Propagation-based phase-contrast x-ray imaging (PB-PCXI) generates image contrast by utilizing sample-imposed phase-shifts. This has proven useful when imaging weakly attenuating samples, as conventional attenuation-based imaging does not always provide adequate contrast. We present a PB-PCXI algorithm capable of extracting the x-ray attenuation β and refraction δ, components of the complex refractive index of distinct materials within an unknown sample. The method involves curve fitting an error-function-based model to a phase-retrieved interface in a PB-PCXI tomographic reconstruction, which is obtained when Paganin-type phase retrieval is applied with incorrect values of δ and β. The fit parameters can then be used to calculate true δ and β values for composite materials. This approach requires no a priori sample information, making it broadly applicable. Our PB-PCXI reconstruction is single-distance, requiring only one exposure per tomographic angle, which is important for radiosensitive samples. We apply this approach to a breast-tissue sample, recovering the refraction component δ, with 0.6–2.4% accuracy compared with theoretical values.

Climate change is affecting many facets of our lives and livelihoods, and food production is one of them. While the world population continues to increase, agricultural land and food production are being impacted by climate change at an ever-increasing rate. This chapter looks at climate change and its impacts on agri-food systems and food production. It briefly looks at the science of climate change, some projections, including rainfall and temperature projections to the end of the 21st century, and then is followed by a discussion of impacts of several climate-change–related stressors on agri-food production. Some of the stressors discussed include extreme weather events, such as droughts, floods, cyclones, and heat waves; sea-level rise, including inundation and salinity; invasive alien plant species; pests and pathogens; and neglected and underutilized crop species.

At the time of writing, the largest state in Australia is once more in full lockdown because of surging cases from the new variant strain of COVID-19. During the last lockdown in early 2020, we conducted a study analyzing the efficacy of mapping best-practice face-to-face university teaching into the online space. This article reports on the results of a survey from the perspective of student belonging. Isolation was the most prevalent theme recorded by students despite not being one of the research questions asked. The importance of adopting the model in online university courses in the current/post-COVID-19 world is presented.

Field education globally, has been highly disrupted by restrictions associated with COVID-19. This disruption has forced many students to engage with online learning. The current article presents a student-led co-operative inquiry exploring the experience of four social work students undertaking a remote research-based placement in regional Australia during a global pandemic. In this inquiry students’ critically self-reflected on the strengths and challenges of remote research-based placements. Despite some initial reservations, the students’ experience was positive overall. This article reports on four key themes that emerged from this inquiry: the translation of social work communication and relationship-building skills to online environments, the development of professional identity in a remote research-based placement, access to supervision in a remote context, and reflection on the experience of completing a research placement guided by the social work value of respect for persons. We conclude that undertaking a remote research placement helped forge students’ appreciation for the role of research in social work, enhanced their communication and research skills, and strengthened students’ sense of professional identity. These findings confirm remote research-based placements can offer relevant and effective placement opportunities that can inform social work field-education heutagogy as we move beyond the restrictions associated with the pandemic.