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Effect of the Application of Ochrobactrum sp.-Immobilised Biochar on the Remediation of Diesel-Contaminated Soil
No full textThe immobilisation of bacteria on biochar has shown potential for enhanced remediation of petroleum hydrocarbon-contaminated soil. However, there is a lack of knowledge regarding the effect of bacterial immobilisation on biosolids-derived biochar for the remediation of diesel-contaminated soil. This current study aimed to assess the impact of the immobilisation of an autochthonous hydrocarbonoclastic bacteria, Ochrobacterium sp. (BIB) on biosolids-derived biochar for the remediation of diesel-contaminated soil. Additionally, the effect of fertiliser application on the efficacy of the BIB treatment was investigated. Biochar (BC) application alone led to significantly higher hydrocarbon removal than the control treatment at all sampling times (4887–11,589 mg/kg higher). When Ochrobacterium sp. was immobilised on biochar (BIB), the hydrocarbon removal was greater than BC by 5533 mg/kg and 1607 mg/kg at weeks 10 and 22, respectively. However, when BIB was co-applied with fertiliser (BIBF), hydrocarbon removal was lower than BIB alone by 6987–11,767 mg/kg. Quantitative PCR (q-PCR) analysis revealed that the gene related to Ochrobacterium sp. was higher in BIB than in the BC treatment, which likely contributed to higher hydrocarbon removal in the BIB treatment. The results of the q-PCR analysis for the presence of alkB genes and FTIR analysis suggest that the degradation of alkane contributed to hydrocarbon removal. The findings of this study demonstrate that bacterial immobilisation on biosolids-derived biochar is a promising technique for the remediation of diesel-contaminated soil. Future studies should focus on optimising the immobilisation process for enhanced hydrocarbon removal.</p
Work-related risk factors for mental ill-health among Australian wildland firefighters
No full textA qualitative study of Australian wildland firefighters employed by a state government agency was undertaken to: (i) explore the perceived impact of work-related stress factors on participants’ psychological health; and (ii) identify organisational strategies or approaches that firefighters believe could help to protect or improve their psychological health. Twenty-five participants took part in the first round of interviews and 24 participants took part in the second round of interviews. A theoretical model of work-related determinants of psychological health developed by Harvey et al. (2017) was used to inform the thematic coding of interview data. Participants reported a wide variety of work-related stressors that they believe affect their psychological wellbeing. All of the stressors identified by Harvey et al. (2017) were evident in the firefighters’ descriptions of work characteristics and experiences that they believe affect their psychological health, including job insecurity, high job demands, low job control, low social support, work-family conflict and issues related to recognition and reward. However, the wildland firefighters also identified exposure to dangerous work, limited training opportunities, inconsistent application of organisational policies and procedures and administrative workload and demands associated with the community interface as affecting their psychological health. The findings indicate that wildland firefighters perceive no single work-related factor as contributing to psychological ill-health. Rather, the firefighters indicated that their psychological health is affected by the experience of multiple psychosocial risk factors that co-exist and interact with one another in the work environment. Firefighters also identified a wide variety of organisational strategies that they believe could reduce the risk of psychological ill-health associated with work stress. Participants’ suggestions provide practical, actionable solutions with the potential to reduce exposure to stressors in the organisational work environment and better protect wildland firefighters against harm to their psychological health.</p
Spin dynamic and magneto optical studies on mixed ferrites nanofluids and nanocomposites
No full textThe remarkable progress in the field of nanotechnology has paved the way for the development of novel materials with unique properties and enhanced functionalities. Among these, materials, mixed ferrites nanofluids and nanocomposites have gained significant attention due to their intriguing magnetic and optical properties. These materials exhibit a combination of ferromagnetic and ferrimagnetic behavior, making them suitable for various technological applications such as data storage, sensors, spintronics, and biomedical devices. Understanding the spin dynamics and magneto-optical properties of these materials is crucial for their effective utilization and further advancement. In recent years, extensive research has been carried out to investigate the spin dynamics of mixed ferrites nanofluids and nanocomposites. The spin dynamics refer to the behavior of electron spins within a material under the influence of