The response of the natriuretic peptide system to water deprivation in the desert rodent, Notomys alexis

Natriuretic peptides (NPs) are regulatory molecules that cause cGMP-mediated diuresis and natriuresis in mammals. Accordingly, it is interesting to consider their role in desert-adapted animals in which water is often limited. This study investigated the response of the natriuretic peptide (NP) system to varying periods of water deprivation (WD) in the Australian desert rodent species, Notomys alexis. It was hypothesised that the expression of the NP system will be down-regulated in water-deprived N. alexis compared to water-replete animals. The plasma levels of ANP were significantly reduced after 3 days of WD, but were unaffected by 7, 14 and 28 days of WD. Water deprivation for 3, 7, 14 days had a variable effect on the mRNA expression of ANP, CNP, NPR-A, NPR-B, and NPR-C, and a uniform down-regulation was not observed. However, after 28 days of WD, mRNA expression was similar to water-replete animals, except for NPR-A. Surprisingly, 7 and 14 days of WD caused an up-regulation in the ability of ANP to stimulate cGMP; this also occurred at 14 days for CNP. Taken together, the mRNA expression and peptide mediated guanylyl cyclase activity data after WD were in the opposite direction to what was predicted. Interestingly, after 28 days of WD, most parameters were similar to those of water-replete animals, which indicates that a down-regulation of the NP system is not part of the physiological response to an absence of free water in N. alexis.

The makings of a reliable interview with a child witness

This paper briefly describes four essential elements of interviews involving children, where the primary goal is to obtain detailed and accurate information about an event (e.g., an alleged incident of sexual abuse). These elements include (a) the establishment of a good rapport with the child, (b) a clear description of the purpose and ground-rules of the interview, (c) objectivity and open-mindness, and (d) effective questioning skills. A rationale for the importance of each of these elements and practical recommendations are offered.

An experimental investigation of pure voting power

We evaluate the accuracy of power indices by experimentally measuring the political power embodied in blocks of votes per se.  The experiment incorporates several players interacting in online chat rooms under supervision.  The chat rooms and the selection process reduce or eliminate extraneous political forces leaving logrolling as the primary political force.  Results show that two standard power indices reflect voting power while other power indices and proportionality do not.

The value of information in an agency model with moral hazard

I show that the principal and the agent may each prefer that the principal or the agent has imperfect information about the principal's technology in a principal-agent environment with moral hazard. Principals expend considerable resources on data cumulation and analysis. However, such investments in information acquisition are benecial only if the agent will know that the principal is not ignorant or it allows the principal to implement a dierent action. When the principal is perfectly informed about her technology, the agent prefers to be ignorant. In addition, the value of perfect information for the agency is negative if the principal would implement the same action with either possible technology. I also investigate the dierences between ex ante and ex post contracting, and the ramications of the principal being ignorant or potentially ignorant about the technology. Finally, I determine if the principal's utility varies continuously with the degree of informativeness of the agent about the principal's technology. In this vein, I determine whether the agent's uncertainty may make the principal better o if she has the less informative technology.

Mental tactility: the ascendance of writing in online management education

A qualitative study of online management education and the role of writing as an indicative measure of thinking and learning. Established educational models, such as Dale's Cone of Experience, are expanded and redeveloped to illustrate the central role of writing as a critical thinking process which appears to be increasing, rather than decreasing, with the advent of online multimedia technology. In an environment of increasing reliance on audiovisual stimulus in online education, the authors contend that tertiary educators may witness an ascendance or re-emergence of writing as central to the academic experience. This may be both supply and demand driven. Drawing on a study of two undergraduate units in the Bachelor of Commerce and applying hermeneutics to develop challenging insights, the authors present a case for educators to remain conversant with the art of teaching writing, and to promote writing to improve educational outcomes.

Designing educational tasks for success in industry: a reflection on the evolution of business communication studies in tertiary education

This paper is the result of a "Rip Van Winkle" experience I had concerning the teaching of Business Communication. The paper focuses on the remarkable expansion in the curriculum of the traditional "Business Communication" or "Business Writing" course offered by many tertiary institutions around the world. Based on 25 years of personal observation and experience in a number of educational settings, the paper will trace the increasing sophistication and complexity of the study of business communication from one that covered little more than lessons in the design of hardcopy memos, letters, and reports to one that now covers a broad spectrum of topics such as "emotional intelligence," "intercultural communication," "effective public speaking," as well as the effects of purpose and audience on the design of a wide variety of business communications.

