950 research outputs found
From non-Brownian Functionals to a Fractional Schr\"odinger Equation
We derive backward and forward fractional Schr\"odinger type of equations for
the distribution of functionals of the path of a particle undergoing anomalous
diffusion. Fractional substantial derivatives introduced by Friedrich and
co-workers [PRL {\bf 96}, 230601 (2006)] provide the correct fractional
framework for the problem at hand. In the limit of normal diffusion we recover
the Feynman-Kac treatment of Brownian functionals. For applications, we
calculate the distribution of occupation times in half space and show how
statistics of anomalous functionals is related to weak ergodicity breaking.Comment: 5 page
XMM-Newton Spectroscopy of the Starburst Dominated Ultra Luminous Infrared Galaxy NGC 6240
We present new XMM-Newton observation of the Ultra Luminous Infrared Galaxy
(ULIRG) NGC 6240. We analyze the reflecting grating spectrometer (RGS) data,
and data from the other instruments, and find a starburst dominated 0.5-3 keV
spectrum with global properties resembling those observed in M82 but with a
much higher luminosity. We show that the starburst region can be divided into
an outer zone, beyond a radius of about 2.1 kpc, with a gas temperature of
about 10^7 K and a central region with temperatures in the range (2-6) x 10^7
K. The gas in the outer region emits most of the observed Oviii Lyman-alpha
line and the gas in the inner region the emission lines of higher ionization
ions, including a strong Fexxv line. We also identify a small inner part, very
close to the active nuclei, with typical Seyfert 2 properties including a large
amount of photoionized gas producing a strong Fe K-alpha 6.4 keV line. The
combined abundance, temperature and emission measure analysis indicates super
solar Ne/O, Mg/O, Si/O, S/O and possibly also Fe/O. The analysis suggests
densities in the range of (0.07-0.28) x epsilon^(-1/2) cm^(-3) and a total
thermal gas mass of about 4 x 10^8 x epsilon^(1/2) solar masses, where epsilon
is the volume filling factor. We used a simple model to argue that a massive
starburst with an age of about 2 x 10^7 years can explain most of the observed
properties of the source. NGC 6240 is perhaps the clearest case of an X-ray
bright luminous AGN, in a merger, whose soft X-ray spectrum is dominated by a
powerful starburst.Comment: 10 pages, 6 diagrams, accepted by ApJ, added a few minor change
Contamination of the environment by pathogenic bacteria in a livestock farm in Limpopo Province, South Africa
The aim of this study was to investigate the occurrence and diversity of pathogenic bacteria in the environment at a livestock farm in Limpopo Province. Environmental samples were collected from three sampling locations: cattle camp (CC), sheep camp (SHC), and goat camp (GC). Samples were processed and analysed for total bacterial counts in the Biotechnology Laboratory, University of Limpopo, South Africa. Identifications were done with Matrix Assisted Laser Disorption Ionisation Time of Flight Mass Spectometry (MALDI-TOF MS) using the simplified on plate technique. The colony forming unit formula per gram of environmental sample (CFU/g) was used to determine total bacterial counts. High counts were observed in CC and low counts in SHC for both soil and faecal samples. Bacillus species were the most dominant across the sampling locations for soil samples. Bacillus cereus occurred in 36 samples (33%), however, the frequency of isolation dominated in the CC with (44.4%), GC (22.2%) and SHC (13%). Staphylococcus aureus had the least frequency (2.2%) followed by Listeria monocytogenes (4.4%). In faecal samples, the occurrence and level of contamination with bacterial species varied across sampling locations with Escherichia coli dominating in the CC with 20% frequency, and abscent from SHC and GC.http://www.aloki.huam2020Veterinary Tropical Disease
Hierarchical spin-orbital polarisation of a giant Rashba system
The Rashba effect is one of the most striking manifestations of spin-orbit
coupling in solids, and provides a cornerstone for the burgeoning field of
semiconductor spintronics. It is typically assumed to manifest as a
momentum-dependent splitting of a single initially spin-degenerate band into
two branches with opposite spin polarisation. Here, combining
polarisation-dependent and resonant angle-resolved photoemission measurements
with density-functional theory calculations, we show that the two "spin-split"
branches of the model giant Rashba system BiTeI additionally develop disparate
orbital textures, each of which is coupled to a distinct spin configuration.
