Urban density, deprivation and road safety: A small area study in the eThekwini metropolitan area, South Africa

Following a general paucity of small area research on road traffic injuries (RTIs), this study examined small area variations in RTIs for the eThekwini Metropolitan Area (comprising predominantly the City of Durban) in South Africa. Population density was used as an organising framework to examine variations in RTI outcomes, and correspondence with a range of measures relating to characteristics of the crashes and to socio-economic deprivation. Analyses were undertaken at the suburb level, using data from 2005–2009 and employing a cross-sectional geographical design. Analyses were also undertaken for disaggregated injury, crash severity, and road user groups. The distribution of the injury outcome measures corresponded with several measures that proxied risks relating to excessive driving speeds, excessive travel exposure, and general social as well as area level deprivation. Negative binomial models, fitted for the injury outcome measures, showed population density to be a significant predictor of all injury outcomes but also that its effects was only partially explained by the explanatory measures considered. The findings on deprivation provide new insights to rural-urban variations in RTIs, at least in the South African setting. The findings also have implications for informing integrated developmental policies and strategies across a range of disciplines and departments, especially at the city level.Keywords: road traffic injury, small area, Durban, population density, densification, deprivatio

A critique of avian CHD-based molecular sexing protocols illustrated by a Z-chromosome polymorphism detected in auklets

The sexes of non-ratite birds can be determined routinely by PCR amplification of the CHD-Z and CHD-W genes. CHD -based molecular sexing of four species of auklets revealed the presence of a polymorphism in the Z chromosome. No deviation from a 1:1 sex ratio was observed among the chicks, though the analyses were of limited power. Polymorphism in the CHD-Z gene has not been reported previously in any bird, but if undetected it could lead to the incorrect assignment of sex. We discuss the potential difficulties caused by a polymorphism such as that identified in auklets and the merits of alternative CHD -based sexing protocols and primers

Baryogenesis, Dark Matter and the Pentagon

We present a new mechanism for baryogenesis, which links the baryon asymmetry of the universe to the dark matter density. The mechanism arises naturally in the Pentagon model of TeV scale physics. In that context, it forces a re-evaluation of some of the assumptions of the model, and we detail the changes that are required in order to fit observations.Comment: JHEP3 LaTeX, 15 pages. New version corrects errors in the electroweak baryon violating and matter radiation temperatures, which were pointed out by the referee. Substantial quantitative but no qualitative change to our conclusion

The use of coconut oil/diesel blends as a fuel for compression ignition engines (ODNRI Bulletin No. 31)

This bulletin describes experimental and evaluative work carried out by the Overseas Development Natural Resources Institute (ODNRI) to investigate fuelling of a standard compression ignition engine with blends of coconut oil and diesel. Initial studies were made of fuel-related properties for pure coconut oil and for a full range of blends with diesel. A major upgrading of the standard engine's fuel filtration system was necessary but thereafter it was found that a blend of 80% coconut oil in diesel, when heated to 45°C, provided a technically feasible substitute fuel. A limited duration engine trial was completed with this alternative arrangement to assess maintenance and operational requirements. On the basis of these results a preliminary economic evaluation was made of the potential for wider adoption of this type of substitute fuelling. Whilst this indicated that at prevailing prices of coconut oil relative to diesel this was unattractive, circumstances were identified in which this technology could have potential application

Petrography and Geochemistry of Metals in Almahata Sitta Ureilites

Ureilites are ultramafic achondrites, predominantly composed of olivine and pyroxenes with accessory carbon, metal and sulfide. The majority of ureilites are believed to represent the mantle of the ureilite parent body (UPB) [1]. Although ureilites have lost much of their original metal [2], the metal that remains retains a record of the formative processes. Almahata Sitta is predominantly composed of unbrecciated ureilites with a wide range of silicate compositions [3,4]. As a fall it presents a rare opportunity to examine fresh ureilite metal in-situ, and analyzing their highly siderophile element (HSE) ratios gives clues to their formation. Bulk siderophile element analyses of Almahata Sitta fall within the range observed in other ureilites [5]. We have examined the metals in seven ureilitic samples of Almahata Sitta (AS) and one associated chondrite fragment (AS#25)

Differing requirements for flavonoids during the formation of lateral roots, nodules and root knot nematode galls in Medicago truncatula

