No Evidence for [O III] Variability in Mrk 142

Using archival data from the 2008 Lick AGN Monitoring Project, Zhang & Feng (2016) claimed to find evidence for flux variations in the narrow [O III] emission of the Seyfert 1 galaxy Mrk 142 over a two-month time span. If correct, this would imply a surprisingly compact size for the narrow-line region. We show that the claimed [O III] variations are merely the result of random errors in the overall flux calibration of the spectra. The data do not provide any support for the hypothesis that the [O III] flux was variable during the 2008 monitoring period.Comment: Response to Zhang & Feng 2016, MNRAS Letters, 457, L64 (arXiv:1512.07673). Accepted for publication in MNRAS Letters. 5 pages, 2 figure

Unambiguous interpretation of atomically resolved force microscopy images of an insulator

The (111) surface of CaF 2 was imaged with dynamic mode scanning force microscopy and modeled using atomistic simulation. Both experiment and theory showed a clear triangular contrast pattern in images, and theory demonstrated that the contrast pattern is due to the interaction of a positive electrostatic potential tip with fluorine ions in the two topmost surface layers. We find a good agreement of position and relative height of scan line features between theory and experiment and thus establish for the first time an unambiguous identification of sublattices of an insulator imaged by force microscopy

Carbon isotope fractionation during aerobic biodegradation of trichloroethene by Burkholderia cepacia G4: a tool to map degradation mechanisms

The strain Burkholderia cepacia G4 aerobically mineralized trichloroethene (TCE) to CO2 over a time period of similar to20 h. Three biodegradation experiments were conducted with different bacterial optical densities at 540 nm (OD(540)s) in order to test whether isotope fractionation was consistent. The resulting TCE degradation was 93, 83.8, and 57.2% (i.e., 7.0, 16.2, and 42.8% TCE remaining) at OD(540)s of 2.0, 1.1, and 0.6, respectively. ODs also correlated linearly with zero-order degradation rates (1.99, 1.11, and 0.64 mumol h(-1)). While initial nonequilibrium mass losses of TCE produced only minor carbon isotope shifts (expressed in per mille delta C- 13(VPDB)), they were 57.2, 39.6, and 17.0parts per thousand between the initial and final TCE levels for the three experiments, in decreasing order of their OD(540)s. Despite these strong isotope shifts, we found a largely uniform isotope fractionation. The latter is expressed with a Rayleigh enrichment factor, E, and was -18.2 when all experiments were grouped to a common point of 42.8% TCE remaining. Although, decreases of epsilon to -20.7 were observed near complete degradation, our enrichment factors were significantly more negative than those reported for anaerobic dehalogenation of TCE. This indicates typical isotope fractionation for specific enzymatic mechanisms that can help to differentiate between degradation pathways

Model for Cumulative Solar Heavy Ion Energy and Linear Energy Transfer Spectra

A probabilistic model of cumulative solar heavy ion energy and LET spectra is developed for spacecraft design applications. Spectra are given as a function of confidence level, mission time period during solar maximum and shielding thickness. It is shown that long-term solar heavy ion fluxes exceed galactic cosmic ray fluxes during solar maximum for shielding levels of interest. Cumulative solar heavy ion fluences should therefore be accounted for in single event effects rate calculations and in the planning of space missions

Obesity Prevalence and Dietary Intake of Antioxidants in Native American Adolescents

Antioxidants are well known for possessing anti-inflammatory properties, which can reduce the risk of chronic disease and obesity. However, very little research has been done to examine antioxidant intake among adolescent minority populations such as Native American adolescents. Our study examined the significance of antioxidant intake among Native American adolescents at an urban residential high school in Southern California. Our study population consisted of 183 male and female Native American adolescents, 14-18 years of age, representing 43 tribes from across the United States. Students' primary source of meals was provided by the school food service. Based on the BMI calculations, the rate of obesity within our population was 38% for males and 40% for females, more than two-fold the national rate indicated by NHANESIII data. We used the Harvard School of Public Health Youth/Adolescent Questionnaire (HSPH YAQ), a semi-quantitative food frequency questionnaire, to examine antioxidant nutrient intake and evaluate the differences in the intake between normal and obese weight students. Statistical analysis of the results showed that intakes of vitamins C, E, and lycopene were the antioxidant nutrients found to be significantly different between normal and obese weight students and intakes of these nutrients were found to be higher among normal weight students (p-values = 0.02451, 0.00847, and 0.04928, respectively). These results suggest that dietary intake of antioxidants could be increased among Native American adolescents. Further research is needed to confirm our findings and identify effective ways for school food service to incorporate antioxidant rich foods into school menus

