Spatial memory and orientation strategies in the elasmobranch Potamotrygon motoro

We investigated whether juvenile freshwater stingrays (Potamotrygon motoro) can solve spatial tasks by constructing a cognitive map of their environment. Two experimental conditions were run: allocentric and ego-allocentric. Rays were trained to locate food within a four-arm maze placed in a room with visual spatial cues. The feeding location (goal) within the maze (room) remained constant while the starting position varied for the allocentrically but not for the ego-allocentrically trained group. After training, all rays solved the experimental tasks; however, different orientation strategies were used within and between groups. Allocentrically trained rays reached the goal via novel routes starting from unfamiliar locations, while ego-allocentrically trained rays primarily solved the task on the basis of an egocentric turn response. Our data suggest that P. motoro orients by constructing a visual cognitive map of its environment, but also uses egocentric and/or other orientation strategies alone or in combination for spatial orientation, a choice which may be governed by the complexity of the problem. We conclude that spatial memory functions are a general feature of the vertebrate brain.

Media, 'Madness' and Ethical Journalism

This article analyses the way newspapers and journalists sometimes fail to acknowledge and resolve some of the contentious ethical dilemmas associated with reporting news. Its focus is on not exploiting and vilifying the vulnerable, especially people with mental illness, through sensationalism and inaccurate and imprecise use of medical terminology such as "psycho ". "schizo" or "lunatic ". Because ethics is central to our understanding of professionalism, this article uses professions and professionalism as benchmarks aginst which to analyse and critique how journalists and newspapers define and report news.Sometimes journalists fail the test of good ethical practice in terms of negative. outdated and inaccurate expressions they use in the news stories they report. Likewise, regulators of news industry standards appear not to recognize and sanction such reporting. The apparent inability to resolve these ethical dilemmas creates a context conducive to tolerance for, not acceptance of. unethical news reporting.

Testing java interrupts and timed waits

Testing concurrent software is difficult due to problems with inherent nondeterminism. In previous work, we have presented a method and tool support for the testing of concurrent Java components. In this paper, we extend that work by presenting and discussing techniques for testing Java thread interrupts and timed waits. Testing thread interrupts is important because every Java component that calls wait must have code dealing with these interrupts. For a component that uses interrupts and timed waits to provide its basic functionality, the ability to test these features is clearly even more important. We discuss the application of the techniques and tool support to one such component, which is a nontrivial implementation of the readers-writers problem.

Rehabilitating the common intention trust

Position of the common intention principle in Australia - the principle should continue to exist - evidentiary difficulties means that the principle is infrequently invoked - claimants who cannot produce sufficient evidence of a common intention may be entitled to relief via equitable estoppel or the joint endeavour principle - the doctrinal foundation of the common intention trust - alternative rationales for the common intention trust.