2,131 research outputs found
“Un epitafio de lo cotidiano” . DavidToscana. \u3cem\u3eDuelo por Miguel Pruneda\u3c/em\u3e. México, EditorialPlaza y Janés. 2002. Edición argentina: Buenos Aires,Editorial Sudamericana, 2002.
Can Twitter be a source of information on allergy? Correlation of pollen counts with tweets reporting symptoms of allergic rhinoconjunctivitis and names of antihistamine drugs
Pollen forecasts are in use everywhere to inform therapeutic decisions for patients with allergic rhinoconjunctivitis (ARC). We exploited data derived from Twitter in order to identify tweets reporting a combination of symptoms consistent with a case definition of ARC and those reporting the name of an antihistamine drug. In order to increase the sensitivity of the system, we applied an algorithm aimed at automatically identifying jargon expressions related to medical terms. We compared weekly Twitter trends with National Allergy Bureau weekly pollen counts derived from US stations, and found a high correlation of the sum of the total pollen counts from each stations with tweets reporting ARC symptoms (Pearson's correlation coefficient: 0.95) and with tweets reporting antihistamine drug names (Pearson's correlation coefficient: 0.93). Longitude and latitude of the pollen stations affected the strength of the correlation. Twitter and other social networks may play a role in allergic disease surveillance and in signaling drug consumptions trends
Surgical outcome after isolated on-pump and off-pump anterior descending coronary revascularisation.
PRINCIPLES: Anterior descending coronary revascularisation can be performed with or without cardiopulmonary bypass. We compared surgical outcomes and postoperative results of two groups of patients operated on for isolated anterior descending coronary revascularisation with the left internal mammary artery, in order to determine the ideal target patient of each technique.
METHODS: From July 1997 to December 2012, 243 consecutive patients underwent off-pump (119) or on-pump (124) surgery for isolated revascularisation of the anterior descending coronary artery. We retrospectively collected, analysed and compared preoperative, intraoperative and postoperative variables.
RESULTS: In the on-pump group, aortic cross-clamp and bypass times were 22 and 35 minutes, respectively. Mean surgical time was 126 minutes for the off-pump group and 160 minutes for the on-pump group. Off-pump patients were more often men (82% vs 66%, p = 0.006), older (median age 67 vs 64 years, p = 0.013), with renal failure (11% vs 2.4%, p = 0.009) and respiratory failure (20% vs 7.3%, p = 0.003), with peripheral vascular disease (17% vs 8%, p = 0.038) and affected by a higher degree of angina (p <0.001). Surgical time was shorter off-pump (p <0.001), but a greater number of urgent procedures were performed on-pump (11% vs 3.4%, p = 0.042). No difference in postoperative characteristics and complications except for the intensive care unit stay, which was shorter off-pump (median 1 vs 2 days, p = 0.046). Hospital mortality was 0.8% off-pump and 1.6% on-pump (p = 0.5).
CONCLUSION: Both on-pump and off-pump surgery for isolated anterior descending coronary revascularization are safe with equal surgical risk. Off-pump procedures seem to be more appropriate in nonurgent patients with higher surgical risk profiles
A new photometric technique for the joint selection of star-forming and passive galaxies at 1.4<z<2.5
A simple two color selection based on B-, z-, and K- band photometry is
proposed for culling galaxies at 1.4<z<2.5 in K-selected samples and
classifying them as star-forming or passive systems. The method is calibrated
on the highly complete spectroscopic redshift database of the K20 survey,
verified with simulations and tested on other datasets. Requiring
BzK=(z-K)-(B-z)>-0.2 (AB) allows to select actively star-forming galaxies at
z>1.4, independently on their dust reddening. Instead, objects with BzK<-0.2
and (z-K)>2.5 (AB) colors include passively evolving galaxies at z>1.4, often
with spheroidal morphologies. Simple recipes to estimate the reddening, SFRs
and masses of BzK-selected galaxies are derived, and calibrated on K<20
galaxies. Based on their UV (reddening-corrected), X-ray and radio
luminosities, the BzK-selected star-forming galaxies with K<20 turn out to have
average SFR ~ 200 Msun yr^-1, and median reddening E(B-V)~0.4. Besides missing
the passively evolving galaxies, the UV selection appears to miss some relevant
fraction of the z~2 star-forming galaxies with K<20, and hence of the
(obscured) star-formation rate density at this redshift. The high SFRs and
masses add to other existing evidence that these z=2 star-forming galaxies may
be among the precursors of z=0 early-type galaxies. Theoretical models cannot
reproduce simultaneously the space density of both passively evolving and
highly star-forming galaxies at z=2. In view of Spitzer Space Telescope
observations, an analogous technique based on the RJL photometry is proposed to
complement the BzK selection and to identify massive galaxies at 2.5<z<4.0.
