A moving mesh method for one-dimensional hyperbolic conservation laws

We develop an adaptive method for solving one-dimensional systems of hyperbolic conservation laws that employs a high resolution Godunov-type scheme for the physical equations, in conjunction with a moving mesh PDE governing the motion of the spatial grid points. Many other moving mesh methods developed to solve hyperbolic problems use a fully implicit discretization for the coupled solution-mesh equations, and so suffer from a significant degree of numerical stiffness. We employ a semi-implicit approach that couples the moving mesh equation to an efficient, explicit solver for the physical PDE, with the resulting scheme behaving in practice as a two-step predictor-corrector method. In comparison with computations on a fixed, uniform mesh, our method exhibits more accurate resolution of discontinuities for a similar level of computational work

Colonial labour policy and Rhodesia

A RJE article on colonial labour policies in the then Rhodesia.The labour policies which were applied in Rhodesia in the early years of colonial rule had their origins in nineteenth century colonial labour policy as formulated after the abolition of slavery. This article sets out to examine the origins of policies which were framed both in the wider colonial context and in South Africa, particularly Natal, and the application of them to Rhodesia. To understand early Rhodesian ideas upon labour, it is necessary to understand the origins of the concept of labour itself, its applications in the colonial environment, theories of tropical abundance and tropical indolence, notions of inefficient indigenous labour and of target working, the relationship among land, tax, and labour, and the development of the indentured labour policy. It will be argued that after the abolition of slavery in the British Empire, the principal problem in the colonial setting was that the position of labour vis-a-vis capital was a powerful one. The prime object of colonial labour policies was therefore to shift the balance of power in colonial economies in the direction of capital

USING RIGHTS OF FIRST REFUSAL FOR FARMLAND RETENTION

How can rights of first refusal protect prime agricultural land? This paper develops a theory for valuing rights of first refusal based on compensation for foreclosing future demand, information asymmetry, and advance purchase of market share. A procedure is developed for governments to use these rights to prevent conversion.Land Economics/Use,

ACTH and polymorphisms at steroidogenic loci as determinants of aldosterone secretion and blood pressure

The majority of genes contributing to the heritable component of blood pressure remain unidentified, but there is substantial evidence to suggest that common polymorphisms at loci involved in the biosynthesis of the corticosteroids aldosterone and cortisol are important. This view is supported by data from genome-wide association studies that consistently link the CYP17A1 locus to blood pressure. In this review article, we describe common polymorphisms at three steroidogenic loci (CYP11B2, CYP11B1 and CYP17A1) that alter gene transcription efficiency and levels of key steroids, including aldosterone. However, the mechanism by which this occurs remains unclear. While the renin angiotensin system is rightly regarded as the major driver of aldosterone secretion, there is increasing evidence that the contribution of corticotropin (ACTH) is also significant. In light of this, we propose that the differential response of variant CYP11B2, CYP11B1 and CYP17A1 genes to ACTH is an important determinant of blood pressure, tending to predispose individuals with an unfavourable genotype to hypertension

Oceanographic processes influencing seasonal and interannual variability in cod spawning habitat in the eastern Baltic Sea

The volume of water with suitable oxygen and salinity conditions for survival and development of cod/eggs in the eastern Baltie Sea varies significantly within and among years. It has recently been shown that this volume of water (nreproduetive volumen), in addition to spawning stock biomass, is a major factor determining recruitment success in this eod population. However, it is unclear which oceanographie mechanisms are responsible for variability in reproductive volume, and how these processes interaet on a seasonal and interannual basis. In this study, we use time series observations to identify inter-relationships between hydrographie and biological processes (e. g., inflows of North Sea water, winter mixing processes, production and decomposition of organic matter) influencing reproductive volumes from 1952-1992. A frequent pattern of seasonal variability in 4 eastern Baltic spawning areas includes a spring maximum which decreases during the summer, followed by an inerease during the fall-winter months. However, this general pattern is violated in many years, and the magnitude of the seasonality is more pronounced, in some spawning areas than others. \Ve have begun to analyse these patterns and interpret them in the context of other fluctuating components of the eastern Baltic pelagic ecosystem. Preliminary results show that reproductive volumes deerease by an average of 9 - 39% between May and August, and that the decrease in the spawning area most important to long-term recruitment (Bornholm Basin) is temperature-dependen1. The seasonal decline in the Bomholm Basin also tends to be larger and more variable after 1964 than in the previous 12-year periode These patterns of reproductive volume variability may be important to eod reproduetive success beeause of a long and variable spawning period

