David F. Treagust : congenial soul, science educator, and international research leader

For almost a half century David F. Treafust has been an exemplary science educator who has contributed through his dedication and commitments to students, curriculum development and collaboration with teachers, and cutting edge research in science education that has impacted the field globally, nationally and locally. A hallmark of his outstanding career is his collaborative style that inspires others to produce their best work.

Modulation of the Chlamydia trachomatis In vitro transcriptome response by the sex hormones estradiol and progesterone

BACKGROUND:Chlamydia trachomatis is a major cause of sexually transmitted disease in humans. Previous studies in both humans and animal models of chlamydial genital tract infection have suggested that the hormonal status of the genital tract epithelium at the time of exposure can influence the outcome of the chlamydial infection. We performed a whole genome transcriptional profiling study of C. trachomatis infection in ECC-1 cells under progesterone or estradiol treatment.RESULTS:Both hormone treatments caused a significant shift in the sub-set of genes expressed (25% of the transcriptome altered by more than 2-fold). Overall, estradiol treatment resulted in the down-regulation of 151 genes, including those associated with lipid and nucleotide metabolism. Of particular interest was the up-regulation in estradiol-supplemented cultures of six genes (omcB, trpB, cydA, cydB, pyk and yggV), which suggest a stress response similar to that reported previously in other models of chlamydial persistence. We also observed morphological changes consistent with a persistence response. By comparison, progesterone supplementation resulted in a general up-regulation of an energy utilising response.CONCLUSION:Our data shows for the first time, that the treatment of chlamydial host cells with key reproductive hormones such as progesterone and estradiol, results in significantly altered chlamydial gene expression profiles. It is likely that these chlamydial expression patterns are survival responses, evolved by the pathogen to enable it to overcome the host's innate immune response. The induction of chlamydial persistence is probably a key component of this survival response.

Tensions in developing a secure collective information practice : the case of Agile Ridesharing

Many current HCI, social networking, ubiquitous computing, and context aware designs, in order for the design to function, have access to, or collect, significant personal information about the user. This raises concerns about privacy and security, in both the research community and main-stream media. From a practical perspective, in the social world, secrecy and security form an ongoing accomplishment rather than something that is set up and left alone. We explore how design can support privacy as practical action, and investigate the notion of collective information-practice of privacy and security concerns of participants of a mobile, social software for ride sharing. This paper contributes an understanding of HCI security and privacy tensions, discovered while “designing in use” using a Reflective, Agile, Iterative Design (RAID) method.

State convergence and the effectiveness of time-memory-data tradeoffs

Various time-memory tradeoffs attacks for stream ciphers have been proposed over the years. However, the claimed success of these attacks assumes the initialisation process of the stream cipher is one-to-one. Some stream cipher proposals do not have a one-to-one initialisation process. In this paper, we examine the impact of this on the success of time-memory-data tradeoff attacks. Under the circumstances, some attacks are more successful than previously claimed while others are less. The conditions for both cases are established.

Test of a model of the effects of parental illness on youth and family functioning

Objective: Parental illness (PI) may have adverse impacts on youth and family functioning. Research in this area has suffered from the absence of a guiding comprehensive framework. This study tested a conceptual model of the effects of PI on youth and family functioning derived from the Family Ecology Framework (FEF; Pedersen & Revenson, 2005). Method. A total of 85 parents with multiple sclerosis and 127 youth completed questionnaires at Time 1 and 12 months later at Time 2. Results. Structural equation modeling results supported the FEF with regards to physical-illness disability. Specifically, the proposed mediators (role redistribution, stress, and stigma) were implicated in the processes that link parental disability to several domains of youth adjustment. The results suggest that the effects of parental depression (PD) are not mediated through these processes; rather, PD directly affects family functioning, which in turn mediates the effects onto youth adjustment. Family functioning further mediated between PD and youth well-being and behavioral-social difficulties. Conclusions. Although results support the effects of parental-illness disability on youth and family functioning via the proposed mediational mechanisms, the additive effects of PD on youth physical and mental health occur through direct and indirect (via family functioning) pathways, respectively.

