Isocyanic acid (HNCO) is a known toxic species and yet the relative importance of primary and secondary sources to regional HNCO and population exposure remains unclear. Off-road diesel fuel combustion has previously been suggested to be an important regional source of HNCO, which implies that major industrial facilities such as the oil sands (OS), which consume large quantities of diesel fuel, can be sources of HNCO. The OS emissions of nontraditional toxic species such as HNCO have not been assessed. Here, airborne measurements of HNCO were used to estimate primary and secondary HNCO for the oil sands. Approximately 6.2 +/- 1.1 kg hr(-1) was emitted from off-road diesel activities within oil sands facilities, and an additional 116-186 kg hr(-1) formed from the photochemical oxidation of diesel exhaust. Together, the primary and secondary HNCO from OS operations represent a significant anthropogenic HNCO source in Canada. The secondary HNCO downwind of the OS was enhanced by up to a factor of 20 relative to its primary emission, an enhancement factor significantly greater than previously estimated from laboratory studies. Incorporating HNCO emissions and formation into a regional model demonstrated that the HNCO levels in Fort McMurray (similar to 10-70 km downwind of the OS) are controlled by OS emissions; > 50% of the monthly mean HNCO arose from the OS. While the mean HNCO levels in Fort McMurray are predicted to be below the 1000 pptv level associated with potential negative health impacts, (similar to 25 pptv in August-September), an order of magnitude increase in concentration is predicted (250600 pptv) when the town is directly impacted by OS plumes. The results here highlight the importance of obtaining at-source HNCO emission factors and advancing the understanding of secondary HNCO formation mechanisms, to assess and improve HNCO population exposure predictions.
A comprehensive field campaign was carried out in summer 2014 in Wangdu, located in the North China Plain. A month of continuous OH, HO2 and RO2 measurements was achieved. Observations of radicals by the laser-induced fluorescence (LIF) technique revealed daily maximum concentrations between (5-15) x 10(6) cm(-3), (3-14) x 10(8) cm(-3) and (3-15) x 10(8) cm 3 for OH, HO2 and RO2, respectively. Measured OH reactivities (inverse OH lifetime) were 10 to 20 s(-1) during daytime. The chemical box model RACM 2, including the Leuven isoprene mechanism (LIM), was used to interpret the observed radical concentrations. As in previous field campaigns in China, modeled and measured OH concentrations agree for NO mixing ratios higher than 1 ppbv, but systematic discrepancies are observed in the afternoon for NO mixing ratios of less than 300 pptv (the model-measurement ratio is between 1.4 and 2 in this case). If additional OH recycling equivalent to 100 pptv NO is assumed, the model is capable of reproducing the observed OH, HO2 and RO2 concentrations for conditions of high volatile organic compound (VOC) and low NOx concentrations. For HO2, good agreement is found between modeled and observed concentrations during day and night. In the case of RO2, the agreement between model calculations and measurements is good in the late afternoon when NO concentrations are below 0.3 ppbv. A significant model underprediction of RO2 by a factor of 3 to 5 is found in the morning at NO concentrations higher than 1 ppbv, which can be explained by a missing RO2 source of 2 ppbvh(-1). As a consequence, the model underpredicts the photochemical net ozone production by 20 ppbv per day, which is a significant portion of the daily integrated ozone production (110 ppbv) derived from the measured HO2 and RO2. The additional RO2 production from the photolysis of ClNO2 and missing reactivity can explain about 10% and 20% of the discrepancy, respectively. The underprediction of the photochemical ozone production at high NOx found in this study is consistent with the results from other field campaigns in urban environments, which underlines the need for better understanding of the peroxy radical chemistry for high NOx conditions.