an external magnetic field. This field of study is of great importance as it provides valuable insights into the magnetic properties, such as magnetization dynamics, spin relaxation, and magnetic resonance, which are vital for designing efficient magnetic devices. One of the primary techniques employed to explore the spin dynamics in these materials is ferromagnetic resonance (FMR) spectroscopy. FMR spectroscopy allows the direct observation of electron spin resonance transitions and provides information about the magnetic interactions, spin-lattice relaxation, anisotropy and g-factor. By utilizing FMR spectroscopy, researchers have successfully investigated the spin dynamics in various mixed ferrites nanofluids and nanocomposites, shedding light on their unique magnetic behaviors. The field of spin dynamics deals with the behavior of electron spins in response to external magnetic fields and their interactions with other spins. Understanding spin dynamics is crucial for the design and development of advanced magnetic materials, as it governs the material's magnetic behavior and influences its potential applications. By investigating the spin dynamics of mixed ferrites, we aim to gain insights into the mechanisms behind their enhanced magnetic properties and shed light on their potential applications in areas such as data storage, spintronics, and magnetic sensors. In addition to spin dynamics, the magneto-optical (MO) properties of mixed ferrites nanofluids and nanocomposites have also attracted significant interest. The magneto-optical effects arise due to the interaction between light and the magnetization in a material. By examining the magneto-optical response of these materials, we can uncover their unique optical properties, including the Faraday and Kerr effects. These effects can be utilized in devices such as magneto-optical switches, isolators, and sensors. Understanding these effects is essential for the development of advanced magneto-optical devices such as magneto-optical sensors, isolators, and modulators. By studying the magneto-optical properties of mixed ferrites nanofluids and nanocomposites, researchers aim to enhance their understanding of the underlying mechanisms and explore their potential applications in the field of photonics. Several experimental techniques, including magneto-optical Kerr effect (MOKE) spectroscopy and Faraday rotation measurements, have been employed to investigate the magneto-optical properties of these materials. Nano-MOKE-III spectroscopy provides valuable information about the magnetic anisotropy, magnetization reversal processes, and magneto-optical constants, while Faraday rotation measurements offer insights into the magneto-optical activity and Verdet constant. By understanding the magneto-optical behavior of mixed ferrite nanofluids and nanocomposites, we aim to unlock their potential for the development of advanced optical devices.
In this study, we aim to contribute to the growing body of knowledge on the spin dynamics and magneto-optical properties of mixed ferrites nanofluids and nanocomposites. By employing advanced experimental techniques and theoretical models, we seek to uncover the intricate interplay between the magnetic and optical properties in these materials. The obtained results will not only deepen our understanding of their fundamental behavior but also pave the way for the development of innovative applications in the fields of spintronics, information storage, and magneto-optical devices. Through this study, we aspire to contribute to the existing knowledge and foster further advancements in this exciting and rapidly evolving field.</p
Studies on Induced Pluripotent Stem Cell Models of Cortical Gyrification and Neurodevelopmental Disorders: Novel Generation of a Ferret Cerebral Organoid
No full textOne of the most distinctive and instantly recognisable characteristics of the human brain is its highly folded cortex. Indeed, these folds – or ‘gyri’ (the outer folds) and ‘sulci’ (the inner folds) – are a critical feature of larger mammalian brains, allowing for greater neuronal density and more complex neural networks to manifest. Consequently, this has facilitated the evolution of brains with greater processing power and the emergence of higher cognitive functions. The process of cortical folding is termed ‘gyrification’, and despite the undeniable importance of this process, the genetic and cellular mechanisms that govern it remain largely unknown. Significantly, the shape, size and structure of folds are highly conserved between individuals of the same species, with the primary cortical folds (which emerge first in development) also being highly similar between gyrencephalic species (e.g. dogs, cats, sheep, and ferrets). As such, gyrification must arise due to tightly regulated genetic mechanisms. Moreover, perturbations in the corticodevelopmental process that impact cortical morphology are associated with numerous neurological disorders, ranging in severity. Notable examples include Rett syndrome – a condition associated with acquired microcephaly, disordered cortical folding and major loss of cognitive function.
