258 research outputs found
Infants hospitalized for Bordetella pertussis infection commonly have respiratory viral coinfections
Background: Whether viral coinfections cause more severe disease than Bordetella pertussis (B. pertussis) alone remains
unclear. We compared clinical disease severity and sought clinical and demographic differences between infants with
B. pertussis infection alone and those with respiratory viral coinfections. We also analyzed how respiratory infections
were distributed during the 2 years study.
Methods: We enrolled 53 infants with pertussis younger than 180 days (median age 58 days, range 17â109 days, 64.
1% boys), hospitalized in the Pediatric Departments at âSapienzaâ University Rome and Bambino GesĂš Childrenâs
Hospital from August 2012 to November 2014. We tested in naso-pharyngeal washings B. pertussis and 14 respiratory
viruses with real-time reverse-transcriptase-polymerase chain reaction. Clinical data were obtained from hospital
records and demographic characteristics collected using a structured questionnaire.
Results: 28/53 infants had B. pertussis alone and 25 viral coinfection: 10 human rhinovirus (9 alone and 1 in coinfection
with parainfluenza virus), 3 human coronavirus, 2 respiratory syncytial virus. No differences were observed in clinical
disease severity between infants with B. pertussis infection alone and those with coinfections. Infants with B. pertussis
alone were younger than infants with coinfections, and less often breastfeed at admission.
Conclusions: In this descriptive study, no associations between clinical severity and pertussis with or without
co-infections were found
Infants hospitalized for Bordetella pertussis infection commonly have respiratory viral coinfections
Isotope tracing of submarine groundwater discharge offshore Ubatuba, Brazil : results of the IAEAâUNESCO SGD project
Author Posting. Š Elsevier B.V., 2008. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Journal of Environmental Radioactivity 99 (2008): 1596-1610, doi:10.1016/j.jenvrad.2008.06.010.Results of groundwater and seawater analyses for radioactive (3H, 222Rn, 223Ra, 224Ra, 226Ra, 228Ra) and stable (2H, 18O)
isotopes are presented together with in situ spatial mapping and time-series 222Rn measurements in seawater, direct seepage
measurements using manual and automated seepage meters, pore water investigations using different tracers and piezometric
techniques, and geoelectric surveys probing the coast. This study represents first time that such a new complex arsenal of radioactive
and non-radioactive tracer techniques and geophysical methods have been used for simultaneous submarine groundwater discharge
(SGD) investigations. Large fluctuations of SGD fluxes were observed at sites situated only a few meters apart (from 0 cm d-1 to 360
cm d-1; the unit represents cm3/cm2/day), as well as during a few hours (from 0 cm d-1 to 110 cm d-1), strongly depending on the tidal
fluctuations. The average SGD flux estimated from continuous 222Rn measurements is 17Âą10 cm d-1. Integrated coastal SGD flux
estimated for the Ubatuba coast using radium isotopes is about 7x103 m3 d-1 per km of the coast. The isotopic composition (δ2H and
δ18O) of submarine waters was characterised by significant variability and heavy isotope enrichment, indicating that the contribution
of groundwater in submarine waters varied from a small percentage to 20%. However, this contribution with increasing offshore
distance became negligible. Automated seepage meters and time-series measurements of 222Rn activity concentration showed a
negative correlation between the SGD rates and tidal stage. This is likely caused by sea level changes as tidal effects induce variations of hydraulic gradients. The geoelectric probing and piezometric measurements contributed to better understanding of the spatial distribution of different water masses present along the coast. The radium isotope data showed scattered distributions with offshore distance, which imply that seawater in a complex coast with many small bays and islands was influenced by local currents and
groundwater/seawater mixing. This has also been confirmed by a relatively short residence time of 1-2 weeks for water within 25 km
offshore, as obtained by short-lived radium isotopes. The irregular distribution of SGD seen at Ubatuba is a characteristic of fractured
rock aquifers, fed by coastal groundwater and recirculated seawater with small admixtures of groundwater, which is of potential
environmental concern and has implications on the management of freshwater resources in the region.This research was
supported by IAEA and UNESCO (IOC and IHP) in the framework of the joint SGD project.
