Multiple-choice versus short-response items: Differences in omit behavior

The overall rate of omission of items for 28,331 17 year old Australian students on a high stakes test of achievement in the common elements or cognitive skills of the senior school curriculum is reported for a subtest in multiple choice format and a subtest in short response format. For the former, the omit rates were minuscule and there was no significant difference by gender or by type of school attended. For the latter, where an item can be 'worth' up to five times that of a single multiple choice item, the omit rates were between 10 and 20 times that for multiple choice and the difference between male and female omit rate was significant as was the difference between students from government and non-government schools. For both formats, females from single sex schools omitted significantly fewer items than did females from co-educational schools. Some possible explanations of omit behaviour are alluded to.

Post-traumatic stress disorder in response to HIV infection

This study investigated the psychological impact of HIV infection through assessment of posttraumatic stress disorder in response to HIV infection. Sixty-one HIV-positive homosexual/bisexual men were assessed for posttraumatic stress disorder in response to HIV infection (PTSD-HIV) using a modified PTSD module of the DIS-III-R. Thirty percent met criteria for a syndrome of posttraumatic stress disorder in response to HIV diagnosis (PTSD-HIV). In over one-third of the PTSD cases, the disorder had an onset greater than 6 months after initial HIV infection diagnosis. PTSD-HIV was associated with other psychiatric diagnoses, particularly the development of first episodes of major depression after HIV infection diagnosis. PTSD-HIV was significantly associated with a pre-HIV history of PTSD from other causes, and other pre-HIV psychiatric disorders and neuroticism scores, indicating a similarity with findings in studies of PTSD from other causes. The findings from this preliminary study suggest that a PTSD response to HIV diagnosis has clinical validity and requires further investigation in this population and other medically ill groups. The results support the inclusion of the diagnosis of life-threatening illness as a traumatic incident that may lead to a posttraumatic stress disorder, which is consistent with the DSM-IV criteria.

Chlamydial infection and spatial ascension of the female genital tract : a novel hybrid cellular automata and continuum mathematical model

Sexually transmitted chlamydial infection initially establishes in the endocervix in females, but if the infection ascends the genital tract, significant disease, including infertility, can result. Many of the mechanisms associated with chlamydial infection kinetics and disease ascension are unknown. We attempt to elucidate some of these processes by developing a novel mathematical model, using a cellular automata–partial differential equation model. We matched our model outputs to experimental data of chlamydial infection of the guinea-pig cervix and carried out sensitivity analyses to determine the relative influence of model parameters. We found that the rate of recruitment and action of innate immune cells to clear extracellular chlamydial particles and the rate of passive movement of chlamydial particles are the dominant factors in determining the early course of infection, magnitude of the peak chlamydial time course and the time of the peak. The rate of passive movement was found to be the most important factor in determining whether infection would ascend to the upper genital tract. This study highlights the importance of early innate immunity in the control of chlamydial infection and the significance of motility-diffusive properties and the adaptive immune response in the magnitude of infection and in its ascension.

Constructive development of the solutions of linear equations in introductory ordinary differential equations

The solution of linear ordinary differential equations (ODEs) is commonly taught in first year undergraduate mathematics classrooms, but the understanding of the concept of a solution is not always grasped by students until much later. Recognising what it is to be a solution of a linear ODE and how to postulate such solutions, without resorting to tables of solutions, is an important skill for students to carry with them to advanced studies in mathematics. In this study we describe a teaching and learning strategy that replaces the traditional algorithmic, transmission presentation style for solving ODEs with a constructive, discovery based approach where students employ their existing skills as a framework for constructing the solutions of first and second order linear ODEs. We elaborate on how the strategy was implemented and discuss the resulting impact on a first year undergraduate class. Finally we propose further improvements to the strategy as well as suggesting other topics which could be taught in a similar manner.

The differential effects of organizational antecedents on dimensions of corporate entrepreneurship

This study seeks to further delineate how organizational antecedents differentially influence the three components of corporate entrepreneurship: innovation, venturing or strategic renewal. We argue that structural differentiation may help organizations to maintain multiple and often conflicting demands of entrepreneurial and mainstream activities. Taking a social capital perspective, our study further examines two contingencies in the form of informal integration mechanisms (i.e. connectedness and TMT social integration). Our findings show structural differentiation has a positive effect on all three components of corporate entrepreneurship, yet the effect is moderated by integration mechanisms. Interunit connectedness has a positive moderation effect regarding innovation and venturing, and TMT social integration has a negative moderation effect regarding strategic renewal. This reveals that innovation is influenced by informal integration mechanisms on the organizational level, strategic renewal on top management team level, while venturing is influenced by integration mechanisms on both levels.

