Late summer changes in burning conditions in the boreal regions and their implications for NO x and CO emissions from boreal fires

Copyright © 2008 American Geophysical Union. All Rights Reserved.Building emission inventories for the fires in boreal regions remains a challenging task with significant uncertainties in the methods used. In this work, we assess the impact of seasonal trends in fuel consumption and flaming/smoldering ratios on emissions of species dominated by flaming combustion (e.g., NO x ) and species dominated by smoldering combustion (e.g., CO). This is accomplished using measurements of CO and NO y at the free tropospheric Pico Mountain observatory in the central North Atlantic during the active boreal fire seasons of 2004 and 2005. ΔNO y /ΔCO enhancement ratios in aged fire plumes had higher values in June-July (7.3 × 10−3 mol mol−1) relative to the values in August-September (2.8 × 10−3 mol mol−1), indicating that NO x /CO emission ratios declined significantly as the fire season progressed. This is consistent with our understanding that an increased amount of fuel is consumed via smoldering combustion during late summer, as deeper burning of the drying organic soil layer occurs. A major growth in fuel consumption per unit area is also expected, due to deeper burning. Emissions of CO and NO x from North American boreal fires were estimated using the Boreal Wildland Fire Emissions Model, and their long-range transport to the sampling site was modeled using FLEXPART. These simulations were generally consistent with the observations, but the modeled seasonal decline in the ΔNO y /ΔCO enhancement ratio was less than observed. Comparisons using alternative fire emission injection height scenarios suggest that plumes with the highest CO levels at the observatory were lofted well above the boundary layer, likely as a result of intense crown fires

Metformin versus placebo in obese pregnant women without diabetes mellitus

Background: Obesity is associated with increased risk of adverse pregnancy outcomes. Lifestyle intervention studies have not improved outcome. Metformin improves insulin sensitivity and leads to less weight gain. Methods: Our double-blind placebo-controlled trial randomized non-diabetic pregnant women with a body mass index >35 kg/m2 to metformin or placebo from 12-18 weeks’ gestation until delivery. Primary outcome was median neonatal birth weight z-score reduction by 0.3 standard deviations (equivalent to a 50% reduction in incidence of large-for-gestational-age neonates from 20% to 10%). Secondary outcomes included maternal gestational weight gain and incidence of gestational diabetes, and preeclampsia, as well as adverse neonatal outcomes. Women were randomized, by computer generated random numbers, to either daily metformin 3.0 grams (n=225) or to placebo (n=225). Analysis was by intention to treat. Results: Fifty women withdrew consent, leaving 202 in the metformin group and 198 in the placebo group. There was no significant difference in median neonatal birth weight z-score (metformin: 0.05, IQR -0.71 to 0.92; placebo: 0.17, IQR -0.62 to 0.89; p=0.655). In the metformin group, compared to placebo, median maternal gestational weight gain was lower (4.6 kg, IQR 1.3-7.2 vs. 6.3 kg, IQR 2.9-9.2, p<0.0001) and incidence of preeclampsia was lower (3.0% vs 11.3%; odds ratio 0.24, 95% CI 0.10-0.61; p=0.001), incidence of side effects was higher; there were no significant differences in gestational diabetes, large for gestational age neonates and adverse neonatal outcomes. Conclusions: In non-diabetic women with BMI >35 kg/m2, antenatal administration of metformin reduces maternal weight gain but not neonatal birth weight. (ClinicalTrials.gov number, NCT01273584

Does regulating private long-term care facilities lead to better care? a study from Quebec, Canada

Objective. In the province of Quebec, Canada, long-term residential care is provided by 2 types of facilities: publicly-funded accredited facilities and privately-owned facilities in which care is privately financed and delivered. Following evidence that private facilities were delivering inadequate care, the provincial government decided to regulate this industry. We assessed the impact of regulation on care quality by comparing quality assessments made before and after regulation. In both periods, public facilities served as a comparison group. Design: A cross-sectional study conducted in 2010-2012 that incorporates data collected in 1995-2000. Settings. Random samples of private and public facilities from 2 regions of Quebec. Participants. Random samples of disabled residents aged 65 years and over. In total, 451 residents from 145 care settings assessed in 1995-2000 were compared to 329 residents from 102 care settings assessed in 2010-2012. Intervention. Regulation introduced by the province in 2005, effective February 2007. Main outcome measure. Quality of care measured with the QUALCARE Scale. Results. After regulation, fewer small-size facilities were in operation in the private market. Between the 2 study periods, the proportion of residents with severe disabilities decreased in private facilities while it remained over 80% in their public counterparts. Meanwhile, quality of care improved significantly in private facilities, while worsening in their public counterparts, even after controlling for confounding. Conclusions. The private industry now provides better care to its residents. Improvement in care quality likely results in part from the closure of small homes and change in resident case-mix

The influence of boreal biomass burning emissions on the distribution of tropospheric ozone over North America and the North Atlantic during 2010

