Photooxidation of 2-methyl-3-buten-2-ol (MBO) as a potential source of secondary organic aerosol

2-Methyl-3-buten-2-ol (MBO) is an important biogenic hydrocarbon emitted in large quantities by pine forests. Atmospheric photooxidation of MBO is known to lead to oxygenated compounds, such as glycolaldehyde, which is the precursor to glyoxal. Recent studies have shown that the reactive uptake of glyoxal onto aqueous particles can lead to formation of secondary organic aerosol (SOA). In this work, MBO photooxidation under high- and low-NO_x conditions was performed in dual laboratory chambers to quantify the yield of glyoxal and investigate the potential for SOA formation. The yields of glycolaldehyde and 2-hydroxy-2-methylpropanal (HMPR), fragmentation products of MBO photooxidation, were observed to be lower at lower NO_x concentrations. Overall, the glyoxal yield from MBO photooxidation was 25% under high-NO_x and 4% under low-NO_x conditions. In the presence of wet ammonium sulfate seed and under high-NO_x conditions, glyoxal uptake and SOA formation were not observed conclusively, due to relatively low (<30 ppb) glyoxal concentrations. Slight aerosol formation was observed under low-NO_x and dry conditions, with aerosol mass yields on the order of 0.1%. The small amount of SOA was not related to glyoxal uptake, but is likely a result of reactions similar to those that generate isoprene SOA under low-NO_x conditions. The difference in aerosol yields between MBO and isoprene photooxidation under low-NO_x conditions is consistent with the difference in vapor pressures between triols (from MBO) and tetrols (from isoprene). Despite its structural similarity to isoprene, photooxidation of MBO is not expected to make a significant contribution to SOA formation

Management by objectives in European public employment services

This paper surveys and compares national experience with performance management in European public employment services (PES) in the form of management by objectives (MBO). Part I of this paper reviews the relevant performance management literature and defines key terms. Part II presents the results of a stocktaking survey of the use of operational objectives, performance indicators, benchmarking and related managerial practices in all 15 EU Member States and Norway. Part III reports the results of a comparative analysis and more in-depth assessment of national experience with management by objectives in Austria, France, Great Britain, and Sweden. Part IV summarizes principal findings and presents main conclusions. Ten of the eighteen PES organizations surveyed were found to use management by objectives: Austria, Denmark, the Flanders regional PES (VDAB) in Belgium, France, Germany, Great Britain, Finland, the Netherlands, Norway, and Sweden. In summary, the impact of MBO-systems depends strongly on design and implementation features. If based on principles of good-practice, MBO can improve the efficiency and effectiveness of PES operations. -- In diesem Papier wird eine Bestandsaufnahme zu Verbreitung und Praxis der Zielsteuerung (Management by Objectives, MBO) in europäischen Arbeitsverwaltungen vorgelegt. Teil I rekapituliert die relevante Forschungsliteratur und entwirft einen analytischen Bezugsrahmen. In Teil II wird ein empirischer Überblick zur Steuerung mittels Zielen und Indikatoren in europäischen Arbeitsverwaltungen gegeben. Unter 18 Arbeitsverwaltungen sind Zielsteuerungsansätze für die zehn Länder Dänemark, Deutschland, Finnland, Flandern (VDAB), Frankreich, Großbritannien, Niederlande, Norwegen, Österreich, und Schweden nachzuweisen. Teil III vergleicht vertiefend die Managementansätzen in den Arbeitsverwaltungen Österreichs, Großbritanniens, Frankreichs und Schwedens. Für den Erfolg (oder Mißerfolg) der Zielsteuerung sind Design- und Implementationsfaktoren entscheidend. Wenn Prinzipien guter Praxis beachtet werden, kann die Effektivität und Effizienz der Arbeitsverwaltung mittels MBO gesteigert werden.

