Domestic drinking water in rural areas : are water tanks on farms a health hazard?

The aim of the research was to gain a better understanding of the relationship between drinking water quality, householders' knowledge and maintenance practices of private water supplies and drinking water-related public health risk on farms. Samples of drinking water were taken from 100 farming households. The Colilert-18 method was used for the detection of total coliforms and Escherichia coli (E. coli) as indicators of water quality. Each household completed a questionnaire about their knowledge and practices relating to a safe water supply. Coliforms were present in 52 water samples and E. coli was present in 38. Seven households reported minor illnesses in the previous three months and two households reported gastroenteritis. Some tank maintenance occurred in 86 households, but tank maintenance activities varied considerably. Four of the households had published guidelines on water quality. None of the participating households had their drinking water tested regularly. There was no obvious relationship between drinking water quality, householder knowledge, maintenance practices and drinking water-related health risk on farms.

Competition and unitization in oil extraction : a tale of two tragedies

This paper compares two organizational modes for extracting oil from a common pool: unitization and competitive extraction. The analysis suggests that the general presumption that unitization is surplus enhancing relative to competitive extraction may not always be valid due to contractual incompleteness associated with unitization contracts. While competitive extraction suffers from the tragedy of the commons, unitization can be subject to the dual tragedy of the anticommons. This provides an explanation for the puzzle confronting the oil industry that firms are often reluctant to voluntarily enter unitization agreements.

Fresh water: new perspectives on water in Australia

Is water a resource or is it the source? Is it something to be consumed or does it have a life of its own? Recent histories of environmental misunderstanding and exploitation shadow our current regime of water management and use. While governments grapple with how to respond to widespread drought, the situation worsens. There is something amiss in current approaches to water. This timely collection of essays addresses the critical and contentious issue of water in Australia today and suggests a need to radically rethink our relationship with this fundamental substance. Contributors from a range of fields, from anthropology to visual arts, discuss the various ways in which we are caught up with water, and challenge us to take up the cultural transformations that underpin a sustainable ecological future

In situ synchrotron SAXS study of polymerizable microemulsions

We present for the first time a real-time small-angle X-ray scattering (SAXS) study of the structural transition of fluid microemulsion to solid polymerized material in a silicone polymerizable microemulsion system. A reactive methacrylate-terminated siloxane macromonomer (MTSM, Mn ∼ 1000 g/mol) was synthesized and used for microemulsion formulations comprising MTSM (oil phase), water, and a mixture of nonionic surfactant (Teric G9A8) with isopropanol. In situ synchrotron SAXS was used to investigate time-dependent nanostructure evolution during the polymerization reaction, which was directly initiated by X-ray radiation. The SAXS data were analyzed using both the Teubner-Strey model and the core-shell model. The results obtained by the Teubner-Strey model showed that the domain size (d) decreased while the correlation length (ξ) increased upon polymerization. The analysis in terms of the core-shell model displayed that adding water to the precursor microemulsion caused the water droplets to start swelling, which resulted in the discontinuity of water in oil microemulsion. There exhibited large differences in morphologies of polymerized materials from the microemulsion formulations with different water and surfactant contents. The core and shell sizes of water droplets decreased during the course of polymerization when there was 15 wt % or more water in the microemulsion formulation; the polymerized material thus exhibited increasingly discrete granular morphology. When there was 10 wt % or less water content in the precursor microemulsion, the rearrangement of water domains could be minimized during the course of polymerization and transparent polymerized material was obtained.

