Modelling grouped survival times in toxicological studies using generalized additive models

A method for combining a proportional-hazards survival time model with a bioassay model where the log-hazard function is modelled as a linear or smoothing spline function of log-concentration combined with a smoothing spline function of time is described. The combined model is fitted to mortality numbers, resulting from survival times that are grouped due to a common set of observation times, using Generalized Additive Models (GAMs). The GAM fits mortalities as conditional binomials using an approximation to the log of the integral of the hazard function and is implemented using freely-available, general software for fitting GAMs. Extensions of the GAM are described to allow random effects to be fitted and to allow for time-varying concentrations by replacing time with a calibrated cumulative exposure variable with calibration parameter estimated using profile likelihood. The models are demonstrated using data from a studies of a marine and a, previously published, freshwater taxa. The marine study involved two replicate bioassays of the effect of zinc exposure on survival of an Antarctic amphipod, Orchomenella pinguides. The other example modelled survival of the daphnid, Daphnia magna, exposed to potassium dichromate and was fitted by both the GAM and the process-based DEBtox model. The GAM fitted with a cubic regression spline in time gave a 61 % improvement in fit to the daphnid data compared to DEBtox due to a non-monotonic hazard function. A simulation study using each of these hazard functions as operating models demonstrated that the GAM is overall more accurate in recovering lethal concentration values across the range of forms of the underlying hazard function compared to DEBtox and standard multiple endpoint probit analyses.

Race lines and spaces of political action among migrant youth

Recently proposed Anti-Racism Strategy established within a framework of the Australian Government's multicultural policy, People of Australia, identifies ‘youth engagement’ as one of the key areas that needs to be promoted and supported. Young people have been invited to join youth councils and youth forums and work with national, state and local policy-makers. Some have taken up this challenge and became public faces and active members of anti-racism campaigns. Others, however, either remained silent about the discrimination they face, or organised their own grassroots youth-based and youth-led initiatives. This paper discusses individual and collective responses to racism among young people in Australia, focusing on Melbourne, and examines possibilities in which racism, as a common experience among migrant youth, can be utilised to form alternative spaces for political action, challenging not only interpersonal, but also systemic forms of racism. By drawing attention towards institutional and systemic forms of racism, and the historical perpetuation of racist practices, these youth initiatives rely on legal measures, and argue that racism should be discussed in the context of the broader Australian society, not only in relation to minority groups.

Library spaces designed with students in mind: an evaluation study of University of Queensland libraries at St Lucia campus

This paper identifies the design qualities of library spaces that matter the most foruniversity students. Drawing upon the data from an online survey made available to students from the University of Queensland, Australia, a number of design-related considerations are examined including: acoustics, furniture, interior architecture, lighting, and thermal comfort. 1505 students completed the survey, which aimed to assess how effective and responsive library spaces are in meeting students’ needs and supporting their learning experiences. The survey included ‘Likert scale questions’ requiring students to rate their levels of satisfaction with different aspects of library spaces and ‘open-ended questions’ asking students to elucidate their ratings. Findings revealed that the qualities of physical spaces were ranked as the third mostsignificant category of reasons accounting for students’ preference for certain library buildings over others, and for their frequency of visit (behind “location” of the library building and then “access to books and course-related materials or resources”). Design-related themes which emerged from qualitative analysis highlighted students’ awareness of the impacts that the design of spaces and furniture can have on their learning experiences. The study concludes with recommendations informed by students’ expectations, needs and preferences in relation to the qualities and features of library spaces.

Evaluation of University of Queensland Library Spaces: three case studies at St Lucia Campus

Introduction: The paper reports on an evaluation study of spaces in the Social Sciences and Humanities (SSHL), Biological Sciences (BSL) and Walter Harrison Law (WHLL) Libraries of the University of Queensland (UQ). The study was part of an evaluation of the quality and patterns of use of spaces in UQ libraries, which aimed to propose recommendations for future improvements and decision-making. This paper presents a study of areas of weakness in existing SSHL spaces, and impacts of the refurbishment of spaces at BSL and WHLL on students’ experiences. The findings evidence a link between students’ learning experiences and the quality of library spaces.Methods: An online survey, “Students’ Experiences and Perceptions of Library Physical Spaces”, was designed to collect data from students. The survey questions addressed seven topics: (1) overall satisfaction with spaces in the UQ Libraries; (2) welcoming nature of the library entry; (3) lighting; (4) acoustics; (5) furniture; (6) wayfinding; and (7) preferences for different space types in the library.Results: 1505 students completed the surveys, with 1098 responses recorded to open-ended questions on why students visited the libraries and the physical characteristics of the spaces that influenced their experiences. Quantitative and qualitative analysis of the data elucidated key design challenges and considerations. In particular, the data suggested that the provision of individual quiet study spaces remains an important role of academic libraries, with Studying Alone identified as the most important reason for student visits.Conclusions: The findings highlight the importance of individual study spaces and propose a number of recommendations in relation to physical space design and management.Relevance: Academic libraries face the challenge to keep pace with change in relation to students’ demographics, pedagogy and technology. In doing so, it is important to have an understanding of the evolving patterns of students’ learning behaviours, space uses and preferences through ongoing evaluation of library spaces.

Obtain confidentiality or/and authenticity in Big Data by ID-based generalized signcryption

Recently, the Big Data paradigm has received considerable attention since it gives a great opportunity to mine knowledge from massive amounts of data. However, the new mined knowledge will be useless if data is fake, or sometimes the massive amounts of data cannot be collected due to the worry on the abuse of data. This situation asks for new security solutions. On the other hand, the biggest feature of Big Data is "massive", which requires that any security solution for Big Data should be "efficient". In this paper, we propose a new identity-based generalized signcryption scheme to solve the above problems. In particular, it has the following two properties to fit the efficiency requirement. (1) It can work as an encryption scheme, a signature scheme or a signcryption scheme as per need. (2) It does not have the heavy burden on the complicated certificate management as the traditional cryptographic schemes. Furthermore, our proposed scheme can be proven-secure in the standard model. © 2014 Elsevier Inc. All rights reserved.

