286 research outputs found
Increase in pertussis cases along with high prevalence of two emerging genotypes of Bordetella pertussis in PerĂș, 2012
As has occurred in many regions worldwide, in 2012 the incidence of pertussis increased in PerĂș. This epidemiologic situation has been associated with a waning vaccine-induced immunity and the adaptation of Bordetella pertussis to vaccine-induced immunity along with improved diagnostic methods. Methods: The study comprised a total of 840 pertussis-suspected cases reported in PerĂș during 2012. We summarize here the distribution of pertussis cases according to age and immunization status along with the immunization-coverage rate. Laboratory diagnosis was performed by culture test and real-time polymerase-chain reaction (PCR). B. pertussis bacteria recovered from infected patients were characterized by pulsed-field gel electrophoresis (PFGE), and the DNA sequencing of the pertussis-toxin (promoter and subunit A), pertactin, and fimbriae (fim2 and fim3) genes. Results: From the total pertussis-suspected cases, 191 (22.7 %) infections were confirmed by real-time PCR and 18 through cultivation of B. pertussis (2.1 %), while one infection of B. parapertussis (0.11 %) was also detected by culture. Pertussis was significantly higher in patients that had had 0-3 vaccine doses (pentavalent vaccine alone) than in those who had had 4-5 vaccine doses (pentavalent plus DwPT boosters) at 94.3 vs. 5.7 %, respectively (p < 0.00001). The relative risk (RR) for patients with 4-5 doses compared to those with fewer than 4 doses or no dose was 0.23 (95 % Confidence Interval: 0.11-0.44), while the vaccine effectiveness was 77 % and coverage 50.5 %. Genetic analysis of B. pertussis isolates from different Peruvian regions detected two clonal groups as identified by PFGE. Those two groups corresponded to the B. pertussis genotypes emerging worldwide ptxP3-ptxA1-prn2 or 9-fim3-1 and ptxP3-ptxA1-prn2 or 9-fim3-2. Conclusions: Two emerging B. pertussis genotypes similar to isolates involved in worldwide epidemics were detected in PerĂș. Low vaccine coverage (<50 %) and genetic divergence between the vaccine-producing strain and the local isolates could contribute to this pertussal epidemic.Fil: Bailon, H. Instituto Nacional de Salud; PerĂșFil: LeĂłn-Janampa, N. Instituto Nacional de Salud; PerĂșFil: Padilla, C.. Instituto Nacional de Salud; PerĂșFil: Hozbor, Daniela Flavia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto de BiotecnologĂa y BiologĂa Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de BiotecnologĂa y BiologĂa Molecular; Argentin
Multiwavelength analysis of the Lyman alpha emitting galaxy Haro 2: relation between the diffuse Lyman alpha and soft X-ray emissions
In order to use Lyman alpha (Lya) emission as star formation tracer in
cosmological studies, we must understand how the resonant scattering affects
the escape fraction of the Lya photons. Thus, high spatial resolution
multiwavelength studies of nearby Lya emitters, like Haro 2, are highly needed.
For that purpose, we have used Chandra X-ray and HST (UV, optical and NIR)
images of Haro 2, and STIS and ground-based spectral images along its major and
minor axes, to characterize the Lya emission and the properties of the stellar
population. The UV, Ha (Halpha) and FIR luminosities of the Haro 2 nuclear
starburst are reproduced using evolutionary synthesis models assuming a young
stellar population with ages ~3.5-5.0 Myr, affected by differential
interstellar extinctions. The observed X-ray emission is attributed to gas
heated by the mechanical energy released by the starburst (soft component) and
a Ultra-Luminous X-ray source candidate (hard). Both compact and diffuse Lya
components are observed. Whereas Lya is spatially decoupled from Balmer lines
emission, Balmer decrement and UV continuum, the diffuse Lya component is
spatially correlated with the diffuse soft X-ray emission. Moreover, unlike the
compact one, diffuse Lya shows luminosities larger than predicted from Ha,
assuming case B recombination and dust extinction as derived from Ha/Hbeta. We
propose that, whereas the compact Lya emission is associated to the massive
stellar clusters and is affected by outflows and dust extinction, the diffuse
Lya originates in gas ionized by the hot plasma responsible for the soft X-ray
radiation, as suggested by their spatial correlation and by the measured
L(Ha)/LsoftX ratios. Calibration of Lya as star formation rate tracer should
therefore include both effects (destruction vs. enhancement) to avoid biases in
the study of galaxies at cosmological distances.Comment: Accepted for publication in A&A, 18 pages, 8 figures, 9 tables. If
problems with quality of images, see
http://www.cab.inta-csic.es/users/otih/haro2-v63.clean.pd
Physical properties and evolutionary state of the Lyman alpha emitting starburst galaxy IRAS 08339+6517
Though Lyman alpha emission (Lya) is one of the most used tracers of massive
star formation at high redshift, a correct understanding of radiation transfer
effects by neutral gas is required to properly quantify the star formation rate
along the history of the Universe. We are embarked in a program to study the
properties of the Lya emission (spectral profile, spatial distribution,
relation to Balmer lines intensity,...) in several local starburst galaxies. We
present here the results obtained for IRAS 08339+6517.
