Children's understanding of pictorial and mental representations

Two studies demonstrate dissociation between children's understanding of pictorial representations (photos and drawings) and mental representations (beliefs). In Study 1, 37 preschoolers were tested on false belief, appearance-reality, false photo, and false drawing tasks. The false picture tasks were significantly easier, and no correlation was found between children's performances on false belief and false picture tasks. Ln Study 2, 30 children who failed a false belief pretest were randomly assigned to 3 training groups: Belief (trained on false belief tasks), Picture (trained on false picture tasks), or Control (trained on number conservation tasks). Training was conducted in 2 sessions over the course of 2 weeks, tasks were presented and feedback was provided. All children were posttested on theory of mind tasks, false picture tasks, and a number conservation task. The posttest results showed differential patterns of performance, with the Belief group scoring highest on the theory of mind posttests, the Picture group scoring highest on the false picture posttests, and the Control group scoring highest on the number conservation posttest. Results are discussed with respect to competing models of theory of mind development.

Towards an understanding of the age and origin of mesothermal gold mineralisation in the Etheridge Goldfield, Georgetown region, north Queensland

Small mesothermal vein quam-gold-base-metal sulfide deposits from which some 20 t of Au-Ag bullion have been extracted, are the most common gold deposits in the Georgetown region of north Queensland-several hundred were mined or prospected between 1870 and 1950. These deposits are mostly hosted by Proterozoic granitic and metamorphic rocks and are similar to the much larger Charters Towers deposits such as Day Dawn and Brilliant, and in some respects to the Motherlode deposits of California. The largest deposit in the region-Kidston (> 138 t of Au and Ag since 1985)- is substantially different. It is hosted by sheeted quartz veins and cavities in brecciated Silurian granite and Proterozoic metamorphics above nested high-level Carboniferous intrusives associated with a nearby cauldron subsidence structure. This paper provides new information (K-Ar and Rb-Sr isotopic ages, preliminary oxygen isotope and fluid-inclusion data) from some of the mesothermal deposits and compares it with the Kidston deposit. All six dated mesothermal deposits have Siluro-Devonian (about 425 to 400 Ma) ages. All nine of such deposits analysed have delta(18)O quartz values in the range 8.4 to 15.7 parts per thousand, Fluid-inclusion data indicate homogenisation temperatures in the range 230-350 degrees C. This information, and a re-interpretation of the spatial relationships of the deposits with various elements of the updated regional geology, is used to develop a preliminary metallogenic model of the mesothermal Etheridge Goldfield. The model indicates how the majority of deposits may have formed from hydrothermal systems initiated during the emplacement of granitic batholiths that were possibly, but not clearly, associated with Early Palaeozoic subduction, and that these fluid systems were dominated by substantially modified meteoric and/or magmatic fluids. The large Kidston deposit and a few small relatives are of Carboniferous age and formed more directly from magmatic systems much closer to the surface.

Targeting local tissues by transdermal application: Understanding drug physicochemical properties that best exploit protein binding and blood flow effects

The targeting of topically applied drug molecules into tissues below a site of application requires an understanding of the complex interrelationships between the drug, its formulation, the barrier properties of the skin, and the physiological processes occurring below the skin that are responsible for drug clearance from the site, tissue, and/or systemic distribution and eventual elimination. There is still a certain amount of controversy over the ability of topically applied drugs to penetrate into deeper tissues by diffusion or whether this occurs by redistribution in the systemic circulation. The major focus of our work in this area has been in determining how changes in drug structure and physicochemical properties, such as protein binding and lipophilicity, affect drug clearance into the local dermal microcirculation and lymphatics, as well as subsequent distribution into deeper tissues below an application site. The present study outlines our recent thinking on the drug molecule optimal physical attributes, in terms of plasma and tissue partitioning behaviour, that offer the greatest potential for deep tissue targeting. Drug Dev. Res. 46:309-315, 1999. (C) 1999 Wiley-Liss, Inc.

