Ultraviolet vision and mate choice in the guppy (Poecilia reticulata)

Ultraviolet (UV) vision is well documented for many species of vertebrates. UV cues are known to be used in foraging, navigation and in mate choice. We conducted a series of behavioral experiments to investigate the role of UV perception in mate choice in both female and male guppies (Poecilia reticulata). In our experiments the visual appearance of potential mates was manipulated using either UV transmitting (UV+) or UV blocking (UV-) filters. Female guppies significantly preferred UV+ males. Male guppies tended to prefer UV- females, but their preferences were marginally nonsignificant. Further experiments investigating the role of luminance, indicate that UV wavelengths are probably being used for color discrimination rather than for detecting differences in brightness. These experiments raise the possibility that UV is used in mate assessment in different ways by male and female guppies. This may reflect the different strategies that the two sexes have in order to maximize reproductive success. To our knowledge, these are the first data showing that UV is used by any fish species in mate selection.

Conservation ecology and breeding biology of the white-browed treecreeper, Climacteris affinis

The White-browed Treecreeper Climacteris affinis is one of many woodland-dependent birds that are at risk from the encroachment of human-dominated land-uses into natural landscapes. The White-browed Treecreeper inhabits semi-arid woodlands in north-west Victoria, Australia, a vegetation community that has undergone extreme modification in the last century due to the expansion of agriculture in the region. Extant woodlands represent only 10% of the original woodland cover in the region, and are highly fragmented and disturbed in many districts. Thus, the survival of the White-browed Treecreeper may depend on active management. However, current knowledge of the ecology and biology of this species is virtually non-existent, and inadequate for informed and effective conservation actions. The aim of this thesis is to redress this situation and provide the ecological basis for sound conservation management of the species. The thesis consists of two parts: an investigation of habitat use at three spatial scales and a study of the social organization, nesting requirements, breeding behaviour and reproductive success of a population of White-browed Treecreepers. Fifty-six patches of remnant woodland in north-west Victoria were surveyed to determine the factors affecting the occurrence of the White-browed Treecreeper at the regional scale. It was detected in 16 patches, and was largely confined to two core districts - Yarrara and, Wyperfeld (Pine Plains). The floristic composition of the dominant tree species was an important determinant of patch occupancy, with the results providing quantitative support for the previously suspected affinity for Belah Casuarina pauper and Slender Cypress-pine Callitris gracilis — Buloke Allocasuarina luehmannii woodlands. However, the absence of the White-browed Treecreeper from several districts was due to factors other than a lack of appropriate habitat. Demographic isolation - the distance from the focal patch to the nearest population of the White-browed Treecreeper - was the most important variable in explaining variation in patch occupancy. Patches isolated from other treecreeper populations by more than 8.3 km in landscapes of non-preferred native vegetation, and 3 km in agricultural landscapes, were unlikely to support the White-browed Treecreeper. The impact of habitat loss and fragmentation on the capacity of individuals to move through the landscape (i.e. functional connectivity) is considered in relation to disruption to dispersal and migration, and the potential collapse of local metapopulations. Habitat use was then examined in a network of patches and linear strips of Belah woodland embedded in a predominantly cultivated landscape. A minimum area of 18.5 ha of Belah woodland was identified as the most important criterion for patch occupancy at the local scale. This landscape appeared to be permeable to movement by the White-browed Treecreeper, facilitated by the extensive network of linear habitat, and clusters of small to medium fragments. The third scale of habitat use investigated the frequency of use of 1-ha plots within tracts of occupied woodland. It is important to discriminate between habitat traits that operate at the population level, and those that act as proximate cues