Reversal of Long-Term Trends in Ethane Identified from the Global Atmosphere Watch Reactive Gases Measurement Network

Reactive gases play an important role in climate and air pollution issues. They control the self-cleansing capability of the troposphere, contribute to air pollution and acid deposition, regulate the lifetimes and provide tracers for deciphering sources and sinks for greenhouse gases. Within GAW, the focus is placed on long-term, high-quality observations of ozone (O3), carbon monoxide (CO), volatile organic compounds (VOC), nitrogen oxides (NOx), and sulfur dioxide (SO2). More than 100 stations worldwide carry out reactive gases measurements with data reported to two World Data Centers. The reactive gases program in GAW cooperates The WMO GAW Reactive Gases Program with regional networks and other global monitoring initiatives in order to attain a complete picture of the tropospheric chemical composition. Observations are being made by in-situ monitoring, measurements from commercial routine air-crafts (e.g. IAGOS), column observations, and from flask sampling networks. Quality control and coordination of measurements between participating stations are a primary emphasis. GAW reactive gases data in rapid delivery mode are used to evaluate operational atmospheric composition forecasts in the EU Copernicus Atmospheric Monitoring Service. Oversight of the program is provided by GAW-WMO coordinated Reactive Gases Scientific Advisory Committee (RG-SAG)

Volatile organic compounds and isoprene oxidation products at a temperate deciduous forest site

Biogenic volatile organic compounds (BVOCs) and their role in atmospheric oxidant formation were investigated at a forest site near Oak Ridge, Tennessee, as part of the Nashville Southern Oxidants Study (SOS) in July 1995. Of 98 VOCs detected, a major fraction were anthropogenic VOCs such as chlorofluorocarbons (CFCs), alkanes, alkenes and aromatic compounds. Isoprene was the dominant BVOC during daytime. Primary products from BVOC oxidation were methylvinylketone, methacrolein and 3-methylfuran. Other compounds studied include the BVOCs α-pinene, camphene, β-pinene, p-cymene, limonene and cis-3-hexenyl acetate and a series of light alkanes, aromatic hydrocarbons and seven of the CFCs. The correlation of meteorological parameters, with the mixing ratios of these different compounds, reveals information on atmospheric oxidation processes and transport. Long-lived VOCs show very steady mixing ratio time series. Regionally and anthropogenically emitted VOCs display distinct diurnal cycles with a strong mixing ratio decrease in the morning from the breakup of the nocturnal boundary layer. Nighttime mixing ratio increases of CFCs and anthropogenic VOCs are suspected to derive from emissions within the Knoxville urban area into the shallow nocturnal boundary layer. In contrast, the time series of BVOCs and their oxidation products are determined by a combination of emission control, atmospheric oxidation and deposition, and boundary layer dynamics. Mixing ratio tune series data for monoterpenes and cis-3-hexenyl acetate suggest a temporarily emission rate increase during and after heavy rain events. The isoprene oxidation products demonstrate differences in the oxidation pathways during night and day and in their dry and wet deposition rates. Copyright 1998 by the American Geophysical Union

Adverse childhood experiences and autonomic regulation in response to acute stress : the role of the sympathetic and parasympathetic nervous systems

Background and objectives: After a previous report demonstrated blunted heart rate (HR) reactivity in association with adverse childhood experiences (ACEs) [Voellmin, A., Winzeler, K., Hug, E., Wilhelm, F. H., Schaefer, V., Gaab, J., … Bader, K. (2015). Blunted endocrine and cardiovascular reactivity in young healthy women reporting a history of childhood adversity. Psychoneuroendocrinology, 51, 58–67. doi:10.1016/j.psyneuen.2014.09.008], the present analysis aimed at clarifying the role of the sympathetic and parasympathetic branches of the autonomic nervous system in this relationship.Design and Methods: One hundred eighteen healthy young women provided data on ACEs and underwent psychosocial stress testing. Systolic blood pressure (SBP) and respiratory sinus arrhythmia (RSA, quantified by high-frequency HR variability) were assessed as measures of sympathetic and parasympathetic cardiovascular activity, respectively. A mediation model was calculated to test the indirect effects of ACEs on HR via SBP and RSA.Results: The effect of ACEs on HR reactivity was mediated by SBP reactivity but not by RSA reactivity. ACEs were associated with reduced SBP at rest.Conclusions: ACEs were associated with down-regulation in a measure of sympathetic but no alteration in a measure of parasympathetic cardiovascular stress reactivity in adulthood. Future research will need to clarify whether this indicates risk or resilience.publishe

Genetic analysis of Streptococcus agalactiae strains isolated from neonates and their mothers.