State convergence in the initialisation of the Sfinks stream cipher

Sfinks is a shift register based stream cipher designed for hardware implementation. The initialisation state update function is different from the state update function used for keystream generation. We demonstrate state convergence during the initialisation process, even though the individual components used in the initialisation are one-to-one. However, the combination of these components is not one-to-one.

Algebraic analysis of the SSS stream cipher

Both the SSS and SOBER-t32 stream cipher designs use a single word-based shift register and a nonlinear filter function to produce keystream. In this paper we show that the algebraic attack method previously applied to SOBER-t32 is prevented from succeeding on SSS by the use of the key dependent substitution box (SBox) in the nonlinear filter of SSS. Additional assumptions and modifications to the SSS cipher in an attempt to enable algebraic analysis result in other difficulties that also render the algebraic attack infeasible. Based on these results, we conclude that a well chosen key-dependent substitution box used in the nonlinear filter of the stream cipher provides resistance against such algebraic attacks.

The lived experience of PTSD for children of Australian Vietnam veterans in Australia

There is a growing area of scholarship that attests to the importance of understanding the impact of Post Traumatic Stress Disorder (PTSD) on the military family (Cozza, Chun, & Polo, 2005; Peach, 2005; Riggs, 2009; Siebler, 2003). Recent research highlights the critical role that the family plays in mitigating the effects of this condition for its members (Chase-Lansdale, Wakschlag, & Brooks-Gunn, 1995; Fiese, Foley, & Spagnola, 2006; Hetherington & Blechman, 1996; Pinkerton & Dolan, 2007; Seedat, Niehaus, & Stein, 2001; Serbin & Karp, 2003; Walsh, 2003), society (Jenson & Fraser, 2006; Seedat, Kaminer, Lockhat, & Stein, 2000; Wood & Geismar, 1989) and the next generation (Davidson & Mellor, 2001; Ender, 2006; Weber, 2005; Westerink & Giarratano, 1999). However, little is understood about the way people who grew up in Australlian military families affected by PTSD describe their experiences and what the implications are for their participation in family life. This study addressed the following research questions: (1) ‘How does a child of a Vietnam veteran understand and describe the experience of PTSD in the family?’ and (2) ‘What are the implications of this understanding on their current participation in family life?’ These questions were addressed through a qualitative analysis of focus-group data collected from adults with a Vietnam veteran parent with PTSD. The key rationale for a qualitative approach was to develop an understanding of these questions in a way which was as faithful as possible to the way they talked about their past and present family experiences. A number of experiential themes common to participants were identified through the data analysis. Participants’ experiences linked together to form a central theme of control, which revealed the overarching narrative of ‘It’s all about control and the fear of losing it’, that responds to the first research queston. The second research question led to a deeper analysis of the ‘control experiences’ to identify the ways in which participants responded to and managed these problematic aspects of family life, and the implications for their current sense of participation in family life. These responses can be understood through the overarching narrative of: ‘Soldier on despite the differences’ which assists them to optimise the impact of control and develop strategies required to maintain a semblance of personal normality and a normal family life. This intensive research has led to the development of theoretical propositions about this group’s experiences and responses that can be tested further in subsequent research to assist families and their members who may be experiencing the intergenerational impacts of psychological trauma acquired from military service.

Utilizing argumentation to teach nature of science

The quest for the achievement of informed nature of science (NOS) views for all learners continues to inspire science educators to seek out effective instructional interventions to aid in the development of learners’ NOS views. Despite the extensive amount of research conducted in the field, the development of informed NOS views has been difficult to achieve, with many studies reporting difficulties in changing learners’ NOS views. Can engaging learners in argumentation lead to improvements in their NOS views? This review answers this question by examining studies which have explored NOS and argumentation in science education. The review also outlines a rationale for incorporating argumentation in science education, together with a brief overview of important recent studies in the field. Implications drawn from this review suggest that the incorporation of explicit NOS and argumentation instruction, together with consideration of various contextual, task-specific and personal factors which could mediate learners’ NOS views and engagement in argumentation, could lead to improvements in learners’ views of NOS.