An investigation of pretend play, mental state terms and false belief understanding: In search of a metarepresentational link

The aim of this study was to investigate the association between false belief comprehension, the exhibition of pretend play and the use of mental state terms in pre-school children. Ferry children, aged between 36 and 54 months were videotaped engaging in free play with each parent. The exhibit-ion of six distinct acts of pretend play and the expression of 16 mental sr:ate terms were coded during play. Each child was also administered a pantomime task and three standard false belief casks. Reliable associations were also found between false belief performance and the pretence categories of object substitution and role assignment, and the exhibition of imaginary object pantomimes. Moreover, the use of mental state terms was positively correlated with false belief and the pretence categories of object substitution, imaginary play and role assignment, and negatively correlated with the exhibition of body part object pantomimes. These findings indicate that the development of a mental state lexicon and some, bur not all, components of pretend play are dependent on the capacity for metarepresentational cognition.

A new graphic format to facilitate the understanding of technological innovation models: the seesaw of competitiveness

Many models exist in the literature to explain the success of technological innovation. However, no studies have been made regarding graphic formats representing the technological innovation models and their impact, or on the understanding of these models by non-specialists in technology management. Thus, the main objective of this paper is to propose a new graphic configuration to represent the technological innovation management. Based on the literature, the innovation model is presented in the traditional format. Next, the same model is designed in the graphic format - named `the see-saw of competitiveness` - showing the interfaces among the identified factors. The two graphic formats were compared by a group of graduate students in terms of the ease in understanding the conceptual model of innovation. The statistical analysis shows that the seesaw of competitiveness is preferred.

Molecular epidemiology: A multidisciplinary approach to understanding parasitic zoonoses

Sound application of molecular epidemiological principles requires working knowledge of both molecular biological and epidemiological methods. Molecular tools have become an increasingly important part of studying the epidemiology of infectious agents. Molecular tools have allowed the aetiological agent within a population to be diagnosed with a greater degree of efficiency and accuracy than conventional diagnostic tools. They have increased the understanding of the pathogenicity, virulence, and host-parasite relationships of the aetiological agent, provided information on the genetic structure and taxonomy of the parasite and allowed the zoonotic potential of previously unidentified agents to be determined. This review describes the concept of epidemiology and proper study design, describes the array of currently available molecular biological tools and provides examples of studies that have integrated both disciplines to successfully unravel zoonotic relationships that would otherwise be impossible utilising conventional diagnostic tools. The current limitations of applying these tools, including cautions that need to be addressed during their application are also discussed.(c) 2005 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

Improved VDC casting of aluminium alloys through an understanding of the surface properties of the molten metal

Vertical direct chill (VDC) casting of aluminium alloys is a mature process that has evolved over many decades through gradual change to both equipment design and casting practice. Today, air-pressurised, continuous lubrication, hot top mould systems with advanced station automation are selected as the process of choice for producing extrusion billet. Specific sets of operating parameters are employed on these stations for each alloy and size combination to produce optimal billet quality. The designs and parameters are largely derived from past experience and accumulated know-how. Recent experimental work at the University of Queensland has concentrated on understanding the way in which the surface properties of liquid aluminium alloys, e.g., surface tension, wetting angle and oxide skin strength, influence the size and shape of the naturally-stab le meniscus for a given alloy, temperature and atmosphere. The wide range of alloy-and condition-dependent values measured has led to the consideration of how these properties impact the stability of the enforced molten metal meniscus within the hot top mould cavity. The actual shape and position of the enforced meniscus is controlled by parameters such as the upstream conduction distance (UCD) from sub-mould cooling and the molten metal head. The degree of deviation of this actual meniscus from the predicted stable meniscus is considered to be a key driver in surface defect formation. This paper reports on liquid alloy property results and proposes how this knowledge might be used to better design VDC mould systems and casting practices.