for habitat selection by individuals. Woodlands that have high tree density, extensive cover of low-stature shrubs, abundant lichen, a complex vertical structure, and relatively low cover of grass and herbs are likely to support larger populations of the White-browed Treecreeper. However, individuals appeared to be using tree dominance (positive) and tall shrub cover (negative) as proximate environmental stimuli for habitat selectivity. A relatively high cover of ground lichen, which probably reflects a ground layer with low disturbance and high structural complexity, was also a reliable indicator of habitat use. Predictive models were developed which could be used to plan vegetation management to enhance habitat for the White-browed Treecreeper. The results of the regional, landscape and patch-scale investigations emphasise that factors operating at multiple spatial scales influence the suitability of remnant vegetation as habitat for the White-browed Treecreeper. The White-browed Treecreeper is typical of many small Australian passerines in that it has high annual survival, small clutches, a long breeding season, multiple broods and relatively low reproductive rates. Reproductive effort is adjusted through the number of clutches laid rather than clutch size. They occupy relatively large, all-purpose territories throughout the year. However, unlike many group territorial birds, territory size was not related to the number of occupants. The White-browed Treecreeper nests in tree hollows. They select hollows with a southerly orientation where possible, and prefer hollows that were higher from the ground. At Yarrara, there was considerable spatial variation in hollow abundance that, in concert with territorial constraints, restricted the actual availability of hollows to less than the absolute abundance of hollows. Thus, the availability of suitable hollows may limit reproductive productivity in some territories, although the magnitude of this constraint on overall population growth is predicted to be small. However, lack of recruitment of hollow-bearing trees would increase the potential for hollow availability to limit population growth. This prospect is particularly relevant in grazed remnants and those outside the reserve system. Facultative cooperative breeding was confirmed, with groups formed through male philopatry. Consequently, natal dispersal is female-biased, although there was no skew in the sex ratio of the fledglings or the general adult population. Helpers were observed performing all activities associated with parenting except copulation and brooding. Cooperatively breeding groups enjoyed higher fledgling productivity than simple pairs, after statistically accounting for territory and parental quality. However, the difference reflected increased productivity in the 1999-breeding season only, when climatic conditions were more favourable than in 1998. Breeding commenced earlier in 1999, and all breeding units were more likely to attempt a second brood. However, only breeders with helpers were successful in fledging second brood young, and it was this difference that accounted for the overall discrepancy in productivity. The key mechanism for increased success in cooperative groups was a reduction hi the interval between first and second broods, facilitated by compensatory reductions in the level of care to the first brood. Thus, females with helpers probably achieved significant energetic savings during this period, which enabled them to re-lay sooner. Furthermore, they were able to recommence nesting when the fledglings from the first brood were younger because there were more adults to feed the dependent juveniles. The current utility, and possible evolutionary pathways, of cooperative breeding is examined from the perspective of both breeders and helpers. Breeders benefit through enhanced fledgling productivity in good breeding conditions and a reduction in the burden of parental care, which may impart significant energetic savings. Further, breeders may facilitate philopatry as a means for ensuring a minimum level of reproductive success. Helpers benefit through an increase in their inclusive fitness in the absence of opportunities for independent breeding (i.e. ecological constraints) and access to breeding vacancies in the natal or adjacent territories (i.e. benefits of philopatry). However, the majority of breeding unit-years comprised unassisted breeders, which suggests that pairs are selectively favoured under certain environmental or demographic conditions.