Learning science through real-world contexts

Curriculum developers and researchers have promoted context based programmes to arrest waning student interest and participation in the enabling sciences at high school and university. Context-based programmes aim for connections between scientific discourse and real-world contexts to elevate curricular relevance without diminishing conceptual understanding. Literature relating to context-based approaches to learning will be reviewed in this chapter. In particular, international trends in curricular development and results from evaluations of major projects (e.g. PLON, Salters Advanced Chemistry, ChemCom) will be highlighted. Research projects that explore context-based interventions focusing on such outcomes as student interest, perceived relevance and conceptual understanding also will feature in the review. The chapter culminates with a discussion of current context-based research that interprets classroom actions from a dialectical socio-cultural framework, and identifies possible new directions for research.

Leading the transformation of learning and praxis in science classrooms

Individual science teachers who have inspired colleagues to transform their classroom praxis have been labelled transformational leaders. As the notion of distributed leadership became more accepted in the educational literature, the focus on the individual teacher-leader shifted to the study of leadership praxis both by individuals (whoever they might be) and by collectives within schools and science classrooms. This review traces the trajectory of leadership research, in the context of learning and teaching science, from an individual focus to a dialectical relationship between individual and collective praxis. The implications of applying an individual-collective perspective to praxis for teachers, students and their designated leaders are discussed.

Risk, uncertainty and complexity in science education

Increasingly societies and their governments are facing important social issues that have science and technology as key features. A number of these socio-scientific issues have two features that distinguish them from the restricted contexts in which school science has traditionally been presented. Some of their science is uncertain and scientific knowledge is not the only knowledge involved. As a result, the concepts of uncertainty, risk and complexity become essential aspects of the science underlying these issues. In this chapter we discuss the nature and role of these concepts in the public understanding of science and consider their links with school science. We argue that these same concepts and their role in contemporary scientific knowledge need to be addressed in school science curricula. The new features for content, pedagogy and assessment of this urgent challenge for science educators are outlined. These will be essential if the goal of science education for citizenship is to be achieved with our students, who will increasingly be required to make personal and collective decisions on issues involving science and technology.

Multi-method, multi-theoretical, multi-level research in the learning sciences

We examine methodologies and methods that apply to multi-level research in the learning sciences. In so doing we describe how multiple theoretical frameworks informs the use of different methods that apply to social levels involving space-time relationships that are not accessible consciously as social life is enacted. Most of the methods involve analyses of video and audio files. Within a framework of interpretive research we present a methodology of event-oriented social science, which employs video ethnography, narrative, conversation analysis, prosody analysis, and facial expression analysis. We illustrate multi-method research in an examination of the role of emotions in teaching and learning. Conversation and prosody analyses augment facial expression analysis and ethnography. We conclude with an exploration of ways in which multi-level studies can be complemented with neural level analyses.

State convergence and keyspace reduction of the mixer stream cipher

This paper presents an analysis of the stream cipher Mixer, a bit-based cipher with structural components similar to the well-known Grain cipher and the LILI family of keystream generators. Mixer uses a 128-bit key and 64-bit IV to initialise a 217-bit internal state. The analysis is focused on the initialisation function of Mixer and shows that there exist multiple key-IV pairs which, after initialisation, produce the same initial state, and consequently will generate the same keystream. Furthermore, if the number of iterations of the state update function performed during initialisation is increased, then the number of distinct initial states that can be obtained decreases. It is also shown that there exist some distinct initial states which produce the same keystream, resulting in a further reduction of the effective key space