Classification of tropospheric ozone profiles over Johannesburg based on MOZAIC aircraft data

International audienceEach ozone profile is a unique response to the photochemical and dynamic processes operating in the troposphere and hence is critical to our understanding of processes and their relative contributions to the tropospheric ozone budget. Traditionally, mean profiles, together with some measure of variability, averaged by season or year at a particular location have been presented as a climatology. However, the mean profile is difficult to interpret because of the counteracting influences present in the micro-structure. On the other hand, case study analysis, whilst revealing, only applies to isolated conditions. In a search for pattern and order within ozone profiles, a classification based on a cluster analysis technique has been applied in this study. Ozone profiles are grouped according to the magnitude and altitude of ozone concentration. This technique has been tested with 56 ozone profiles at Johannesburg, South Africa, recorded by aircraft as part of the MOZAIC (Measurement of Ozone and Water Vapor aboard Airbus In-service Aircraft) program. Six distinct groups of ozone profiles have been identified and their characteristics described. The widely recognized spring maximum in tropospheric ozone is identified through the classification, but a new summertime mid-tropospheric enhancement due to the penetration of tropical air masses from continental regions in central Africa has been identified. Back trajectory modeling is used to provide evidence of the different origins of ozone enhancements in each of the classes. Continental areas over central Africa are shown to be responsible for the low to mid-tropospheric enhancement in spring and the mid-tropospheric peak in summer, whereas the winter low-tropospheric enhancement is attributed to local sources. The dominance of westerly winds through the troposphere associated with the passage of a mid-latitude cyclone gives rise to reduced ozone values

India's Climate Policy: Squaring the Circle

The Durban Platform process towards a new global climate agreement has thrown open for debate all issues, including those earlier settled in the Kyoto Protocol. Any new compact must ensure sharply reduced global emissions as required by science, while adhering to principles of equity between nations regarding utilisation of the atmospheric commons. India faces serious difficulties in reconciling international expectations and domestic developmental priorities. India's recent economic growth, increased emissions and great power ambitions suggest greater need and capacity for mitigation whereas its continuing burden of income and energy poverty severely inhibits additional commitments. This article examines the factors driving India's negotiating position. It argues that an equitable development perspective within India, a clearer appreciation of climate science and its likely impacts, and a more balanced view of its diplomatic interests especially in the global South, would yield a more coherent position than a US or first world?driven agenda and inevitable defensive reactions

Village-Integrated Eye Worker trial (VIEW): rationale and design of a cluster-randomised trial to prevent corneal ulcers in resource-limited settings.

IntroductionCorneal opacity is a leading cause of blindness worldwide. In resource-limited settings, untreated traumatic corneal abrasions may result in infection and ultimately, opacity. Although antimicrobial treatment of corneal ulcers may successfully cure infections, the scarring that accompanies the resolution of infection can still result in visual impairment. Prevention may be the optimal approach for reducing corneal blindness. Studies have employed community health workers to provide prompt administration of antimicrobials after corneal abrasions to prevent infections, but these studies were not designed to determine the effectiveness of such a programme.Methods and analysisThe Village-Integrated Eye Worker trial (VIEW) is a cluster-randomised trial designed to assess the effectiveness of a community health worker intervention to prevent corneal ulcers. Twenty-four Village Development Committees (VDCs) in Nepal were randomised to receive a corneal ulcer prevention programme or to no intervention. Female Community Health Volunteers (FCHVs) in intervention VDCs are trained to diagnose corneal abrasions, provide antimicrobials and to refer participants when needed. An annual census is conducted over 3 years in all study VDCs to assess the incidence of corneal ulceration via corneal photography (primary outcome). Masked outcome assessors grade corneal photographs to determine the presence or absence of incident corneal opacities. The primary analysis is negative binomial regression to compare the incidence of corneal ulceration by study arm.Ethics and disseminationThe University of California San Francisco Committee on Human Research, Nepal Netra Jyoti Sangh and the Nepal Health Research Council have given ethical approval for the trial. The results of this trial will be presented at local and international meetings and submitted to peer-reviewed journals for publication.Trial registration numberNCT01969786; Pre-results