A comprehensive field campaign was carried out in summer 2014 in Wangdu, located in the North China Plain. A month of continuous OH, HO2 and RO2 measurements was achieved. Observations of radicals by the laser-induced fluorescence (LIF) technique revealed daily maximum concentrations between (5-15) x 10(6) cm(-3), (3-14) x 10(8) cm(-3) and (3-15) x 10(8) cm 3 for OH, HO2 and RO2, respectively. Measured OH reactivities (inverse OH lifetime) were 10 to 20 s(-1) during daytime. The chemical box model RACM 2, including the Leuven isoprene mechanism (LIM), was used to interpret the observed radical concentrations. As in previous field campaigns in China, modeled and measured OH concentrations agree for NO mixing ratios higher than 1 ppbv, but systematic discrepancies are observed in the afternoon for NO mixing ratios of less than 300 pptv (the model-measurement ratio is between 1.4 and 2 in this case). If additional OH recycling equivalent to 100 pptv NO is assumed, the model is capable of reproducing the observed OH, HO2 and RO2 concentrations for conditions of high volatile organic compound (VOC) and low NOx concentrations. For HO2, good agreement is found between modeled and observed concentrations during day and night. In the case of RO2, the agreement between model calculations and measurements is good in the late afternoon when NO concentrations are below 0.3 ppbv. A significant model underprediction of RO2 by a factor of 3 to 5 is found in the morning at NO concentrations higher than 1 ppbv, which can be explained by a missing RO2 source of 2 ppbvh(-1). As a consequence, the model underpredicts the photochemical net ozone production by 20 ppbv per day, which is a significant portion of the daily integrated ozone production (110 ppbv) derived from the measured HO2 and RO2. The additional RO2 production from the photolysis of ClNO2 and missing reactivity can explain about 10% and 20% of the discrepancy, respectively. The underprediction of the photochemical ozone production at high NOx found in this study is consistent with the results from other field campaigns in urban environments, which underlines the need for better understanding of the peroxy radical chemistry for high NOx conditions.
Objective: To estimate the current prevalence, temporal incidence trends, and contribution of risk factors for stroke in China.Methods: The China National Stroke Screening Survey (CNSSS) is an ongoing nationwide population-based program. A representative sample of 1,292,010 adults over 40 years old with 31,188 identified stroke cases from the 2013 and 2014 CNSSS database was analyzed to provide descriptive statistics of the prevalence and risk factors for stroke in 2014. In addition, a retrospective evaluation of 12,526 first-ever stroke cases in 2002-2013 and stroke mortality data from the 2002-2013 China Public Health Statistical Yearbook was conducted to estimate the incidence rates.Results: In 2014, the adjusted stroke prevalence was 2.06% in adults aged 40 years and older. After full adjustments, all risk factors assessed showed significant associations with stroke (p < 0.01); the largest contributor was hypertension (population-attributable risk 53.2%), followed by family history, dyslipidemia, atrial fibrillation, diabetes, physical inactivity, smoking, and overweight/ obesity. The incidence of first-ever stroke in adults aged 40-74 years increased from 189/100,000 individuals in 2002 to 379/100,000 in 2013-an overall annual increase of 8.3%. Stroke-specific mortality in adults aged 40-74 years has remained stable, at approximately 124 deaths/100,000 individuals in both 2002 and 2013.Conclusions: In 2002-2013, the incidence of stroke in China increased rapidly. Combined with a high prevalence, a trend toward a younger age, and stable mortality, this finding suggests that additional clinical and behavioral interventions for metabolic and lifestyle risk factors are necessary to prevent stroke, particularly in certain populations.
Recurrent tuberculosis is an important indicator of the effectiveness of tuberculosis control and can occur by relapse or exogenous reinfection. We conducted a retrospective cohort study on all bacteriologically confirmed tuberculosis cases that were successfully treated between 2000 and 2012 in Shanghai, an urban area with a high number but a low prevalence rate of tuberculosis cases and a low prevalence of HIV infection. Genotyping the Mycobacterium tuberculosis from clinical isolates was used to distinguish between relapse and reinfection. In total, 5.3% (710/13,417) of successfully treated cases had a recurrence, a rate of 7.55 (95% CI 7.01-8.13) episodes per 1000 person-years, more than 18 times the rate of tuberculosis in the general population. Patients who were male, age 30-59, retreatment cases, had cavitation, diabetes, drug-resistant or multidrug-resistant tuberculosis in their initial episode of tuberculosis, were at high risk for a recurrence. Among 141 recurrent cases that had paired isolates, 59 (41.8%) had different genotypes, indicating reinfection with a different strain. Patients who completed treatment were still at high risk of another episode of tuberculosis and exogenous reinfection contributed a significant proportion of the recurrent tuberculosis cases. Targeted control strategies are needed to prevent new tuberculosis infections in this setting.