This necessitates a re-interpretation of spin splitting in Rashba-like systems,
and opens new possibilities for controlling spin polarisation through the
orbital sector.Comment: 11 pages including supplemental figures, accepted for publication at
Science Advance
Effect of green-Mediterranean diet on intrahepatic fat: the DIRECT PLUS randomised controlled trial
18openInternationalBothObjective To examine the effectiveness of green-Mediterranean (MED) diet, further restricted in red/processed meat, and enriched with green plants and polyphenols on non-alcoholic fatty liver disease (NAFLD), reflected by intrahepatic fat (IHF) loss.
Design For the DIRECT-PLUS 18-month randomized clinical trial, we assigned 294 participants with abdominal obesity/dyslipidaemia into healthy dietary guidelines (HDG), MED and green-MED weight-loss diet groups, all accompanied by physical activity. Both isocaloric MED groups consumed 28 g/day walnuts (+440 mg/day polyphenols provided). The green-MED group further consumed green tea (3–4 cups/day) and Mankai (a Wolffia globosa aquatic plant strain; 100 g/day frozen cubes) green shake (+1240 mg/day total polyphenols provided). IHF% 18-month changes were quantified continuously by proton magnetic resonance spectroscopy (MRS).
Results Participants (age=51 years; 88% men; body mass index=31.3 kg/m2; median IHF%=6.6%; mean=10.2%; 62% with NAFLD) had 89.8% 18-month retention-rate, and 78% had eligible follow-up MRS. Overall, NAFLD prevalence declined to: 54.8% (HDG), 47.9% (MED) and 31.5% (green-MED), p=0.012 between groups. Despite similar moderate weight-loss in both MED groups, green-MED group achieved almost double IHF% loss (−38.9% proportionally), as compared with MED (−19.6% proportionally; p=0.035 weight loss adjusted) and HDG (−12.2% proportionally; p<0.001). After 18 months, both MED groups had significantly higher total plasma polyphenol levels versus HDG, with higher detection of Naringenin and 2-5-dihydroxybenzoic-acid in green-MED. Greater IHF% loss was independently associated with increased Mankai and walnuts intake, decreased red/processed meat consumption, improved serum folate and adipokines/lipids biomarkers, changes in microbiome composition (beta-diversity) and specific bacteria (p<0.05 for all).
Conclusion The new suggested strategy of green-Mediterranean diet, amplified with green plant-based proteins/polyphenols as Mankai, green tea, and walnuts, and restricted in red/processed meat can double IHF loss than other healthy nutritional strategies and reduce NAFLD in half.openYaskolka Meir, Anat; Rinott, Ehud; Tsaban, Gal; Zelicha, Hila; Kaplan, Alon; Rosen, Philip; Shelef, Ilan; Youngster, Ilan; Shalev, Aryeh; Blüher, Matthias; Ceglarek, Uta; Stumvoll, Michael; Tuohy, Kieran; Diotallevi, Camilla; Vrhovsek, Urska; Hu, Frank; Stampfer, Meir; Shai, IrisYaskolka Meir, A.; Rinott, E.; Tsaban, G.; Zelicha, H.; Kaplan, A.; Rosen, P.; Shelef, I.; Youngster, I.; Shalev, A.; Blüher, M.; Ceglarek, U.; Stumvoll, M.; Tuohy, K.; Diotallevi, C.; Vrhovsek, U.; Hu, F.; Stampfer, M.; Shai, I
Analysis of aflatoxin biomarkers in the hair of experimental animals
Data Availability Statement:
Not applicable.Copyright © 2021 by the authors. Analysis of body fluids and tissues of aflatoxin exposed individuals for the presence of aflatoxins and aflatoxin metabolites has emerged as a reliable indicator of exposure and metabolism of aflatoxins. However, current aflatoxin biomarkers are not appropriate for investigating the long-term effects of aflatoxin exposure. In this explorative study, we investigated the analysis of hair as a complementary or alternative matrix for the assessment of biomarkers of long-term aflatoxin exposure. Three groups of guinea pigs were orally dosed with 5 ugkg−1bw−1, 50 ugkg−1bw−1, and 100 ugkg−1bw−1 of AFB1. Urine and hair samples were collected on days 0, 1, 2, 3, 7, 30, 60, and 90 and analysed for AFB1 and AFM1 using UHPLC-MS/MS. AFB1 and AFM1 were detected in 75% and 13.6%, respectively, of the day 1 to day 7 urine samples. AFB1 was detected in hair samples collected from day 3 up to day 60. This is the first report to confirm the deposition of AFB1 in the hair of experimental animals. These findings indicate that hair analysis has the potential to provide an accurate long-term historical record of aflatoxin exposure with potentially important implications for the field of aflatoxin biomarkers.This research received no external funding