The role of physiological understanding in plant breeding; From a breeding perspective

The role of physiological understanding in improving the efficiency of breeding programs is examined largely from the perspective of conventional breeding programs. Impact of physiological research to date on breeding programs, and the nature of that research, was assessed from (i) responses to a questionnaire distributed to plant breeders and physiologists, and (ii) a survey of literature abstracts. Ways to better utilise physiological understanding for improving breeding programs are suggested, together with possible constraints to delivering beneficial outcomes. Responses from the questionnaire indicated a general view that the contribution by crop physiology to date has been modest. However, most of those surveyed expected the contribution to be larger in the next 20 years. Some constraints to progress perceived by breeders and physiologists were highlighted. The survey of literature abstracts indicated that from a plant breeding perspective, much physiological research is not progressing further than making suggestions about possible approaches to selection. There was limited evidence in the literature of objective comparison of such suggestions with existing methodology, or of development and application of these within active breeding programs. It is argued in this paper that the development of outputs from physiological research for breeding requires a good understanding of the breeding program(s) being serviced and factors affecting its performance. Simple quantitative genetic models, or at least the ideas they represent, should be considered in conducting physiological research and in envisaging and evaluating outputs. The key steps of a generalised breeding program are outlined, and the potential pathways for physiological understanding to impact on these steps are discussed. Impact on breeding programs may arise through (i) better choice of environments in which to conduct selection trials, (ii) identification of selection criteria and traits for focused introgression programs, and (iii) identifying traits for indirect selection criteria as an adjunct to criteria already used. While many breeders and physiologists apparently recognise that physiological understanding may have a major role in the first area, there appears to be relatively Little research activity targeting this issue, and a corresponding bias, arguably unjustified, toward examining traits for indirect selection. Furthermore, research on traits aimed at crop improvement is often deficient because key genetic parameters, such as genetic variation in relevant breeding populations and genetic (as opposed to phenotypic) correlations with yield or other characters of economic importance, are not properly considered in the research. Some areas requiring special attention for successfully interfacing physiology research with breeding are discussed. These include (i) the need to work with relevant genetic populations, (ii) close integration of the physiological research with an active breeding program, and (iii) the dangers of a pre-defined or narrow focus in the physiological research.

Understanding systemic lupus erythematosus physiopathology in the light of primary immunodeficiencies

Introduction Associations between systemic lupus erythematosus (SLE) and primary immunodeficiencies (PIDs) were analyzed to gain insight into the physiopathology of SLE. Some PIDs have been consistently associated with SLE or lupus-like manifestations: (a) homozygous deficiencies of the early components of the classical complement pathway in the following decreasing order: in C1q, 93% of affected patients developed SLE; in C4, 75%; in C1r/s, 57%; and in C2, up to 25%; (b) female carriers of X-linked chronic granulomatous disease allele; and (c) IgA deficiency, present in around 5% of juvenile SLE. Discussion In the first two groups, disturbances of cellular waste-disposal have been proposed as the main mechanisms of pathogenesis. On the other hand and very interestingly, there are PIDs systematically associated with several autoimmune manifestations in which SLE has not been described, such as autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED), immunedys-regulation polyendocrinopathy enteropathy X-linked (IPEX), and autoinumme lymphoproliferative syndrome (ALPS), suggesting that mechanisms considered as critical players for induction and maintenance of tolerance to autoantigens, such as (1) AME-mediated thymic negative selection of lymphocytes, (2) Foxp3+ regulatory T cell-mediated peripheral tolerance, and (3) deletion of auto-reactive lymphocytes by Fas-mediated apoptosis, could not be relevant in SLE physiopathology. The non-description of SLE and neither the most characteristic SLE clinical features among patients with agammaglobulinemia are also interesting observations, which reinforce the essential role of B lymphocytes and antibodies for SLE pathogenesis. Conclusion Therefore, monogenic PIDs represent unique and not fully explored human models for unraveling components of the conundrum represented by the physiopathology of SLE, a prototypical polygenic disease.