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Police Responses to Rape in Metropolitan India
No full textMuch of the published research on police responses to rape is located in the West. This study conducted in-depth interviews with three adult victim-survivors and 15 police personnel to explore police responses to rape in the metropolitan city of Kolkata, India. Using an intersectional feminist framework, a reflexive thematic analysis indicated both sensitive and insensitive responses and showed that police responses were often based on discretion rather than being guided by the law. Police responses were also shaped by occupational culture, the socio-political environment, the police–criminal nexus and media coverage. The research sheds light on the unique cultural context of policing rape in metropolitan India. It adds to discussions regarding women’s police stations and changes in policing to address sexual violence.</p
Liquid metals for renewable energy synthesis and storage
No full textGrowing concerns regarding increasing emission levels and climate change have expedited extensive research on finding alternative fuel resources to fossil fuels. Sustainable production of renewable fuels from renewable resources is seen as one of the most promising solutions. In addition, efficient energy storage systems are crucial to ensure a reliable and resilient power supply. One main challenge faced by current technologies regarding the synthesis and storage of renewable fuels is the lack of efficient catalytic materials and electrode materials. In recent years, liquid metals emerged as a new class of materials with superior catalytic activities and intriguing properties for energy storage. In this minireview, we have presented the latest liquid metal research in the field of renewable fuel synthesis and energy storage along with recommendations for their future development.</p
A Poetic Inquiry Into Journalists’ Experiences of Covering Institutional Child Sexual Abuse
No full textThis article introduces a spectrum of poetic approaches that have emerged in the analysis of research interviews with journalists who covered Australia’s Royal Commission into Institutional Responses to Child Sexual Abuse and related stories. Six poem excerpts, from two of the poets involved in the project, are presented to explore how engaging with a spectrum of approaches—from found poetry transcription to generative methods—can be used to shed light on the situated experiences of research participants. Considering the various functions of “poetry” in this context—as container or vehicle for data, as tool for analysis, or as artistic/affective expression—the article not only explores the multiple outputs and their roles for a variety of audiences but also how these poems can evoke/ provoke/ excavate alternative perspectives—both expected and surprising—on the data.</p
Temporal Analysis of Human Mesenchymal Stem Cells under External Stimulation with Q-AFM
No full textHuman mesenchymal stem cells (hMSCs) are gaining significant interest due to their capabilities of self-renewal and differentiation into various cell types such as osteoblast, adipocyte, chondrocyte and neuron.1–6 These characteristics make hMSCs a promising cell source for tissue engineering aimed at repairing or replacing damaged tissues. Various approaches were developed to regulate stem cell fate, including mechanical forces and chemical treatments. However, the mechanisms underlying cell fate regulation are still unclear, resulting in reduced effectiveness in controlling cell fate and limiting clinical applications.
Among external stimulations on cell fate regulation, electrical stimulation (E-STIM) stands out due to its potential to yield different cell types, possibly using the same device with varying inputs. Research has primarily focused on final outcomes of stem cell differentiation, often neglecting the temporal response of cells under stimulation. Limited studies have reported cytoskeleton reorganisation and activation of mechanotransduction in response to E-STIM.7,8 Understanding these temporal dynamics is critical for uncovering the pathways leading to cell fate commitment and designing effective stimulation treatments.
The cytoskeleton is crucial in supporting cell structure, signal transmission, and influencing stem cell behaviour, including shape, and fate decisions.9,10 When stem cells are cultured on substrates with varying stiffness, cytoskeletal remodelling occurs. Cell stiffness, largely determined by cytoskeleton, eventually aligns with the substrate stiffness, guiding cells to differentiate into specific types, such as osteoblasts on substrates mimicking bone collagen stiffness (25-40 kPa).11
Fluorescence imaging, commonly used to observe cytoskeletal structures, requires cell fixation, preventing real-time observation of same cells. Other technique like particle tracking maintains cell viability but involves invasive procedures that could alter cell behaviour. Quantitative atomic force microscopy (Q-AFM) offers a non-invasive alternative for characterising live cell mechanics. Q-AFM allows simultaneous cell mechanics and topography characterisation, correlating mechanical properties with intracellular structures. It operates faster and provides higher resolution images than traditional AFM, making it ideal for real-time monitoring cell dynamics.
