New contributions of measurements in Europe to the global inventory of the stable isotopic composition of methane

Recent climate change mitigation strategies rely on the reduction of methane (CH4) emissions. Carbon and hydrogen isotope ratio (δ13CCH4 and δ2HCH4) measurements can be used to distinguish sources and thus to understand the CH4 budget better. The CH4 emission estimates by models are sensitive to the isotopic signatures assigned to each source category, so it is important to provide representative estimates of the different CH4 source isotopic signatures worldwide. We present new measurements of isotope signatures of various, mainly anthropogenic, CH4 sources in Europe, which represent a substantial contribution to the global dataset of source isotopic measurements from the literature, especially for δ2HCH4. They improve the definition of δ13CCH4 from waste sources, and demonstrate the use of δ2HCH4 for fossil fuel source attribution. We combined our new measurements with the last published database of CH4 isotopic signatures and with additional literature, and present a new global database. We found that microbial sources are generally well characterised. The large variability in fossil fuel isotopic compositions requires particular care in the choice of weighting criteria for the calculation of a representative global value. The global dataset could be further improved by measurements from African, South American, and Asian countries, and more measurements from pyrogenic sources. We improved the source characterisation of CH4 emissions using stable isotopes and associated uncertainty, to be used in top-down studies. We emphasise that an appropriate use of the database requires the analysis of specific parameters in relation to source type and the region of interest. The final version of the European CH4 isotope database coupled with a global inventory of fossil and non-fossil δ13CCH4 and δ2HCH4 source signature measurements is available at 10.24416/UU01-YP43IN

Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants

Summary Background Comparable global data on health and nutrition of school-aged children and adolescents are scarce. We aimed to estimate age trajectories and time trends in mean height and mean body-mass index (BMI), which measures weight gain beyond what is expected from height gain, for school-aged children and adolescents. Methods For this pooled analysis, we used a database of cardiometabolic risk factors collated by the Non-Communicable Disease Risk Factor Collaboration. We applied a Bayesian hierarchical model to estimate trends from 1985 to 2019 in mean height and mean BMI in 1-year age groups for ages 5–19 years. The model allowed for non-linear changes over time in mean height and mean BMI and for non-linear changes with age of children and adolescents, including periods of rapid growth during adolescence. Findings We pooled data from 2181 population-based studies, with measurements of height and weight in 65 million participants in 200 countries and territories. In 2019, we estimated a difference of 20 cm or higher in mean height of 19-year-old adolescents between countries with the tallest populations (the Netherlands, Montenegro, Estonia, and Bosnia and Herzegovina for boys; and the Netherlands, Montenegro, Denmark, and Iceland for girls) and those with the shortest populations (Timor-Leste, Laos, Solomon Islands, and Papua New Guinea for boys; and Guatemala, Bangladesh, Nepal, and Timor-Leste for girls). In the same year, the difference between the highest mean BMI (in Pacific island countries, Kuwait, Bahrain, The Bahamas, Chile, the USA, and New Zealand for both boys and girls and in South Africa for girls) and lowest mean BMI (in India, Bangladesh, Timor-Leste, Ethiopia, and Chad for boys and girls; and in Japan and Romania for girls) was approximately 9–10 kg/m2. In some countries, children aged 5 years started with healthier height or BMI than the global median and, in some cases, as healthy as the best performing countries, but they became progressively less healthy compared with their comparators as they grew older by not growing as tall (eg, boys in Austria and Barbados, and girls in Belgium and Puerto Rico) or gaining too much weight for their height (eg, girls and boys in Kuwait, Bahrain, Fiji, Jamaica, and Mexico; and girls in South Africa and New Zealand). In other countries, growing children overtook the height of their comparators (eg, Latvia, Czech Republic, Morocco, and Iran) or curbed their weight gain (eg, Italy, France, and Croatia) in late childhood and adolescence. When changes in both height and BMI were considered, girls in South Korea, Vietnam, Saudi Arabia, Turkey, and some central Asian countries (eg, Armenia and Azerbaijan), and boys in central and western Europe (eg, Portugal, Denmark, Poland, and Montenegro) had the healthiest changes in anthropometric status over the past 3·5 decades because, compared with children and adolescents in other countries, they had a much larger gain in height than they did in BMI. The unhealthiest changes—gaining too little height, too much weight for their height compared with children in other countries, or both—occurred in many countries in sub-Saharan Africa, New Zealand, and the USA for boys and girls; in Malaysia and some Pacific island nations for boys; and in Mexico for girls. Interpretation The height and BMI trajectories over age and time of school-aged children and adolescents are highly variable across countries, which indicates heterogeneous nutritional quality and lifelong health advantages and risks

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Methane mapping, emission quantification, and attribution in two European cities: Utrecht (NL) and Hamburg (DE)