Water in the Indic Traditions

The essay critically discusses the predominant role played by water in the lives of people from Vedic times to the present day, in the Hindu world. A number of ceremonies both happy or auspicious-making and secular have been associated with water. Several hymns of the Vedas, Brāhmanas, Mahābhārata, Āgamic and Purānic texts are drawn upon to bring out the legends and myths, and genuine beliefs, connected with water that underscore the sacred and profane, purificatory, healing and resuscitating dimensions of water. The essay treats readers to many ancient motifs concerning the pervasive value and utility of water. These comprise, variously, sacrifice, fertility rites, water-medium birth, divine metamorphosis, self-conceiving cosmic birth, totemism life-cycle rites, sanctifications, consecration and installation of icons and edifices, food rituals, monsoon rites, to pacifications, possession and exorcism, death, after-life and rebirth rituals. Reference is also made to the ecology of water resources, the economy of water scarcity, ‘war-wars’ or water imperialism, and water justice in the socio-political arenas of post independent India, in a rapidly liberalising and globalising world. In that regard practical applications of the knowledge-base are explored through the work of NGOs and Water Swamis in the subcontinent.

Changes in oil content, lipid class and fatty acid composition of the microalga Chaetoceros calcitrans over different phases of batch culture

 Abstract
The diatom Chaetoceros calcitrans is a microalgal species used as food for larva in aquaculture for many species worldwide. Chaetoceros calcitrans is an important source of omega 3 long chain (C ≥ 20) polyunsaturated fatty acids (n-3 LC PUFA), chiefly eicosapentaenoic acid (EPA, 20:5n-3). This article reports lipid content, lipid class composition and fatty acid profiles of each lipid class during the growth cycle of batch cultures of C. calcitrans. Total lipid content and the concentration of neutral lipid were highest in the late stationary growth phase (day 12). However, the amount of EPA was highest during the logarithmic growth phase (1.24 pg/cell on day 4). EPA was initially concentrated in the glycolipid fraction, but this fraction decreased during logarithmic growth, coinciding with the increase in neutral lipid. Docosahexaenoic acid (22:6n-3, DHA) (0.91 pg/cell) was reported as a major fatty acid (>10 mg/100 g) in all lipid classes on day 1. DHA was depleted quickly from the neutral lipid and glycolipid classes, but at a slower rate from the polar lipid fraction. This work confirms that C. calcitrans is a good source of lipid, in particular EPA, for larval and adult filter feeders in aquaculture.

Occurrence of antibiotic resistance genes in reclaimed water and river water in the Werribee Basin, Australia

The purpose of this study was to investigate the occurrence of antibiotic resistance genes (ARGs) in water used for irrigation in the Werribee River Basin, Australia, including river water and reclaimed effluent water (reclaimed water). Samples of reclaimed water, collected over a one-year period, were screened for the occurrence of ARGs using PCR detection assays. The presence of ARGs in the reclaimed water samples were contrasted with that of water samples taken from the Werribee River Basin, collected over the same time period, from five points selected for varying levels of urban and agricultural impact. Of the 54 river water samples collected, 2 (4%), 2 (4%), 0 and 0 were positive for methicillin, sulfonamide, gentamicin and vancomycin-resistant genes, respectively, while 6 of 11 reclaimed water samples were positive for methicillin (9%) and sulfonamide (45%). The presence/absence of ARGs did not appear to correlate with other measured water quality parameters. The low detection of ARGs in river water indicates that, regardless of its poor quality, the river has not yet been severely contaminated with ARGs. The greater prevalence of ARGs in reclaimed water indicates that this important agricultural water source will need to be monitored into the future.

Ionic liquid adsorption and nanotribology at the silica-oil interface: hundred-fold dilution in oil lubricates as effectively as the pure ionic liquid

The remarkable physical properties of ionic liquids (ILs) make them potentially excellent lubricants. One of the challenges for using ILs as lubricants is their high cost. In this article, atomic force microscopy (AFM) nanotribology measurements reveal that a 1 mol % solution of IL dissolved in an oil lubricates the silica surface as effectively as the pure IL. The adsorption isotherm shows that the IL surface excess need only be approximately half of the saturation value to prevent surface contact and effectively lubricate the sliding surfaces. Using ILs in this way makes them viable for large-scale applications.