Additionally, FluidFM enables single-cell manipulation such as extraction using hollow tips connected to microfluidic system. By applying negative pressure, fractions of cytosol can be extracted for molecule analysis while maintaining cell viability. This capability allows for monitoring gene expression changes in real-time, providing insights into cell response mechanisms.
This thesis aimed to investigate hMSCs behaviour under external stimulation. By integrating stimulation and Q-AFM measurement, we monitored changes in cytoskeletal structure and cell mechanics during and post-stimulation. Developing protocols for cell extraction with FluidFM could enable comprehensive analysis of single-cell behaviour in response to external stimulation, advancing our understanding of the mechanisms governing stem cell fate.
After developing protocols for Q-AFM measurements on hMSCs and a customised data processing program for fitting Young's modulus, in collaboration with Dr. Joseph Berry, we correlated Q-AFM measurements with fluorescent imaging. Major features observed in Q-AFM topographical images corresponded to cytoskeletal structures, specifically actin filaments. Young's modulus mappings highlighted features corresponding to actin structures observed in the topographical images, suggesting that cell stiffness was primarily contributed by actin stiffness.
To further demonstrate Q-AFM’s capabilities for real-time intracellular measurements, we applied various cytoskeleton disruptors and monitored cytoskeletal structure and cell mechanics. 1 µg/mL Cytochalasin D (CytD) significantly disrupted cytoskeletal network and reduced cell stiffness by 22%. Upon CytD removal, cells began to rebuild their cytoskeletal network, with average stiffness returning to pre-treatment values. This was the first study to monitor changes in intracellular structures and mechanics in single cells with chemical treatment.
Next, we conducted two collaborative projects to demonstrate that Q-AFM could be coupled with existing external stimulation devices to monitor the effects of physical stimulation on stem cells. Firstly, in collaboration with Prof. Leslie Yeo, 10 MHz surface acoustic wave (SAW) was applied to hMSCs for 8 minutes. The cytoskeleton alignment towards the cell's original elongation direction was observed immediately post stimulation. Stress fibre remodelling resulted in around 1.5-fold cell stiffening at 65 minutes post-stimulation. Another device used was confined microchannels designed by Asst. Prof. Andrew Holle’s from National University of Singapore. The microchannels (3 and 10 µm width) were modified to fit into 35 mm cell dishes for Q-AFM scanning. Cells became softer after emerging from the channels, as the narrow space broke down the cytoskeleton structure. The narrower the channel, the more significant the breakdown effect. This was the first study quantifying cell mechanics changes with confinement stimulation.
Next, we designed our own E-STIM device that fit Q-AFM measurements to monitor cell behaviour with E-STIM. The charge was directly injected into the cells via an electrode made of conductive polymer Polypyrrole. Electrical signals of 0.005V, 0.3V, 0.5V at 1Hz were applied to hMSCs for 1 hour. With the low charge 0.005V, fully adhered hMSCs showed an increase or no significant change in Young's modulus, along with cytoskeleton realignment and stress fibre formation. At 0.3V, thicker stress fibres formed with less aligned cytoskeleton, resulting in overall unchanged cell stiffness. When applying a 0.5V signal, the Young's modulus of all the scanned cells decreased, along with a decrease in the amount of stress fibres.
Finally, we developed protocols for intracellular manipulation via FluidFM. A cell-impermeable DNA stain propidium iodide, was successfully injected into nuclear regions of hMSCs using pressure +200 mbar for 20 seconds. The injected cells exhibited red fluorescence. Due to temporary system malfunction, the extraction process was not explored. The primary goal was to extract fractions of cytosol for downstream molecule analysis while maintaining cell viability. This would enable real-time monitoring of gene expression changes with E-STIM, helping comprehensively understand the intracellular response and provide guidance for fine-tuning E-STIM parameters to achieve precise cell fate control.