These color criteria should help in completing the census of the stellar mass
and of the star-formation rate density at high redshift (abridged).Comment: 19 pages, 17 figures, to appear on ApJ (20 December 2004 issue
Ground-based monitoring of comet 67P/Churyumov-Gerasimenko gas activity throughout the <i>Rosetta</i> mission
Simultaneously to the ESA Rosetta mission, a world-wide ground-based campaign provided measurements of the large scale activity of comet 67P/Churyumov-Gerasimenko through measurement of optically active gas species and imaging of the overall dust coma. We present more than two years of observations performed with the FORS2 low resolution spectrograph at the VLT, TRAPPIST, and ACAM at the WHT. We focus on the evolution of the CN production, as a tracer of the comet activity. We find that it is asymmetric with respect to perihelion and different from that of the dust. The CN emission is detected for the first time at 1.34 au pre-perihelion and production rates then increase steeply to peak about two weeks after perihelion at (1.00±0.10) ×1025 molecules s−1, while the post-perihelion decrease is more shallow. The evolution of the comet activity is strongly influenced by seasonal effects, with enhanced CN production when the Southern hemisphere is illuminated
The micro-Jy Radio Source Population: the VLA-CDFS View
We analyse the 267 radio sources from our deep (flux limit of 42 microJy at
the field center at 1.4 GHz) Chandra Deep Field South 1.4 and 5 GHz VLA survey.
The radio population is studied by using a wealth of multi-wavelength
information, including morphology and spectral types, in the radio, optical,
and X-ray bands. The availability of redshifts for ~ 70% of our sources allows
us to derive reliable luminosity estimates for the majority of the objects.
Contrary to some previous results, we find that star-forming galaxies make up
only a minority (~ 1/3) of sub-mJy sources, the bulk of which are faint radio
galaxies, mostly of the Fanaroff-Riley I type.Comment: 6 pages, 3 figures, to appear in the proceedings of "At the Edge of
the Universe", Sintra, Portugal, Oct. 9 - 13, 200
Global Measles Epidemic Risk: Current Perspectives on the Growing Need for Implementing Digital Communication Strategies
A safe vaccine against measles has been available and globally recommended since 1974. The World health Organization established measles elimination as a goal for 2020 but, unfortunately, this objective has not been achieved yet and outbreaks still occur. Herd immunity, ie, a population immunity higher than 95%, is required to stop the measles virus transmission. Communication plays a crucial role in immunization strategy to obtain high coverage levels, as it helps to fight barriers against vaccination. Delay and refusal of measles vaccination have become widespread due to misinformation, fake news and barriers to effective communication. This phenomenon has been defined as "vaccine hesitancy" and is considered as one of the top ten risks for global health. The alleged association between measles vaccination and autism has caused a sharp decline in vaccination rates. In this current situation, mass communication integrated into public health policies is fundamental to sway people's positive attitudes toward vaccination. Digital communication strategies based on social media and other internet platforms may represent useful tools to promote immunization and discourage skepticism and complement information provided by health-care professionals who have been considered as the most credible source on risk/benefits on vaccines for families. Digital communication strategies that may help supporting the measles elimination strategy include monitoring information needs online, integrating digital communication into immunization programs, involving a multidisciplinary group in communication, developing content that balances facts with positive messaging, using multiple communication channels. Further research activities should be promoted in the field of effective communication for immunization
Experimental evaluation and modeling of physical hardening in asphalt binders
The research described in this paper deals with the experimental evaluation and modeling of physical hardening in asphalt binders. The term physical hardening refers to a reversible phenomenon occurring at low temperatures that causes time-dependent changes in viscoelastic properties. The experimental approach, followed to quantitatively assess physical hardening, was based on flexural creep tests carried out by means of the Bending Beam Rheometer at various temperatures and conditioning times. The results obtained confirmed that hardening phenomena have a significant influence on the creep response of asphalt binders, to an extent that can be quantitatively assessed by referring to the appropriate rheological parameters and by applying the loading time–conditioning time superposition principle. The experimental data were fitted to a mechanical model proposed in the literature (composed of a single Kelvin–Voigt element) and thereafter to an improved model (with two Kelvin–Voigt elements in series). Both models were assessed in terms of their prediction accuracy. The improved model was found to better describe physical hardening effects in the case of both short-and long-term conditioning. Practical implications of the study were finally highlighted by referring to possible ranking criteria to be introduced in acceptance procedures for the comparative evaluation of asphalt binders
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