The effects of precipitation chemistry and catchment area lithology on the quality of river water in selected catchments in eastern Australia

The results of partial chemical analyses of precipitation and river water samples from north-east Queensland and south-eastern New South Wales are presented. Comparisons of water quality in the two areas are made using ionic ratios. While the sodium and chloride contents of precipitation in the two areas are similar, higher concentrations of calcium, magnesium and potassium occur in precipitation samples collected in New South Wales. Precipitation supplies between 25% and 70% of the total solute loads of the rivers studied. In the Southern Tablelands of New South Wales more chloride is supplied to the catchment areas than is removed by the rivers. River water quality reflects catchment lithology more than the climatic contrasts between the two study areas. Nevertheless, precipitation chemistry exerts an influence on the ionic ratios of these Australian rivers with low total dissolved solids concentrations

Dynamic equilibrium in applied geomorphology: Two case studies

Engineering works and agricultural activity which change the relationship between rainfall and river flow lead to modifications of river channels with attendant erosion and deposition problems. In the Swiss Jura Lakes area, the natural flooding of the River Aare became such an acute problem by the mid-nineteenth century that extensive engineering works were carried out to alleviate flooding. The land thus reclaimed became a valuable agricultural asset, but the fall of the water table following removal of the annual flood risk, led to a fall in the level of the land as peat was changed into humus. Renewed flooding occurred. The natural readjustment following the first series of flood alleviation works reproduced the original problem and a second series of engineering works has had to be undertaken to remedy the situation. On the Belgian coast, harbour construction and the spread of buildings over the sand dunes have resulted in severe beach erosion in the eastern seaside resorts. Extensive engineering works have had to be undertaken to restore the beach. These examples illustrate how man's challenges to nature are often recurrent phenomena, and how the alteration of one aspect of the physical environment may lead to a succession of readjustments. Each phase of engineering activity may be considered a break in natural equilibrium, and each period of natural erosion or deposition a trend towards a new equilibrium

On the Authenticity of De-Extinct Organisms, and the Genesis Argument

Are the methods of synthetic biology capable of recreating authentic living members of an extinct species? An analogy with the restoration of destroyed natural landscapes suggests not. The restored version of a natural landscape will typically lack much of the aesthetic value of the original landscape because of the different historical processes that created it—processes that involved human intentions and actions, rather than natural forces acting over millennia. By the same token, it would appear that synthetically recreated versions of extinct natural organisms will also be less aesthetically valuable than the originals; that they will be, in some strong sense, ‘inauthentic’, because of their peculiar history and mode of origin. I call this the ‘genesis argument’ against de-extinction. In this article I critically evaluate the genesis argument. I highlight an important disanalogy between living organisms and natural landscapes: viz., it is of the essence of the former, but not of the latter, to regularly reproduce and die. The process of iterated natural reproduction that sustains the continued existence of a species through time obviously does not undermine the authenticity of the species. I argue that the authenticity of a species will likewise be left intact by the kind of artificial copying of genes and traits that a de-extinction project entails. I conclude on this basis that the genesis argument is unsound

The Eightfold Way: Why Analyticity, Apriority and Necessity are Independent

This paper concerns the three great modal dichotomies: (i) the necessary/contingent dichotomy; (ii) the a priori/empirical dichotomy; and (iii) the analytic/synthetic dichotomy. These can be combined to produce a tri-dichotomy of eight modal categories. The question as to which of the eight categories house statements and which do not is a pivotal battleground in the history of analytic philosophy, with key protagonists including Descartes, Hume, Kant, Kripke, Putnam and Kaplan. All parties to the debate have accepted that some categories are void. This paper defends the contrary view that all eight categories house statements—a position I dub ‘octopropositionalism’. Examples of statements belonging to all eight categories are given

Does the solar system compute the laws of motion?

The counterfactual account of physical computation is simple and, for the most part, very attractive. However, it is usually thought to trivialize the notion of physical computation insofar as it implies ‘limited pancomputationalism’, this being the doctrine that every deterministic physical system computes some function. Should we bite the bullet and accept limited pancomputationalism, or reject the counterfactual account as untenable? Jack Copeland would have us do neither of the above. He attempts to thread a path between the two horns of the dilemma by buttressing the counterfactual account with extra conditions intended to block certain classes of deterministic physical systems from qualifying as physical computers. His theory is called the ‘algorithm execution account’. Here we show that the algorithm execution account entails limited pancomputationalism, despite Copeland’s argument to the contrary. We suggest, partly on this basis, that the counterfactual account should be accepted as it stands, pancomputationalist warts and all

Food Insecurity and Its Determinants in Asia and the Pacific

In Asian-Pacific developing countries, the prevalence of food insecurity has diminished dramatically in the past generation. Despite this, many millions continue to suffer from persistent or periodic food insecurity. The causes of food insecurity are both structural and market-related, including influences of public policy on market operations. The most vulnerable populations are those that simultaneously experience both these forms of insecurity. The places they inhabit tend to have poor-quality land, are exposed to climatic and other environmental risks, or both. These same populations either have relatively weak links with the non-food economy, in which higher wages and better income-earning opportunities make food self-sufficiency less important, or are prevented from accessing opportunities in the non-food economy because of poor or misguided policies.

The association between Parkinson's disease and anti-epilepsy drug carbamazepine: a case-control study using the UK General Practice Research Database.

AIMS: To investigate whether the use of carbamazepine is associated with reduced risk of Parkinson's disease. METHODS: We conducted a population-based, matched case-control study of patients randomly selected from the UK General Research Practice Database. We identified 8549 patients with Parkinson's disease using diagnosis criteria with a positive predictive value of 90%. These patients were compared with 42, 160 control subjects matched for age, sex and general practice. RESULTS: Overall, 3.0% of cases (257 of 8549) had at least one recorded prescription for carbamazepine compared with 2.5% (1050 of 42, 160) of controls. The crude odds ratio for the association between Parkinson's disease and carbamazepine was 1.22 (95% confidence interval 1.06-1.40), but this reduced to 0.93 (95% confidence interval 0.81-1.08, P = 0.34) after adjusting for annual consultation rate. Further adjustment for body mass index, smoking status, alcohol consumption or use of calcium channel blockers did not affect results. There was no evidence that risk decreased with higher doses or longer duration of carbamazepine use. CONCLUSIONS: There was little to no evidence that use of carbamazepine is associated with reduced risk of Parkinson's disease. Although the study was underpowered, it does indicate that any effect of carbamazepine is likely to be small

Scale formation in saline water distillation

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