(Uniform) convergence of twisted ergodic averages

a

First L-band Interferometric Observations of a Young Stellar Object: Probing the Circumstellar Environment of MWC 419

We present spatially-resolved K- and L-band spectra (at spectral resolution R = 230 and R = 60, respectively) of MWC 419, a Herbig Ae/Be star. The data were obtained simultaneously with a new configuration of the 85-m baseline Keck Interferometer. Our observations are sensitive to the radial distribution of temperature in the inner region of the disk of MWC 419. We fit the visibility data with both simple geometric and more physical disk models. The geometric models (uniform disk and Gaussian) show that the apparent size increases linearly with wavelength in the 2-4 microns wavelength region, suggesting that the disk is extended with a temperature gradient. A model having a power-law temperature gradient with radius simultaneously fits our interferometric measurements and the spectral energy distribution data from the literature. The slope of the power-law is close to that expected from an optically thick disk. Our spectrally dispersed interferometric measurements include the Br gamma emission line. The measured disk size at and around Br gamma suggests that emitting hydrogen gas is located inside (or within the inner regions) of the dust disk.Comment: Accepted for publication in Ap

A note on polynomially growing C-0-semigroups

We characterize polynomial growth of a $C_0$-semigroup in terms of the first power of the resolvent of its generator. We do this for a class of semigroups which includes $C_0$-semigroups on Hilbert spaces and analytic semigroups on Banach spaces. Furthermore, we characterize polynomial growth for discrete semigroups

Paraoxonase 2 overexpression inhibits tumor development in a mouse model of ovarian cancer.

Ovarian cancer (OC) is most lethal malignancy among all gynecological cancer. Large bodies of evidences suggest that mitochondrial-derived ROS play a critical role in the development and progression of OC. Paraoxonase 2 (PON2) is a membrane-associated lactonase with anti-oxidant properties. PON2 deficiency aggravates mitochondrial ROS formation, systemic inflammation, and atherosclerosis. The role of PON2 in cancer development remains unknown. In this report, in human, we identified that PON2 expression is higher in early stages (but not in late stages) of OC when compared to normal tissue. Using a mouse xenograft model of OC, we demonstrate that overexpression of PON2 prevents tumor formation. Mechanistically, PON2 decreases OC cell proliferation by inhibiting insulin like growth factor-1 (IGF-1) expression and signaling. Intriguingly, PON2 reduces c-Jun-mediated transcriptional activation of IGF-1 gene by decreasing mitochondrial superoxide generation. In addition, PON2 impairs insulin like growth factor-1 receptor (IGF-1R) signaling in OC cells by altering cholesterol homeostasis, which resulted in reduced caveolin-1/IGF-1R interaction and IGF-1R phosphorylation. Taken together, we report for the first time that PON2 acts as a tumor suppressor in the early stage of OC by reducing IGF-1 production and its signaling, indicating PON2 activation might be a fruitful strategy to inhibit early stage ovarian tumor

A contracting circumbinary molecular ring with an inner cavity of about 140 AU around Ori 139-409

Sensitive and subarcsecond resolution ($\sim$ 0.7\arcsec) CH$_3$OH(7$_{-2,6}$ $\to$ 6$_{-2,5}$) line and 890 $\mu$m continuum observations made with the Submillimeter Array (SMA) towards the hot molecular circumbinary ring associated with the young multiple star Ori 139-409 are presented. The CH$_3$OH(7$_{-2,6}$ - 6$_{-2,5}$) emission from the ring is well resolved at this angular resolution revealing an inner cavity with a size of about 140 AU. A LTE model of a Keplerian disk with an inner cavity of the same size confirms the presence of this cavity. Additionally, this model suggests that the circumbinary ring is contracting with a velocity of V$_{inf}$ $\sim$ 1.5 km s$^{-1}$ toward the binary central compact circumstellar disks reported at a wavelength of 7 mm. {\bf The inner central cavity seems to be formed by the tidal effects of the young stars in the middle of the ring.} The ring appears to be not a stationary object. Furthermore, the infall velocity we determine is about a factor of 3 slower than the free-fall velocity corresponding to the dynamical mass. This would correspond to a mass accretion rate of about 10$^{-5}$ M$_\odot$/yr. We found that the dust emission associated with Ori 139-409 appears to be arising from the circumstellar disks with no strong contribution from the molecular gas ring. A simple comparison with other classical molecular dusty rings (e.g. GG Tau, UZ Tau, and UY Aur) suggests that Ori 139-409 could be one of the youngest circumbinary rings reported up to date. Finally, our results confirm that the circumbinary rings are actively funneling fresh gas material to the central compact binary circumstellar disks, i.e. to the protostars in the very early phases of their evolution.Comment: Accepted by MNRA

Social influences, peer delinquency, and low self-control: An examination of time-varying and reciprocal effects on delinquency over adolescence

