California, USA. Using evidence from the published literature and case reports indexed in PubMed and other sources, we present an overview of the various applications of Instagram and WhatsApp in health and healthcare. We also briefly describe the main issues surrounding the uses of these two apps in health and medicine.

Introduction. Severe acquired brain injury (sABI) is considered the most common cause of death and disability worldwide. sABI patients are supported by their caregivers who often exhibit high rates of psychological distress, mood disorders, and changes in relationship dynamics and family roles. Objectives. To explore lifestyle changes of caregivers of sABI patients during the postacute rehabilitation, by investigating possible differences between primary and secondary caregivers. Primary caregivers spend most of the time with the patient, providing daily care and taking most responsibility for the day-to-day decisions, while secondary caregivers are those who provide additional support. Methods. Three hundred forty-seven caregivers of sABI patients were asked to fill in an unpublished self-report questionnaire to explore their possible lifestyles changes. Results. A statistically significant difference was found between primary and secondary caregivers in time spent in informal caregiving (p<0.001). The primary caregivers reduced all leisure activities compared to secondary carers (p<0.05). Conclusions. By comparing the percentage of leisure activities performed by caregivers before and after the patient’s sABI onset, all caregivers showed high percentages of changes in lifestyle and habits, even though primary caregivers reported more negative lifestyle changes than secondary caregivers. Further studies are needed to investigate needs and burden experienced by caregivers of sABI patients during the postacute rehabilitation phase, also in relation to the patients’ outcome, to address support interventions for them and improve their quality of life.

Abstract Objectives To describe the h-index as a measure of scientific output. Methods The formula for this index is based on (1) the number of papers published by an author and (2) the number of citations per paper. The h-index can be used to evaluate performance by individuals or by groups of scientists working in university departments or research institutes. Results While the h-index is both objective and quantitative, it has some deficiencies. It does not take into account first or last author publications, numbers of coauthors, or self-citations. Numerous alternative indices have been proposed to better reflect scientists’ contributions in their fields. Conclusions Pathologists and clinical laboratory scientists should be familiar with the h-index, as it may be used in decisions about professional advancement.

To describe the h-index as a measure of scientific output. The formula for this index is based on (1) the number of papers published by an author and (2) the number of citations per paper. The h-index can be used to evaluate performance by individuals or by groups of scientists working in university departments or research institutes. While the h-index is both objective and quantitative, it has some deficiencies. It does not take into account first or last author publications, numbers of coauthors, or self-citations. Numerous alternative indices have been proposed to better reflect scientists' contributions in their fields. Pathologists and clinical laboratory scientists should be familiar with the h-index, as it may be used in decisions about professional advancement.