5,282 research outputs found
Evaluation of the relative contribution of meteorological and oceanic forces to the drift of ice islands offshore Newfoundland
On 29 April 2015, four beacons were deployed onto an ice island in the Strait of Belle Isle to record positional data. The ice island later broke up into many fragments, four of which were tracked by the beacons. The relative influences of wind drag, current drag, Coriolis force, sea surface height gradient and sea-ice force on the drift of the tracked ice island fragments were analyzed. Using atmospheric and oceanic model outputs, the sea-ice force was calculated as the residual of the fragments' net forces and the sum of all other forces. This was compared against the force obtained through ice concentration-dependent relationships when sea ice was present. The sea-ice forces calculated from the residual approach and concentration-dependent relationships were significant only when sea ice was present at medium-high concentrations in the vicinity of the ice island fragments. The forces from ocean currents and sea surface tilt contributed the most to the drift of the
Investigating Ca II emission in the RS CVn binary ER Vulpeculae using the Broadening Function Formalism
The synchronously rotating G stars in the detached, short-period (0.7 d),
partially eclipsing binary, ER Vul, are the most chromospherically active
solar-type stars known. We have monitored activity in the Ca II H & K reversals
for almost an entire orbit. Rucinski's Broadening Function Formalism allows the
photospheric contribution to be objectively subtracted from the highly blended
spectra. The power of the BF technique is also demonstrated by the good
agreement of radial velocities with those measured by others from less crowded
spectral regions. In addition to strong Ca II emission from the primary and
secondary, there appears to be a high-velocity stream flowing onto the
secondary where it stimulates a large active region on the surface 30 - 40
degrees in advance of the sub-binary longitude. A model light curve with a spot
centered on the same longitude also gives the best fit to the observed light
curve. A flare with approximately 13% more power than at other phases was
detected in one spectrum. We suggest ER Vul may offer a magnified view of the
more subtle chromospheric effects synchronized to planetary revolution seen in
certain `51 Peg'-type systems.Comment: Accepted to AJ; 17 pages and 16 figure
Experimental study of fire containment using water mist curtains in a reduced-scale deck of a ro-ro ship
Experiments have been conducted to evaluate the containment of smoke and heat using water mist curtains in a model setup of a ro-ro ship's cargo deck with a scale of 1:13, providing practical insights into the application of such fire protection systems in the cargo deck as well as valuable data for future numerical simulations. In this regard, the requirements of the international convention of Safety of Life at Sea (SOLAS) are studied for the side openings of so-called âopen decksâ in comparison with âclosed decksâ, especially to examine the feasibility of using water mist curtains for creating isolated subdivisions in the ro-ro space as a fire management strategy. The water mist curtains are created with one or two rows of water mist nozzles at pressures ranging from 3 to 8 bar, while the source of smoke and heat is a liquid pool fire, and inert cargo items are used in some experiments. Correspondingly, the interaction between the water mist curtain(s) and the fire is evaluated in terms of its heat release rate, and the containment effect is quantified via measurements of smoke flow through the deck and through the windows, concentrations of gaseous species, as well as gas temperatures at various key locations. The study shows that water mist curtains have a strong effect on fire dynamics and smoke propagation, but containment is dependent on the configuration of side openings and the location of fire, among other important factors
SLIPT in Joint Dimming Multi-LED OWC Systems with Rate Splitting Multiple Access
Optical wireless communication (OWC) systems with multiple light-emitting
diodes (LEDs) have recently been explored to support energy-limited devices via
simultaneous lightwave information and power transfer (SLIPT). The energy
consumption, however, becomes considerable by increasing the number of
incorporated LEDs. This paper proposes a joint dimming (JD) scheme that lowers
the consumed power of a SLIPT-enabled OWC system by controlling the number of
active LEDs. We further enhance the data rate of this system by utilizing rate
splitting multiple access (RSMA). More specifically, we formulate a data rate
maximization problem to optimize the beamforming design, LED selection and RSMA
rate adaptation that guarantees the power budget of the OWC transmitter, as
well as the quality-of-service (QoS) and an energy harvesting level for users.
