Context. According to traditional gas-phase chemical models, O 2 should be abundant in molecular clouds, but until recently, attempts to detect interstellar O 2 line emission with ground-and space-based observatories have failed. Aims. Following the multi-line detections of O 2 with low abundances in the Orion and ρ Oph A molecular clouds with Herschel, it is important to investigate other environments, and we here quantify the O 2 abundance near a solar-mass protostar. Methods. Observations of molecular oxygen, O 2 , at 487 GHz toward a deeply embedded low-mass Class 0 protostar, NGC 1333-IRAS 4A, are presented, using the Heterodyne Instrument for the Far Infrared (HIFI) on the Herschel Space Observatory. Complementary data of the chemically related NO and CO molecules are obtained as well. The high spectral resolution data are analysed using radiative transfer models to infer column densities and abundances, and are tested directly against full gas-grain chemical models. Results. The deep HIFI spectrum fails to show O 2 at the velocity of the dense protostellar envelope, implying one of the lowest abundance upper limits of O 2 /H 2 at ≤6 × 10 −9 (3σ). The O 2 /CO abundance ratio is less than 0.005. However, a tentative (4.5σ) detection of O 2 is seen at the velocity of the surrounding NGC 1333 molecular cloud, shifted by 1 km s −1 relative to the protostar. For the protostellar envelope, pure gas-phase models and gas-grain chemical models require a long pre-collapse phase (∼0.7-1 × 10 6 years), during which atomic and molecular oxygen are frozen out onto dust grains and fully converted to H 2 O, to avoid overproduction of O 2 in the dense envelope. The same model also reproduces the limits on the chemically related NO molecule if hydrogenation of NO on the grains to more complex molecules such as NH 2 OH, found in recent laboratory experiments, is included. The tentative detection of O 2 in the surrounding cloud is consistent with a low-density PDR model with small changes in reaction rates. Conclusions. The low O 2 abundance in the collapsing envelope around a low-mass protostar suggests that the gas and ice entering protoplanetary disks is very poor in O 2 .

We present Herschel-HIFI, SPIRE, and PACS 50-670 µm imaging and spectroscopy of six FU Orionis-type objects and candidates (FU Orionis, V1735 Cyg, V1515 Cyg, V1057 Cyg, V1331 Cyg, and HBC 722), ranging in outburst date from 1936-2010, from the "FOOSH" (FU Orionis Objects Surveyed with Herschel) program, as well as ancillary results from Spitzer-IRS and the Caltech Submillimeter Observatory. In their system properties (L bol , T bol , line emission), we find that FUors are in a variety of evolutionary states. Additionally, some FUors have features of both Class I and II sources: warm continuum consistent with Class II sources, but rotational line emission typical of Class I, far higher than Class II sources of similar mass/luminosity. Combining several classification techniques, we find an evolutionary sequence consistent with previous mid-IR indicators. We detect [O I] in every source at luminosities consistent with Class 0/I protostars, much greater than in Class II disks. We detect transitions of 13 CO (J up of 5 to 8) around two sources (V1735 Cyg and HBC 722) but attribute them to nearby protostars. Of the remaining sources, three (FU Ori, V1515 Cyg, and V1331 Cyg) exhibit only low-lying CO, but one (V1057 Cyg) shows CO up to J = 23 → 22 and evidence for H 2 O and OH emission, at strengths typical of protostars rather than T Tauri stars. Rotational temperatures for "cool" CO components range from 20-81 K, for ∼ 10 50 total CO molecules. We detect [C I] and [N II] primarily as diffuse emission.

Endometrial cancer is the most common gynecological cancer in the United States. We wanted to identify epigenetic aberrations involving microRNAs (miRNAs), whose genes become hypermethylated in endometrial primary tumors. By integrating known miRNA sequences from the miRNA database (miRBase) with DNA methylation data from methyl-CpG-capture sequencing, we identified 111 differentially methylated regions (DMRs) associated with CpG islands (CGIs) and miRNAs. Among them, 22 DMRs related to 29 miRNAs and within 8 kb of CGIs were hypermethylated in endometrial tumors but not in normal endometrium. miR-137 was further validated in additional endometrial primary tumors. Hypermethylation of miR-137 was found in both endometrioid and serous endometrial cancer (P < 0.01), and it led to the loss of miR-137 expression. Treating hypermethylated endometrial cancer cells with epigenetic inhibitors reactivated miR-137. Moreover, genetic overexpression of miR-137 suppressed cancer cell proliferation and colony formation in vitro. When transfected cancer cells were implanted into nude mice, the cells that overexpressed miR-137 grew more slowly and formed smaller tumors (P < 0.05) than vector transfectants. Histologically, xenograft tumors from cancer cells expressing miR-137 were less proliferative (P < 0.05), partly due to inhibition of EZH2 and LSD1 expression (P < 0.01) in both the transfected cancer cells and tumors. Reporter assays indicated that miR-137 targets EZH2 and LSD1. These results suggest that miR-137 is a tumor suppressor that is repressed in endometrial cancer because the promoter of its gene becomes hypermethylated.

We analyze the submillimeter emission surrounding the new FU Orionis-type object, HBC 722. We present the first epoch of observations of the active environs of HBC 722, with imaging and spectroscopy from PACS, SPIRE, and HIFI aboard the Herschel Space Observatory, as well as CO J= 2-1 and 350 µm imaging (SHARC-II) with the Caltech Submillimeter Observatory. The primary source of submillimeter continuum emission in the region -2MASS 20581767+4353310 -is located 16 ′′ south-southeast of the optical flaring source while the optical and near-IR emission is dominated by HBC 722. A bipolar outflow extends over HBC 722; the most likely driver is the submillimeter source. We detect warm

We report observations of molecular oxygen (O 2 ) rotational transitions at 487 GHz, 774 GHz, and 1121 GHz toward Orion Peak A. The O 2 lines at 487 GHz and 774 GHz are detected at velocities of 10-12 km s −1 with line widths ∼3 km s −1 ; however, the transition at 1121 GHz is not detected. The observed line characteristics, combined with the results of earlier observations, suggest that the region responsible for the O 2 emission is 9 (6 × 10 16 cm) in size, and is located close to the H 2 Peak 1 position (where vibrationally excited H 2 emission peaks), and not at Peak A, 23 away. The peak O 2 column density is 1.1 × 10 18 cm −2 . The line velocity is close to that of the 621 GHz water maser emission found in this portion of the Orion Molecular Cloud, and having a shock with velocity vector lying nearly in the plane of the sky is consistent with producing maximum maser gain along the line of sight. The enhanced O 2 abundance compared to that generally found in dense interstellar clouds can be explained by passage of a low-velocity C shock through a clump with preshock density 2 × 10 4 cm −3 , if a reasonable flux of UV radiation is present. The postshock O 2 can explain the emission from the source if its line-of-sight dimension is 10 times larger than its size on the plane of the sky. The special geometry and conditions required may explain why O 2 emission has not been detected in the cores of other massive star-forming molecular clouds.