We have analysed the sensitivity of the tropospheric ozone distribution over North America and the North Atlantic to boreal biomass burning emissions during the summer of 2010 using the GEOS-Chem 3-D global tropospheric chemical transport model and observations from in situ and satellite instruments. We show that the model ozone distribution is consistent with observations from the Pico Mountain Observatory in the Azores, ozonesondes across Canada, and the Tropospheric Emission Spectrometer (TES) and Infrared Atmospheric Sounding Instrument (IASI) satellite instruments. Mean biases between the model and observed ozone mixing ratio in the free troposphere were less than 10 ppbv. We used the adjoint of GEOS-Chem to show the model ozone distribution in the free troposphere over Maritime Canada is largely sensitive to NO&lt;sub&gt;x&lt;/sub&gt; emissions from biomass burning sources in Central Canada, lightning sources in the central US, and anthropogenic sources in the eastern US and south-eastern Canada. We also used the adjoint of GEOS-Chem to evaluate the Fire Locating And Monitoring of Burning Emissions (FLAMBE) inventory through assimilation of CO observations from the Measurements Of Pollution In The Troposphere (MOPITT) satellite instrument. The CO inversion showed that, on average, the FLAMBE emissions needed to be reduced to 89% of their original values, with scaling factors ranging from 12% to 102%, to fit the MOPITT observations in the boreal regions. Applying the CO scaling factors to all species emitted from boreal biomass burning sources led to a decrease of the model tropospheric distributions of CO, PAN, and NO&lt;sub&gt;x&lt;/sub&gt; by as much as −20 ppbv, −50 pptv, and −20 pptv respectively. The modification of the biomass burning emission estimates reduced the model ozone distribution by approximately −3 ppbv (−8%) and on average improved the agreement of the model ozone distribution compared to the observations throughout the free troposphere, reducing the mean model bias from 5.5 to 4.0 ppbv for the Pico Mountain Observatory, 3.0 to 0.9 ppbv for ozonesondes, 2.0 to 0.9 ppbv for TES, and 2.8 to 1.4 ppbv for IASI

The influence of boreal biomass burning emissions on the distribution of tropospheric ozone over North America and the North Atlantic during 2010

We have analysed the sensitivity of the tropospheric ozone distribution over North America and the North Atlantic to boreal biomass burning emissions during the summer of 2010 using the GEOS-Chem 3-D global tropospheric chemical transport model and observations from in situ and satellite instruments. We show that the model ozone distribution is consistent with observations from the Pico Mountain Observatory in the Azores, ozonesondes across Canada, and the Tropospheric Emission Spectrometer (TES) and Infrared Atmospheric Sounding Instrument (IASI) satellite instruments. Mean biases between the model and observed ozone mixing ratio in the free troposphere were less than 10 ppbv. We used the adjoint of GEOS-Chem to show the model ozone distribution in the free troposphere over Maritime Canada is largely sensitive to NOx emissions from biomass burning sources in Central Canada, lightning sources in the central US, and anthropogenic sources in the eastern US and south-eastern Canada. We also used the adjoint of GEOS-Chem to evaluate the Fire Locating And Monitoring of Burning Emissions (FLAMBE) inventory through assimilation of CO observations from the Measurements Of Pollution In The Troposphere (MOPITT) satellite instrument. The CO inversion showed that, on average, the FLAMBE emissions needed to be reduced to 89% of their original values, with scaling factors ranging from 12% to 102%, to fit the MOPITT observations in the boreal regions. Applying the CO scaling factors to all species emitted from boreal biomass burning sources led to a decrease of the model tropospheric distributions of CO, PAN, and NOx by as much as -20 ppbv, -50 pptv, and -20 pptv respectively. The modification of the biomass burning emission estimates reduced the model ozone distribution by approximately -3 ppbv (-8%) and on average improved the agreement of the model ozone distribution compared to the observations throughout the free troposphere, reducing the mean model bias from 5.5 to 4.0 ppbv for the Pico Mountain Observatory, 3.0 to 0.9 ppbv for ozonesondes, 2.0 to 0.9 ppbv for TES, and 2.8 to 1.4 ppbv for IASI

Impact of Body Mass Index on Tumor Recurrence Among Patients Undergoing Curative - Intent Resection of Intrahepatic Cholangiocarcinoma - a Multi-institutional International Analysis

Background: The association between body mass index (BMI) and long-term outcomes of patients with ICC has not been well defined. We sought to define the presentation and oncologic outcomes of patients with ICC undergoing curative-intent resection, according to their BMI category. Methods: Patients who underwent resection of ICC were identified in a multi-institutional database. Patients were categorized as normal weight (BMI 18.5-24.9 kg/m2), overweight (BMI 25.0-29.9 kg/m2) and obese (BMI≥30 kg/m2) according to the World Health Organization (WHO) definition. Impact of clinico-pathological factors on recurrence-free survival (RFS) was assessed using Cox proportional hazards model among patients in the three BMI categories. Results: Among a total of 790 patients undergoing curative-intent resection of ICC in the analytic cohort, 399 (50.5%) had normal weight, 274 (34.7%) were overweight and 117 (14.8%) were obese. Caucasian patients were more likely to be obese (66.7%, n = 78) and overweight (47.1%, n = 129) compared with Asian (obese: 18.8%, n = 22; overweight: 46%, n = 126) and other races (obese: 14.5%, n = 17; overweight: 6.9%, n = 19)(p 0.05). On multivariable analysis, increased BMI was an independent risk factor for tumor recurrence (OR 1.16, 95% CI 1.02-1.32, for every 5 unit increase). Conclusion: Increasing BMI was associated with incremental increases in the risk of recurrence following curative-intent resection of ICC. Future studies should aim to achieve a better understanding of BMI-related factors relative to prognosis of patients with ICC.info:eu-repo/semantics/publishedVersio