In summary, we established a platform that allows monitoring cell responses under external stimulations. High-resolution topographical images and mechanics mappings can be obtained within 30 minutes using Q-AFM. With the integrated FluidFM system, gene expression changes in single cells can be monitored, providing deeper understandings of the mechanisms behind the external stimulation effects on stem cells. This platform has facilitated wide ranges of collaborations, from cell mechanics measurement to intracellular manipulation, aiding in understanding stem cell behaviour and regulating stem cell commitment for tissue engineering applications.</p
THAT’S KAMP!: SPECULATIVE LANDSCAPE ARCHITECTURAL APPROACHES TOWARDS QUEER MEMORIALIZATION IN MELBOURNE
No full textThis article discusses a pedagogical approach towards producing Queer memorial concepts in St Kilda (Melbourne, Australia), which formed part of a collaborative landscape architecture design research studio. This paper is structured in three parts. The first section discusses the studio’s philosophical positioning in Queer Ecological theory and its application to the design of Queer memorials. The second part introduces the context of St Kilda and provides an overview of its evolving Queer heritage during the 20th and 21st centuries. This overview is supplemented by reflections from Queer community members, who describe their past trauma and journey towards a place of Pride. Lastly, part three explains how students engaged these narratives and histories through the studio learning experience and by utilising multiple creative tactics (photo essays, computational modelling and simulation, ecological design, and drawing) to iterate and refine their Queer memorials. This approach offered an evolved methodology for conceptualising Queer spaces in St Kilda, which has implications for future landscape architectural projects that seek to challenge the contemporary homogenisation of the urban landscape.</p
Application of a Robust Maximum Diversified Portfolio to a Small Economy’s Stock Market: An Application to Fiji’s South Pacific Stock Exchange
No full textIn this study, we apply a novel approach of portfolio diversification—the robust maximum diversified (RMD)—to a small and developing economy’s stock market. Using monthly returns data from August 2019 to May 2024 of 18/19 stocks listed on Fiji’s South Pacific Stock Exchange (SPX), we construct the RMD portfolio and simulate with additional constraints. To implement the RMD portfolio, we replace the covariance matrix with a matrix comprising unexplained variations. The RMD procedure diversifies weights, and not risks, hence we need to run a pairwise regression between two assets (stocks) and extract the R-square to create a P-matrix. We compute each asset’s beta using the market-weighted price index, and the CAPM to calculate market-adjusted returns. Next, together with other benchmark portfolios (1/N, minimum variance, market portfolio, semi-variance, maximum skewness, and the most diversified portfolio), we examine the expected returns against the risk-free (RF) rate. From the simulations, in terms of expected return, we note that eight portfolios perform up to the RF rate. Specifically, for returns between 4 and 5%, we find that max. RMD with positive Sharpe and Sortino (as constraints) and the most diversified portfolio offer comparable returns, although the latter has slightly lower standard deviation and downside volatility and contains 94% of all the stocks. Portfolios with returns between 5% and the RF rate are the minimum-variance, the semi-variance, and the max. RMD with positive Sharpe; the latter coincides with the RF rate and contains the most (94%) stocks compared to the other two. An investor with a diversification objective, some risk tolerance and return preference up to the RF rate can consider the max. RMD with positive Sharpe. However, depending on the level of risk-averseness, the minimum-variance or the semi-variance portfolio can be considered, with the latter having lower downside volatility. Two portfolios offer returns above the RF rate—the market portfolio (max. Sharpe) and the maximum Sortino. Although the latter has the highest return, this portfolio is the least diversified and has the largest standard deviation and downside volatility. To achieve diversification and returns above the RF rate, the market portfolio should be considered.</p
Essays on Peer Information Environment in Corporate Finance
No full textThis thesis explores the general research problems on peer information environment in corporate finance in the U.S. equity market. Surrounding this general theme, this thesis aims to focus on three corporate aspects: the influence of the peer information environment, specifically the external information about peer firms conveyed by information intermediaries, on focal firms’ (i) stock price crash risk; (ii) investment efficiency; and (iii) innovation activities, in three empirical chapters. This thesis is structured into six chapters: Chapter One provides an introduction and outlines the research questions. Chapter Two reviews the relevant literature. Chapters Three, Four and Five separately present the three core empirical studies, and Chapter Six concludes.