We propose a dynamic resource allocation solution based on proximal policy
optimization (PPO) reinforcement learning. In simulations, the optimal dimming
level is determined to initiate a trade-off between the data rate and power
consumption. It is also verified that RSMA significantly improves the data
rate.Comment: Accepted in ICC 202
Epidemiology and histopathology of breast cancer in iran versus other middle eastern countries
Background: Breast cancer is the most prevalent cancer among females worldwide. This study compares the results of the most cited published Iranian studies and studies from other Middle East countries on breast cancer with data from the Ministry of Health and Medical Education and approximately 2000 cases from the Cancer Research Center of Shahid Beheshti Medical University of Iran. Methods: Data from the Cancer Registry System of the Ministry of Health and Medical Education and the Cancer Research Center were obtained in addition to data from other published Iranian articles to increase the accuracy of incidence, prevalence, disease burden, risk factors, clinical staging, clinical pathology, biological markers, clinical subtypes, and survival rate of breast cancer in the last decade and compare the epidemiological data with other areas of the world. Results: Overall, breast cancer was the most common cancer in Iran. The age-standardized rate for breast cancer was 33.21 per 100,000 according to the latest national databases. The mortality rate for breast cancer has not changed in the past 30 years in Iran. The age-standardized rate for mortality was 14.2 per 100,000 with a mean age of 49.84 years. The most common cancer in Iran is invasive ductal carcinoma. In our last review, 65.5-70.5 of cases were in the early stages (1 and 2) and less than 30 were in the advanced stages. The five-year overall survival rate was estimated at 72 in women and 60 in men. The stage and number of positive lymph nodes significantly affected the survival rate. In the Gulf Cooperation Council, ASR of the Kingdom of Saudi Arabia was (12.9), Bahrain (46.4), Kuwait (44.3), Qatar (35.5), United Arab Emirates (19.2), and Oman (14.4) per 100,000. Conclusion: Our study shows that epidemiology and histopathology of cancer is different with other neighborhood countries and is multi-dimension and needs multi-center involvement from government authorities, clinicians and scientists. ĂŠ 2018, Shiraz University of Medical Sciences. All rights reserved
UltraâSpecific Isolation of Circulating Tumor Cells Enables RareâCell RNA Profiling
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134266/1/advs147_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134266/2/advs147-sup-0001-S1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134266/3/advs147.pd
Novel fluorinated benzimidazole-based scaffolds and their anticancer activity in vitro
A small library of twelve, structurally diverse, fluoroaryl benzimidazoles was prepared using a simple synthetic strategy employing SNAr reactions. This allowed rapid assembly of heterocyclic structures containing linked and tethered fluoroaryl benzimidazoles. X-ray crystal structures of seven compounds were obtained including those of two macrocyclic compounds containing 21- and 24-membered rings. Three tethered fluoroaryl benzimidazole derivatives demonstrated micromolar inhibition against K-562 and MCF-7 cell lines. These compounds, in addition to 1-tetrafluoropyrid-4-yl-2-tetrafluoropyrid-4-ylsulfanyl-1H-benzimidazole, also demonstrated micromolar inhibition against G361 and HOS cell lines. Two of the compounds were found to activate caspases leading to apoptosis
Search for New Physics with Jets and Missing Transverse Momentum in pp collisions at sqrt(s) = 7 TeV
A search for new physics is presented based on an event signature of at least
three jets accompanied by large missing transverse momentum, using a data
sample corresponding to an integrated luminosity of 36 inverse picobarns
collected in proton--proton collisions at sqrt(s)=7 TeV with the CMS detector
at the LHC. No excess of events is observed above the expected standard model
backgrounds, which are all estimated from the data. Exclusion limits are
presented for the constrained minimal supersymmetric extension of the standard
model. Cross section limits are also presented using simplified models with new
particles decaying to an undetected particle and one or two jets
Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV
A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay
channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7
TeV is presented. The data were collected at the LHC, with the CMS detector,
and correspond to an integrated luminosity of 4.6 inverse femtobarns. No
significant excess is observed above the background expectation, and upper
limits are set on the Higgs boson production cross section. The presence of the
standard model Higgs boson with a mass in the 270-440 GeV range is excluded at
95% confidence level.Comment: Submitted to JHE
X-ray emission from the Sombrero galaxy: discrete sources
We present a study of discrete X-ray sources in and around the
bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival
Chandra observations with a total exposure of ~200 ks. With a detection limit
of L_X = 1E37 erg/s and a field of view covering a galactocentric radius of ~30
kpc (11.5 arcminute), 383 sources are detected. Cross-correlation with Spitler
et al.'s catalogue of Sombrero globular clusters (GCs) identified from HST/ACS
observations reveals 41 X-rays sources in GCs, presumably low-mass X-ray
binaries (LMXBs). We quantify the differential luminosity functions (LFs) for
both the detected GC and field LMXBs, whose power-low indices (~1.1 for the
GC-LF and ~1.6 for field-LF) are consistent with previous studies for
elliptical galaxies. With precise sky positions of the GCs without a detected
X-ray source, we further quantify, through a fluctuation analysis, the GC LF at
fainter luminosities down to 1E35 erg/s. The derived index rules out a
faint-end slope flatter than 1.1 at a 2 sigma significance, contrary to recent
findings in several elliptical galaxies and the bulge of M31. On the other
hand, the 2-6 keV unresolved emission places a tight constraint on the field
LF, implying a flattened index of ~1.0 below 1E37 erg/s. We also detect 101
sources in the halo of Sombrero. The presence of these sources cannot be
interpreted as galactic LMXBs whose spatial distribution empirically follows
the starlight. Their number is also higher than the expected number of cosmic
AGNs (52+/-11 [1 sigma]) whose surface density is constrained by deep X-ray
surveys. We suggest that either the cosmic X-ray background is unusually high
in the direction of Sombrero, or a distinct population of X-ray sources is
present in the halo of Sombrero.Comment: 11 figures, 5 tables, ApJ in pres
- âŚ