Photo-reverberation mapping of a protoplanetary accretion disk around a T Tauri star

This is the final version. Available from the American Astronomical Society via the DOI in this recordTheoretical models and spectroscopic observations of newborn stars suggest that protoplantary disks have an inner "wall" at a distance set by the disk interaction with the star. Around T Tauri stars, the size of this disk hole is expected to be on a 0.1 au scale that is unresolved by current adaptive optics imaging, though some model-dependent constraints have been obtained by near-infrared interferometry. Here we report the first measurement of the inner disk wall around a solar-mass young stellar object, YLW 16B in the ρ Ophiuchi star-forming region, by detecting the light-travel time of the variable radiation from the stellar surface to the disk. Consistent time lags were detected on two nights, when the time series in H (1.6 μm) and K (2.2 μm) bands were synchronized while the 4.5 μm emission lagged by 74.5 ± 3.2 s. Considering the nearly edge-on geometry of the disk, the inner rim should be 0.084 au from the protostar on average, with an error of order 0.01 au. This size is likely larger than the range of magnetospheric truncations and consistent with an optically and geometrically thick disk front at the dust sublimation radius at ∼1500 K. The widths of the cross-correlation functions between the data in different wavebands place possible new constraints on the geometry of the disk.National Science Foundation (NSF

Alkylation of the Tumor Suppressor PTEN Activates Akt and β-Catenin Signaling: A Mechanism Linking Inflammation and Oxidative Stress with Cancer

PTEN, a phosphoinositide-3-phosphatase, serves dual roles as a tumor suppressor and regulator of cellular anabolic/catabolic metabolism. Adaptation of a redox-sensitive cysteinyl thiol in PTEN for signal transduction by hydrogen peroxide may have superimposed a vulnerability to other mediators of oxidative stress and inflammation, especially reactive carbonyl species, which are commonly occurring by-products of arachidonic acid peroxidation. Using MCF7 and HEK-293 cells, we report that several reactive aldehydes and ketones, e.g. electrophilic α,β-enals (acrolein, 4-hydroxy-2-nonenal) and α,β-enones (prostaglandin A2, Δ12-prostaglandin J2 and 15-deoxy-Δ-12,14-prostaglandin J2) covalently modify and inactivate cellular PTEN, with ensuing activation of PKB/Akt kinase; phosphorylation of Akt substrates; increased cell proliferation; and increased nuclear β-catenin signaling. Alkylation of PTEN by α,β-enals/enones and interference with its restraint of cellular PKB/Akt signaling may accentuate hyperplastic and neoplastic disorders associated with chronic inflammation, oxidative stress, or aging

Pancreatitis after percutaneous ethanol injection into HCC: a minireview of the literature

Deaths after percutaneous ethanol injection (PEI) into hepatocellular carcinoma (HCC) may occur within a few hours to a few days following the procedure because of hemoperitoneum and haemorrhage from oesophageal varices or hepatic insufficiency. Pancreatitis has been recently reported as a rare lethal complication of intra-arterial PEI, another modality for treating HCCs. In this minireview, we analyze the literature concerning the development of acute pancreatitis after PEI. Pathogenesis of pancreatitis from opioids and ethanol is also addressed. Treatment with opioids to reduce the patient's abdominal pain after PEI in combination with the PEI itself may lead to direct toxic effects, thus favouring the development of pancreatitis

When Do Stalled Stars Resume Spinning Down? Advancing Gyrochronology with Ruprecht 147