The bereavement response : a cluster analysis

BACKGROUND: Literature and clinical experience suggest that some people experience atypical, complicated or pathological bereavement reactions in response to a major loss. METHOD: Three groups of community-based bereaved subjects--spouses (n = 44), adult children (n = 40), and parents (n = 36)--were followed up four times in the 13 months after a loss. A 17-item scale of core bereavement times was developed and used to investigate the intensity of the bereavement response over time. RESULTS: Cluster analysis revealed a pattern of bereavement-related symptoms approximating a syndrome of chronic grief in 11 (9.2%) of the 120 subjects. None of the respondents displayed a pattern consistent with delayed or absent grief. CONCLUSIONS: In a non-clinical community sample of bereaved people, delayed or absent grief is infrequently seen, unlike chronic grief, which is demonstrated in a minority.

Response efficacy : the key to minimizing rejection and maximizing acceptance of emotion-based anti-speeding messages

This study sought to improve understanding of the persuasive process of emotion-based appeals not only in relation to negative, fear-based appeals but also for appeals based upon positive emotions. In particular, the study investigated whether response efficacy, as a cognitive construct, mediated outcome measures of message effectiveness in terms of both acceptance and rejection of negative and positive emotion-based messages. Licensed drivers (N = 406) participated via the completion of an on-line survey. Within the survey, participants received either a negative (fear-based) appeal or one of the two possible positive appeals (pride or humor-based). Overall, the study's findings confirmed the importance of emotional and cognitive components of persuasive health messages and identified response efficacy as a key cognitive construct influencing the effectiveness of not only fear-based messages but also positive emotion-based messages. Interestingly, however, the results suggested that response efficacy's influence on message effectiveness may differ for positive and negative emotion-based appeals such that significant indirect (and mediational) effects were found with both acceptance and rejection of the positive appeals yet only with rejection of the fear-based appeal. As such, the study's findings provide an important extension to extant literature and may inform future advertising message design.

The response to dryness in Australia

The drought Australia now faces is leading to shifts in the perception of the continent, of Australians and the world. The ideals of lush green landscapes are making way for landscape designs in which dryness is a quality of the design. On a map of the world, Australia is enormous, and seems empty because development is concentrated around its edges. Its heart must be red, in the cultural projections of the world from images of Uluru, 'the rock', set in a flat desert with no relief. Of course the country is not really all desert - surely? - with low shrubs pretty much throughout. Inhabitation seems to cling to the edges where teh continent feels microclimatic effects from the adjacent oceans and edging mountain ranges, which screen the population from the real state of the environment - dry, harsh, amazing and unique. Australia is rightly proud of this harsh difference from its edges, but prefers the harshness to be 'out there'. At the moment however, the country is pretty much universally in drought, and the contrast between green and brown, that it has celebrated, even built its identity around, is disappearing to become brown throughout. Without the browning of Australia, some areas, such as tropical Queensland, are having their designed public landscapes and gardens revealed as an elaborate mythology, a landscape fraud.

Differential reporting and the effect on loan evaluations : an experimental study

This study utilises a mexed design laboratory experiment to test the impact of differential reporting on one group of external financial report users-lenders. The results indicate that the judgments of bank loan officers' assessment of the ability of a borrower to repay, are not significantly affected by differential reporting (in this case, presentation on non-GAAP financial reports compared to GAAP financial reports). However, bankers request additional information from borrowers when non-GAAP financial reports are presented.

Thermal transition properties of spagehetti measured by Differential Scanning Calorimetry (DSC) and Thermal Mechanical Compression Test (TMCT)

Glass transition temperature of spaghetti sample was measured by thermal and rheological methods as a function of water content.

Simultaneous determination of three synthetic glucocorticoids by differential pulse stripping voltammetry with the aid of chemometrics

A novel voltammetric method for simultaneous determination of the glucocorticoid residues prednisone, prednisolone, and dexamethasone was developed. All three compounds were reduced at a mercury electrode in a Britton-Robinson buffer (pH 3.78), and well-defined voltammetric waves were observed. However, the voltammograms of these three compounds overlapped seriously and showed nonlinear character, and thus, it was difficult to analyze the compounds individually in their mixtures. In this work, two chemometrics methods, principal component regression (PCR) and partial least squares (PLS), were applied to resolve the overlapped voltammograms, and the calibration models were established for simultaneous determination of these compounds. Under the optimum experimental conditions, the limits of detection (LOD) were 5.6, 8.3, and 16.8 µg l-1 for prednisone, prednisolone, and dexamethasone, respectively. The proposed method was also applied for the determination of these glucocorticoid residues in the rabbit plasma and human urine samples with satisfactory results.