Using evolutionary population synthesis models, we have characterized the
properties of the starburst (UV continuum, Halpha, total infrared and X-ray
emissions, etc.), which transformed 1.4e+8 Mo of gas into stars around 5-6 Myr
ago. In addition to the central compact emission blob, we have identified a
diffuse Lya emission component smoothly distributed over the whole central area
of IRAS 08339+6517. This diffuse emission is spatially decoupled from the UV
continuum, the Halpha emission or the Halpha/Hbeta ratio. Both locally and
globally, the Lya/Halpha ratio is lower than the Case B predictions, even after
reddening correction, with an overall Lya escape fraction of only 4%.
We conclude that in IRAS 08339+6517 the resonant scattering of Lya photons by
an outflowing shell of neutral gas causes their highly-efficient destruction by
dust, which explains the low Lya escape fraction measured. These results stress
again the importance of a proper correction of scattering and transfer effects
when using Lya to derive the star formation rate in high-redshift galaxies.Comment: Accepted for publication in A&A, 17 pages, 13 figures, 8 tables. If
problems with quality of images, see
https://cloud.cab.inta-csic.es/public.php?service=files&file=%2Fotih%2Ffiles%2Foti_mas%2Firas%2Firas-v53.ack_referee.pd
OPTICAL SPECTROSCOPIC OBSERVATIONS OF GAMMA-RAY BLAZAR CANDIDATES. VI. FURTHER OBSERVATIONS FROM TNG, WHT, OAN, SOAR, AND MAGELLAN TELESCOPES
IndexaciĂłn: Web of ScienceBlazars, one of the most extreme classes of active galaxies, constitute so far the largest known population of.-ray sources, and their number is continuously growing in the Fermi catalogs. However, in the latest release of the Fermi catalog there is still a large fraction of sources that are classified as blazar candidates of uncertain type (BCUs) for which optical spectroscopic observations are necessary to confirm their nature and their associations. In addition, about one-third of the gamma-ray point sources listed in the Third Fermi-LAT Source Catalog (3FGL) are still unassociated and lacking an assigned lower-energy counterpart. Since 2012 we have been carrying out an optical spectroscopic campaign to observe blazar candidates to confirm their nature. In this paper, the sixth of the series, we present optical spectroscopic observations for 30 gamma-ray blazar candidates from different observing programs we carried out with the Telescopio Nazionale Galileo, William Herschel Telescope, Observatorio Astronomico Nacional, Southern Astrophysical Research Telescope, and Magellan. Telescopes. We found that 21 out of 30 sources investigated are BL Lac objects, while the remaining targets are classified as flat-spectrum radio quasars showing the typical broad emission lines of normal quasi-stellar objects. We conclude that our selection of gamma-ray blazar. candidates based on their multifrequency properties continues to be a successful way to discover potential low-energy counterparts of the Fermi. unidentified gamma-ray sources and to confirm the nature of BCUs.http://iopscience.iop.org/article/10.3847/0004-6256/151/4/95/met
Quantitative Analysis of Bloggers Collective Behavior Powered by Emotions
Large-scale data resulting from users online interactions provide the
ultimate source of information to study emergent social phenomena on the Web.
From individual actions of users to observable collective behaviors, different
mechanisms involving emotions expressed in the posted text play a role. Here we
combine approaches of statistical physics with machine-learning methods of text
analysis to study emergence of the emotional behavior among Web users. Mapping
the high-resolution data from digg.com onto bipartite network of users and
their comments onto posted stories, we identify user communities centered
around certain popular posts and determine emotional contents of the related
comments by the emotion-classifier developed for this type of texts. Applied
over different time periods, this framework reveals strong correlations between
the excess of negative emotions and the evolution of communities. We observe
avalanches of emotional comments exhibiting significant self-organized critical
behavior and temporal correlations. To explore robustness of these critical
states, we design a network automaton model on realistic network connections
and several control parameters, which can be inferred from the dataset.
