The Dark Star of Baisun-tau: a history of cave exploration in Southern Uzbekistan, 1990–2013

Very little is known about the karst and caves in southern Uzbekistan, where some of the deepest caves in Asia have been discovered. In particular, the limestone plateau of the Baisun-tau mountain range has a tremendous potential for exploration. This region is also important for palaeoclimate studies, as it is situated in the transition zone between the Westerlies and the Indian Summer Monsoon. For more than 15 years Festival’naya Cave, now the Festival’naya–Ledopadnaya cave system, was the main focus of cavers’ attention. Then, in 2011 the great potential of Dark Star Cave was revealed, after extensive new discoveries were made. Since then, additional expeditions with international teams of cavers, led by the Ekaterinburg Speleological Club and with the support of the Speleological Association of the Urals (SAU, Russia), have continued the exploration of these unique high altitude caves of the Baisun-tau. Both the length and depth of Dark Star have been increased almost two-fold every year. So far, six entrances and 9,537m of surveyed passages have been discovered to a depth of −858m, and Dark Star has now become the focus of exploration for expeditions to the area

The Economic Rationale for Agricultural Regeneration and Rural Infrastructure Investment in South Africa

This paper informs government policy insofar as it relates to the agricultural and rural de- velopment sectors and infrastructure investment within these sectors. The paper first quantfies the role of agriculture in the South African economy. This is done within the context of, inter alia, food security, agriculture's contribution to gross domestic product (GDP), economic link- ages and multipliers with respect to the agricultural sector, as well as agriculture's employment creation and external stabilisation capacity. Investment in the agricultural and rural sectors are then analysed with a view of supporting the argument that agriculture's role in the economy is su¢ ciently important to warrant regenerative strategies, including renewed emphasis on agricul- tural and rural infrastructure investment by South African policy makers. The quantification of the agricultural sector in relation to the total economy and that of agricultural and rural infrastructure investment are investigated against the backdrop of declining government sup- port, increasing production risks due to a variety of exogenous events like climate change, and increasing dynamic trade impacts. In this paper, the authors offer both supporting arguments in terms of current economic policy and recommendations for more decisive policy measures aimed at agricultural regeneration and rural infrastructure investment.

Coping with dating errors in causality estimation

We consider the problem of estimating causal influences between observed processes from time series possibly corrupted by errors in the time variable (dating errors) which are typical in palaeoclimatology, planetary science and astrophysics. "Causality ratio" based on the Wiener-Granger causality is proposed and studied for a paradigmatic class of model systems to reveal conditions under which it correctly indicates directionality of unidirectional coupling. It is argued that in the case of a priori known directionality, the causality ratio allows a characterization of dating errors and observational noise. Finally, we apply the developed approach to palaeoclimatic data and quantify the influence of solar activity on tropical Atlantic climate dynamics over the last two millennia. A stronger solar influence in the first millennium A.D. is inferred. The results also suggest a dating error of about 20 years in the solar proxy time series over the same period

Introduction to special issue: Aesthetics in mathematics

Mathematicians often appreciate the beauty and elegance of particular theorems, proofs, and definitions, attaching importance not only to the truth but also to the aesthetic merit of their work. As Henri Poincaré [1930, p. 59] put it, mathematical beauty is a ‘real aesthetic feeling that all true mathematicians recognise’. Others went further, regarding mathematical beauty as a key motivation driving the formulation of mathematical proofs and even as a criterion for choosing one proof over another. As Hermann Weyl famously and provocatively declared, ‘My work always tried to unite the true with the beautiful, but when I had to choose one or the other, I usually chose the beautiful’ (cited [Chandrasekhar, 1987, p. 52])....Talk of the beauty of mathematical theorems, proofs, and definitions may thus be commonplace

The Economic Rationale for Agricultural Regeneration and Rural Infrastructure Investment in South Africa

This paper informs government policy insofar as it relates to the agricultural and rural development sectors and infrastructure investment within these sectors. The paper first quantifies the role of agriculture in the South African economy. This is done within the context of, inter alia, food security, agriculture’s contribution to gross domestic product (GDP), economic linkages and multipliers with respect to the agricultural sector, as well as agriculture’s employment creation and external stabilisation capacity. Investment in the agricultural and rural sectors are then analysed with a view of supporting the argument that agriculture’s role in the economy is sufficiently important to warrant regenerative strategies, including renewed emphasis on agricultural and rural infrastructure investment by South African policy makers. The quantification of the agricultural sector in relation to the total economy and that of agricultural and rural infrastructure investment are investigated against the backdrop of declining government support, increasing production risks due to a variety of exogenous events like climate change, and increasing dynamic trade impacts. In this paper, the authors offer both supporting arguments in terms of current economic policy and recommendations for more decisive policy measures aimed at agricultural regeneration and rural infrastructure investment.