Critical care nurses' haemodynamic decision making

For cardiac surgical patients, the immediate 2-hour recovery period is distinguished by potentially life-threatening haemodynamic instability. To ensure optimum patient outcomes, nurses of varying levels of experience must make rapid and accurate decisions in response to episodes of haemodynamic instability. Decision complexity, nurses’ characteristics, and environmental characteristics, have each been found to influence nurses' decision making in some form. However, the effect of the interplay between these influences on decision outcomes has not been investigated. The aim of the research reported in this thesis was to explore variability in critical care nurses' haemodynamic decision making as a function of interplay between haemodynamic decision complexity, nurses' experience, and specific environmental characteristics by applying a naturalistic decision making design. Thirty-eight nurses were observed recovering patients in the immediate 2-hour period after cardiac surgery. A follow-up semi-structured interview was conducted. A naturalistic decision making approach was used. An organising framework for the goals of therapy related to maintaining haemodynamic stability after cardiac surgery was developed to assist the observation and analysis of practice. The three goals of therapy were the optimisation of cardiovascular performance, the promotion of haemostasia, and the reestablishment of normothermia. The research was conducted in two phases. Phase One explored issues related to observation as method, and identified emergent themes. Phase Two incorporated findings of Phase 1, investigating the variability in nurses' haemodynamic decision making in relation to the three goals of therapy. The findings showed that patients had a high acuity after cardiac surgery and suffered numerous episodes of haemodynamic instability during the immediate 2-hour recovery period. The quality of nurses' decision making in relation to the three goals of therapy was influenced by the experience of the nurse and social interactions with colleagues. Experienced nurses demonstrated decision making that reflected the ability to recognise subtle changes in haemodynamic cues, integrate complex combinations of cues, and respond rapidly to instability. The quality of inexperienced nurses' decision making varied according to the level and form of decision support as well as the complexity of the task. When assistance was provided by nursing colleagues during the reception and recovery of patients, the characteristics of team decision making were observed. Team decision making in this context was categorised as either integrated or non integrated. Team decision making influenced nurses' emotions and actions and decision making practices. Findings revealed nurses' experience affected interactions with other team members and their perceptions of assuming responsibility for complex patients. Interplay between decision complexity, nurses' experience, and the environment in which decisions were made influenced the quality of nurses' decision making and created an environment of team decision making, which, in turn, influenced nurses' emotional responses and practice outcomes. The observed variability in haemodynamic decision making has implications for nurse education, nursing practice, and system processes regarding patient allocation and clinical supervision.

Monaural sound localization : mechanisms and processes

A review of the literature established that localization acuity measured during monaural listening conditions was directly related to various methodological considerations. These included method of attenuation, segment of auditory space where monaural localization was measured, and the presence or absence of head movements. An extensive measurement of monaural localization was made with due consideration of these factors, allowing a more comprehensive evaluation of monaural acuity and the underlying processes that were involved. Establishing a monaural condition is dependent both on the attenuation level of the occluded ear and the signal level, both of which are clearly inter-related since the attenuation level of the occluded ear sets the maximum level of die stimulus. In a series of experiments it was established that there was a minimum signal level for accurate localization. Testing on both sides of the head revealed that there were three regions of monaural localization acuity. The first was about the interaural axis on the ipsilateral ear where monaural localization was relatively accurate, the second a region either side of the MSP where there was some loss of localization, and a third about the interaural axis on the ipsilateral side where virtually no monaural localization ability existed. In the final series of experiments it was established that head-movements allowed subjects to extend the accuracy of the first region by minimizing the distance between the sound and the ipsilateral interaural axis, thus compensating for the loss of localization ability in the second and third regions. This was determined from changes recorded in the error data, and also the extent and direction of measured head-movements. The results of this series of experiments demonstrated the relationship between spectral cues and monaural localization. Firstly, monaural localization was not possible in the absence of accurate spectral information. Thus large errors were observed in the third region where there was blockage of the high-frequencies by the head, and in all regions during the presentation of low signal levels where the high-frequencies fell below threshold. Secondly, the inaccuracy of the second region due to the loss of information from the second pinna suggested that there was a binaural component with relation to pinna cues. It seems that for sounds in this region the spectral modifications from both pinnae are processed to determine a sound's location in space.