Silica aerogel, with mesoporous structure and high hydrophobicity, is a promising adsorbent for oil spill clean-up. To make it economic and environmental-friendly, hydrocarbon desorption and silica aerogel regeneration were investigated. After hydrocarbon desorption at 80°C, silica aerogel maintained its hydrophobicity. After toluene, petrol, and diesel desorption, shrinkage of mesopores (from 19.9 to 16.8, 13.5, and 13.4nm) of silica aerogels occurred, causing decreased adsorption capacities (from 12.4, 11.2, and 13.6 to 12.0, 6.5, and 2.3g/g). Low surface tension of petrol caused high stress on mesopores during its desorption, resulting in significant pore shrinkage. For diesel, its incomplete desorption and oxidation further hindered the regeneration. Therefore, diesel desorption was also conducted at 200°C. Severe diesel oxidation occurred under aerobic condition and destroyed the mesopores. Under anaerobic condition, no diesel oxidation occurred and the decreases in pore size (to 13.2nm) and adsorption efficiency (to 10.0g/g) of regenerated silica aerogels were much less, compared with under aerobic condition. This study provided new insights on silica aerogel regeneration for oil spill clean-up.
In the recent Intergovernmental Panel on Climate Change assessment, multimodel ensembles (arithmetic model averaging, AMA) were constructed with equal weights given to Earth system models, without considering the performance of each model at reproducing current conditions. Here we use Bayesian model averaging (BMA) to construct a weighted model ensemble for runoff projections. Higher weights are given to models with better performance in estimating historical decadal mean runoff. Using the BMA method, we find that by the end of this century, the increase of global runoff (9.81.5%) under Representative Concentration Pathway 8.5 is significantly lower than estimated from AMA (12.21.3%). BMA presents a less severe runoff increase than AMA at northern high latitudes and a more severe decrease in Amazonia. Runoff decrease in Amazonia is stronger than the intermodel difference. The intermodel difference in runoff changes is mainly caused not only by precipitation differences among models, but also by evapotranspiration differences at the high northern latitudes.
The fundamental problems inherent in relativistic explicit correlation are highlighted, with practical suggestions for guiding future development of relativistic explicitly correlated wave function methods.
Particulate organonitrates are formed from volatile organic compounds (VOCs) oxidation by radicals. A portion of semi-volatile gas-phase organonitrates can be incorporate into aerosol by oxidation reactions or portioning, and has been an important component of secondary organic aerosol (SOA). Particulate organonitrates study has become one of the important aspects of atmospheric chemistry. Given the large number and variability of chemical constituents, and possible chemical transformations of organonitrates, such characterization presents a key problem for research. Based on recent research progress on particulate organonitrates, this paper summarizes the formation mechanism and quantification method of particulate organonitrates. Profiting from the application of high time resolution techniques, field measurements has become the major approach of particulate organonitrates study. Thermal dissociation-laser induced fluorescence (TD-LIF) and aerosol mass spectrometers (AMS) have been used to quantify and provide the evolution processes of particulate organonirates. Meanwhile, chemical ionization mass spectrometer(CIMS)allows for the determination of molecular ion composition of organonitrates, promising to become the important direction of study of particulate organonirates in future field measurements. To have a deep insight on precursor and atmospheric chemistry processes of particulate organonirates, future research should focus on the combination of field measurement, modeling simulation and laboratory simulation, and these will also lead to a more comprehensive understanding of formation mechanism of particulate organonirates
Particulate organonitrates are formed from volatile organic compounds (VOCs) oxidation by radicals. A portion of semi-volatile gas-phase organonitrates can be incorporate into aerosol by oxidation reactions or portioning, and has been an important component of secondary organic aerosol (SOA). Particulate organonitrates study has become one of the important aspects of atmospheric chemistry. Given the large number and variability of chemical constituents, and possible chemical transformations of organonitrates, such characterization presents a key problem for research. Based on recent research progress on particulate organonitrates, this paper summarizes the formation mechanism and quantification method of particulate organonitrates. Profiting from the application of high time resolution techniques, field measurements has become the major approach of particulate organonitrates study. Thermal dissociation-laser induced fluorescence (TD-LIF) and aerosol mass spectrometers (AMS) have been used to quantify and provide the evolution processes of particulate organonirates. Meanwhile, chemical ionization mass spectrometer(CIMS)allows for the determination of molecular ion composition of organonitrates, promising to become the important direction of study of particulate organonirates in future field measurements. To have a deep insight on precursor and atmospheric chemistry processes of particulate organonirates, future research should focus on the combination of field measurement, modeling simulation and laboratory simulation, and these will also lead to a more comprehensive understanding of formation mechanism of particulate organonirates