Sr-isotope analysis of speleothems by LA-MC-ICP-MS: High temporal resolution and fast data acquisition

Speleothems are well established climate archives. A wide array of geochemical proxies, including stable isotopes and trace elements are present within speleothems to reconstruct past climate variability. However, each proxy is influenced by multiple factors, often hampering robust interpretation. Sr isotope ratios (87Sr/86Sr) can provide useful information about water residence time and water mixing in the host rock, as they are not fractionated during calcite precipitation. Laser ablation multi-collector-inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) has rarely been used for determination of Sr isotope signatures in speleothems, as speleothems often do not possess appropriately high concentrations of Sr to facilitate this analysis. Yet the advantages of this approach include rapid data acquisition, higher spatial resolution, larger sample throughput and the absence of chemical treatment prior to analysis. We present LA-MC-ICP-MS Sr isotope data from two speleothems from Morocco (Grotte de Piste) and India (Mawmluh Cave), and we compare linescan and spot analysis ablation techniques along speleothem growth axes. The analytical uncertainty of our LA-MC-ICP-MS Sr data is comparable to studies conducted on other carbonate materials. The results of both ablation techniques are reproducible within analytical error, implying that this technique yields robust results when applied to speleothems. In addition, several comparative measurements of different carbonate reference materials (i.e. MACS-3, JCt-1, JCp-1), including tests with standard bracketing and comparison of the 87Sr/86Sr ratios with a nanosecond laser ablation system and a state-of-the-art femtosecond laser ablation system, highlight the robustness of the method

Group Theoretical Quantum Tomography

The paper is devoted to the mathematical foundation of the quantum tomography using the theory of square-integrable representations of unimodular Lie groups.Comment: 13 pages, no figure, Latex2e. Submitted to J.Math.Phy

The beauty of science without the science of beauty: Kant and the rationalists on the aesthetics of cognition

Claims about the beauty of theories and explanations are often inspired by the Platonic vision that beauty will lead us to truth. By contrast, Kant’s aesthetics is commonly regarded as providing the most influential critique of this vision. In this paper I show that this popular contrast is mistaken in important respects. By examining Kant’s views in comparison with those of his immediate contemporaries, A. G. Baumgarten and G. F. Meier, I show that the Kantian position offers an important contender to the Platonic ideal, namely, a conception of the beauty of science that is independent of the science of beauty.I gratefully acknowledge the support of the Leverhulme Trust and CRASSH, Cambridge for funding my research.This is the author accepted manuscript. It is currently under an indefinite embargo pending publication by Johns Hopkins University Press

Analysis of trans-resveratrol in oilseeds by high-performance liquid chromatography

Oilseeds are very popular edibles that are often used to enhance the fibre content of baked goods, and specific types are used for preserving and seasoning. Polyphenol-related researches have been receiving growing attention in the last 20 years, especially the ones concentrating on stilbenoids. In previous studies, resveratrol concentrations have been determined from oilseeds such as peanut.The aim of our research was to define the composition of oilseeds with a focus on the bioactive compounds, more specifically the resveratrol.Research took place in 2010–2011 at the University of Pécs, Medical School, using non-random, convenience sampling. Oilseeds studied in the research were: sunflower seed, roasted peanut, un-roasted peanut, sesame seed, pumpkin seed, almond, linseed, bio white mustard seed, bio black mustard seed, mustard seed of foreign provenance, and wild black mustard seed. All of these oilseeds can be purchased from trade. Samples used in the research were obtained from the producers and collectors. High Performance Liquid Chromatography (HPLC) was used for the measurements.Summarising our results, it can be stated that each type of oilseed analysed in our research can be regarded as good sources of resveratrol. The highest level of resveratrol was detected in the sunflower seeds (0.00398±0.0001 mg g−1), almonds (0.00176±0.00021 mg g−1), roasted peanut (0.00206±0.00013 mg g−1), and wild black mustard seeds (0.0023±0.0007 mg g−1)