1,345 research outputs found
Prognostic significance of DNA cytometry in cutaneous malignant lymphomas.
The current classification of cutaneous malignant lymphomas (ML) into low-grade and high-grade lymphomas was found to be of limited reproducibility and permitted only a rough prediction about outcome. With this in mind, the relationship between nuclear DNA content and both prognosis and histologic grading according to the Kiel classification was evaluated on Feulgen-stained imprint specimens. In all, 49 cases of malignant non-Hodgkin's lymphoma, primary of the skin or with an involvement of the skin as one of the first symptoms, were studied using a computerized high-resolution image analysis system. The 2c deviation index (2cDI), which reflects the variation of the nuclear DNA values around the normal diploid peak, was found to be the best prognostically relevant criterion. Using the 2cDI, a significant discrimination (P less than 0.001 in the U test) between low-grade and high-grade ML was achieved. The prognostic benefit of the 2cDI was well documented by a significant inverse correlation between the 2cDI and the period of time until the patients progressed at least into one higher stage or died of lymphoma (r equals -0.63, P less than 0.05). In addition, the 2cDI enabled prognosis of the course of disease. In the group with low 2cDI values (2cDI, less than 0.5), no progression of the disease was observed after 1 year. In the groups presenting with a 2cDI between 0.5 and 1.0 and higher than 1.0, a progression was found in 57% and 64% of the cases studied, respectively. In conclusion, these measurements indicate that the determination of DNA distribution patterns in imprint specimens allows a precise and objective prognostic evaluation of cutaneous ML
Altruism and the pressure to share: Lab evidence from Tanzania
We propose a novel laboratory experiment to document the pressure to share income within
social networks in Africa. We find that the redistributive pressure exerted via the possibility
of receiving a claim increases altruism, while the possibility of hiding from such claim
reduces it. Our results indicate that sharing norms are crucial drivers of giving to other members of the network. We also find that pressure to share has a detrimental effect on the
undertaking of profitable but risky investments
Applicability of Neural Networks for Driving Style Classification and Maneuver Detection
Maneuver and driving style detection are of ongoing interest for the extension of vehicle's functionalities. Existing machine learning approaches require extensive sensor data and demand for high computational power. For vehicle onboard implementation, poorly generalizing rule-based approaches are currently state of the art. Not being restricted to neither comprehensive environmental sensors like camera or radar, nor high computing power (both of what is today only present in upper class' vehicles), our approach allows for cross-vehicle use: In this work, the applicability of small artificial neural networks (ANN) as efficient detectors is tested using a prototypal vehicle implementation. During test drives, overtaking maneuvers have been detected 1.2 s prior to the competing rule-based approach in average, also greatly improving the detection performance. Regarding driving style recognition, ANN-based results are closer to targets and more patient at driving style transitions. A recognition rate of over 75 % is achieved
Chitosan-dextran sulfate hydrogels as a potential carrier for probiotics
Physical and chemical (crosslinked with genipin) hydrogels based on chitosan and dextran sulfate were developed and characterized as novel bio-materials suitable for probiotic encapsulation. The swelling of the hydrogels was dependent on the composition and weakly influenced by the pH of the media. The morphology analysis supports the swelling data showing distinct changes in microstructure depending on the composition. The viability and culturability tests showed approx. 3.6 log CFLI/mL decrease of cells (L acidophilus as model) incorporated into chemical hydrogels when compared to the number of viable native cells. However, the live/dead viability assay evidenced that a considerable amount of viable cells were still entrapped in the hydrogel network and therefore the viability is most likely underestimated. Overall, the developed systems are robust and their structure, rheology and swelling properties can be tuned by changing the blend ratio, thus constituting appealing bio-matrices for cell encapsulation. (C) 2017 Elsevier Ltd. All rights reserved.People Programme (Marie Curie Actions) of the European Union's Seventh Framework Programme FP7/under REA grant [606713]Portuguese Foundation for Science and Technology (FCT) [PTDC/AGR-TEC/4814/2014, IF/01005/2014]Swedish Research Councilinfo:eu-repo/semantics/publishedVersio
Weak gravitational lensing in the standard Cold Dark Matter model, using an algorithm for three-dimensional shear
We investigate the effects of weak gravitational lensing in the standard Cold
Dark Matter cosmology, using an algorithm which evaluates the shear in three
dimensions. The algorithm has the advantage of variable softening for the
particles, and our method allows the appropriate angular diameter distances to
be applied to every evaluation location within each three-dimensional
simulation box. We investigate the importance of shear in the distance-redshift
relation, and find it to be very small. We also establish clearly defined
values for the smoothness parameter in the relation, finding its value to be at
least 0.88 at all redshifts in our simulations. From our results, obtained by
linking the simulation boxes back to source redshifts of 4, we are able to
observe the formation of structure in terms of the computed shear, and also
note that the major contributions to the shear come from a very broad range of
redshifts. We show the probability distributions for the magnification, source
ellipticity and convergence, and also describe the relationships amongst these
quantities for a range of source redshifts. We find a broad range of
magnifications and ellipticities; for sources at a redshift of 4, 97{1/2}% of
all lines of sight show magnifications up to 1.3 and ellipticities up to 0.195.