Ecology of epifaunal caridean shrimps in the Hopkins River estuary, and the role of estuaries in the life history of the atyid "Paratya Australiensis" Kemp, 1917 in south-eastern Australia

This study examined the factors affecting the distribution and abundance of epifaunal caridean shrimps in seagrass meadows of the Hopkins River estuary in south-western Victoria, Australia, and investigated the life history patterns of the freshwater Parana australiensis, found for the first time in estuaries. Adult and sub-adult shrimps were surveyed in seagrass meadows along the estuary over two years, and their planktonic larvae were surveyed in adjacent waters. Three species were collected. The marine Palaemon serenus occurred only near the mouth, summer to autumn, in high salinities. The marine/estuarine Macrobrachium intermedium occurred throughout the estuary. Adults were most abundant in late autumn, and least abundant in summer (unlike trends reported in marine meadows). Densities were higher and less variable in downstream meadows. P. australiensis occurred in the upper estuary all year, most abundantly in spring, due to migration from the river after peak discharge. Ovigerous females dominated, while males, showing less migration into the estuary, dominated above estuarine influence. Adults disappeared from the estuary in summer as salinity rose. Breeding period for P. australiensis was briefer in the estuary (September-December) than upstream (July-April). M. intermedium began breeding later in the upper estuary (November/December-March) than in the lower estuary (October-March), probably reflecting a physiological response to lower salinity, rather than an interaction with P. australiensis. No ovigerous P. serenus were found in the estuary. Larvae of P. australiensis and M intermedium occurred abundantly throughout the estuary, but P. serenus larvae did not. P. australiensis was an early coloniser to the plankton after peak discharge (November-December). Larvae concentrated in the deep saline layer at the head of the intruding salt wedge, thus probably maintaining longitudinal position. Diurnal vertical migrations were evident within the salt wedge, and in a deep pool above tidal influence. M. intermedium larvae occurred October-May in the lower estuary and November-April in the upper estuary, peaking in abundance one to two months after P. australiensis. They were associated with low surface flows and surface salinities greater than 10, over an anoxic deeper layer. All three species exhibited extended development of euryhaline larvae in the laboratory. Tolerances and optimal salinities of larvae of the three species reflected their distributions. M. intermedium was the most euryhaline species. P. australiensis larvae were tolerant of higher salinities than juveniles of adults: capable of developing in salinity of at least 15. Most P. australiensis juveniles recruited to the estuary November-December, after which numbers declined dramatically. After settlement, most recruits probably migrated upstream out of the estuary. Two cohorts of M. intermedium recruited to the estuary from larvae in summer (December and February), but some juveniles also migrated from adjacent coastal waters. Post-larval migration was at least as important a determinant of abundance as direct recruitment from estuarine, planktonic larvae in all three species. Distributions among seagrass meadows along the estuary were determined primarily by physico-chemical patterns driven by hydrological changes. Seasonal variations in salinity and temperature were strongly associated with seasonal variations in shrimp abundance. Salinity tolerances of adults of the three species reflected their distribution patterns. Biotic interactions were more important in determining distributions within meadows. P. australiensis, when abundant, were associated with seagrass biomass. M. intermedium were also, but when seagrass was sparsest and least extensive. The two species apparently partitioned the seagrass meadow according to depth in early summer. Laboratory experiments suggested P. australiensis was displaced from deeper water by M. intermedium. Preference for vegetative complexity and competition for position within meadows suggest the underlying importance of predation in regulating shrimp populations. A survey of south-eastern Australian estuaries found P. australiensis larvae abundant in all stable, open, well-developed, salt-wedge estuaries where adults were abundant. Adults were most abundant in low salinities among submerged leafy macrophytes. Reproductive traits of P. australiensis were compared in estuarine and fresh reaches of three rivers. Early in the breeding season, egg size was smaller, and (size-specific) egg number larger in estuaries than upstream. A trade-off between egg size and egg number resulted in no difference in total (size-specific) reproductive investment between locations. Reproductive investment tended to decrease at some locations over the breeding season, and this decrease was a result of decreased egg size in most cases. The decrease in reproductive investment probably reflected reduced food availability for the adult, while the reduced egg size was probably a response to improved conditions for larval development. In the Hopkins River, larger egg size at upstream sites was reflected in larger early stage larvae. Later stage larvae were larger in the estuary, suggesting more favourable conditions for larval development. Allozyme electrophoresis showed the P. australiensis populations in each of the three rivers to be distinct. Allozyme frequencies were not different within the Hopkins River, but upstream and estuarine locations in the Curdies and Gellibrand were different. Although some variation in reproductive traits within catchments may have been due to genotypic differences, trade-offs between egg size and number, and decreases in egg size over summer were probably due to plastic responses to environmental cues. It is proposed P. australiensis inhabits and reproduces in both estuarine and freshwater environments by plastic response to environmental conditions. Recruitment to estuaries is dependent on the presence of suitable adult, littoral habitat, and a stable salt wedge for larval retention. Estuaries are important recruitment sites for P. australiensis, potentially allowing an extra brood each year before riverine recruitment. Estuarine broods could constitute a large part of the total fecundity of P. australiensis females. Euryhaline larvae and estuarine recruitment of P. australiensis suggest marine transport of larvae between estuaries as a possible dispersal mechanism for Paratya species.

