Outdoor air pollution and emergency department visits for asthma among children and adults: A case-crossover study in northern Alberta, Canada

<p>Abstract</p> <p>Background</p> <p>Recent studies have observed positive associations between outdoor air pollution and emergency department (ED) visits for asthma. However, few have examined the possible confounding influence of aeroallergens, or reported findings among very young children.</p> <p>Methods</p> <p>A time stratified case-crossover design was used to examine 57,912 ED asthma visits among individuals two years of age and older in the census metropolitan area of Edmonton, Canada between April 1, 1992 and March 31, 2002. Daily air pollution levels for the entire region were estimated from three fixed-site monitoring stations. Similarly, daily levels of aeroallergens were estimated using rotational impaction sampling methods for the period between 1996 and 2002. Odds ratios and their corresponding 95% confidence intervals were estimated using conditional logistic regression with adjustment for temperature, relative humidity and seasonal epidemics of viral related respiratory disease.</p> <p>Results</p> <p>Positive associations for asthma visits with outdoor air pollution levels were observed between April and September, but were absent during the remainder of the year. Effects were strongest among young children. Namely, an increase in the interquartile range of the 5-day average for NO₂and CO levels between April and September was associated with a 50% and 48% increase, respectively, in the number of ED visits among children 2 – 4 years of age (p < 0.05). Strong associations were also observed with these pollutants among those 75 years of age and older. Ozone and particulate matter were also associated with asthma visits. Air pollution risk estimates were largely unchanged after adjustment for aeroallergen levels.</p> <p>Conclusion</p> <p>Our findings, taken together, suggest that exposure to ambient levels of air pollution is an important determinant of ED visits for asthma, particularly among young children and the elderly.</p

Habitability on Early Mars and the Search for Biosignatures with the ExoMars Rover

The second ExoMars mission will be launched in 2020 to target an ancient location interpreted to have strong potential for past habitability and for preserving physical and chemical biosignatures (as well as abiotic/prebiotic organics). The mission will deliver a lander with instruments for atmospheric and geophysical investigations and a rover tasked with searching for signs of extinct life. The ExoMars rover will be equipped with a drill to collect material from outcrops and at depth down to 2 m. This subsurface sampling capability will provide the best chance yet to gain access to chemical biosignatures. Using the powerful Pasteur payload instruments, the ExoMars science team will conduct a holistic search for traces of life and seek corroborating geological context information. Key Words: Biosignatures—ExoMars—Landing sites—Mars rover—Search for life. Astrobiology 17, 471–510

Endothelial Progenitor Cells Enhance Islet Engraftment, Influence b-Cell Function, and Modulate Islet Connexin 36 Expression

This article has been made available by the publisher under a Creative Commons Attribution Non-Commercial (CC BY NC) license. https://www.cognizantcommunication.com/general-subscription-policies/open-access-policy Accessed 10/2/15The success of pancreatic islet transplantation is limited by delayed engraftment and suboptimal function in the longer term. Endothelial progenitor cells (EPCs) represent a potential cellular therapy that may improve the engraftment of transplanted pancreatic islets. In addition, EPCs may directly affect the function of pancreatic β-cells. The objective of this study was to examine the ability of EPCs to enhance pancreatic islet transplantation in a murine syngeneic marginal mass transplant model and to examine the mechanisms through which this occurs. We found that cotransplanted EPCs improved the cure rate and initial glycemic control of transplanted islets. Gene expression data indicate that EPCs, or their soluble products, modulate the expression of the β-cell surface molecule connexin 36 and affect glucose-stimulated insulin release in vitro. In conclusion, EPCs are a promising candidate for improving outcomes in islet transplantation, and their mechanisms of action warrant further study

Maternal Exposure to Aeroallergens and the Risk of Early Delivery.