Historically, the field of neuroscience (and bioscience as a whole) has learned much from the use of mice and rats as model organisms. However, while these species have been useful in the study of corticodevelopment and gyrification, the insights they can provide are ultimately limited due to their brains being lissencephalic (i.e. smooth/lacking in cortical folds). As such, scientists have turned their attention to the study of a naturally gyrencephalic mammal – the ferret. This creature is one of the smallest mammals known to develop a gyrified brain, thus making it ideal from a housing and welfare standpoint. Furthermore, unlike the vast majority of larger mammals that commence gyrification in utero around the start of the second trimester, the ferret is born smooth-brained before undergoing gyrification shortly after. This, along with its generally short gestational period of 42 days and generally contracted corticogenesis timeline, make it an ideal model of gyrification.
While many incredible insights concerning gyrification have been gained from the study of the ferret, the advent of novel technologies in recent years has raised the possibility of alternative models that do not require the ongoing sacrifice of animal life. Specifically, our discovery of the genetic factors required to reprogramme highly specialised cells back into the undifferentiated state – named ‘induced pluripotent stem cells’ (iPSCs) – has revolutionised biomedical research. IPSCs have proven to be invaluable laboratory models as they can be differentiated into virtually any cell type in vitro and used to study development. Furthermore, iPSCs generated from the tissue of patients carrying a genetic disorder can be used to create a highly specific model of that disorder. Strikingly, the advent of iPSCs has greatly advanced our ability to generate highly complex 3D in vitro models (known as ‘organoids’). Indeed, brain – or ‘cerebral’ organoids have already proved incredibly accurate at modelling early corticodevelopment and have also been instrumental in unravelling previously unknown mechanisms of neurodevelopmental disorders. However, it is important to note that this technology is still in its infancy and, as a result, has several limitations. In particular, brain organoids are notoriously poor at recapitulating the late-stage features of cortical development that are typically seen in vivo. This may be due to a variety of factors, including a lack of vascularisation (and subsequent hypoxia-induced core necrosis) and a complete intrauterine environment, the impact of which becomes increasingly evident as organoid development progresses. Furthermore, it has been widely shown that cerebral organoids conserve their species-specific in vivo developmental timeline, as exemplified by the rapid maturation of mouse organoids relative to human organoids. Consequently, a human cerebral organoid that can faithfully recapitulate the cortical folds has not yet been achieved. More broadly, given the rapid speed at which the field of iPSC research has evolved, guidelines on the best practices concerning their generation, validation, and overall use to ensure scientific validity have struggled to keep up. As such, the following studies were conducted as part of this thesis:
Study 1 of this thesis comprises a systematic review of the methodological practices and reporting standards surrounding the generation and use of iPSC models of Rett syndrome.
Study 2 aimed to conduct a spatiotemporal characterisation of key neural progenitor and neuronal markers throughout the developing ferret cortex, with the intention of this data serving as a useful resource for the wider research community. Moreover, this data was used as an in vivo benchmark for the characterisation of the novel model generated in Study 3.