Hypothesis generation for management intelligence

Investigation of the role of hypothesis formation in complex (business) problem solving has resulted in a new approach to hypothesis generation. A prototypical hypothesis generation paradigm for management intelligence has been developed, reflecting a widespread need to support management in such areas as fraud detection and intelligent decision analysis. This dissertation presents this new paradigm and its application to goal directed problem solving methodologies, including case based reasoning. The hypothesis generation model, which is supported by a dynamic hypothesis space, consists of three components, namely, Anomaly Detection, Abductive Reasoning, and Conflict Resolution models. Anomaly detection activates the hypothesis generation model by scanning anomalous data and relations in its working environment. The respective heuristics are activated by initial indications of anomalous behaviour based on evidence from historical patterns, linkages with other cases, inconsistencies, etc. Abductive reasoning, as implemented in this paradigm, is based on joining conceptual graphs, and provides an inference process that can incorporate a new observation into a world model by determining what assumptions should be added to the world, so that it can explain new observations. Abductive inference is a weak mechanism for generating explanation and hypothesis. Although a practical conclusion cannot be guaranteed, the cues provided by the inference are very beneficial. Conflict resolution is crucial for the evaluation of explanations, especially those generated by a weak (abduction) mechanism.The measurements developed in this research for explanation and hypothesis provide an indirect way of estimating the ‘quality’ of an explanation for given evidence. Such methods are realistic for complex domains such as fraud detection, where the prevailing hypothesis may not always be relevant to the new evidence. In order to survive in rapidly changing environments, it is necessary to bridge the gap that exists between the system’s view of the world and reality.Our research has demonstrated the value of Case-Based Interaction, which utilises an hypothesis structure for the representation of relevant planning and strategic knowledge. Under, the guidance of case based interaction, users are active agents empowered by system knowledge, and the system acquires its auxiliary information/knowledge from this external source. Case studies using the new paradigm and drawn from the insurance industry have attracted wide interest. A prototypical system of fraud detection for motor vehicle insurance based on an hypothesis guided problem solving mechanism is now under commercial development. The initial feedback from claims managers is promising.