Measurement of the Broad Line Region Size in Two Bright Quasars
We present 4 years of spectrophotometric monitoring data for two radio-quiet
quasars, PG 0804+762 and PG 0953+414, with typical sampling intervals of
several months. Both sources show continuum and emission line variations. The
variations of the H line follow those of the continuum with a time lag,
as derived from a cross-correlation analysis, of 9330 days for PG 0804+762
and 11155 days for PG 0953+414. This is the first reliable measurement of
such a lag in active galactic nuclei with luminosity erg s.
The broad line region (BLR) size that is implied is almost an order of
magnitude larger than that measured in several Seyfert 1 galaxies and is
consistent with the hypothesis that the BLR size grows as .Comment: 5 pages, LaTeX (including aas2pp4 and epsf), including 4 EPS figures.
Accepted for publication in Astrophysical Journal Letter
Far Ultraviolet Spectroscopic Explorer Spectroscopy of Absorption and Emission Lines from the Narrow-Line Seyfert 1 Galaxy NGC 4051
We present three Far Ultraviolet Spectroscopic Explorer (FUSE) observations
of the Narrow-Line Seyfert 1 galaxy NGC4051. The most prominent features in the
far-ultraviolet (FUV) spectrum are the OVI emission and absorption lines and
the HI Lyman series absorption lines which are detected up to the Lyman edge.
We also identify weak emission from NIII, CIII, and HeII. The CIII line shows
absorption while none is detected in the NIII and HeII lines. In HI and CIII we
detect two main absorption systems at outflow velocities of -50+/-30 and
-240+/-40 km/s, as well as a possible third one at ~ -450 km/s. These systems
are consistent in velocity with the 10 absorption systems found previously in
CIV, NV, and SiIV, though the individual systems are blended together in the
FUV spectrum. We estimate column densities of the two main absorption systems
and find that the HI column density is lower for systems with larger outflow
velocity. We detect no flux or spectral variations of NGC4051 at FUV
wavelengths during three epochs spanning one year. This is consistent with the
optical light curve which shows no variations between the three epochs. It is
also consistent with the X-ray light curve which shows consistent flux levels
at the three epochs of the FUSE observations, although the X-ray light curve
shows strong variations on much shorter timescales.Comment: 9 pages, 7 figures (5 in color), emulateapj, accepted for publication
in The Astronomical Journa
The Centurion 18 telescope of the Wise Observatory
We describe the second telescope of the Wise Observatory, a 0.46-m Centurion
18 (C18) installed in 2005, which enhances significantly the observing
possibilities. The telescope operates from a small dome and is equipped with a
large-format CCD camera. In the last two years this telescope was intensively
used in a variety of monitoring projects.
The operation of the C18 is now automatic, requiring only start-up at the
beginning of a night and close-down at dawn. The observations are mostly
performed remotely from the Tel Aviv campus or even from the observer's home.
The entire facility was erected for a component cost of about 70k$ and a labor
investment of a total of one man-year.
We describe three types of projects undertaken with this new facility: the
measurement of asteroid light variability with the purpose of determining
physical parameters and binarity, the following-up of transiting extrasolar
planets, and the study of AGN variability. The successful implementation of the
C18 demonstrates the viability of small telescopes in an age of huge
light-collectors, provided the operation of such facilities is very efficient.Comment: 16 pages, 13 figures, some figures quality was degraded, accepted for
publication in Astrophysics and Space Scienc
- …