The peer information environment plays a vital role in conveying incremental information to managers and shareholders (Leary & Roberts, 2014). For managers, it enriches the information available for corporate decisions. For shareholders, they can leverage peer information to discipline managerial behaviour and reduce principle-agent issues. One related managerial behaviour is the tendency of bad news hoarding, which could result in extreme adverse outcomes in the stock market, known as price crashes (Jin & Myers 2006). Motivated by the theory of peer learning motives and bad news hoarding theory of crash risk, the first research question, presented in Chapter Three, investigates the influences of peer information environment on a firm’s stock price crash risk. Using peer analyst coverage as a proxy, I find that the peer information environment is negatively associated with the focal firm’s stock price crash risk. This finding is consistent with the view that peer information plays a vital role in conveying information to managers and shareholders, reducing information asymmetry. The finding also supports the view that peer information serves as a monitoring mechanism in reducing principle-agent issues. Moreover, I find that larger peer firms and more relevant peer firms tend to strengthen the relationship between the peer information and focal firms’ stock price crash risk. Peer information also enhances the relationship between the focal firm’s information environment and its crash risk.
In the subject matter of how firms efficiently allocate scarce funds on assets, the second research question explores the link between peer information environment and firm investment efficiency. Roychowdhury, Shroff and Verdi (2019) suggest that peer managers could learn from peer disclosures to complement their own internal information in determining the optimal investment decision. New information about peer firms analysed and conveyed by peers’ analysts allows peer managers to compare their own information environment with that of peers, enrich managerial information set, which results in optimal investment decisions. Results indicate a positive impact of peer information environment, proxied by peer analyst coverage, on the efficiency of firms’ investment. The effect is more salient when a focal firm has a poorer information environment, weaker corporate governance, and a higher volume of informed trading. These findings align with the view that peer information plays a dual role, contributing to both information accumulation and monitoring function, which in turn helps reduce information asymmetry between shareholders and managers. Additional tests also reveal that the positive association is more pronounced in firms with higher similarity scores with their peers, indicating that more relevant peers represent more effective information dissemination in influencing the focal firms. However, it is important to highlight that the positive impact of peer information is temporary, diminishing within a two-year timeframe.
Research and development (R&D) is a costly, time-intensive aspect of corporate innovation, yet essential to a country’s economic growth (Schumpeter 1911). Innovation is inherently high risk in nature, primarily due to information asymmetry and uncertainties, and, given the significant capital expenditure involved, motivating managers to innovate can be challenging (Brown, Martinsson & Petersen 2013). If the availability of peer information could lead to information accumulation, this would reduce information uncertainties surrounding innovative projects, ultimately encouraging firms to innovate. As such, the third research question attempts to examine the impact of the peer information environment on corporate innovation. Using two natural experiments, broker house closures and mergers, as the sources of exogenous shocks to analyst coverage reduction experienced by the peer firms, this study finds that an exogenous drop in analyst covering peer firms contributes to a lower level of innovation output. This finding aligns with the information accumulation effect of financial analysts, highlighting their role in reducing information asymmetry and uncertainty in facilitating innovation. Cross-sectional analyses further reveal that the positive association is more pronounced in focal firms with richer information environments, more robust corporate governance, fewer financial constraints, and higher product similarity with their peers.
In all three empirical studies, peers of a focal firm are identified using the Text-Based Network Industry Classification (TNIC) developed by Hoberg and Phillips (2016, 2010). This classification system uses textual analysis of business descriptions to dynamically identify peers based on product similarity, which allows for a flexible, time-sensitive approach to categorizing firms. This peer classification that provides time-varying pairs of peers also allows for identification strategy in the attempts to alleviate endogeneity concerns.