This is the final version. Available on open access from IOP Publishing via the DOI in this recordRecent measurements of rotation periods () in the benchmark open clusters Praesepe (670 Myr), NGC 6811 (1 Gyr), and NGC 752 (1.4 Gyr) demonstrate that, after converging onto a tight sequence of slowly rotating stars in mass-period space, stars temporarily stop spinning down. These data also show that the duration of this epoch of stalled spin-down increases toward lower masses. To determine when stalled stars resume spinning down, we use data from the K2 mission and the Palomar Transient Factory to measure for 58 dwarf members of the 2.7 Gyr old cluster Ruprecht 147, 39 of which satisfy our criteria designed to remove short-period or near-equal-mass binaries. Combined with the Kepler data for the approximately coeval cluster NGC 6819 (30 stars with M ∗ > 0.85, our new measurements more than double the number of ≈2.5 Gyr benchmark rotators and extend this sample down to ≈0.55. The slowly rotating sequence for this joint sample appears relatively flat (22 ± 2 days) compared to sequences for younger clusters. This sequence also intersects the Kepler intermediate-period gap, demonstrating that this gap was not created by a lull in star formation. We calculate the time at which stars resume spinning down and find that 0.55 stars remain stalled for at least 1.3 Gyr. To accurately age-date low-mass stars in the field, gyrochronology formulae must be modified to account for this stalling timescale. Empirically tuning a core-envelope coupling model with open cluster data can account for most of the apparent stalling effect. However, alternative explanations, e.g., a temporary reduction in the magnetic braking torque, cannot yet be ruled out.National Science Foundation (NSF)European Union Horizon 2020NASADunlap FellowshipDanish National Research FoundationPennsylvania State UniversityEberly College of Scienc

Severity of Depression, Anxious Distress and the Risk of Cardiovascular Disease in a Swedish Population-Based Cohort.

Background: Depression is known to be associated with cardiovascular diseases (CVD). This population-based cohort study aimed to determine the association between depression of varying severity and risk for CVD and to study the effect of concomitant anxious distress on this association. Methods: We utilized data from a longitudinal cohort study of mental health, work and relations among adults (20–64 years), with a total of 10,443 individuals. Depression and anxious distress were assessed using psychiatric rating scales and defined according to DSM-5. Outcomes were register-based and self-reported cardiovascular diseases. Findings: Overall increased odds ratios of 1.5 to 2.6 were seen for the different severity levels of depression, with the highest adjusted OR for moderate depression (OR 2.1 (95% CI 1.3, 3.5). Similar odds ratios were seen for sub-groups of CVD: ischemic/hypertensive heart disease and stroke, 2.4 (95% CI 1.4, 3.9) and OR 2.1 (95%CI 1.2, 3.8) respectively. Depression with anxious distress as a specifier of severity showed OR of 2.1 (95% CI 1.5, 2.9) for CVD. Conclusion: This study found that severity level of depression seems to be of significance for increased risk of CVD among depressed persons, although not in a dose-response manner which might be obscured due to treatment of depression. Further, we found a higher risk of CVD among depressed individuals with symptoms of anxious distress

c-Rel Deficiency Increases Caspase-4 Expression and Leads to ER Stress and Necrosis in EBV-Transformed Cells

LMP1-mediated activation of nuclear factor of kappaB (NF-κB) is critical for the ligand independent proliferation and cell survival of in vitro EBV-transformed lymphoblastoid cell lines (LCLs). Previous experiments revealed that a majority of LMP1-dependent responses are regulated by NF-κB. However, the extent that individual NF-κB family members are required for these responses, in particular, c-Rel, whose expression is restricted to mature hematopoietic cells, remains unclear. Here we report that low c-Rel expression in LCLs derived from a patient with hyper-IgM syndrome (Pt1), resulted in defects in proliferation and cell survival. In contrast to studies that associated loss of NF-κB with increased apoptosis, Pt1 LCLs failed to initiate apoptosis and alternatively underwent autophagy and necrotic cell death. Whereas the proliferation defect appeared linked to a c-Rel-associated decrease in c-myc expression, identified pro-survival and pro-apoptotic targets were expressed at or near control levels consistent with the absence of apoptosis. Ultrastructural examination of Pt1 LCLs revealed a high level of cellular and ER stress that was further supported by gene expression profiling showing the upregulation of several genes involved in stress and inflammation. Apoptosis-independent cell death was accompanied by increased expression of the inflammatory marker, caspase-4. Using gene overexpression and siRNA knockdown we demonstrated that levels of c-Rel directly modulated expression of caspase-4 as well as other ER stress genes. Overall, these findings reveal the importance of c-Rel in maintaining LCL viability and that decreased expression results in ER stress and a default response leading to necrotic cell death