Spatial and temporal disparities in aurally aided visual search

Research over the last decade has shown that auditorily cuing the location of visual targets reduces the time taken to locate and identify targets for both free-field and virtually presented sounds. The first study conducted for this thesis confirmed these findings over an extensive region of free-field space. However, the number of sound locations that are measured and stored in the data library of most 3-D audio spatial systems is limited, so that there is often a discrepancy in position between the cued and physical location of the target. Sampling limitations in the systems also produce temporal delays in which the stored data can be conveyed to operators. To investigate the effects of spatial and temporal disparities in audio cuing of visual search, and to provide evidence to alleviate concerns that psychological research lags behind the capabilities to design and implement synthetic interfaces, experiments were conducted to examine (a) the magnitude of spatial separation, and (b) the duration of temporal delay that intervened between auditory spatial cues and visual targets to alter response times to locate targets and discriminate their shape, relative to when the stimuli were spatially aligned, and temporally synchronised, respectively. Participants listened to free-field sound localisation cues that were presented with a single, highly visible target that could appear anywhere across 360° of azimuthal space on the vertical mid-line (spatial separation), or extended to 45° above and below the vertical mid-line (temporal delay). A vertical or horizontal spatial separation of 40° between the stimuli significantly increased response times, while separations of 30° or less did not reach significance. Response times were slowed at most target locations when auditory cues occurred 770 msecs prior to the appearance of targets, but not with similar durations of temporal delay (i.e., 440 msecs or less). When sounds followed the appearance of targets, the stimulus onset asynchrony that affected response times was dependent on target location, and ranged from 440 msecs at higher elevations and rearward of participants, to 1,100 msecs on the vertical mid-line. If targets appeared in the frontal field of view, no delay of acoustical stimulation affected performance. Finally, when conditions of spatial separation and temporal delay were combined, visual search times were degraded with a shorter stimulus onset asynchrony than when only the temporal relationship between the stimuli was varied, but responses to spatial separation were unaffected. The implications of the results for the development of synthetic audio spatial systems to aid visual search tasks was discussed.

Case study of electronic networking in an initial teacher education course

Electronic networking ('computer-mediated communication1), considered to be ‘unique domain for educational activity’ (Harasim, 1989:50) and ‘new educational paradigm’ (Mason & Kaye, 1989:23), has been widely used and researched in K-12 schooling, place-based undergraduate subjects and distance education courses. However, only a limited number of reports of usage with experienced teachers (professional development), beginning teachers (induction support) and trainee teachers (initial training) have been published. Hence, little is known about the ways in which this new medium might contribute to the acquisition and maintenance of professional knowledge in the field of teacher education. The purpose of this study was to document an application of electronic networking in an initial 'school-based1 teacher education course. Three factors which were considered to be important in the adoption of electronic networking were specifically addressed: (a) the potential of the medium to attract and maintain a representative and comprehensive audience', (b) the willingness of participants to use the medium for the notation of ideas about teaching; and, (c) the extent to which reflection on practice was evident in network messages. This study also identified and investigated other effects which emerged as participants attempted to negotiate personal relationships with new technology. A case study was selected to investigate audience, notation, reflection, and other effects, in a particular application. Data were collected using participant observation, software-generated statistics, printed documentation, university records, questionnaires, interviews and content analysis of messages. These data were used to describe and analyse network participation by trainee teachers, classroom teachers and university staff. The data revealed that an audience did exist on the electronic network but that this was not comprehensive. Teachers had difficulty accessing the network because of other school commitments, access to equipment and personal competence with microcomputers. These difficulties indicated that developing and maintaining the teacher audience may be a major problem with electronic networking in initial teacher education. This case study revealed that deeply held concerns about notation of ideas by trainee teachers and classroom teachers can be powerful reasons for limited network participation. For trainee teachers, recording ideas publicly presented special difficulties associated with written communication. They were concerned about writing for an audience; about what to write about and how to write it. The loss of visual and verbal cues which form part of face-to-face communication was also a problem leading to concerns about how messages would be received by others. However, the overwhelming concern of almost all trainee teachers about presenting their own ideas was Tear of criticism' from peers (in particular), and other participants on the network. Trainee teachers expressed concerns about the 'dangers' of putting their thoughts in writing, the scrutiny their messages might have received from others, and the public 'criticism' about what they wrote which might have appeared on the network. Knowing that messages were stored on the network, and could be retrieved at some later date, heightened anxiety about the vulnerability of written communication; what was written on one occasion may have to be defended at some later date when the views expressed initially were no longer held. Classroom teachers were also unsure about recording their own ideas in an electronic form. Like trainee teachers, they were concerned about the scrutiny their contributions might receive from other users, and the lack of visual and verbal cues which they had learnt to use in face-to-face communication. Notating ideas in text-based messages which were archived (by the software), and retrievable by others later, was also daunting to many teachers. Another major 'danger' for teachers was the possible repercussions of 'public comment' about curriculum policy and initiatives which they thought might get them into 'trouble' with their employer. Since very few messages were contributed to conferences, there was little evidence of reflection in network communication. In the main, the network was not used to share information and ideas about curriculum and teaching. Public examples of collaboration between participants were not evident, and the 'special knowledge' held by members in each distinct group of users was not elaborated and discussed. Messages were not used to request information or clarification about issues, to outline the processes by which decisions about teaching were reached, or to synthesis ideas from different sources. The potential of the medium to operationalise reflective practice was not realised. Among the effects observed, the use of an anonymous account to access the network, and the impact this had on participation (in one conference) was considered to be a particularly significant finding. While the opportunity to systematically investigate the effects of anonymity on network participation and message contributions was not realised (by the author) while the research was in progress, the effects observed and discussed are considered to be important and worthy of further investigation. In this case study, the anonymous account helped trainee teachers mask concerns about personal writing skills and fear of criticism from others, indicating that anonymity may alter communication patterns, particularly in the early stages of network use. Given the data collected in this case study, and the interpretations placed on it by the author, a pessimistic assessment of the place of electronic networking in initial teacher education courses was presented. For this situation to change - that is, for electronic discussions to become more fully integrated into course activities - four issues which need to be addressed were identified and discussed. These included clarification of the role of collaboration amongst participants in initial teacher education, the ways in which collaboration can be facilitated using electronic networking, the problems of notation - such as the difficulty of expressing ideas about teaching in written form, and the concerns about permanently archived messages - for teachers and trainee teachers, and the lack of skills which many trainee teachers bring to electronic discussions. In the context of initial teacher education, it was suggested that these four aspects require clarification and development before the potential advantages of electronic networking can be realised. Some specific suggestions about how these issues might be resolved were presented.