Science support for some U.S. investigators was provided by grants from the National Science
Foundation (OCE03-50514 to WCB and OCE02-33657 to WSM)
Insights from the Paleogene tropical Pacific: Foraminiferal stable isotope and elemental results from Site 1209, Shatsky Rise
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94995/1/palo1207.pd
Isotopic, geophysical and biogeochemical investigation of submarine groundwater discharge : IAEA-UNESCO intercomparison exercise at Mauritius Island
Author Posting. Š The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Journal of Environmental Radioactivity 104 (2012): 24-45, doi:10.1016/j.jenvrad.2011.09.009.Submarine groundwater discharge (SGD) into a shallow lagoon on the west coast of Mauritius Island (Flic-en-Flac) was
investigated using radioactive (3H, 222Rn, 223Ra, 224Ra, 226Ra, 228Ra) and stable (2H, 18O) isotopes and nutrients. SGD
intercomparison exercises were carried out to validate the various approaches used to measure SGD including radium and radon
measurements, seepage-rate measurements using manual and automated meters, sediment bulk conductivity and salinity surveys.
SGD measurements using benthic chambers placed on the floor of the Flic-en-Flac Lagoon showed discharge rates up to 500
cm/day. Large variability in SGD was observed over distances of a few meters, which were attributed to different
geomorphological features. Deployments of automated seepage meters captured the spatial and temporal variability of SGD with
a mean seepage rate of 10 cm/day. The stable isotopic composition of submarine waters was characterized by significant
variability and heavy isotope enrichment and was used to predict the contribution of fresh terrestrially derived groundwater to
SGD (range from a few % to almost 100 %). The integrated SGD flux, estimated from seepage meters placed parallel to the
shoreline, was 35 m3/m day, which was in a reasonable agreement with results obtained from hydrologic water balance
calculation (26 m3/m day). SGD calculated from the radon inventory method using in situ radon measurements were between 5
and 56 m3/m per day. Low concentrations of radium isotopes observed in the lagoon water reflected the low abundance of U and
Th in the basalt that makes up the island. High SGD rates contribute to high nutrients loading to the lagoon, potentially leading to
eutrophication. Each of the applied methods yielded unique information about the character and magnitude of SGD. The results
of the intercomparison studies have resulted a better understanding of groundwater-seawater interactions in coastal regions. Such
information is an important pre-requisite for the protection management of coastal freshwater resources.The
financial support provided by the IOC and IHP of UNESCO for travel arrangements, and by the IAEAâs Marine
Environment Laboratories for logistics is highly acknowledged. MAC and MEG were supported in part by the US
National Science Foundation (OCE-0425061 and OCE-0751525). PPP acknowledges a support provided by the EU
Research & Development Operational Program funded by the ERDF (project No. 26240220004), and the Slovak
Scientific Agency VEGA (grant No. 1/108/08). The International Atomic Energy Agency is grateful to the
Government of the Principality of Monaco for support provided to its Marine Environment Laboratories
Assessment of Renal Function by the Stable Oxygen and Hydrogen Isotopes in Human Blood Plasma
Water (H2O) is the most abundant and important molecule of life. Natural water contains small amount of heavy isotopes. Previously, few animal model studies have shown that the isotopic composition of body water could play important roles in physiology and pathophysiology. Here we study the stable isotopic ratios of hydrogen (δ2H) and oxygen (δ18O) in human blood plasma. The stable isotopic ratio is defined and determined by δsampleâ=â[(Rsample/RSTD)â1] * 1000, where R is the molar ratio of rare to abundant, for example, 18O/16O. We observe that the δ2H and the δ18O in human blood plasma are associated with the human renal functions. The water isotope ratios of the δ2H and δ18O in human blood plasma of the control subjects are comparable to those of the diabetes subjects (with healthy kidney), but are statistically higher than those of the end stage renal disease subjects (p<0.001 for both ANOVA and Student's t-test). In addition, our data indicate the existence of the biological homeostasis of water isotopes in all subjects, except the end stage renal disease subjects under the haemodialysis treatment. Furthermore, the unexpected water contents (δ2H and δ18O) in blood plasma of body water may shed light on a novel assessment of renal functions
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