Patterns of intergroup contact in public spaces: micro-ecology of segregation in Australian communities

The use of public spaces can promote social cohesion and facilitate interpersonal interactions within the community. However, the ways racial and ethnic groups interact in public spaces can also reflect and influence informal segregation in the wider community. The present study aimed to examine patterns of intergroup contact within public spaces in Victoria, Australia through short-term observation in four localities. Data were collected on within-group, intergroup and absence of contact for people from minority and majority groups. A total of 974 contacts were observed. Findings indicate that in the observed public spaces, people from visible minority groups tended to have no contact with others or to interact with people from other ethnic/racial groups. In contrast, those from the majority group tended to interact predominately with other majority group members. This suggests that majority group members are more likely to ‘self-segregate’ in public spaces than those from minority groups.

New generalized Halanay inequalities with applications to stability of nonlinear non-autonomous time-delay systems

In this paper, a general class of Halanay-type non-autonomous functional differential inequalities is considered. A new concept of stability, namely global generalized exponential stability, is proposed. We first prove some new generalizations of the Halanay inequality. We then derive explicit criteria for global generalized exponential stability of nonlinear non-autonomous time-delay systems based on our new generalized Halanay inequalities. Numerical examples and simulations are provided to illustrate the effectiveness of the obtained results.

'Unconscionable mystification'? : rooms, spaces and the prose poem

Since the 19th century, when a number of French writers—most conspicuously Charles Baudelaire and Arthur Rimbaud—introduced what we may think of as the modern prose poem into European literature, prose poetry has been part of a significant debate about the contemporary usefulness of existing literary modes and genres. While early French practitioners partly used the form to subvert and problematise traditional poetic prosody, once this aim was achieved prose poetry remained a significant contemporary literary form, achieving wide acceptance. In the context of contemporary developments and manifestations of prose poetry, this article discusses John Frow’s comments that texts might “‘perform’ a genre, or modify it in ‘using’ it, or only partially realise a generic form, or … be composed of a mix of different genres” (2015: 11). It also discusses the authors’ Rooms and Spaces project, which explores—and exemplifies through its component of creative practice—ways in which prose poetry may be considered “poetic”; how the forms of prose poetry may be room-like and condensed; or open and highly suggestive (sometimes both at once); how prose poetry is intertextual and polysemous; and how prose poetry frequently conveys a sense of completeness despite tending to be fragmentary. Prose poetry may generically problematic but the authors suggest that this may make it an exemplary post-postmodern form of writing; and that reading prose poetry may provide significant insights into understanding how unstable genre boundaries really are.

Locating learning: making connections between virtual and physical spaces with mobile touch-screen devices

This paper is concerned with the potential of mobile touch-screen devices and emerging socio-technological practices to support pedagogies of place that provide a means for young people to reflect critically on the social construction of place and to take actions that speak of and to their own locatedness. Drawing on de Certeau’s (1984) concept of space as a practiced place and Massey’s (2005) perspective of spatiality and interrelatedness, we examine two school-based examples of learning activities that bring together the virtual and physical as in experiences and representations of place. The first example is an Australian local history unit, where lower secondary school students participated in a series of field trips, planned and conducted under the guidance of an indigenous elder. They used Smartphones and iPads to capture and create personalised audio-visual records of their knowledge of place that were then used to create geo-location games. In the second example, upper primary school students worked with local authorities and environmental educators to select sites for two environmental monitoring posts, which were then installed and provided a locus for the students’ school-based environmental science learning as well as a vehicle for community engagement. Drawing on interview, video and photographic data, this paper examines the way mobile technologies were deployed for student knowledge production, engagement with place, reconstruction of place and engagement with community.

Designing blended spaces to maximise student learning in work integrated learning programs

This paper describes a case study at a large metropolitan university in Australia where a range of technology-enabled blended spaces are used for interaction, communication and reflection between the work and university environments to enrich students' learning experiences during their work placement year. Blended space design requirements to maximise the learning experience of students undertaking work integrated learning are identified. © 2009 Friederika Kaider, Kathy Henschke, Joan Richardson and Mary Paulette Kelly.

Generalized characteristics of photo-elastic birefringence in polymer strip waveguides

This work investigates the material birefringence in a polymer strip waveguide which originates from thermal stress during the fabrication process. The stress is estimated through a comprehensive numerical study based on a realistic finite element model. The characteristics of birefringence are obtained in a generalized form and expressed by an empirical formula, which is applicable to various polymer materials. The developed formula can be employed to specify the photo-elastic birefringence of a polymer strip channel only by knowing the birefringence in its planar film. This will eliminate the necessity of extensive numerical analysis of thermal stress in such polymer waveguides, and accordingly help the management of stress-induced effects efficiently.

Forecasting electricity demand using generalized long memory

This paper studies the electricity hourly load demand in the area covered by a utility situated in the southeast of Brazil. We propose a stochastic model which employs generalized long memory (by means of Gegenbauer processes) to model the seasonal behavior of the load. The model is proposed for sectional data, that is, each hour’s load is studied separately as a single series. This approach avoids modeling the intricate intra-day pattern (load profile) displayed by the load, which varies throughout days of the week and seasons. The forecasting performance of the model is compared with a SARIMA benchmark using the years of 1999 and 2000 as the out-of-sample. The model clearly outperforms the benchmark. We conclude for general long memory in the series.