There is clear evidence that the magnification is not linear in the
convergence, as might be expected for weak lensing, but contains contributions
from higher order terms in both the convergence and the shear.Comment: 14 pages, LaTeX, 15 figures include
Continuum enhancements, line profiles and magnetic field evolution during consecutive flares
During solar flares, magnetic energy can be converted into electromagnetic
radiation from radio waves to rays. Enhancements in the continuum at
visible wavelengths give rise to white-light flares, as well as continuum
enhancements in the FUV and NUV passbands. In addition, the strong energy
release in these events can lead to the rearrangement of the magnetic field at
the photospheric level, causing morphological changes in large and stable
magnetic structures like sunspots. In this context, we describe observations
acquired by satellite instruments (IRIS, SDO/HMI, Hinode/SOT) and ground-based
telescopes (ROSA/DST) during two consecutive C7.0 and X1.6 flares occurred in
active region NOAA 12205 on 2014 November 7. The flare was accompanied by an
eruption. The results of the analysis show the presence of continuum
enhancements during the evolution of the events, observed both in ROSA images
and in \textit{IRIS} spectra. In the latter, a prominent blue-shifted component
is observed at the onset of the eruption. We investigate the role played by the
evolution of the sunspots of the active region in the flare
triggering, and finally we discuss the changes in the penumbrae surrounding
these sunspots as a further consequence of these flares.Comment: 19 pages, accepted for ApJ; some figures are in B/W to accomplish
size limit
Type IIb Supernova SN 2011dh: Spectra and Photometry from the Ultraviolet to the Near-Infrared
We report spectroscopic and photometric observations of the Type IIb SN
2011dh obtained between 4 and 34 days after the estimated date of explosion
(May 31.5 UT). The data cover a wide wavelength range from 2,000 Angstroms in
the UV to 2.4 microns in the NIR. Optical spectra provide line profiles and
velocity measurements of HI, HeI, CaII and FeII that trace the composition and
kinematics of the SN. NIR spectra show that helium is present in the atmosphere
as early as 11 days after the explosion. A UV spectrum obtained with the STIS
reveals that the UV flux for SN 2011dh is low compared to other SN IIb. The HI
and HeI velocities in SN 2011dh are separated by about 4,000 km/s at all
phases. We estimate that the H-shell of SN 2011dh is about 8 times less massive
than the shell of SN 1993J and about 3 times more massive than the shell of SN
2008ax. Light curves (LC) for twelve passbands are presented. The maximum
bolometric luminosity of erg s occurred
about 22 days after the explosion. NIR emission provides more than 30% of the
total bolometric flux at the beginning of our observations and increases to
nearly 50% of the total by day 34. The UV produces 16% of the total flux on day
4, 5% on day 9 and 1% on day 34. We compare the bolometric light curves of SN
2011dh, SN 2008ax and SN 1993J. The LC are very different for the first twelve
days after the explosions but all three SN IIb display similar peak
luminosities, times of peak, decline rates and colors after maximum. This
suggests that the progenitors of these SN IIb may have had similar compositions
and masses but they exploded inside hydrogen shells that that have a wide range
of masses. The detailed observations presented here will help evaluate
theoretical models for this supernova and lead to a better understanding of SN
IIb.Comment: 23 pages, 14 figures, 9 tables, accepted by Ap
The role of ion dissolution in metal and metal oxide surface inactivation of SARS CoV-2
Funding: This work was funded by UKRI-NIHR (MRC MR/V028464/1) COVID-19 Rapid Response Initiative.Anti-viral surface coatings are under development to prevent viral fomite transmission from high-traffic touch surfaces in public spaces. Copperâs anti-viral properties have been widely documented, but the anti-viral mechanism of copper surfaces is not fully understood. We screened a series of metal and metal oxide surfaces for anti-viral activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease (COVID-19). Copper and copper oxide surfaces exhibited superior anti-SARS-CoV-2 activity; however, the level of anti-viral activity was dependent on the composition of the carrier solution used to deliver virus inoculum. We demonstrate that copper ions released into solution from test surfaces can mediate virus inactivation, indicating a copper ion dissolution-dependent anti-viral mechanism. The level of anti-viral activity is, however, not dependent on the amount of copper ions released into solution per se. Instead, our findings suggest that degree of virus inactivation is dependent on copper ion complexation with other biomolecules (e.g., proteins/metabolites) in the virus carrier solution that compete with viral components. Although using tissue culture-derived virus inoculum is experimentally convenient to evaluate the anti-viral activity of copper-derived test surfaces, we propose that the high organic content of tissue culture medium reduces the availability of âuncomplexedâ copper ions to interact with the virus, negatively affecting virus inactivation and hence surface anti-viral performance. We propose that laboratory anti-viral surface testing should include virus delivered in a physiologically relevant carrier solution (saliva or nasal secretions when testing respiratory viruses) to accurately predict real-life surface anti-viral performance when deployed in public spaces.PostprintPeer reviewe
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