SARS Another Emerging Disease

Severe acute respiratory syndrome, SARS, is an illness that has been recently reported in Asia, North America, Europe and Africa. SARS appears to be a new disease. The first known case of atypical pneumonia occurred on 16 November 2002 in Foshan City, Guangdong Province, China. However, its significance was not known until later. The disease soon spread to the rest of the Guangdong Province and then further points in South East Asia. The World Health Organization (WHO) started to track the disease actively during mid-February 2003

ATM Surcharges and the Expansion of Consumer Choice

Since the imposition of surcharges for the use of automatic teller machines became widespread in 1996, the number of ATMs has increased significantly. That increase has benefited consumers greatly by making bank transactions more easily accessible. Critics of surcharges claim that banks are not passing cost savings generated by large ATM networks on to consumers. Such claims are false; operating ATMs is expensive and forces banks to use their own resources to meet consumer demand for ATMs. And surcharges are not anti-competitive; the banking industry remains competitive. Surcharges have created a new area of competition among banks as they try to meet consumer needs for fast and easy access to banks. Consumers who do not want to pay surcharges have plenty of options for accessing their bank accounts without paying a fee. A ban on ATM surcharges, as proposed by Sen. Alfonse D'Amato (R-N.Y.), would serve only to deny an important timesaving option to consumers who are willing to pay for the convenience of ATMs

Improved mass cultivation of the marine diatom Chaetoceros calcitrans for shellfish hatcheries : a thesis presented in partial fulfilment of the requirements for the degree of Master of Philosophy in Biotechnology at Massey University, Palmerston North, New Zealand

A medium for the optimal growth of Chaetoceros calcitrans in batch and continuous culture systems was developed. A method was developed for continuous culture of C. calcitrans that was free from detrimental infection by bacteria. The concentration of tested nutrients in the developed medium were sodium nitrate, 160 mg/L; sodium dihydrogen orthophosphate, 40 mg/L; and the molar Si:N ratio was 0.25 (99.9 mg/L sodium metasilicate). Isolated bacterial strains were shown to be detrimental to the growth of C. calcitrans in batch and continuous culture. Electrolytically treated water was suitable for the growth of C. calcitrans, but a subsequent flourish of bacterial growth at the late exponential phase reduced the quality of the algal cells and made the culture unsuitable for feeding to shellfish larvae. Heat treated water (95°C for ten and a half minutes) gave stable growth for the continuous culture of C. calcitrans in 38 L plastic bioreactor bags for at least 38 days. The superficial gas velocity in the culture bags was 0.09 L/min. Higher superficial gas velocities (e.g. 0.40 L/min were detrimental to C. calcitrans

Electrical transport properties of two-dimensional hole gases in the Si/Si[subscript 1-x]Ge[subscript x] system

This thesis is a report of experimental investigations of hole transport properties in quantum wells formed in Si/SiGe heterostructures grown by Molecular Beam Epitaxy. Initial work was concerned with elucidating the dominant hole scattering mechanisms, the aim being to relate this to the growth conditions and consequently produce enhanced mobility material for further study. Accordingly, low temperature resistance and Hall measurements (down to 4 K) were undertaken, in order to minimise the effect of phonon scattering. The first samples exhibited strongly localised hole states at liquid helium temperatures, but subsequently, the introduction of growth interrupts as well as the use of higher growth temperatures was shown to give rise to conduction by extended states, with a maximum 5 K mobility of nearly 4000 cm2V',s1. Interface impurities at the Si/SiGe heterojunction with a density of 2xl0n cm-2 are shown to be responsible for the typical carrier mobility of 2000 cm:V-'s'1 obtained in structures grown at 550 °C, and using a model developed by the author this density is found to be consistent with the dependence of experimental data on structural and doping parameters. Magnetotransport measurements carried out in fields up to 12 T in strength and at temperatures down to 0.3 K yielded the first observation of weak localisation and carrier-carrier interaction phenomena in this materials system. It is possible to confirm that strain lifts the light hole and heavy hole band degeneracy associated with unstrained Si. In addition, a temperature dependence of the Boltzmann conductivity is observed and attributed to the variation of screening efficiency with thermal disorder. Deviations from the expected InT dependence of the Hall coefficient in the presence of enhanced interaction phenomena might be understood in terms of a recent theory for the weak localisation correction to the Hall conductivity near the metal-insulator transition

High resolution agriculture land cover using aerial digital photography and GIS : a case study for small island states

Chapter 7With the advent of site-specific crop management, sustainability and profitability, land farming now requires information and technology-based management system to identify, analyse and manage spatial and temporal resource variability. Th is approach is being made increasingly possible by recent innovation in information technologies such as mobile devices, geographic information systems, positioning technologies (such as Geographical Position system), and Earth Observations. Such innovation now off ers a holistic approach to micro-manage agricultural resources. (Robert et al., 1994). Basic mapping and farm-level record keeping is one of the first precision agriculture practices that must be implemented in a typical productive agriculture operation (Stombaugh et al., 2001). Typical tasks include mapping of variations that occur in largescale field features such as vegetation stress, crop rotation, inventorying, irrigation, soil drainage and erosion, pest control, etc. Th e search for a low cost methodology that takes into account the growth of information technology in data capture and surveying, data processing, database creation and geographic information systems becomes mandatory in order to respond to such needs. Th e study constitutes, for the first time in Malta, the collection of high precision farming statistics that makes use of an inexpensive system for aerial mapping that requires minimal ground truthing. Th e effectiveness of such a method for small areas was later demonstrated by Galdies and Borg (2006) related to coastal and beach management in the Maltese islands. In the current case, digital aerial remote sensing enabled the accurate mapping of agricultural variables, and coupled with ground survey data, resulted in the production of precise, high resolution agricultural crop-cover maps. Additional information can be further derived from this data that can be used for the optimisation of micro agriculture practices.peer-reviewe

An Emergentist Account of Collective Cognition in Collaborative Problem Solving

As a first step toward an emergentist theory of collective cognition in collaborative problem solving, we present a proto-theoretical account of how one might conceive and model the intersubjective processes that organize collective cognition into one or another--convergent, divergent, or tensive--cognitive regime. To explore the sufficiency of our emergentist proposal we instantiate a minimalist model of intersubjective convergence and simulate the tuning of collective cognition using data from an empirical study of small-group, collaborative problem solving. Using the results of this empirical simulation, we test a number of preliminary hypotheses with regard to patterns of interaction, how those patterns affect a cognitive regime, and how that cognitive regime affects the efficacy of a problem-solving group