This thesis not only contributes to the literature of peer effect, but also adds to a growing body of research in stock price crash risk, investment efficiency and corporate innovation, particularly in examining how these corporate issues can be influenced by such an additional peer-driven factor. This thesis also raises several practical implications. To the investors, knowing that managers base their decisions on peers, they must consider the information of peers of the company they invest in when making individual investment decisions. To the managers, not only do they need to be cognizant of the impact of peer information on firm value due to their information disclosure and corporate decisions, but they must also understand how the share market participants would react to their release of information and decisions and that of their peers. To the regulators, the importance of peer information should be factored into their assessment of the disclosure adequacy of companies. Changes in corporate decisions and policies characterised by peer environment can also contribute to better transparency in financial reporting and decision-making due to peer pressure, ultimately resulting in market efficiency.</p
Transcriptomic and metabolomic responses of maize under conventional and biodegradable microplastic stress
No full textThe increasing accumulation of microplastics in agricultural soils potentially threatens crop safety and quality. However, studies regarding the molecular mechanisms underlying the effects of conventional and biodegradable microplastics on plant growth remain limited. Herein, we estimated the effects of biodegradable polybutylene adipate terephthalate, poly (butylene succinate), polylactic acid, and conventional non‐biodegradable polyethylene and polystyrene microplastics (at a concentration of 1% [w/w]) on the growth and physiological performance of maize (Zea mays L.). In addition, we studied the molecular mechanisms underlying the effects of these microplastics on maize. Exposure to microplastics induced the production of antioxidant enzymes and antioxidants at varying levels in the maize. While the maize antioxidant systems were induced against biodegradable microplastic exposure, maize photosynthesis was relatively more important for conventional microplastic treatments. Additionally, metabolomics and transcriptomic analyses revealed that the pathways of secondary metabolite biosynthesis, photosynthesis, energy metabolism, and carbohydrate metabolism were regulated by biodegradable and conventional microplastics. Specifically, microplastics induced the plant hormone signal transduction and mitogen‐activated protein kinase signaling pathways. Our results further indicated that microplastics could impact the plant through changing the soil environmental variables or altering the soil microbial communities. This study provides a molecular‐scale perspective on the responses of crops to microplastic contamination, and these findings will contribute to the ecological risk assessment of biodegradable and conventional microplastics.</p
Exploring Factors Contributing to Graduate Outcomes: Using Career Registration Methodology (CRM) to Track Students’ Employability Activities, Career Readiness, and Graduate Outcomes
No full textGraduate outcomes are a key indicator of university performance, yet the progression of students in career preparation during university is ill-understood. The Career Registration Methodology (CRM) addresses this gap by tracking students’ career planning and participation in employability and professional experiences (EPEs) throughout their university enrolment. This research used CRM to monitor students’ employability development and career readiness, assessing their impact on graduate outcomes. By analysing longitudinal CRM data and Graduate Outcomes Survey (GOS) results from 1653 students, this study examined how EPEs and career readiness influenced full-time employment, job offers, the perceived value of qualifications, and perceptions of overqualification. Correlation and trend analyses revealed positive associations between career readiness over time and employment outcomes, with regression analyses identifying EPEs as the most significant factor. Practical implications of the findings highlight CRM’s value in aiding higher education institutions, especially Work Integrated Learning (WIL) and Career Development Learning (CDL) educators, to identify trends and tailor support whilst students are still in the university. As the first CRM study in Australia based on the first available cohort, the exploratory nature of this research is acknowledged along with recommendations to refine periodic, non-intrusive measurements such as CRM for enhanced validity and reliability.</p
Generative Design Of Light-weight Structural Systems
No full textLight-weighting for vehicle design is an important consideration and is often achieved through structural optimisation. Light-weight component geometries which were previously not manufacturable through subtractive means, are now manufacturable using additive manufacturing technologies. Additionally, tools such as topology optimisation allow designers to generate novel light-weight component designs with improved performance characteristics.
Opportunities exist, in the integration of these light-weighting tools into automated workflows. This approach to design is known as generative design; an algorithmic approach to the design process which can generate and evaluate solutions to a design problem in an automated fashion. The application of generative design principles has the potential to provide several important improvements to the design process, including reduced lead times, reduced effect of designer fixation, increased size of solution space exploration, and redundancy provided through parallel design.
Key challenges exist in the creation of successful generative design workflows for application in light-weighting: a means to utilise algorithmic form generation tools in an efficient, low computational cost manner, for the exploration of potential problem solutions must be developed; parameterisation techniques are required to connect form generation tools to performance evaluating models; structural optimisation techniques need to be incorporated into automated workflows, to define and refine solution geometry.