Characterizing and attributing methane (CH4) emissions across varying scales are important from environmental, safety, and economic perspectives and are essential for designing and evaluating effective mitigation strategies. Mobile real-time measurements of CH4 in ambient air offer a fast and effective method to identify and quantify local CH4 emissions in urban areas. We carried out extensive campaigns to measure CH4 mole fractions at the street level in Utrecht, the Netherlands (2018 and 2019), and Hamburg, Germany (2018). We detected 145 leak indications (LIs; i.e., CH4 enhancements of more than 10% above background levels) in Hamburg and 81 LIs in Utrecht. Measurements of the ethane-to-methane ratio (C2:C1), methane-to-carbon dioxide ratio (CH4:CO2), and CH4 isotope composition (δ13C and δD) show that in Hamburg about 1/3 of the LIs, and in Utrecht 2/3 of the LIs (based on a limited set of C2:C1 measurements), were of fossil fuel origin. We find that in both cities the largest emission rates in the identified LI distribution are from fossil fuel sources. In Hamburg, the lower emission rates in the identified LI distribution are often associated with biogenic characteristics or (partly) combustion. Extrapolation of detected LI rates along the roads driven to the gas distribution pipes in the entire road network yields total emissions from sources that can be quantified in the street-level surveys of 440±70tyr-1 from all sources in Hamburg and 150±50tyr-1 for Utrecht. In Hamburg, C2:C1, CH4:CO2, and isotope-based source attributions show that 50%-80% of all emissions originate from the natural gas distribution network; in Utrecht more limited attribution indicates that 70%-90% of the emissions are of fossil origin. Our results confirm previous observations that a few large LIs, creating a heavy tail, are responsible for a significant proportion of fossil CH4 emissions. In Utrecht, 1/3 of total emissions originated from one LI and in Hamburg > 1/4 from two LIs. The largest leaks were located and fixed quickly by GasNetz Hamburg once the LIs were shared, but 80% of the (smaller) LIs attributed to the fossil category could not be detected and/or confirmed as pipeline leaks. This issue requires further investigation

Methane mapping, emission quantification, and attribution in two European cities: Utrecht (NL) and Hamburg (DE)

Characterizing and attributing methane (CH4) emissions across varying scales are important from environmental, safety, and economic perspectives and are essential for designing and evaluating effective mitigation strategies. Mobile real-time measurements of CH4 in ambient air offer a fast and effective method to identify and quantify local CH4 emissions in urban areas. We carried out extensive campaigns to measure CH4 mole fractions at the street level in Utrecht, the Netherlands (2018 and 2019), and Hamburg, Germany (2018). We detected 145 leak indications (LIs; i.e., CH4 enhancements of more than 10% above background levels) in Hamburg and 81 LIs in Utrecht. Measurements of the ethane-to-methane ratio (C2:C1), methane-to-carbon dioxide ratio (CH4:CO2), and CH4 isotope composition (δ13C and δD) show that in Hamburg about 1/3 of the LIs, and in Utrecht 2/3 of the LIs (based on a limited set of C2:C1 measurements), were of fossil fuel origin. We find that in both cities the largest emission rates in the identified LI distribution are from fossil fuel sources. In Hamburg, the lower emission rates in the identified LI distribution are often associated with biogenic characteristics or (partly) combustion. Extrapolation of detected LI rates along the roads driven to the gas distribution pipes in the entire road network yields total emissions from sources that can be quantified in the street-level surveys of 440±70tyr-1 from all sources in Hamburg and 150±50tyr-1 for Utrecht. In Hamburg, C2:C1, CH4:CO2, and isotope-based source attributions show that 50%-80% of all emissions originate from the natural gas distribution network; in Utrecht more limited attribution indicates that 70%-90% of the emissions are of fossil origin. Our results confirm previous observations that a few large LIs, creating a heavy tail, are responsible for a significant proportion of fossil CH4 emissions. In Utrecht, 1/3 of total emissions originated from one LI and in Hamburg > 1/4 from two LIs. The largest leaks were located and fixed quickly by GasNetz Hamburg once the LIs were shared, but 80% of the (smaller) LIs attributed to the fossil category could not be detected and/or confirmed as pipeline leaks. This issue requires further investigation

Mesenchymal Stem Cell (MSC) Based Cord Blood (CB) Expansion (Exp) Leads to Rapid Engraftment of Platelets and Neutrophils