We examine an integrated dynamic model of social influences and internal controls on delinquency in adolescence. We assessed to what extent parental bonds, peer delinquency, and self-control were reciprocally related to delinquency throughout adolescence, and whether their effects were time varying. We applied cross-lagged panel models to analyze these relationships using three waves of data from a sample of Swiss youth at ages 13 to 17. Results suggest that self-control is a strong predictor for future delinquent behavior. Moreover, social influences affect self-control into adolescence, contributing to a growing area of research on the dynamic properties of self-control over the life course. Social influences, in particular peer delinquency, are also reciprocally related to delinquency, implying that delinquency can lead to cumulative disadvantages that further entrench individuals in antisocial pathways over the life course.</jats:p

Strong Near-Infrared Emission Interior to the Dust-Sublimation Radius of Young Stellar Objects MWC275 and AB Aur

Using the longest optical-interferometeric baselines currently available, we have detected strong near-infrared (NIR) emission from inside the dust-destruction radius of Herbig Ae stars MWC275 and AB Aur. Our sub-milli-arcsecond resolution observations unambiguously place the emission between the dust-destruction radius and the magnetospheric co-rotation radius. We argue that this new component corresponds to hot gas inside the dust-sublimation radius, confirming recent claims based on spectrally-resolved interferometry and dust evaporation front modeling.Comment: 12 pages, 4 figures, Accepted for publication in ApJ

Massive Protoplanetary Disks in the Trapezium Region

(abridged) We determine the disk mass distribution around 336 stars in the young Orion Nebula cluster by imaging a 2.5' x 2.5' region in 3 mm continuum emission with the Owens Valley Millimeter Array. For this sample of 336 stars, we observe 3 mm emission above the 3-sigma noise level toward ten sources, six of which have also been detected optically in silhouette against the bright nebular background. In addition, we detect 20 objects that do not correspond to known near-IR cluster members. Comparisons of our measured fluxes with longer wavelength observations enable rough separation of dust emission from thermal free-free emission, and we find substantial dust emission toward most objects. For the ten objects detected at both 3 mm and near-IR wavelengths, eight exhibit substantial dust emission. Excluding the high-mass stars and assuming a gas-to-dust ratio of 100, we estimate circumstellar masses ranging from 0.13 to 0.39 Msun. For the cluster members not detected at 3 mm, images of individual objects are stacked to constrain the mean 3 mm flux of the ensemble. The average flux is detected at the 3-sigma confidence level, and implies an average disk mass of 0.005 Msun, comparable to the minimum mass solar nebula. The percentage of stars in Orion surrounded by disks more massive than ~0.1 Msun is consistent with the disk mass distribution in Taurus, and we argue that massive disks in Orion do not appear to be truncated through close encounters with high-mass stars. Comparison of the average disk mass and number of massive dusty structures in Orion with similar surveys of the NGC 2024 and IC 348 clusters constrains the evolutionary timescales of massive circumstellar disks in clustered environments.Comment: 27 pages, including 7 figures. Accepted by Ap

A Novel HDL-Mimetic Peptide HM-10/10 Protects RPE and Photoreceptors in Murine Models of Retinal Degeneration.

Age-related macular degeneration (AMD) is a leading cause of blindness in the developed world. The retinal pigment epithelium (RPE) is a critical site of pathology in AMD. Oxidative stress plays a key role in the development of AMD. We generated a chimeric high-density lipoprotein (HDL), mimetic peptide named HM-10/10, with anti-oxidant properties and investigated its potential for the treatment of retinal disease using cell culture and animal models of RPE and photoreceptor (PR) degeneration. Treatment with HM-10/10 peptide prevented human fetal RPE cell death caused by tert-Butyl hydroperoxide (tBH)-induced oxidative stress and sodium iodate (NaIO3), which causes RPE atrophy and is a model of geographic atrophy in mice. We also show that HM-10/10 peptide ameliorated photoreceptor cell death and significantly improved retinal function in a mouse model of N-methyl-N-nitrosourea (MNU)-induced PR degeneration. Our results demonstrate that HM-10/10 protects RPE and retina from oxidant injury and can serve as a potential therapeutic agent for the treatment of retinal degeneration

On Phase Transition of NH4H2PO4NH_{4}H_{2}PO_{4}-Type Crystals by Cluster Variation Method

The Cluster Variation Method (CVM) is applied to the Ishibashi model for ammonium dihydrogen phosphate ($\rm NH_{4}H_{2}PO_{4}$) of a typical hydrogen bonded anti-ferroelectric crystal. The staggered and the uniform susceptibility without hysteresis are calculated at equilibrium. On the other hand, by making use of the natural iteration method (NIM) for the CVM, hysteresis phenomena of uniform susceptibility versus temperature observed in experiments is well explained on the basis of local minimum in Landau type variational free energy. The polarization $P$ curves against the uniform field is also calculated.Comment: 14 pages, 10 figure