Dosimetric accuracy of a deterministic radiation transport based 192Ir brachytherapy treatment planning system: Part III. Comparison to Monte Carlo simulation in voxelized anatomical computational models

To compare TG43-based and Acuros deterministic radiation transport-based calculations of the BrachyVision treatment planning system (TPS) with corresponding Monte Carlo (MC) simulation results in heterogeneous patient geometries, in order to validate Acuros and quantify the accuracy improvement it marks relative to TG43

Effect of Surgical Margin Width on Patterns of Recurrence among Patients Undergoing R0 Hepatectomy for T1 Hepatocellular Carcinoma: an International Multi-Institutional Analysis

Introduction: Although a positive surgical margin is a known prognostic factor for recurrence, the optimal surgical margin width in the context of an R0 resection for early-stage hepatocellular carcinoma (HCC) is still debated. The aim of the current study was to examine the impact of wide (> 1 cm) versus narrow (< 1 cm) surgical margin status on the incidence and recurrence patterns among patients with T1 HCC undergoing an R0 hepatectomy. Methods: Between 1998 and 2017, patients with T1 HCC who underwent R0 hepatectomy for stage T1 HCC were identified using an international multi-institutional database. Recurrence-free survival (RFS) was estimated, and recurrence patterns were examined based on whether patients had a wide versus narrow resection margins. Results: Among 404 patients, median patient age was 66 years (IQR: 58-73). Most patients (n = 326, 80.7%) had surgical margin 1 cm margin. The majority of patients had early recurrences ( 1 cm: 85.7%, p = 0.141); recurrence site was mostly intrahepatic ( 1 cm: 61.9%, p = 0.169). The 1-, 3-, and 5-year RFS among patients with margin 1 cm, respectively (p = 0.02). Among patients undergoing anatomic resection, resection margin did not impact RFS (3-year RFS: 1 cm: 58.9%, p = 0.169), whereas in the non-anatomic resection group, margin width > 1 cm was associated with a better 3-year RFS compared to margin 1 cm remained protective against recurrence (HR = 0.50, 95%CI 0.28-0.89), whereas Child-Pugh B (HR = 2.13, 95%CI 1.09-4.15), AFP > 20 ng/mL (HR = 1.71, 95%CI 1.18-2.48), and presence of microscopic lymphovascular invasion (HR = 1.48, 95%CI 1.01-2.18) were associated with a higher hazard of recurrence. Conclusion: Resection margins > 1 cm predicted better RFS among patients undergoing R0 hepatectomy for T1 HCC, especially small (< 5 cm) HCC. Although resection margin width did not influence outcomes after anatomic resection, wider margins were more important among patients undergoing non-anatomic liver resections.info:eu-repo/semantics/publishedVersio

Prognosis After Resection of Barcelona Clinic Liver Cancer (BCLC) Stage 0, A, and B Hepatocellular Carcinoma: A Comprehensive Assessment of the Current BCLC Classification

Background: Although the Barcelona Clinic Liver Cancer (BCLC) staging system has been largely adopted in clinical practice, recent studies have questioned the prognostic stratification of this classification schema, as well as the proposed treatment allocation of patients with a single large tumor. Methods: Patients who underwent curative-intent hepatectomy for histologically proven hepatocellular carcinoma (HCC) between 1998 and 2017 were identified using an international multi-institutional database. Overall survival (OS) among patients with BCLC stage 0, A, and B was examined. Patients with a single large tumor were classified as BCLC stage A1 and were independently assessed. Results: Among 814 patients, 68 (8.4%) were BCLC-0, 310 (38.1%) were BCLC-A, 279 (34.3%) were BCLC-A1, and 157 (19.3%) were BCLC-B. Five-year OS among patients with BCLC stage 0, A, A1, and B HCC was 86.2%, 69.0%, 56.9%, and 49.9%, respectively (p < 0.001). Among patients with very early- and early-stage HCC (BCLC 0, A, and A1), patients with BCLC stage A1 had the worst OS (p = 0.0016). No difference in survival was noted among patients undergoing surgery for BCLC stage A1 and B HCC (5-year OS: 56.9% vs. 49.9%; p = 0.259) even after adjusting for competing factors (hazard ratio 0.83, 95% confidence interval 0.54-1.28; p = 0.40). Conclusion: Prognosis following liver resection among patients with BCLC-A1 HCC was similar to patients presenting with BCLC-B tumors. Surgery provided acceptable long-term outcomes among select patients with BCLC-B HCC. Designation into BCLC stage B should not be considered an a priori contraindication to surgery.info:eu-repo/semantics/publishedVersio