BACKGROUND: Daily changes in aeroallergens during pregnancy could trigger early labor, but few investigations have evaluated this issue. This study aimed to investigate the association between exposure to aeroallergens during the week preceding birth and the risk of early delivery among preterm and term pregnancies. METHODS: We identified data on 225,234 singleton births that occurred in six large cities in the province of Ontario, Canada, from 2004 to 2011 (April to October) from a birth registry. We obtained daily counts of pollen grains and fungal spores from fixed-site monitoring stations in each city and assigned them to pregnancy period of each birth. Associations between exposure to aeroallergens in the preceding week and risk of delivery among preterm (<37 gestational weeks), early-term (37-38 weeks), and full-term (≥39 weeks) pregnancies were evaluated with Cox regression models, adjusting for maternal characteristics, meteorologic parameters, and air pollution concentrations, and pooled across the six cities. RESULTS: The risk of delivery increased by 3% per interquartile range width (IQRw = 22.1 grains/m) increase in weed pollen the day before birth among early-term (hazard ratio [HR] = 1.03; 95% confidence interval [CI]: 1.01, 1.05) and full-term pregnancies (HR = 1.03; 95% CI: 1.01, 1.04). Exposure to fungal spores cumulated over 0 to 2 lagged days was associated with increased risk of delivery among full-term pregnancies only (HR = 1.07; 95% CI: 1.01, 1.12). We observed no associations among preterm deliveries. CONCLUSIONS: Increasing concentrations of ambient weed pollen and fungal spores may be associated with earlier delivery among term births

Bayesian atmospheric tomography for detection and quantification of methane emissions : application to data from the 2015 Ginninderra release experiment

Detection and quantification of greenhouse-gas emissions is important for both compliance and environment conservation. However, despite several decades of active research, it remains predominantly an open problem, largely due to model errors and assumptions that appear at each stage of the inversion processing chain. In 2015, a controlled-release experiment headed by Geoscience Australia was carried out at the Ginninderra Controlled Release Facility, and a variety of instruments and methods were employed for quantifying the release rates of methane and carbon dioxide from a point source. This paper proposes a fully Bayesian approach to atmospheric tomography for inferring the methane emission rate of this point source using data collected during the experiment from both point-and path-sampling instruments. The Bayesian framework is designed to account for uncertainty in the parameterisations of measurements, the meteorological data, and the atmospheric model itself when performing inversion using Markov chain Monte Carlo (MCMC). We apply our framework to all instrument groups using measurements from two release-rate periods. We show that the inversion framework is robust to instrument type and meteorological conditions. From all the inversions we conducted across the different instrument groups and release-rate periods, our worst-case median emission rate estimate was within 36% of the true emission rate. Further, in the worst case, the closest limit of the 95% credible interval to the true emission rate was within 11% of this true value

Insulin-like growth factor-II (IGF-II) prevents proinflammatory cytokine-induced apoptosis and significantly improves islet survival after transplantation

BackgroundThe early loss of functional islet mass (50-70%) due to apoptosis after clinical transplantation contributes to islet allograft failure. Insulin-like growth factor (IGF)-II is an antiapoptotic protein that is highly expressed in β-cells during development but rapidly decreases in postnatal life.MethodsWe used an adenoviral (Ad) vector to overexpress IGF-II in isolated rat islets and investigated its antiapoptotic action against exogenous cytokines interleukin-1β- and interferon-γ-induced islet cell death in vitro. Using an immunocompromised marginal mass islet transplant model, the ability of Ad-IGF-II-transduced rat islets to restore euglycemia in nonobese diabetic/severe combined immunodeficient diabetic recipients was assessed.ResultsAd-IGF-II transduction did not affect islet viability or function. Ad-IGF-II cytokine-treated islets exhibited decreased cell death (40% ± 2.8%) versus Ad-GFP and untransduced control islets (63.2% ± 2.5% and 53.6% ± 2.3%, respectively). Ad-IGF-II overexpression during cytokine treatment resulted in a marked reduction in terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positive apoptotic cells (8.3% ± 1.4%) versus Ad-GFP control (41% ± 4.2%) and untransduced control islets (46.5% ± 6.2%). Western blot analysis confirmed that IGF-II inhibits apoptosis via activation of the phosphatidylinositol 3-kinase/Akt signaling pathway. Transplantation of IGF-II overexpressing islets under the kidney capsule of diabetic mice restored euglycemia in 77.8% of recipients compared with 18.2% and 47.5% of Ad-GFP and untransduced control islet recipients, respectively (PConclusionsAntiapoptotic IGF-II decreases apoptosis in vitro and significantly improved islet transplant outcomes in vivo. Antiapoptotic gene transfer is a potentially powerful tool to improve islet survival after transplantation.Hughes, Amy; Mohanasundaram, Daisy; Kireta, Svjetlana; Jessup, Claire F.; Drogemuller, Chris J.; Coates, P. Toby H