An example of an effective task that involves a number of on the job activities is provided in the form of a ready to use assignment that is applicable in a number of contexts.

Rhetorical theory of public relations: opening the door to semiotic and pragmatism approaches

The 2001 Handbook of Public Relations edited by Robert Heath contains a prominent article advocating the use of rhetorical theory or ‘rhetorical enactment rational’ as a fruitful way of advancing theoretical understandings of public relations. In 2004 Heath and Dan Millar edited: Responding to Crisis: A Rhetorical Approach to Crisis Communication. These are the latest excursions into a perspective on public relations reflecting the extensive study of rhetoric in North America. Other examples are Public Relations Inquiry as Rhetorical Criticism (Elwood, 1995); Rhetorical and Critical Approaches to Public Relations (Toth and Heath, 1992); and a chapter Public Relations? No, Relations with Publics: A Rhetorical-Organisational Approach to Contemporary Corporate Communication (Cheney and Dionisopoulos, in Botan and Hazleton (Eds.) 1989).

The conventional notion of rhetoric is argumentation and persuasion stemming from the ancient Greek sophists, such as Aristotle, and from the Romans, particularly Cicero and Quintillion. Rhetoric became a fundamental plank of the trivium of ancient and medieval education: grammar, logic and rhetoric. Then in the 20th century Kenneth Burke, Stephen Toulmin and Chaim Perelman with Lucie Olbrechts-Tyteca extended Aristotle’s suggestion that: “Rhetoric is the counterpart of dialectic” Aristotle (trans. 1991). To use the rhetorical approach to argue that rational discourse cannot describe the world on its own. Instead living, enculturated human beings have to perceive ‘their’ truths. They take a perceptual ‘position’ on reason.

Public relations, is an industry for influencing perceptual ‘positions’. But the study of perception and attempts to influence perception cannot be claimed by rhetorical scholars alone. Semioticians and linguists who take the perspective of linguistic pragmatics also claim this field. This paper takes the example of ‘public relations’ as a focus for the confluence of rhetorical, semiotic and pragmatism approaches to the ‘problematic’ of understanding and truth.

Induction of epithelial to mesenchymal transition in PMC42-LA human breast carcinoma cells by carcinoma-associated fibroblast secreted factors

Background
Breast carcinoma is accompanied by changes in the acellular and cellular components of the microenvironment, the latter typified by a switch from fibroblasts to myofibroblasts.


Methods
We utilised conditioned media cultures, Western blot analysis and immunocytochemistry to investigate the differential effects of normal mammary fibroblasts (NMFs) and mammary cancer-associated fibroblasts (CAFs) on the phenotype and behaviour of PMC42-LA breast cancer cells. NMFs were obtained from a mammary gland at reduction mammoplasty, and CAFs from a mammary carcinoma after resection.


Results
We found greater expression of myofibroblastic markers in CAFs than in NMFs. Medium from both CAFs and NMFs induced novel expression of α-smooth muscle actin and cytokeratin-14 in PMC42-LA organoids. However, although conditioned media from NMFs resulted in distribution of vimentin-positive cells to the periphery of PMC42-LA organoids, this was not seen with CAF-conditioned medium. Upregulation of vimentin was accompanied by a mis-localization of E-cadherin, suggesting a loss of adhesive function. This was confirmed by visualizing the change in active β-catenin, localized to the cell junctions in control cells/cells in NMF-conditioned medium, to inactive β-catenin, localized to nuclei and cytoplasm in cells in CAF-conditioned medium.


Conclusion
We found no significant difference between the influences of NMFs and CAFs on PMC42-LA cell proliferation, viability, or apoptosis; significantly, we demonstrated a role for CAFs, but not for NMFs, in increasing the migratory ability of PMC42-LA cells. By concentrating NMF-conditioned media, we demonstrated the presence of factor(s) that induce epithelial-mesenchymal transition in NMF-conditioned media that are present at higher levels in CAF-conditioned media. Our in vitro results are consistent with observations in vivo showing that alterations in stroma influence the phenotype and behaviour of surrounding cells and provide evidence for a role for CAFs in stimulating cancer progression via an epithelial-mesenchymal transition. These findings have implications for our understanding of the roles of signalling between epithelial and stromal cells in the development and progression of mammary carcinoma.