Identification of H2_2CCC as a diffuse interstellar band carrier

We present strong evidence that the broad, diffuse interstellar bands (DIBs) at 4881 and 5450\,\AA are caused by the $B\,^1$B$_1$\,$\leftarrow$\,$X\,^1$A$_1$ transition of H$_2$CCC (l-C$_3$H$_2$). The large widths of the bands are due to the short lifetime of the $B\,^1$B$_1$ electronic state. The bands are predicted from absorption measurements in a neon matrix and observed by cavity ring-down in the gas phase and show exact matches to the profiles and wavelengths of the two broad DIBs. The strength of the 5450\,\AA DIB leads to a l-C$_3$H$_2$ column density of $\sim5\times10^{14}$ cm$^{-2}$ towards HD\,183143 and $\sim2\times10^{14}$\,cm$^{-2}$ to HD\,206267. Despite similar values of $E$($B-V$), the 4881 and 5450\,\AA DIBs in HD\,204827 are less than one third their strength in HD\,183143, while the column density of interstellar C$_3$ is unusually high for HD\,204827 but undetectable for HD\,183143. This can be understood if C$_3$ has been depleted by hydrogenation to species such as l-C$_3$H$_2$ towards HD\,183143. There are also three rotationally resolved sets of triplets of l-C$_3$H$_2$ in the 6150$-$6330\,\AA region. Simulations, based on the derived spectroscopic constants and convolved with the expected instrumental and interstellar line broadening, show credible coincidences with sharp, weak DIBs for the two observable sets of triplets. The region of the third set is too obscured by the $\alpha$-band of telluric O$_2$.Comment: 22 pages, 9 figure

Probing the unusual anion mobility of LiBH_4 confined in highly ordered nanoporous carbon frameworks via solid state NMR and quasielastic neutron scattering

Particle size and particle–framework interactions have profound effects on the kinetics, reaction pathways, and even thermodynamics of complex hydrides incorporated in frameworks possessing nanoscale features. Tuning these properties may hold the key to the utilization of complex hydrides in practical applications for hydrogen storage. Using carefully synthesized, highly-ordered, nanoporous carbons (NPCs), we have previously shown quantitative differences in the kinetics and reaction pathways of LiBH_4 when incorporated into the frameworks. In this paper, we probe the anion mobility of LiBH_4 confined in NPC frameworks by a combination of solid state NMR and quasielastic neutron scattering (QENS) and present some new insights into the nanoconfinement effect. NMR and QENS spectra of LiBH_4 confined in a 4 nm pore NPC suggest that the BH_4− anions nearer the LiBH_4–carbon pore interface exhibit much more rapid translational and reorientational motions compared to those in the LiBH_4 interior. Moreover, an overly broadened BH_4− torsional vibration band reveals a disorder-induced array of BH_4− rotational potentials. XRD results are consistent with a lack of LiBH_4 long-range order in the pores. Consistent with differential scanning calorimetry measurements, neither NMR nor QENS detects a clear solid–solid phase transition as observed in the bulk, indicating that borohydride–framework interactions and/or nanosize effects have large roles in confined LiBH_4

Going-Concern Audit Report Recipients Before and After SAS No. 59

In an attempt to provide information to make an evaluation on whether the requirements under SAS No. 59 have had any significant effect on auditor reporting decisions, a study was conducted that examined companies receiving going-concern modified reports before and after the implementation of SAS No. 59. We wanted to assess whether auditors were issuing going-concern modified reports to clients exhibiting different levels of financial stress and also whether the bankruptcy rate of such companies was different after the adoption of SAS No. 59

Direct damage controlled seismic design of plane steel degrading frames

A new method for seismic design of plane steel moment resisting framed structures is developed. This method is able to control damage at all levels of performance in a direct manner. More specifically, the method: (a) can determine damage in any member or the whole of a designed structure under any given seismic load, (b) can dimension a structure for a given seismic load and desired level of damage and (c) can determine the maximum seismic load a designed structure can sustain in order to exhibit a desired level of damage. In order to accomplish these things, an appropriate seismic damage index is used that takes into account the interaction between axial force and bending moment at a section, strength and stiffness degradation as well as low cycle fatigue. Then, damage scales are constructed on the basis of extensive parametric studies involving a large number of frames exhibiting cyclic strength and stiffness degradation and a large number of seismic motions and using the above damage index for damage determination. Some numerical examples are presented to illustrate the proposed method and demonstrate its advantages against other methods of seismic design. © 2014, Springer Science+Business Media Dordrecht

Effect of dietary zinc supplementation on ovarian folliculogenesis in buffalo heifers