Analyzing how climate change affects vegetation distribution is one of the central issues of global change ecology as this has important implications for the carbon budget of terrestrial vegetation. Mapping vegetation distribution under historical climate scenarios is essential for understanding the response of vegetation distribution to future climatic changes. The reconstructions of palaeovegetation based on pollen data provide a useful method to understand the relationship between climate and vegetation distribution. However, this method is limited in time and space. Here, using species distribution model (SDM) approaches, we explored the climatic determinants of contemporary vegetation distribution and reconstructed the distribution of Chinese vegetation during the Last Glacial Maximum (LGM, 18,000 14C yr BP) and Middle-Holocene (MH, 6000 14C yr BP). The dynamics of vegetation distribution since the LGM reconstructed by SDMs were largely consistent with those based on pollen data, suggesting that the SDM approach is a useful tool for studying historical vegetation dynamics and its response to climate change across time and space. Comparison between the modeled contemporary potential natural vegetation distribution and the observed contemporary distribution suggests that temperate deciduous forests, subtropical evergreen broadleaf forests, temperate deciduous shrublands and temperate steppe have low range fillings and are strongly influenced by human activities. In general, the Tibetan Plateau, North and Northeast China, and the areas near the 30°N in Central and Southeast China appeared to have experienced the highest turnover in vegetation due to climate change from the LGM to the present.
Edelmann-Singer’s Koina und Concilia is a work aimed to highlight socio-economic aspects of provincial councils, which have often been downplayed or ignored in discourses concerning Roman provincial administration; but there is much more. Building upon seminal studies by Larsen ( Representative Governments in Greek and Roman History, 1955) and Deininger ( Die Provinziallandtage der römischen Kaiserzeit, 1965), Koina und Concilia attempts to shift away from the practice of studying the provincial councils separately as koina of the Greek East and conciliaof the Latin West, a separation exemplified by the important works by Fishwick ( Imperial Cult of the Latin West, 1987-2005) and Price ( Rituals and Power, 1984). The result is a general theory regarding the origin, formation processes, and functions of Roman provincial councils. Koina und Concilia is organized thematically: a literature review and the methodology of the book in the introductory chapter (chapter I, p. 13-40); historical analyses of koina and concilia in chapter II (p. 41-140); institutional analyses of the provincial councils’ legal basis and their personnel in chapter III (p. 141-192); evidence on the provincial councils’ socio-economic functions and their fostering of provincial identity in chapter IV (p. 193-309). Chapter V (p. 309-312) rehearses the main arguments. The main thrust of the book, as set out in the introduction, is Edelmann-Singer’s objection to Deininger’s view that provincial councils were of limited significance to the administrative and economic aspects of Roman provinces (p. 16-24). Her fourth chapter marshals a considerable amount of evidence to show that the members of provincial councils were involved in regional and trans-regional socio-economic activities, at times even taking on administrative tasks such as tax collection, census surveys, construction and maintenance of road networks, providing logistical support for large scale movement of troops, and monetizing the local economy. Edelmann-Singer attributes much of the disinterest in academia regarding the importance of the provincial councils to Deininger’s influential view that provincial councils were only concerned with the provincial imperial cult, the hosting of provincial games and festivities, and representing the interests of provincials against Roman provincial administration, and thus had little real impact on the life of a Roman province (p. 193). Edelmann-Singer compiles the known cases of the provincial councils’ regular and extraordinary revenues and expenditures, and examines the individual activities of their leading