A global perspective on aerosol from low-volatility organic compounds

Global production of organic aerosol from primary emissions of semivolatile (SVOCs) and intermediate (IVOCs) volatility organic compounds is estimated using the global chemical transport model, GEOS-Chem. SVOC oxidation is predicted to be a larger global source of net aerosol production than oxidation of traditional parent hydrocarbons (terpenes, isoprene, and aromatics). Using a prescribed rate constant and reduction in volatility for atmospheric oxidation, the yield of aerosol from SVOCs is predicted to be about 75% on a global, annually-averaged basis. For IVOCs, the use of a naphthalene-like surrogate with different high-NOx and low-NOx parameterizations produces a global aerosol yield of about 30%, or roughly 5 Tg/yr of aerosol. Estimates of the total global organic aerosol source presented here range between 60 and 100 Tg/yr. This range reflects uncertainty in the parameters for SVOC volatility, SVOC oxidation, SVOC emissions, and IVOC emissions, as well as wet deposition. The highest estimates result if SVOC emissions are significantly underestimated (by more than a factor of 2) or if wet deposition of the gas-phase semivolatile species is less effective than previous estimates. A significant increase in SVOC emissions, a reduction of the volatility of the SVOC emissions, or an increase in the enthalpy of vaporization of the organic aerosol all lead to an appreciable reduction of prediction/measurement discrepancy. In addition, if current primary organic aerosol (POA) inventories capture only about one-half of the SVOC emission and the Henrys Law coefficient for oxidized semivolatiles is on the order of 10^3 M/atm, a global estimate of OA production is not inconsistent with the top-down estimate of 140 Tg/yr by (Goldstein and Galbally, 2007). Additional information is needed to constrain the emissions and treatment of SVOCs and IVOCs, which have traditionally not been included in models

Mechanisms underlying the production of carapace vibrations and associated waterborne sounds in the American lobster, Homarus americanus

American lobsters produce carapace vibrations, which also lead to waterborne acoustic signals, by simultaneously contracting the antagonistic remotor and promotor muscles located at the base of the second antenna. These vibrations have a mean frequency of 183.1 Hz (range 87–261 Hz), range in duration from 68 to 1720 ms (mean 277.1 ms) and lead to waterborne sounds of similar frequencies. Lobsters most often produce these signals using only one pair of muscles at a time and alternate between the muscles of the left and right antennae when making a series of vibrations. Occasionally, they vibrate their carapace by simultaneously contracting both sets of muscles. While the remotor muscle is required for producing carapace vibrations, the promotor appears to play a secondary role. Electrical stimulation of the remotor, but not the promotor, results in the production of vibrations, while lesions of the remotor, but not promotor, eliminate the ability of lobsters to vibrate their carapace. Lobsters of all sizes and both sexes produce these signals when startled, grasped or threatened. However, at this time, the behavioral significance of vibration and/or sound production by American lobsters is not known

Modelling sustainable urban travel in a whole systems energy model

Many proposed low carbon transitions of the transport system have focused on decarbonisation in terms of technological transformation; however, significant opportunities exist for behavioural or demand side orientated measures to play an important role. This paper explores how one such option, mode shift, can contribute to low-carbon energy systems. For the first time, endogenous mode choice is integrated into a whole energy systems model, ESME, by representing mode speed, travel time budgets, infrastructure costs, and maximum rates of modal shift. Results indicate that the cost-optimal model solution favours sustainable transport modes, although this is strongly contingent on financial disincentives for car travel and measures to make slower modes more attractive. This approach is relevant in many different country contexts, as the need to assess options for lower carbon, more sustainable urban transport systems increases

The oncological relevance of fragile sites in cancer

Recent developments in sequencing the cancer genome have provided the first in-depth mapping of structural variants (SV) across 38 tumour types. Sixteen signatures of structural variants have been proposed which broadly characterise the variation seen across cancer types. One signature shows increased duplications and deletions at fragile sites, with little association with the typical DNA repair defects. We discuss how, for many of these fragile sites, the clinical impacts are yet to be explored. One example is NAALADL2, one of the most frequently altered fragile sites in the cancer genome. The copy-number variations (CNVs) which occur at fragile sites, such as NAALADL2, may span many genes without typical DNA repair defects and could have a large impact on cell signalling