Residential proximity to school and the active travel choices of parents

Issue addressed: Walking for transport can contribute significantly to health-enhancing physical activity. We examined the prevalence and duration of walking to and from school, together with perceived influences on doing so, among parents of primary school children. Methods: Questionnaires were completed by parents from four primary schools (one government and three private) located in south-east Queensland (n=559; 40% response rate). Results: Eighteen per cent of parents reported walking for at least 10 minutes during journeys to school. Significantly greater proportions of parents with only one car in their household, with a child who attended a government school, with no driver’s licence, who had less than 11 years of education, and lived within two kilometres of the school walked for at least 10 minutes during the school journey. Factors perceived by parents most strongly to influence walking to school were: being physically active; safety concerns for the child walking alone; not having to park; walking being the child’s preferred option; too much motor vehicle traffic; and their child’s age and level of road sense. Conclusions: Despite the overall low prevalence of walking to school by parents, health-enhancing benefits may be achieved even when other modes of transport are used in conjunction with walking.

Approaches to learning accounting : a cross-cultural study

Purpose – The purpose of this study is to examine the relationship between the cultural background of students and their learning approaches in a first year undergraduate accounting program.

Design/methodology/approach – While prior research in this area has more generally focused on the investigation of the approaches to learning by accounting students, there appears to have been little investigation into the learning approaches of students from different cultures who are studying accounting together at the same institution. The paper presents the results of a study of 550 students enrolled in an undergraduate accounting program at a multi-campus university in Victoria, Australia, which used Biggs' study process questionnaire (SPQ) to assess the approaches to learning utilised by local and Chinese students.

Findings – The results showed that, while there were no significant differences in the use of surface and deep learning strategies by the Chinese and Australian students, there were significant differences in the learning motives of the two groups. Furthermore, the results contradict prior claims that Asian students rely principally on the memorisation and reproduction of factual information as a means of achieving academic success.

Originality/value – The study provides support for the notion that Chinese students may in fact have a culturally induced bias towards seeking understanding through deeper approaches to study.

Osmoregulation in elephant fish Callorhinchus Milii (Holocephali), with special reference to the rectal gland

Osmoregulatory mechanisms in holocephalan fishes are poorly understood except that these fish are known to conduct urea-based osmoregulation as in elasmobranchs. We, therefore, examined changes in plasma parameters of elephant fish Callorhinchus milii, after gradual transfer to concentrated (120%) or diluted (80%) seawater (SW). In control fish, plasma Na and urea concentrations were about 300 mmol l^–1 and 450 mmol l^–1, respectively. These values were equivalent to those of sharks and rays, but the plasma urea concentration of elephant fish was considerably higher than that reported for chimaeras, another holocephalan. After transfer to 120% SW, plasma osmolality, urea and ion concentrations were increased, whereas transfer to 80% SW resulted in a fall in these parameters. The rises in ion concentrations were notable after transfer to 120% SW, whereas urea concentration decreased predominantly following transfer to 80% SW. In elephant fish, we could not find a discrete rectal gland. Instead, approximately 10 tubular structures were located in the wall of post-valvular intestine. Each tubular structure was composed of a putative salt-secreting component consisting of a single-layered columnar epithelium, which was stained with an anti-Na⁺,K⁺-ATPase serum. Furthermore, Na⁺,K⁺-ATPase activity in the tubular structures was significantly increased after acute transfer of fish to concentrated SW (115%). These results suggest that the tubular structures are a rectal gland equivalent, functioning as a salt-secreting organ. Since the rectal gland of elephant fish is well developed compared to that of Southern chimaera, the salt-secreting ability may be higher in elephant fish than chimaeras, which may account for the lower plasma NaCl concentration in elephant fish compared to other chimaeras. Since elephant fish have also attracted attention from a viewpoint of genome science, the availability of fish for physiological studies will make this species an excellent model in holocephalan fish group.

A case for an international consortium on system-of-systems engineering

A system-of-systems (SoS) conceptualization is essential in resolving issues involving heterogeneous independently operable systems to achieve a unique purpose. Successful operation as an SoS requires communication among appropriate individuals and groups across enterprises through an effective protocol. This paper presents a position on the creation of a consortium of concerned system engineers and scientists worldwide to examine the problems and solutions strategies associated with SoS. The consortium could lead efforts in clarifying ambiguities and in seeking remedies to numerous open questions with respect to SoS analysis, SoS engineering (SoSE), as well as differences between systems engineering (SE) and SoSE. The mission of this consortium is envisioned to: 1) act as a neutral party; 2) provide a forum to put forth Calls to Action; and 3) establish a community of interest to recommend a set of solutions.