Evidence for a Supermassive Black Hole in the S0 Galaxy NGC 3245

The S0 galaxy NGC 3245 contains a circumnuclear disk of ionized gas and dust with a radius of 1.1" (110 pc), making it an ideal target for dynamical studies with the Hubble Space Telescope (HST). We have obtained spectra of the nuclear disk with the Space Telescope Imaging Spectrograph, using a 0.2" wide slit at five parallel positions. Measurements of the Hα and [N II] emission lines are used to map out the kinematic structure of the disk in unprecedented detail. The data reveal a rotational velocity field with a steep velocity gradient across the innermost 0.4". We construct dynamical models for a thin gas disk in circular rotation, using HST optical images to map out the gravitational potential due to stars. Our modeling code includes the blurring due to the telescope point-spread function and the nonzero slit width, as well as the instrumental shift in measured wavelength for light entering the slit off-center, so as to simulate the data as closely as possible. The Hα+[N II] surface brightness measured from an HST narrowband image is folded into the models, and we demonstrate that many of the apparent small-scale irregularities in the observed velocity curves are the result of the patchy distribution of emission-line surface brightness. Over most of the disk, the models are able to fit the observed radial velocity curves closely, although there are localized regions within the disk that appear to be kinematically disturbed relative to the overall rotational pattern. The velocity dispersion of [N II] λ6584 rises from σ~50 km/s in the outer disk to ~160 km/s at the nucleus, and most of this line width cannot be attributed to rotational or instrumental broadening. To account for the possible dynamical effect of the intrinsic velocity dispersion in the gas, we also calculate models that include a correction for asymmetric drift. This correction increases the derived black hole mass by 12% but leads to slightly poorer fits to the data. A central dark mass of (2.1+/-0.5)×10^8 Msolar is required for the models to reproduce the steep central velocity gradient. This value for the central mass is consistent with recently discovered correlations between black hole mass and bulge velocity dispersion.Peer reviewe

ID-based user-centric data usage auditing scheme for distributed environments

Recent years have witnessed the trend of increasingly relying on remote and distributed infrastructures, mainly owned and managed by third parties. This increased the number of reported incidents of security breaches compromising users' personal data, where involved entities may massively collect and process massive amounts of such data. Toward these challenges, this paper combines hierarchical Identity Based Cryptographic (IBC) mechanisms with emerging blockchain technologies and introduces a blockchain-based data usage auditing architecture ensuring availability and accountability in a personal data-preserving fashion. The proposed approach relies on smart auditable contracts deployed in blockchain infrastructures. Thus, it offers transparent and controlled data access, sharing and processing, so that unauthorized entities cannot process data without data subjects' consent. Moreover, thanks to the usage of hierarchical ID-based encryption and signature schemes, the proposed solution protects and ensures the confidentiality of users' personal data shared with multiple data controllers and processors. It also provides auditing capacities with tamper-proof evidences for data usage compliance, supported by the intrinsic properties of the blockchain technology

Usefulness of fair valuation of biological assets for cash flow prediction

This study develops an empirical analysis of the relevance of accounting information when biological assets are measured at fair value. We use an international sample of firms with biological assets.We find that biological assets influence unpredictability when they are measured at historical cost (HC). In this case, the ability of accounting data to predict future cash flows diminishes as the proportion of biological assets on total assets increases. The valuation at fair value (FV) switches this negative influence of biological assets to a positive one. We find that when they are measured at FV, the prediction accuracy of future cash flows improves as the ratio of biological assets to total assets increases. This evidence is robust to differentmeasures of prediction accuracy, as well as to the improvement of accounting standards, regardless of FV, over time. The evidence is weaker for bearer plants