Study 3 aimed to address the limitations of human cerebral organoids by creating for the first time a novel-species cerebral organoid derived from ferret-iPSCs. It was hypothesised that the highly contracted corticogenesis timeline of the in vivo ferret brain would result in a rapidly developing ferret cerebral organoid. It was further hypothesised that a cerebral organoid with a contracted developmental timeline would recapitulate more advanced corticodevelopmental features before factors arising from the in vitro environment impact development, thus enabling the manifestation of cortical folds.</p
Students’ values in science education: a scoping review
No full textThere is growing recognition that when students’ values (i.e. the things they consider important) are acknowledged, relationships are strengthened, academic engagement and achievement improve, and student wellbeing is enhanced. However, surprisingly, limited studies have examined the values espoused by students in science education. This review begins by arguing for a greater values focus in science education, defines key terms, and then reviews the limited studies explicitly examining values in science education. A scoping review is then undertaken to tease out students’ values across the science education literature using a methodology developed in mathematics education values research involving extracting students’ values from closely related constructs (e.g. attitudes, beliefs, identities). In total, 55 different values were extracted across 91 publications. Across geographical regions, both value similarities and differences were found. We also explored the values that often co-occur. Our review develops important knowledge about student values in science education by defining, extracting, and then examining the relationships between students’ values. It also points to target areas that may improve students’ positive learning experiences and wellbeing in science education.</p
Fostering effective collaboration between library and information science academics and practitioners in Bangladesh: Insights, challenges and recommendations
No full textEffective collaboration between library and information science academics and practitioners is vital for the professional growth and success of individuals working in the field. It facilitates the exchange of knowledge, skills and innovative practices, which, in turn, enhance the quality of library services. It allows for the integration of theoretical knowledge with practical experience, resulting in more effective and efficient library operations. However, the lack of studies on fostering collaboration between library and information science academics and practitioners in Bangladesh presents a notable research gap. Addressing this gap is critical as it directly impacts the career success of library and information science professionals and the development of library services, particularly in a rapidly developing nation like Bangladesh. This study utilized a qualitative approach to gather data through semi-structured, unstructured, and focus group interviews with renowned Bangladeshi academics and experienced library practitioners. The research has broader implications for the global library and information science community, adding a valuable perspective from a developing nation. The results highlight the significance of mindset and attitude in influencing collaborative efforts, urging academics and practitioners to adopt an open-minded approach without ego-related conflicts. The study identifies the strengths, weaknesses, barriers and opportunities in relation to effective collaboration between library and information science academicians and practitioners. Additionally, the research proposes viable solutions and outlines the potential for academic and professional success through collaboration.</p
Evaluating the Mechanism of Cell Death in Melanoma Induced by the Cannabis Extract PHEC-66
No full textResearch suggests the potential of using cannabinoid-derived compounds to function as anticancer agents against melanoma cells. Our recent study highlighted the remarkable in vitro anticancer effects of PHEC-66, an extract from Cannabis sativa, on the MM418-C1, MM329, and MM96L melanoma cell lines. However, the complete molecular mechanism behind this action remains to be elucidated. This study aims to unravel how PHEC-66 brings about its antiproliferative impact on these cell lines, utilising diverse techniques such as real-time polymerase chain reaction (qPCR), assays to assess the inhibition of CB1 and CB2 receptors, measurement of reactive oxygen species (ROS), apoptosis assays, and fluorescence-activated cell sorting (FACS) for apoptosis and cell cycle analysis. The outcomes obtained from this study suggest that PHEC-66 triggers apoptosis in these melanoma cell lines by increasing the expression of pro-apoptotic markers (BAX mRNA) while concurrently reducing the expression of anti-apoptotic markers (Bcl-2 mRNA). Additionally, PHEC-66 induces DNA fragmentation, halting cell progression at the G1 cell cycle checkpoint and substantially elevating intracellular ROS levels. These findings imply that PHEC-66 might have potential as an adjuvant therapy in the treatment of malignant melanoma. However, it is essential to conduct further preclinical investigations to delve deeper into its potential and efficacy.</p