A study was undertaken to investigate the effect of zinc (Zn) supplementation on ovarian folliculogenesis in buffalo heifers. Eighteen buffalo heifers with an average body weight of 278.7+16.82 kg were randomly allotted to 3 groups in a completely randomized design. The dietary treatments were viz., Basal diet (BD; 29.72 ppm Zn from feed ingredients), BD supplemented with 80 and 140 ppm Zn as ZnSO4 7H2 O (22% Zn). Heifers were fed the respective diets at 3% of body weight to meet the nutrient requirements (NRC, 2001) of dairy cattle except Zn throughout for an experimental period of 150 days. After 2 months of feeding trial, ovarian folliculogenesis study was made on all animals daily with help of B-mode linear array ultrasound scanner equipped with 7.5 MHz transducer. The proportion of large follicles (>8 mm) was higher (P<0.05) with 140 ppm (5.29%) Zn supplementation followed by 80 ppm (3.38%) compared to no Zn supplementation. However, no large sized follicles on ovary were observed in heifers supplemented with no Zn. While the mean number of small (3 to 5 mm) and medium follicles (5 to 8 mm) were not affected by Zn concentration in diet. The study indicated significant effect of Zn supplementation on ovarian follicular development with greater number of large follicles with 140 ppm Zn supplementation

Rethinking non-traditional resistance at work : the case of the Indian Diaspora in Mauritius

Resistance at work can take many forms and this is reflected in the multiple ways it has been theorised in research. In this paper, I use postcolonial theory to analyse employee resistance in Mauritius. To do this, I deploy Homi Bhabha’s concepts of mimicry, ambivalence and hybridity to explore non-traditional forms of resistance among the Indian Diaspora working in the hotel industry. Using ethnographic research, I firstly look at its ‘home’-making practices as it is within the home that visions of community emerge (Bhabha, 1994) which could later influence behaviours at work. I argue that the Diaspora maintains connections with its ancestral roots via routine religious practices and language use while concomitantly resisting assimilation in the local context. The analysis is then extended to their workplace where further forms of non-traditional resistance are found to be enacted which are strongly influenced by the same values emerging at home

Revisiting seismic hazard assessment for Peninsular Malaysia using deterministic and probabilistic approaches

Seismic hazard assessments, both deterministic and probabilistic, for Peninsular Malaysia have been carried out using peak ground acceleration (PGA) data recorded between 2004 and 2016 by the Malaysian Meteorological Department using triaxial accelerometers placed at 19 seismic stations on the peninsula. Seismicity source modelling for the deterministic seismic hazard assessment (DSHA) used historical point sources whereas in the probabilistic (PSHA) approach, line and areal sources were used. The earthquake sources comprised the Sumatran subduction zone (SSZ), Sumatran fault zone (SFZ) and local intraplate (LI) faults. Gutenberg–Richter law b value for the various zones identified within the SSZ ranged between 0.56 and 1.06 (mean = 0.82) and for the zones within the SFZ, between 0.57 and 1.03 (mean = 0.89). Suitable ground motion prediction equations (GMPEs) for Peninsular Malaysia along with other pertinent information were used for constructing a logic tree for PSHA of the region. The DSHA critical-worst scenario suggests PGAs of 0.07–0.80&thinsp;ms−2 (0.7–8.2 percent g), whilst the PSHA suggests mean PGAs of 0.11–0.55&thinsp;ms−2 (0.5–5.4 percent g) and 0.20–1.02&thinsp;ms−2 (1.9–10.1 percent g) at 10&thinsp;% and 2&thinsp;% probability of exceedance in 50 years, respectively. DSHA and PSHA, despite using different source models and methodologies, both conclude that the central-western cities of Peninsular Malaysia, located between 2 and 4°&thinsp;N, are most susceptible to high PGAs, due to neighbouring active Sumatran sources, SFZ and SSZ. Of the two Sumatran sources, surprisingly, the relatively less active SFZ source with low magnitude seismicity appeared as the major contributor due to its proximity. However, potential hazards due to SSZ mega-earthquakes should not be dismissed. Finally, DSHA performed using the limited LI seismic data from the Bukit Tinggi fault at a reasonable moment magnitude (Mw) value of 5.0 predicted a PGA of  ∼ 0.40&thinsp;ms−2 at Kuala Lumpur.</p