Fair pay/play in the UK voice-over industries: a survey of 200+ voice-overs

This is the final version. Available from the publisher via the DOI in this record.The emergence of online peer-to-peer recruitment platforms, which have introduced Uber-like business models for the commissioning of creative content, brings both threats and opportunities to the UK creative economy. This research investigates the impact of these platforms from the perspective of a specific market: the UK voice-over industries. This is done by analyzing levels of remuneration, recruitment and contractual practices as well as the role played by intellectual property rights in monetizing the work of voice-over performers. This pilot study follows two recent reforms of EU regulations: the first regards fairness in relation to authors’ and performers’ remuneration (via intellectual property rights); the second focuses on fairness and transparency in the contractual terms and conditions practiced by online intermediation services (such as online peer-to-peer recruitment platforms).[1] This research is also preceded by a report on the remuneration of creative labour in the digital environment published by the World Intellectual Property Organization[2] and important seminal academic work on this question.[3] In a two-part analysis, this study demonstrates that online peer-to-peer recruitment platforms defeat the framework of intellectual property (copyright and performers’ rights) on a global scale. The research findings are outlined in two reports. The first report (this document) analyzes the findings of the online survey carried by the research team to capture the experience of voice-over performers on remuneration, recruitment, contract and intellectual property. The second report contrasts these results with a review of online peer-to-peer recruitment platforms’ terms and conditions, scheduled to be released by January 2020. The results of the survey show that: online peer-to-peer recruitment platforms are perceived very negatively by voice-over performers; the use of written contracts, summarizing the key aspects of a transaction is extremely rare; and, there is a critical lack of awareness of intellectual property rights within voice-over performers paired with a perceived lack of representation by unions or organizations to defend and advance their rights. At the same time, the survey also evidences that the UK voice-over market is extremely versatile, and contributes to an impressive range of cultural, communication and entertainment sectors. The survey thus evidences that the UK voice-over industries are a key contributor to the country’s creative economy. As such, national policy-makers must take measures to safeguard the market’s resilience in the global digital environment, which in this case, includes addressing the role and impact of online peer-to-peer recruitment platforms. The research concludes that the contractual terms currently practiced by online peer-to-peer recruitment platforms pose a threat to the UK intellectual property framework. However, preliminary investigation also suggests that these platforms could become an opportunity to introduce principles of contractual best practice on a global scale, should their terms and conditions be appropriately revised. [1] Directive (EU) 2019/790 of the European Parliament and of the Council of 17 April 2019 on copyright and related rights in the Digital Single Market and amending Directives 96/9/EC and 2001/29/EC (Text with EEA relevance.). PE/51/2019/REV/1. OJ L 130, 17.5.2019, p. 92–125; Regulation (EU) 2019/1150 of the European Parliament and of the Council of 20 June 2019 on promoting fairness and transparency for business users of online intermediation services (Text with EEA relevance) PE/56/2019/REV/1 OJ L 186, 11.7.2019, p. 57–79. [2] Alexander Cuntz, Creators’ Income Situation in the Digital Age, Economic Research Working Paper No 49 (WIPO, 2018). [3] Focusing on the UK and EU studies, Martin Kretschmer and others, UK Authors’ Earnings and Contracts 2018: A Survey of 50,000 Writers, CREATe, 2019); Lucie Guibault and others, Remuneration of authors and performers for the use of their works and the fixations of their performances (Study for European Commission DG Communications Networks, Content & Technology, 2015); Lucie Guibault and Olivia Salamanca (Europe Economics), Remuneration of authors of books and scientific journals, translators, journalists and visual artists for the use of their works (Study for European Commission DG Communications Networks, Content & Technology, 2016). On creators use of intellectual property: Townley and others, Creating Economy: Enterprise, Intellectual Property and the Valuation of Goods (OUP, 2018).Economic and Social Research Council (ESRC