Seeing disability in children's made for television programmes: An Australian case study
No full textDisability awareness is an issue that can inform societal understanding of marginalised groups. Contemporary literature continues to show the importance of inclusion in society and the impact inclusion has on people with disabilities and society more broadly. The importance of disability awareness is important in the context of the daily challenges faced such as discriminatory practices, stigma, stereotyping and exclusion and manifested in areas such as access to buildings, educational opportunities, and visibility in the media. Given the importance of disability awareness and the significant influence of media, especially on children today, this research investigated the inclusion of disability as one element of ‘awareness’ in one ‘made-for-children’ (2–5 years old) television programme. Drawing on a social model of disability, three key concepts of Diversity, Inclusion, and Equity were used to explore the way that disability is portrayed for early learners. Analysis of 265 episodes (2015–2021) revealed that inclusion of disability appeared in fewer than 15% of episodes and was not representative of the community broadly speaking. This lack of representation exposed the limited potential that the media currently has as an educative function for preschool children in disability awareness and understanding of disability as part of contemporary society. Including more people with disabilities in made-for-preschool children's programmes is one way to both build awareness and progressively ameliorate this position.</p
MalBoT-DRL: Malware Botnet Detection Using Deep Reinforcement Learning in IoT Networks
No full textIn the dynamic landscape of cyber threats, multistage malware botnets have surfaced as significant threats of concern. These sophisticated threats can exploit Internet of Things (IoT) devices to undertake an array of cyberattacks, ranging from basic infections to complex operations, such as phishing, cryptojacking, and Distributed Denial-of-Service (DDoS) attacks. Existing machine learning solutions are often constrained by their limited generalizability across various data sets and their inability to adapt to the mutable patterns of malware attacks in real world environments, a challenge known as model drift. This limitation highlights the pressing need for adaptive intrusion detection systems (IDSs), capable of adjusting to evolving threat patterns and new or unseen attacks. This article introduces MalBoT-DRL, a robust malware botnet detector using deep reinforcement learning (RL). Designed to detect botnets throughout their entire lifecycle, MalBoT-DRL has better generalizability and offers a resilient solution to model drift. This model integrates damped incremental statistics with an attention reward mechanism, a combination that has not been extensively explored in the literature. This integration enables MalBoT-DRL to dynamically adapt to the ever-changing malware patterns within IoT environments. The performance of MalBoT-DRL has been validated via trace-driven experiments using two representative data sets: 1) MedBIoT and 2) N-BaIoT, resulting in exceptional average detection rates of 99.80% and 99.40% in the early and late detection phases, respectively. To the best of our knowledge, this work introduces one of the first studies to investigate the efficacy of RL in enhancing the generalizability of IDS.</p
Molecular interactions with bilayer membrane stacks using neutron and X-ray diffraction
No full textLamellar unit cell reconstruction from neutron and X-ray diffraction data provides information about the disposition and position of molecules and molecular segments with respect to the bilayer. When supplemented with the judicious use of molecular deuteration, the technique probes the molecular interactions and conformations within the bilayer membrane and the water layer which constitute the crystallographic unit cell. The perspective is model independent, and potentially, with a higher degree of resolution than is available with other techniques. In the case of neutron diffraction the measurement consists of carefully normalised diffracted intensity under conditions of contrast variation of the water layer. The subsequent Fourier reconstruction of the unit cell is made using the phase information from variation of peak intensities with contrast. Although the phase problem is not as easily solved for the corresponding X-ray measurements, an intuitive approach can often suffice. Here we discuss the two complimentary techniques as probes of scattering length density profiles of a bilayer, and how such a perspective provides information about the location and orientation of molecules within or between lipid bilayers. Within the basic paradigm of lamellar phases this method has provided, for example, detailed insights into the location and interaction of cryoprotectants and stress proteins, of the mechanisms of actions of viral proteins, antimicrobial compounds and drugs, and the underlying structure of the stratum corneum. In this paper we review these techniques and provide examples of the systems that have been examined. We finish with a future outlook on the use of these techniques to improve our understanding of the interactions of membranes with biomolecules.</p