Dissemination of emotions by a small fraction of very active users appears to
critically tune the collective states
Suzaku observation of the Phoenix Galaxy
In recent years, several Seyfert 2 galaxies have been discovered that change
state when observed in X-rays a few years apart, switching from Compton-thin to
reflection-dominated or viceversa. We observed a member of this class of
"Changing-look" sources, the Phoenix Galaxy, with Suzaku, with the aim of
better understanding the nature of the variations. The Suzaku spectrum was
analyzed, and the results compared with previous ASCA and XMM-Newton
observations. The source was caught in a Compton-thin state, as in XMM-Newton,
but differently from ASCA. Comparing the Suzaku and XMM-Newton observations, a
variation in the column density of the absorber on a time scale of years is
discovered. A similar change, but on much shorter time scales (i.e. ks) may
also explain the count-rate variations during the Suzaku observations. A soft
excess is also present, likely due to continuum and line emission from
photoionized circumnuclear matter.Comment: Accepted for publication in Astronomy & Astrophysic
Nuclear activity and massive star formation in the low luminosity AGN NGC4303: Chandra X-ray observations
We present evidence of the co-existence of either an AGN or an ultraluminous
X-ray source (ULX), together with a young super stellar cluster in the 3
central parsecs of NGC4303. The galaxy contains a low luminosity AGN and hosts
a number of starburst regions in a circumnuclear spiral, as well as in the
nucleus itself. A high spatial resolution Chandra image of this source reveals
that the soft X-ray emission traces the ultraviolet nuclear spiral down to a
core, which is unresolved both in soft and hard X-rays. The astrometry of the
X-ray core coincides with the UV core within the Chandra positioning accuracy.
The total X-ray luminosity of the core, 1.5*10^{39} erg/s, is similar to that
from some LINERs or from the weakest Seyferts detected so far. The soft X-rays
in both the core and the extended structure surrounding it can be well
reproduced by evolutionary synthesis models (which include the emission
expected from single stars, the hot diffuse gas, supernova remnants and binary
systems), consistent with the properties of the young stellar clusters
identified in the UV. The hard X-ray tail detected in the core spectrum,
however, most likely requires the presence of an additional source. This
additional source could either be a weak active nucleus black hole or an
ultraluminous X-ray object. The implications of these results are discussed.Comment: 37 pages, 7 figures, ApJ accepte
Vertebrates from the Holocene site of Kobeaga II (Ispaster, Bizkaia)
In this paper the faunistic sample, the stratigraphy and the chronology of the archaeological site of Kobeaga
II cave (Ispaster, Bizkaia) is described. The five Classes of vertebrates are represented in this site, where,
the mammals are the most abundant with five Orders, nine Families, and fifteen Genera. To end, it is
remarked the interest of some species as a paleoecological indicator in the general sketch of the Holocene
in the North of the Iberian Peninsul
Exploring the integration of local and scientific knowledge in early warning systems for disaster risk reduction: a review
The occurrence and intensity of some natural hazards (e.g. hydro-meteorological) increase due to climate change, with growing exposure and socio-economic vulnerability, leading to mounting risks. In response, Disaster Risk Reduction policy and practice emphasize people-centred Early Warning Systems (EWS). Global policies stress the need for including local knowledge and increasing the literature on integrating local and scientific knowledge for EWS. In this paper, we present a review to understand and outline how local and scientific knowledge integration is framed in EWS, namely: (1) existing integration approaches, (2) where in the EWS integration happens, (3) outcomes, (4) challenges, and (5) enablers. The objective is to critically evaluate integration and highlight critical questions about assumptions, goals, outcomes, and processes. In particular, we unpack the impact of power and knowledges as plural. We find a spectrum of integration between knowledges in EWS, mainly with dichotomy at the start: focus on people or technology. The most popular integration approaches are participatory methods such as âGIS mappingâ (technology) and methods that focus on âtriangulationâ (people). We find that critical analysis of power relations and social interaction is either missed or framed as a challenge within integration processes. Knowledge is often seen as binary, embedded in the concept of âintegrationâ. It is important to know what different knowledges can and cannot do in different contexts and acknowledge the hybrid reality of knowledge used for EWS. We argue that how we approach different knowledges in EWS has fundamental implications for the approaches to integration and its meaning. To this end, attention to the social processes, power dynamics, and context is crucial
Vertebrates from the Dolmen of Errekatxuetako Atxa (Holocene) (Zeanuri, Bizkaia)
During the excavation of the Dolmen of Errekatxuetako Atxa in 2006 several vertebrate remains were
found. Mammals are represented in the site by one lagomorph, six rodents, three insectivores, three
artiodactyls, two carnivores and one primate, the reptilians by one saurian and one ophidian and the
amphibians by one urodele and three anuran. The amphibians and reptilies are the most abundant
microvertebrate.which is not usual in other Holocene archeological and Paleontological sites of the
Cantabrian Basin. This could result from the presence of a wetland near the studied site. The vertebrate
assemblage indicates a humid temperate climate quite similar to that occurring in the area at present da
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