In this study, we tested whether the organogenesis of symbiotic root nodules, lateral roots and root galls induced by parasitic root knot nematodes (Meloidogyne javanica) was regulated by the presence of flavonoids in the roots of Medicago truncatula. Flavonoids accumulate in all three types of root organ, and have been hypothesized previously to be required for secondary root organogenesis because of their potential role as auxin transport regulators. • Using RNA interference to silence the flavonoid biosynthetic pathway in M. truncatula, we generated transformed flavonoid-deficient hairy roots which were used to study flavonoid accumulation, cell division and organogenesis of nodules, lateral roots and root galls. • Flavonoid-deficient roots did not form nodules, as demonstrated previously, but showed altered root growth in response to rhizobia. By contrast, flavonoid-deficient roots showed no difference in the number of lateral roots and root galls. Galls on flavonoid-deficient roots formed normal giant cells, but were shorter, and were characterized by reduced numbers of dividing pericycle cells. • We rejected the hypothesis that flavonoids are required as general regulators of the organogenesis of secondary root organs, but flavonoids appear to be necessary for nodulation. Possible reasons for this difference in the requirement for flavonoids are discussed

Weak Singular Hybrid Automata

The framework of Hybrid automata, introduced by Alur, Courcourbetis, Henzinger, and Ho, provides a formal modeling and analysis environment to analyze the interaction between the discrete and the continuous parts of cyber-physical systems. Hybrid automata can be considered as generalizations of finite state automata augmented with a finite set of real-valued variables whose dynamics in each state is governed by a system of ordinary differential equations. Moreover, the discrete transitions of hybrid automata are guarded by constraints over the values of these real-valued variables, and enable discontinuous jumps in the evolution of these variables. Singular hybrid automata are a subclass of hybrid automata where dynamics is specified by state-dependent constant vectors. Henzinger, Kopke, Puri, and Varaiya showed that for even very restricted subclasses of singular hybrid automata, the fundamental verification questions, like reachability and schedulability, are undecidable. In this paper we present \emph{weak singular hybrid automata} (WSHA), a previously unexplored subclass of singular hybrid automata, and show the decidability (and the exact complexity) of various verification questions for this class including reachability (NP-Complete) and LTL model-checking (PSPACE-Complete). We further show that extending WSHA with a single unrestricted clock or extending WSHA with unrestricted variable updates lead to undecidability of reachability problem

Characterising the within-field scale spatial variation of nitrogen in a grassland soil to inform the efficient design of in-situ nitrogen sensor networks for precision agriculture

The use of in-situ sensors capable of real-time monitoring of soil nitrogen (N) may facilitate improvements in agricultural N-use efficiency (NUE) through better fertiliser management. The optimal design of such sensor networks, consisting of clusters of sensors each attached to a data logger, depends upon the spatial variation of soil N and the relative cost of the data loggers and sensors. The primary objective of this study was to demonstrate how in-situ networks of N sensors could be optimally designed to enable the cost-efficient monitoring of soil N within a grassland field (1.9 ha). In the summer of 2014, two nested sampling campaigns (June & July) were undertaken to assess spatial variation in soil amino acids, ammonium (NH4+) and nitrate (NO3−) at a range of scales that represented the within (less than 2 m) and between (greater than 2 m) data logger/sensor cluster variability. Variance at short range (less than 2 m) was found to be dominant for all N forms. Variation at larger scales (greater than 2 m) was not as large but was still considered an important spatial component for all N forms, especially NO3−. The variance components derived from the nested sampling were used to inform the efficient design of theoretical in-situ networks of NH4+ and NO3− sensors based on the costs of a commercially available data logger and ion-selective electrodes (ISEs). Based on the spatial variance observed in the June nested sampling, and given a budget of £5000, the NO3− field mean could be estimated with a 95% confidence interval width of 1.70 μg N g−1 using 2 randomly positioned data loggers each with 5 sensors. Further investigation into “aggregate-scale” (less than 1 cm) spatial variance revealed further large variation at the sub 1-cm scale for all N forms. Sensors, for which the measurement represents an integration over a sensor-soil contact area of diameter less than 1 cm, would be subject to this aggregate-scale variability. As such, local replication at scales less than 1 cm would be needed to maintain the precision of the resulting field mean estimation. Adoption of in-situ sensor networks will depend upon the development of suitable low‐cost sensors, demonstration of the cost-benefit and the construction of a decision support system that utilises the generated data to improve the NUE of fertiliser N management

Symbolic Algebra and Renormalization of Gauge Theories

Symbolic algebra relevant to the renormalization of gauge theories can be efficiently performed by machine using modern packages. We devise a scheme for representing and manipulating the objects involved in perturbative calculations of gauge theories. This scheme is readily implemented using the general purpose package, Mathematica. The techniques discussed are used to calculate renormalization group functions for a non-abelian $SU(m)$ gauge theory with massless fermions in a representation R, in the two-loop approximation, and to simplify some expressions arising in electroweak calculations at the two loop level.Comment: 16 pages, LaTex, 2 diagrams drawn with FEYNMAN, uses cite.sty Entire manuscript available as a ps file at http://www.physics.adelaide.edu.au/theory/home.html Also available via anonymous ftp at ftp://adelphi.adelaide.edu.au/pub/theory/ADP-95-41.T193.ps Accepted for publication in Computer Physics Communicatio