Ground-Based Mobile Measurements to Track Urban Methane Emissions from Natural Gas in 12 Cities across Eight Countries.

To mitigate methane emission from urban natural gas distribution systems, it is crucial to understand local leak rates and occurrence rates. To explore urban methane emissions in cities outside the U.S., where significant emissions were found previously, mobile measurements were performed in 12 cities across eight countries. The surveyed cities range from medium size, like Groningen, NL, to large size, like Toronto, CA, and London, UK. Furthermore, this survey spanned across European regions from Barcelona, ES, to Bucharest, RO. The joint analysis of all data allows us to focus on general emission behavior for cities with different infrastructure and environmental conditions. We find that all cities have a spectrum of small, medium, and large methane sources in their domain. The emission rates found follow a heavy-tailed distribution, and the top 10% of emitters account for 60-80% of total emissions, which implies that strategic repair planning could help reduce emissions quickly. Furthermore, we compare our findings with inventory estimates for urban natural gas-related methane emissions from this sector in Europe. While cities with larger reported emissions were found to generally also have larger observed emissions, we find clear discrepancies between observation-based and inventory-based emission estimates for our 12 cities.

Gastrostomy with peritoneal collar versus percutaneous endoscopic gastrostomy.

Aim. The present study aimed to perform a medico-surgical comparative analysis of the 2 most widely used techniques: gastrostomy with peritoneal collar versus percutaneous endoscopic gastrostomy, based on the vast clinical experience in an Upper Digestive Surgery Clinic. Materials and method. A retrospective study was carried out between January 2010 and January 2015 on the patients admitted for a surgical solution for feeding. The indications, preoperative preparation, surgical techniques, and postoperative outcomes were analyzed. Results. Out of the 94 cases admitted for a surgical solution for feeding, 67 underwent gastrostomy with peritoneal collar (GPC) and in 27 cases percutaneous endoscopic gastrostomy (PEG) was performed. The indications for GPC were benign or malign causes of dysphagia, the most frequent being malign tumors of tongue, pharynx and larynx (47.76%), advanced inoperable esophageal or eso-cardiac cancers (26,86%), post-caustic esophageal stenosis (10.44%). PEG was performed in patients with functional difficulties of swallowing: sequelae of cerebral vascular accidents (44.44%), low Glasgow Coma Scale Score (29.62%) of different etiologies, Parkinson disease (18.51%) advanced dementia (7.4%), early nasopharyngeal cancer (2 cases). The intraoperatory and postoperatory complications were few and of minor importance in both techniques, but PEG allowed an immediate retake of alimentation (vs. at least 48 hours wait in GPC), with less gastric stasis, biliary reflux and aspiration related respiratory problems. Conclusions. Both techniques are easy and safe to perform, but an appropriate selection is required according to the cause of the swallowing difficulty. In cases with permeable digestive tube, PEG may be an excellent minimally invasive solution, but the costs and availability of the PEG kit and prehydrolyzed nutritive solution, as well as the co-existence of an upper digestive endoscopy service were limitations that had to be taken into account.