Reinforcement sensitivity theory : a paradigm for understanding the motivational processes underlying alcohol use

Provides an examination of the processes which motivate individuals to drink alcohol. It was found that heavier drinkers are highly sensitive to reward yet more likely to experience negative affect, both generally, and in response to alcohol-related cues. Based on these findings a model focusing on the links between personality, mood and craving for alcohol was developed.

Spatial ecology of E. australis

This research investigated links between the occurrence of endangered southern right whales and characteristics of their habitat. Habitat selection is based on physical environmental features, with important roles for social cues and site fidelity. This complex interaction of factors affects spatial recovery capacity and presents challenges for conservation management.

Connection between commonly used financial ratios and misrepresentation of financial statements of collapsed corporations

This paper unravels dynamic and intriguing shifts in the use of financial ratios in signaling corporate collapse. An empirical examination of the anecdotal evidences from notable recent corporate collapses coupled with the short-lived usefulness of financial ratios in various prediction models suggest that companies(1) that deliberately misrepresent their financial statements may have taken cues from the ratios that are commonly investigated. This proposition is supported by an extensive examination of over 50 studies conducted between 1968 and 2002. The erosion in the reliability of numbers in financial statements has led to significant distortions in the predictive power of financial ratios when used in signaling corporate collapse. Recent collapses such as Parmalat in Europe, Enron and WorldCom in the U.S. and HIH in Australia, present yet another reminder that financial statement items are being misrepresented. These are all large corporations with well-established household names, and are for sure closely monitored by financial communities around the globe. Nevertheless, a common thread seems to link the collapse of these companies: none of these collapses were foreseen by credit rating agencies or foretold by the widely accepted bankruptcy prediction models. Why? This paper attempts to use some anecdotal evidence in order to provide logical explanations to the existence of such a common thread. It argues that there appears to be anecdotal evidence to suggest that directors of publicly listed companies that have collapsed may have deliberately misrepresented financial statement items.