Echo Delay and Overlap with Emitted Orientation Sounds and Doppler-shift Compensation in the Bat, Rhinolophus ferrumequinum

The compensation of Doppler-shifts by the bat, Rhinolophusferrumequinum, functions only when certain temporal relations between the echo and the emitted orientation sound are given. Three echo configurations were used: a) Original orientation sounds were electronically Doppler-shifted and played back either cut at the beginning (variable delay) or at the end (variable duration) of the echo. b) Artificial constant frequency echoes with variable delay or duration were clamped to the frequency of the emitted orientation sound at different Doppler-shifts. c) The echoes were only partially Doppler-shifted and the Doppler-shifted component began after variable delays or had variable durations. With increasing delay or decreasing duration of the Doppler-shifted echo the compensation amplitude for a sinusoidally modulated + 3 kHz Dopplershift (modulation rate 0.08 Hz) decreases for all stimulus configurations (Figs. 1, 2, 3). The range of the Doppler-shift compensation system is therefore limited by the delay due to acoustic travel time to about 4 m distance between bat and target. In this range the overlap duration of the echo with the emitted orientation sound is always sufficiently long, when compared with data on the orientation pulse length during target approach from Schnitzler (1968) (Fig. 5)

Suzaku Discovery of the Strong Radiative Recombination Continuum of Iron from the Supernova Remnant W49B

We present a hard X-ray spectrum of unprecedented quality of the Galactic supernova remnant W49B obtained with the Suzaku satellite. The spectrum exhibits an unusual structure consisting of a saw-edged bump above 8 keV. This bump cannot be explained by any combination of high-temperature plasmas in ionization equilibrium. We firmly conclude that this bump is caused by the strong radiative recombination continuum (RRC) of iron, detected for the first time in a supernova remnant. The electron temperature derived from the bremsstrahlung continuum shape and the slope of the RRC is 1.5 keV. On the other hand, the ionization temperature derived from the observed intensity ratios between the RRC and K-alpha lines of iron is 2.7 keV. These results indicate that the plasma is in a highly overionized state. Volume emission measures independently determined from the fluxes of the thermal and RRC components are consistent with each other, suggesting the same origin of these components.Comment: 5 pages,4 figures, accepted for publication in ApJ Lette

Secondary organic aerosol (SOA) formation from reaction of isoprene with nitrate radicals (NO_3)

Secondary organic aerosol (SOA) formation from the reaction of isoprene with nitrate radicals (NO3) is investigated in the Caltech indoor chambers. Experiments are performed in the dark and under dry conditions (RH<10%) using N2O5 as a source of NO3 radicals. For an initial isoprene concentration of 18.4 to 101.6 ppb, the SOA yield (defined as the ratio of the mass of organic aerosol formed to the mass of parent hydrocarbon reacted) ranges from 4.3% to 23.8%. By examining the time evolutions of gas-phase intermediate products and aerosol volume in real time, we are able to constrain the chemistry that leads to the formation of low-volatility products. Although the formation of ROOR from the reaction of two peroxy radicals (RO2) has generally been considered as a minor channel, based on the gas-phase and aerosol-phase data it appears that RO2+RO2 reaction (self reaction or cross-reaction) in the gas phase yielding ROOR products is a dominant SOA formation pathway. A wide array of organic nitrates and peroxides are identified in the aerosol formed and mechanisms for SOA formation are proposed. Using a uniform SOA yield of 10% (corresponding to Mo≅10 μg m−3), it is estimated that ~2 to 3 Tg yr−1 of SOA results from isoprene + NO3. The extent to which the results from this study can be applied to conditions in the atmosphere depends on the fate of peroxy radicals (i.e. the relative importance of RO2+RO2 versus RO2+NO3 reactions) in the nighttime troposphere