From mood to movement: English nationalism, the European Union and taking back control

This article considers whether the 2016 EU referendum can be perceived as an English nationalist movement. Specifically, attention is given to examining how memories of the former British Empire were nostalgically enveloped in anxieties regarding England’s location within the devolved UK state. The comments and work of Enoch Powell and George Orwell are used to help explore the link between nostalgia and anxiety in accounts of English nationalism. Despite their opposing political orientations, when considered together, it is argued that both men provide a unique cross-political perspective on Englishness, empire and nostalgia. By way of exploring these themes in relation to the EU referendum, Aughey’s assertion that English nationalism can be perceived as both a ‘mood’ and ‘movement’ is used to highlight how a sense of English anxiety regarding its lack of national sovereignty (mood), as well as a desire to reclaim this sovereignty by renegotiating trade relations with the ‘Anglo-sphere’ (movement), were conjoined in the popular referendum slogan, ‘take back control’. In conclusion, it is argued that the contextualization of the referendum can be predicated upon an orientation to empire that steers away from glorifying pro-imperial images of England/Britain, towards a more positive and progressive appropriation of the EU referendum as a statement of national change and belonging

Differences in chronic conditions and lifestyle behaviour between people with a history of cancer and matched controls

OBJECTIVE: To determine whether people with a history of cancer have a higher prevalence of chronic conditions or different lifestyle behaviour compared with controls.  DESIGN, SETTING AND PARTICIPANTS: Cross-sectional, self-reported data from a telephone survey conducted between 1 January 2010 and 31 March 2012 of adult residents of South Australia who self-reported a previous cancer diagnosis (cases) and randomly selected age- and sex-matched residents with no cancer diagnosis (controls).  MAIN OUTCOME MEASURES: Self-reported medically diagnosed cardiovascular disease, hypertension, hyperlipidaemia, diabetes and osteoporosis; lifestyle behaviour (smoking, physical activity and diet); body mass index (BMI); psychological distress and self-reported health.  RESULTS: A total of 2103 cases and 4185 controls were included in the analyses. For men, after adjusting for age, cancer survivors were more likely than controls to have ever had cardiovascular disease (P<0.001), high blood pressure (P=0.001), high cholesterol (P<0.001) and diabetes (P=0.04). These associations remained significant after controlling for socioeconomic status (SES), with the exception of high blood pressure (P=0.09). For women, there was an increased prevalence of high cholesterol (P=0.005), diabetes (P=0.02) and osteoporosis (P=0.005) in cancer cases, but after adjusting for SES, these associations were no longer significant. Women with a previous cancer diagnosis were more likely than controls to have ever smoked, after adjusting for SES (P=0.001). There were no other differences in lifestyle behaviour or BMI between cases and controls for men or women.  CONCLUSION: Despite similar lifestyle habits and BMI, the prevalence of chronic conditions was significantly higher among people with a history of cancer than among controls without cancer. This supports the importance of chronic disease management as part of health care after a diagnosis of cancer

Implementation of Epigenetic Variation in Sorghum Selection and Implications for Crop Resilience Breeding

Crop resilience and yield stability are complex traits essential for food security. Sorghum bicolor is an important grain crop that shows promise for its natural resilience to drought and potential for marginal land production. We have developed sorghum lines in the Tx430 genetic background suppressed for MSH1 expression as a means of inducing de novo epigenetic variation, and have used these materials to evaluate changes in plant growth vigor. Plant crossing and selection in two distinct environments revealed features of phenotypic plasticity derived from MSH1 manipulation. Introduction of an epigenetic variation to an isogenic sorghum population, in the absence of selection, resulted in 10% yield increase under ideal field conditions and 20% increase under extreme low nitrogen conditions. However, incorporation of early-stage selection amplified these outcomes to 36% yield increase under ideal conditions and 64% increase under marginal field conditions. Interestingly, the best outcomes were derived by selecting mid-range performance early-generation lines rather than highest performing. Data also suggested that phenotypic plasticity derived from the epigenetic variation was nonuniform in its response to environmental variability but served to reduce genotype x environment interaction. The MSH1-derived growth vigor appeared to be associated with enhanced seedling root growth and altered expression of auxin response pathways, and plants showed evidence of cold tolerance, features consistent with observations made previously in Arabidopsis. These data imply that the MSH1 system is conserved across plant species, pointing to the value of parallel model plant studies to help devise effective plant selection strategies for epigenetic breeding in multiple crops