Brand salience for fast-moving consumer goods : an empirically based model

Brand salience, or the prominence of a brand in memory, has been linked to brand choice and purchase by consumers. The research reported in this paper proposed and tested a model of brand salience for fast-moving consumer goods, which incorporates knowledge, media consumption, and brand image as antecedents. A quasi-experimental method was utilised, where 270 respondents undertook a free recall exercise using category cues, and then completed multiitem measures of brand knowledge, brand associations, and purchase likelihood. Analysis of the data using SEM found support for an empirical model of brand salience where there was a relationship between brand salience and purchase likelihood. The empirical evidence supports building a brand in a primary category, in order to build the depth and breadth of the brand’s associations in consumer memory.

Identification of an attractin-like pheromone in the mucus-secreting hypobranchial gland of the abalone Haliotis asinina linnaeus.

Pheromones are chemicals used to communicate between animals of the same species, and are thought to be used by most marine animals. With limited vision, abalone primarily sense their world chemically, and pheromones may play an important role in settlement, attraction, recognition, alarm, and reproduction. Despite this, there has been no detailed investigation into pheromone substances, both in their precise biochemical nature or pheromonal function. In this study, we investigated the presence of pheromonelike substances from the hypobranchial gland of the abalone Haliotis asinina using bioassays, immunohistochemistry, Western blotting, and reverse-phase high-performance liquid chromatography (RP-HPLC). The hypobranchial gland of many prosobranchial marine molluscs has been classified as a sex auxiliary gland releasing unknown substances during spawning. In our study, cephalic tentacle assays demonstrated that the cell extracts of the hypobranchial gland contain chemical cues that are sensed by conspecifics. An antibody against the sea slug “attractin” pheromone was used as a probe to localize a similar protein in the mucin-secreting cells of the epithelial lining the hypobranchial gland of both male and female abalone. The approximate molecular weight of this abalone attractin-like protein is 30 kDa in both males and females. Fractionation of hypobranchial gland extracts by C5 RP-HPLC could not selectively purify this protein, and no sex-specific differences were observed. We predict that the attractin-like protein could be one of a number of important proteins involved in maturation, aggregation, and/or spawning behavior of abalone. In future research, additional hypobranchial gland components will be tested further for these types of behavior.

A suite of evidence-based continence assessment tools for residential aged care

The management of incontinence in residential aged care facilities presents staff with considerable challenges. In order to support the residential aged care workforce to provide evidence-based continence care, we developed a suite of evidence-based continence assessment tools and an accompanying educational resource for use in the residential aged care sector. The tools comply with international and accreditation standards. They address urinary and faceal incontinence and other bladder and bowel symptoms. They also include a number of cues to guide staff to assess and manage residents’ continence care needs and refer as needed. An evaluation of the tools conducted in 18 residential aged care facilities across three states revealed that staff members found the tools helpful, clear, simple and user-friendly. This paper provides a description of the newly developed suite of continence assessment tools for residential aged care and the accompanying education resources, and presents staff perspectives on their clinical usefulness.

Do male guppies distinguish virgin females from recently mated ones?

In some mating systems males should benefit from mating with virgin females because of their higher reproductive value. We determined experimentally whether and how males distinguish between virgin and recently mated females in the guppy, Poecilia reticulata, a promiscuous livebearer. In a free-swimming experiment, males showed flexible mating behaviour by adjusting their tactics according to the mating status of the female they encountered, virgin or mated. Males followed, nipped and copulated with virgins more than with mated females, but they performed more sneaky copulations with mated females, possibly because the latter were more reluctant to mate than virgin females. When, in another set of experiments, males received only the visual cues of both virgins and mated females they showed no preference for either, but when they were exposed only to the female olfactory cues, they associated considerably more with the smell of virgin females. These results suggest that male guppies assess female behavioural and olfactory cues to determine female virginity and then use different mating tactics depending on the female's status. It is possible that the changes in male mating behaviour increase male reproductive success.