Item does not contain fulltextStreptococcus agalactiae or group B streptococcus (GBS) is the most common cause of neonatal sepsis and meningitis in neonates. One of the major questions is whether the GBS strains able to cause neonatal invasive disease have peculiar genetic features. A collection of S. agalactiae strains, isolated from cervix, vagina and rectum of 10 mothers and from throat, ear and umbilicus of their newborns was genetically characterized by pulsed-field gel electrophoresis (PFGE). This study demonstrated that the strains isolated from each mother and her child were all genetically identical but that the strains from the 10 mother/child pairs mutually were genetically heterogeneous and 10 different PFGE patterns were found. Although it has been suggested that PFGE would be able to identify virulence traits to direct decisions in antibiotic management, the heterogeneous feature of GBS strains does not support broad application

The Role of Snow in Controlling Halogen Chemistry and Boundary Layer Oxidation During Arctic Spring: A 1D Modeling Case Study

International audienceReactive chlorine and bromine species emitted from snow and aerosols can significantly alter the oxidative capacity of the polar boundary layer. However, halogen production mechanisms from snow remain highly uncertain, making it difficult for most models to include descriptions of halogen snow emissions and to understand the impact on atmospheric chemistry. We investigate the influence of Arctic halogen emissions from snow on boundary layer oxidation processes using a one-dimensional atmospheric chemistry and transport model (PACT-1D). To understand the combined impact of snow emissions and boundary layer dynamics on atmospheric chemistry, we model Cl2 and Br2 primary emissions from snow and include heterogeneous recycling of halogens on both snow and aerosols. We focus on a 2-day case study from the 2009 Ocean-Atmosphere-Sea Ice-Snowpack campaign at Utqiaġvik, Alaska. The model reproduces both the diurnal cycle and high quantity of Cl2 observed, along with the measured concentrations of Br2, BrO, and HOBr. Due to the combined effects of emissions, recycling, vertical mixing, and atmospheric chemistry, reactive chlorine is typically confined to the lowest 15 m of the atmosphere, while bromine can impact chemistry up to and above the surface inversion height. Upon including halogen emissions and recycling, the concentration of HOx (HOx = OH + HO2) at the surface increases by as much as a factor of 30 at mid-day. The change in HOx due to halogen chemistry, as well as chlorine atoms derived from snow emissions, significantly reduce volatile organic compound lifetimes within a shallow layer near the surface

Antarctic Tropospheric Chemistry Investigation (ANTCI) 2003 overview

The Antarctic Tropospheric Chemistry Investigation (ANTCI) was carried out from late November to December 2003 with both extended ground-based and tethered balloon studies at Amundsen Scott Station, South Pole. ANTCI 2003 was the first of two Antarctic field studies with the primary goal of further exploring the active photochemistry of the South Pole region that was first identified in the previous Investigation of Sulfur Chemistry in the Antarctic Troposphere (ISCAT) program. Since ISCAT was fully ground-based, ANTCI 2003 goals included expanding chemical studies both vertically upward to investigate mixing and horizontally to better understand large-scale plateau NO, production and transport. Thus, in addition to ground-based experiments at South Pole, Twin Otter aircraft sampling took place out to hundreds of kilometers in several directions from the South Pole. These were designed to specifically address the issue of how representative past South Pole chemical measurements are of the surrounding high plateau region. The Twin Otterwas also used to make transects along the coast both north and south of McMurdo Station. The present paper summarizes the overall setting and results of this investigation and highlights the many new findings that were obtained

The journey of C2-C5 alkane emissions from the oil and gas sector: atmospheric and air quality implications

info:eu-repo/semantics/nonPublishe

Defizite von öffentlichen Allgemeinkrankenhäusern in Deutschland: Empirische Befunde von 1998 bis 2004 und wirtschaftspolitische Implikationen

We determine the level and development of deficits during the period from 1998 to 2004 in German public hospitals and analyze the reasons for these deficits. Furthermore we discuss their implications for economic policy. In 2004, the deficits reach a peak of 3 billion Euro. Fixed effects estimations suggest that both the duration of treatment and the number of employees have a significant positive influence on the development of the deficits while the number of cases has a significant negative influence. The payment of public hospital deficits out of general budget resources constitutes an unjustified subsidy. Copyright 2009 die Autoren Journal compilation 2009, Verein für Socialpolitik und Blackwell Publishing Ltd.