Temperature-related changes in airborne allergenic pollen abundance and seasonality across the northern hemisphere : a retrospective data analysis

BACKGROUND: Ongoing climate change might, through rising temperatures, alter allergenic pollen biology across the northern hemisphere. We aimed to analyse trends in pollen seasonality and pollen load and to establish whether there are specific climate-related links to any observed changes. METHODS: For this retrospective data analysis, we did an extensive search for global datasets with 20 years or more of airborne pollen data that consistently recorded pollen season indices (eg, duration and intensity). 17 locations across three continents with long-term (approximately 26 years on average) quantitative records of seasonal concentrations of multiple pollen (aeroallergen) taxa met the selection criteria. These datasets were analysed in the context of recent annual changes in maximum temperature (T) and minimum temperature (T) associated with anthropogenic climate change. Seasonal regressions (slopes) of variation in pollen load and pollen season duration over time were compared to T, cumulative degree day T, T, cumulative degree day T, and frost-free days among all 17 locations to ascertain significant correlations. FINDINGS: 12 (71%) of the 17 locations showed significant increases in seasonal cumulative pollen or annual pollen load. Similarly, 11 (65%) of the 17 locations showed a significant increase in pollen season duration over time, increasing, on average, 0·9 days per year. Across the northern hemisphere locations analysed, annual cumulative increases in T over time were significantly associated with percentage increases in seasonal pollen load (r=0·52, p=0·034) as were annual cumulative increases in T (r=0·61, p=0·010). Similar results were observed for pollen season duration, but only for cumulative degree days (higher than the freezing point [0°C or 32°F]) for T (r=0·53, p=0·030) and T (r=0·48, p=0·05). Additionally, temporal increases in frost-free days per year were significantly correlated with increases in both pollen load (r=0·62, p=0·008) and pollen season duration (r=0·68, p=0·003) when averaged for all 17 locations. INTERPRETATION: Our findings reveal that the ongoing increase in temperature extremes (T and T) might already be contributing to extended seasonal duration and increased pollen load for multiple aeroallergenic pollen taxa in diverse locations across the northern hemisphere. This study, done across multiple continents, highlights an important link between ongoing global warming and public health-one that could be exacerbated as temperatures continue to increase. FUNDING: None

The Ginninderra CH4 and CO2 release experiment: An evaluation of gas detection and quantification techniques

A methane (CH4) and carbon dioxide (CO2) release experiment was held from April to June 2015 at the Ginninderra Controlled Release Facility in Canberra, Australia. The experiment provided an opportunity to compare different emission quantification techniques against a simulated CH4 and CO2 point source release, where the actual release rates were unknown to the participants. Eight quantification techniques were assessed: three tracer ratio techniques (two mobile); backwards Lagrangian stochastic modelling; forwards Lagrangian stochastic modelling; Lagrangian stochastic (LS) footprint modelling; atmospheric tomography using point and using integrated line sensors. The majority of CH4 estimates were within 20% of the actual CH4 release rate (5.8 g/min), with the tracer ratio technique providing the closest estimate to both the CH4 and CO2 release rates (100 g/min). Once the release rate was known, the majority of revised estimates were within 10% of the actual release rate. The study illustrates the power of measuring the emission rate using multiple simultaneous methods and obtaining an ensemble median or mean. An ensemble approach to estimating the CH4 emission rate proved successful with the ensemble median estimate within 16% for the actual release rate for the blind release experiment and within 2% once the release rate was known. The release also provided an opportunity to assess the effectiveness of stationary and mobile ground and aerial CH4 detection technologies. Sensor detection limits and sampling rates were found to be significant limitations for CH4 and CO2 detection. A hyperspectral imager\u27s capacity to image the CH4 release from 100 m, and a Boreal CH4 laser sensor\u27s ability to track moving targets suggest the future possibility to map gas plumes using a single laser and mobile aerial reflector