This research addressed these challenges through the development of novel generative design workflows for three distinct structural light-weighting design cases: truss, frame, and shell structures respectively. Within this generative design approach, topology optimisation is utilised as a form generation tool. Novel parameterisation methods are developed utilising image processing algorithms to parameterise topology optimisation solutions into low-fidelity representations which are suitable as inputs to performance evaluating computer-aided engineering tools. Shape and sizing optimisation algorithms are then successfully applied to determine optimal geometry of parameterised solutions.
The generative design techniques proposed within this research were developed first for the design of trusses in two dimensions. Form generation is conducted utilising topology optimisation. The solution space is explored through alteration of topology optimisation control variables, whose solutions are then parameterised into connectivity definitions. An algorithm is proposed which can transform parameterised solutions into statically determinate representations of pin-jointed truss structures. Performance of the parameterised solutions is evaluated using the method of joints. Shape optimisation is then conducted using gradient descent algorithms for solution search, with constraints on stress and buckling, as well as a bounding on member cross-section size. A case study was conducted for three loading scenarios: Simply supported beam, Messerschmidt-Bölkow-Blohm beam, and cantilever beam. A set of high-performing solutions was generated for each of the loading cases. The capability of the generative design method to produce high-performing solutions was confirmed through the generation of known optimal Michell structures.
The generative design method was developed further in three-dimensions for the design of space frame structures. The parameterisation method developed for trusses was expanded to three dimensions successfully. Performance evaluation was conducted using a finite element method beam model. Shape optimisation solution search was conducted with a gradient descent algorithm. This was constrained using the method of gradient summation, with regards to maximum stress, critical buckling stress, and a bounding on maximum and minimum frame member cross-section. An experimental case study was conducted, applying the generative design method to an industry type problem, through the light-weighting of an aerospace bracket. Through this case study, the effect of topology optimisation resolution on design outcomes, as well as the performance of the parameterisation method, was assessed. A resolution threshold was identified at which point parameterisation performance is compromised. Six high-performing topologies were identified and found to be generated many times using low resolution topology optimisation. This finding confirms that reductions in computational cost within generative design workflows can be achieved through low resolution simulation, while still generating high-performance outcomes. The method was benchmarked against solutions generated with Autodesk’s Fusion and were found to outperform these commercial software outcomes.
The generative design approach was applied to the light-weighting of a shell component. A novel approach was developed, whereby two-dimensional topology optimisation simulations are conducted on slices taken through the span-wise length of the incumbent shell geometry. A novel parameterisation technique was created which translates structures within these solutions into trajectories which are used to generate surfaces running through the the incumbent geometry span. Four solutions to a constant external pressure loading problem were generated by altering topology optimisation simulation resolution. Sizing optimisation was conducted on three of the generated solutions, alongside a control, using a shell finite element model, evaluating deflection with regards to surface thickness. Pareto fronts of deflection-to-mass were created from sizing optimisation results, and solutions were selected from the Pareto front for a target deflection. Each selected component was manufactured out of Acrylonitrile-butadiene-styrene using fused filament fabrication, and compressively tested to evaluate the components stiffness. The generated components were found to have improved stiffness-to-weight ratio when compared to the incumbent component. The solutions were also benchmarked against open-source topology optimisation software, top3D for runtime, showing a marked improvement in time required for simulation. The performance of solutions under compressive loading was also benchmarked against a solution generated using commercial software Fusion by Autodesk, and all solutions generated using the proposed method were found to outperform the Fusion solution with regards to stiffness and stiffness-to-mass ratio.
The findings of this research contribute to the field of generative design through discussion of the field’s history, the tools required, and approaches for successful application of generative design in light-weighting. Additionally, through the implementation of generative design strategies for the design of light-weight truss, frame and shell structures, this research proposes novel generative design approaches that can successfully achieve design outcomes utilising low computational cost. Application of the proposed methods for two industry type problems within Chapter 4 and Chapter 5 shows the potential for improvements in lead times and performance within the embodiment design phase, while allowing for redundancy that can improve the light-weighting design process. These research contributions improve on the understanding of generative design processes and their implementations, providing opportunities to improve the uptake and effectiveness of generative design use within industry.</p