Organosulfates as Tracers for Secondary Organic Aerosol (SOA) Formation from 2‑Methyl-3-Buten-2-ol (MBO) in the Atmosphere

2-Methyl-3-buten-2-ol (MBO) is an important biogenic volatile organic compound (BVOC) emitted by pine trees and a potential precursor of atmospheric secondary organic aerosol (SOA) in forested regions. In the present study, hydroxyl radical (OH)-initiated oxidation of MBO was examined in smog chambers under varied initial nitric oxide (NO) and aerosol acidity levels. Results indicate measurable SOA from MBO under low-NO conditions. Moreover, increasing aerosol acidity was found to enhance MBO SOA. Chemical characterization of laboratory-generated MBO SOA reveals that an organosulfate species (C_5H_(12)O_6S, MW 200) formed and was substantially enhanced with elevated aerosol acidity. Ambient fine aerosol (PM_(2.5)) samples collected from the BEARPEX campaign during 2007 and 2009, as well as from the BEACHON-RoMBAS campaign during 2011, were also analyzed. The MBO-derived organosulfate characterized from laboratory-generated aerosol was observed in PM_(2.5) collected from these campaigns, demonstrating that it is a molecular tracer for MBO-initiated SOA in the atmosphere. Furthermore, mass concentrations of the MBO-derived organosulfate are well correlated with MBO mixing ratio, temperature, and acidity in the field campaigns. Importantly, this compound accounted for an average of 0.25% and as high as 1% of the total organic aerosol mass during BEARPEX 2009. An epoxide intermediate generated under low-NO conditions is tentatively proposed to produce MBO SOA

My Experience in Bharata Natyam (Indian Dance)

Have you ever thought of learning a new style of dance? Or exploring a new way to consider a particular dance or music? Well! Let me suggest that you try an Indian dance class, particularly Bharata Natyam, and push yourself out of your common dance style. In addition, you will rediscover some hidden talents and expand your circle of friends. Those aspects are what I found during my journey in Bharata Natyam, Indian dance

Simultaneous real-time measurement of isoprene and 2-methyl-3-buten-2-ol emissions from trees using SIFT-MS

The C5 hemiterpenes isoprene and 2-methyl-3-buten-2-ol (MBO) are important biogenic volatiles emitted from terrestrial vegetation. Isoprene is emitted from many plant groups, especially trees such as Populus, while emission of MBO is restricted to certain North American conifers, including species of Pinus. MBO is also a pheromone emitted by several conifer bark beetles. Both isoprene and MBO have typically been measured by proton-transfer reaction mass spectrometry (PTR-MS), but this method cannot accurately distinguish between them because of their signal overlap. Our study developed a method for using selective ion flow tube mass spectrometry (SIFT-MS) that allows simultaneous on-line measurement of isoprene and MBO by employing different reagent ions. The use of m/z(NO+) = 68 u for isoprene and m/z(O2 +) = 71 u for MBO gave minimal interference between the compounds. We tested the suitability of the method by measuring the emission of young trees of Populus, Picea, and Pinus. Our results largely confirm previous findings that Populus nigra, Picea glauca, and Picea abies emit isoprene and Pinus ponderosa emits MBO, but we also found MBO to be emitted by Picea abies. Thus SIFT-MS provides a reliable, easy to use, on-line measuring tool to distinguish between isoprene and MBO. The method should be of use to atmospheric chemists, tree physiologists and forest entomologists, among others

Long-term predictive factors of the morphology based outcome in bare platinum coiled intracranial aneurysms: Evaluation by pre- and post-contrast 3D time-of-flight MR angiography

Purpose Our aim was to identify long-term predictive factors of the morphology-based outcome (MBO) of bare platinum coiled intracranial aneurysms. Materials and Methods A retrospective analysis of 96 bare platinum coiled intracranial aneurysms followed up from 1997 to 2016 using pre- and post-contrast 3D time-of-flight MR angiography (MRA) was performed. Logistic regression analysis was used to identify factors associated with a positive history of surrounding coil mass enhancement (SCME) and poor MBO. Spearman's rank correlation test was used to analyze the relationship between the initial angiographic result (IAR) class, sequential change of the SCME category, and MBO grade. Results Factors independently associated with poor MBO were incomplete IAR (OR=14.94, 95%CI: 2.46, 289.21, P=0.002) and a history of SCME (OR=4.13, 95% CI: 1.05, 18.65, P=0.043). The MBO grade strongly correlated with the IAR class (correlation coefficient [r]=0.84, P&lt;0.0001). MBO grade correlated with sequential change of the SCME category (r=0.56, P&lt;0.0001). The sequential change of the SCME category correlated with IAR class (r=0.53, P&lt;0.0001). Conclusion Although IAR and its class were strong long-term predictive factors of MBO, a history of SCME and upgrading of sequential change of SCME category were also long-term predictive factors of the MBO of bare platinum coiled intracranial aneurysms

My Experience in Public Speech

This essay is a reflection on the student\u27s experiences giving a speech as a nonnative English speaker in a communications class at Parkland College