Abstract Abstract 362 Delayed engraftment and low rates of platelet transfusion independence are frequently observed after CB transplantation (CBT). We conducted a study of ex-vivo co-culture of CB mononuclear cells with either third party haploidentical family member marrow derived MSCs (N=8) or off-the-shelf mesenchymal progenitor cells (MPCs) from Angioblast (N=24). Patients received a double cord blood transplant, with one of the 2 units undergoing ex vivo expansion using this system. MSCs create a microenvironment that promotes expansion and fosters the differentiation of hematopoietic cells. Patients must have had two CB units matched in at least 4/6 HLA antigens, with a minimum of 1×107 TNC/Kg per unit. Method: Diagnoses were AML/MDS (n=21), ALL (n=6), NHL (n=2), CLL (n=2), and HD (n=1). Fourteen patients (44%) were in CR (CR1, n=3, CR2 or more, n=11) and 18 (56%) had active disease at CBT. Preparative regimen: myeloablative fludarabine, melphalan, thiotepa and ATG (n=32), with rituximab in the 4 NHL/CLL cases. GVHD prophylaxis: tacrolimus and MMF. Median weight was 75.2 Kg (range, 15–118) and median age was 35.3 years (2.8-62 years). Donor-recipient HLA matching was 6 of 6 in 5%, 5 of 6 in 28% and 4 of 6 in 67% of the cases, respectively. Ex-vivo EXP: 100 ml of marrow was aspirated from the family donor and MSCs generated in ten T175 flasks, which took ∼21 days (n=8) or one vial of Angioblast MPCs was thawed and expanded to confluence in 10 flasks within 4 days (n=24). The CB unit with the lowest TNC dose was then thawed, divided into 10 fractions, and each placed into 1 flask containing the confluent layers of MSCs in expansion media with SCF, FLT3-ligand, G-CSF and TPO. After 7 days at 37°C, the non-adherent cells were removed from each flask, placed into each of ten one-liter Teflon-coated culture bags (American Fluoroseal) and cultured for an additional 7 days (14 days total), while 50 ml of media/growth factors was added to the flasks to culture the remaining adherent layer during that time period. On day 14 the cells from the bags and the flasks were combined, washed and infused along with a second unmanipulated CB unit. Result: The median number of total nucleated cell (TNC) and CD34+ cells infused/Kg in unmanipulated CB was 2.35 × 107 (range 0.2–8.2) and 0.95 × 105 (range 0–4). The median number of TNC and CD34+ cells infused/Kg after EXP was 5.8 × 107 (range, 0.3–14.4) and 8.7 × 105 (range, 0–93.4). This represented a median expansion of 14-fold (range 1–30) for TNC and 40-fold (range 4–140) for the CD34+ cells. Median time to neutrophil and platelet engraftment was 15 days (range 9–42) and 40 days (range 13–62). There were no toxicities attributable to the EXP cells. Thirty-one (97%) and 26 (81%) of all patients engrafted neutrophils and platelets, respectively. One patient died before engraftment. Thirty and one-hundred day non-relapse mortality is respectively 6% and 19%. Median donor(s) chimerism was 100% in the mononuclear, T lymphocyte and myeloid cell populations. On transplant day+21, EXP unit contributed with a mean of 19% of mononuclear cell, 16% of T cell, and 14% of myeloid chimerism. Subsequently, hematopoiesis was increasingly derived from the unexpanded unit with long-term engraftment provided by the unexpanded unit by six months posttransplant. Acute grade II-IV and III-IV GVHD rate was 50% and 16%; 25% of the grade II-IV GVHDs occurred beyond 100 days, and two patients developed chronic GVHD. With a median follow-up of 9 months, 11 patients are alive; actuarial one-year survival is 40%. Mortality was due to relapse in 26% and non-relapse causes in 74% of patients. Conclusion: MSC-CB Exp is feasible and leads to fast engraftment of neutrophils and platelets, and high-rates of platelet transfusion independence. Disclosures: No relevant conflicts of interest to declare

New contributions of measurements in Europe to the global inventory of the stable isotopic composition of methane

International audienceAbstract. Recent climate change mitigation strategies rely on the reduction of methane (CH4) emissions. Carbon and hydrogen isotope ratio (δ13CCH4 and δ2HCH4) measurements can be used to distinguish sources and thus to understand the CH4 budget better. The CH4 emission estimates by models are sensitive to the isotopic signatures assigned to each source category, so it is important to provide representative estimates of the different CH4 source isotopic signatures worldwide. We present new measurements of isotope signatures of various, mainly anthropogenic, CH4 sources in Europe, which represent a substantial contribution to the global dataset of source isotopic measurements from the literature, especially for δ2HCH4. They improve the definition of δ13CCH4 from waste sources, and demonstrate the use of δ2HCH4 for fossil fuel source attribution. We combined our new measurements with the last published database of CH4 isotopic signatures and with additional literature, and present a new global database. We found that microbial sources are generally well characterised. The large variability in fossil fuel isotopic compositions requires particular care in the choice of weighting criteria for the calculation of a representative global value. The global dataset could be further improved by measurements from African, South American, and Asian countries, and more measurements from pyrogenic sources. We improved the source characterisation of CH4 emissions using stable isotopes and associated uncertainty, to be used in top-down studies. We emphasise that an appropriate use of the database requires the analysis of specific parameters in relation to source type and the region of interest. The final version of the European CH4 isotope database coupled with a global inventory of fossil and non-fossil δ13CCH4 and δ2HCH4 source signature measurements is available at https://doi.org/10.24416/UU01-YP43IN (Menoud et al., 2022a)