men, to refine Deininger’s paradigm. In the following, I provide further synopses and observations. The second chapter deals with questions of the origin and dissemination of provincial councils. Edelmann-Singer argues that the similarities in the structural design of pre-Roman and Roman koina suggest affiliation in concept (p. 35; p. 44-45), particularly with Classical and Hellenistic traditions of city-leagues that had political-institutional, religious functions, and communicative-ritual aspects (p. 54). One could perhaps understand her position as a convergence of Deininger’s Hellenistic “precursor” proposal (Deininger, Provinziallandtag, 1965, p. 7-12) and Larsen’s “hybrid” model (Larsen, Representative Government, 1955, p. 128-9), but with a historical approach or “Transferprozess” (II.6). She identifies several phases based on known foundation dates of eastern and western provincial councils to construct a dissemination narrative. The experimental phase of the Roman provincialization process with Hellenistic and Late Republican eastern koina is presented in II.2 to II.3, followed by the Augustan dissemination as described in Cassius Dio’s account of the foundation of the cult of Roma and Augustus in II.4, then to II.5, where she discusses the numerous provincial councils that appeared in a relatively short span during the early Julio-Claudian period. Most important is Edelmann-Singer’s observation that the Julio-Claudian foundations were readily found across the empire, and already consisted of varied forms of local and Roman initiatives. This observation is a strong challenge to both the so-called Lex Krascheninnikoff (that less “civilized” provinces in the Roman west were first to be installed with a provincial council and the imperial cult), as well as to Fishwick’s argument that koina and concilia established during the Julio-Claudian period were planned, while Flavian foundations were spontaneous (p. 137; also see p. 114-126 for Edelmann-Singer’s objection to Fishwick’s Flavian dating of the so-called Lex Narbonensis). The third chapter deals with the organizational aspect of provincial councils, focusing on their legal basis and officials. Edelmann-Singer asks what were the legal bases for provincial councils to possess right to assemble, to maintain independent control of revenue and expenditure, and to petition (p. 142-153). Edelmann-Singer assumes that Cassius Dio’s passage describing the foundation of the worship of divine Augustus in Pergamon and Nikomedeia implies that the provincial councils in Asia and Bithynia received a new legal status as a religious association, though this could not be proved (p. 143-144). To further substantiate this claim, she highlights literary and epigraphic evidence demonstrating that the provincial councils were treated by Roman authorities as subordinate although independent (Tac. Ann. 15.20-22; Aelius Arstides εἰς Ῥώμην 32; Cicero Verr. 2.2.137 & 145; Cod. Theod. 12.12.1 & 12.12.9). The most definitive piece of evidence seems to be the Calendar Decree of Asia, in which a letter issued by the proconsul to the Koinon of Asia included a diatagma-edictum, ordering the provincial council to reform the calendar of Asia to observe Augustus’ birthday, effectively rendering the koinon a subordinate institution (p. 150). Another important document is the so-called Lex Narbonensis (p. 148-149), which provides a glimpse of a lex collegii, with which Edelmann-Singer bundles the Dionysiac Technitai together as a reconstruction of what a provincial council might have looked like had it been indeed a private collegium (as opposed to the amplissima collegia and the sodalitates sacrae, p. 147-148). Regarding the officials of the provincial councils, Edelmann-Singer discusses in particular the provincial priesthood (III.2.1) and the koinarchy (III.2.2). She argues that the two offices represent two stages of the historical development of the provincial council in the east (p. 174). One could perhaps also read these subsections as an attempt to revise the mainstream honor-oriented discourse (such as Lendon’s approach in Empire of Honour 1997, p. 166-172) from a “provincial” perspective. While local elites indeed took part in the activities of the provincial councils in order to display wealth and prestige, the accumulative experience led to a qualitative change. Elites participated in the fostering of a “province-based” system of honor, and in turn defined a sense of provincial belonging and self-identity (p. 174-179). The fourth chapter is the longest and most complex of the book. Edelmann-Singer argues that the provincial councils were similar and comparable institutions across the empire, because the collated evidence from both the Greek East and Latin West indicates that provincial councils provided services with self-sustaining revenue structure based on trading, banking, financing, and minting operations, in addition to their relatively better known activities such emperor worship and imperial communications relating to petitions or arbitration (IV.1-IV.3). Particularly interesting is the scale of ordinary revenues that could be deduced from the epigraphical evidence found at Myra and Kaunos. If assuming an average contribution of each of the 33 cities of the Lycian koinon, one would expect no less than 165,000 denarii in annual contributions (p. 235-239). Yet, with no evidence for salaries paid to middle-status personnel, and with no comparable evidence on expenditure and revenue from provincial councils other than Lycia, the significance of the Lycian financial data becomes difficult to ascertain. Edelmann-Singer also argues that provincial councils could be tapped by imperial authorities from time to time to provide many services, such as conducting the census, collecting taxes, supplying and quartering of troops, constructing roads, and policing, among others. The proposal is intriguing, but the evidence available seems to indicate that these were extraordinary services, as Edelmann-Singer herself observed while discussing the case of Caius Valerius Arabinus, a high priest of the provincial council of Hispania exterior, who was awarded an honorific statue for having faithfully administered the office of the census (p. 260-266). Edelmann-Singer introduces transaction cost theory from New Institutional Economics to explain why koina and concilia were attractive to Roman administrators and provincial elites (IV.4.1-IV.4.3, p. 193-253; IV.4.4, p. 253-269). For Tres Galliae in particular, eleven inscriptions concerning the treasury of the provincial council that honor members of the local elite show that nearly 40% of the men who worked at the treasury were members who worked in business corporations, some even having attained senior positions, and about 55% of the treasury staff had links to the private sector or served as extraordinary financial controllers for Roman administrators (p. 253-257; esp. 254). Edelmann-Singer interprets this information as indicative of the members’ networking with each other and their awareness of lowering and stabilizing transaction costs, a speculative but nevertheless intriguing way to approach the limited evidence at hand. Finally, Edelmann-Singer discusses provincial coinage (IV.5). Cistophoric and Macedonian provincial issues are used in particular to discuss questions concerning rights of coinage, economic benefits, and the fiscal and political importance of provincial issues. Provincial coinage was issued to prepare for the large movement of troops during large military campaigns and to prepare to receive the large retinue of the emperors during imperial visits, but it was also issued to bolster the visibility of the provincial council as an active and competent body, and hence a legitimate agent, authority, and partner for a variety of purposes. One curious choice Edelmann-Singer makes is to leave out the so-called “landschaftliche Koina” (as coined by Kornmann in his 1900 RE article) – namely the leagues of cities that were region- instead of province-oriented, such as the Boiotian, Phokian, Thessalian, Arkadian and the Eleutherolakonian “leagues” in Provincia Achaia – with relatively little explanation, other than that they were not “provincial” and did not last into Late Antiquity (p. 28). This exclusion of the “landschaftliche Koina” and the reasoning behind it seem to follow Deininger’s methodology (Deininger, Provinziallandtage, 1965, p. 6). Occasionally, the distinction between these categories breaks down, as in the case of the Messenians and the Achaian koinon honoring Ti. Flavius Polybius with two statues in Olympia in the second century CE, where Edelmann-Singer even adds a footnote stating that the self-presentation of elite representatives of the regional councils shows a similar pattern to that of the members of the provincial councils (p. 177, fn. 193). Perhaps further treatment comparing regional and provincial councils would enhance our understanding of regional vs. provincial associations. To conclude, Edelmann-Singer’s book has the potential to change the discourse on provincial councils and Roman provincial administration altogether. Her extensive review of the origins, formation processes, legal bases, personnel, expenditures, revenues and activities of provincial councils in the Greek East and the Latin West, as well as her introduction of New Institutional Economics and the numismatic approach to flesh out the significance of provincial councils, demonstrate how the study of provincial councils ought to be extended from existing discourse on honor and emperor worship to socio-economic and even cultural factors. Perhaps more tabulations are needed to bring clarity to each chapter, since foundation dates and the changing status, rights and activities of provincial councils through time can be hard to follow. Nevertheless, Edelmann-Singer’s work provides an extensive dossier of evidence pertaining provincial councils as well as a intriguing set of theoretical proposals which will enable students of Roman provincial administration to reconsider existing analytical paradigms.