St. Paul speaks about the church as the body of Christ, and he also speaks about the Eucharist as the body of Christ. How are these two affirmations related? Christian medieval authors gave consideration to the notion of the church as the “mystical body” of Christ and understood the church as the fruit or result of eucharistic communion in the “true body” of Christ. This chapter examines the thought of Thomas Aquinas on the church and its relation to the sacraments. It also shows how this conception has deeply informed the modern idea of the church as a sign and instrument of grace for all human beings, called to communion in the one Christ.

This chapter provides a broad overview of the richness and diversity of rock art in western Arnhem Land. Emphasising the cultural connectivity between rock art, history, culture, Ancestral Beings, language, and land, we introduce the cultural context for rock art creation as well as the paradox whereby an apparently conservative artistic tradition might also shed light on historical particularity and change.

Transverse myelitis is an inflammation of the spinal cord that commonly presents with acute to subacute bilateral motor weakness and sensation changes below the level of the spinal cord lesion, as well as anal and urinary sphincter control impairment. The causes of transverse myelitis can be viral, bacterial, parasitic, rheumatological/antibody-mediated, vascular, paraneoplastic, demyelinating, or idiopathic. Idiopathic transverse myelitis is typically a monophasic illness. Most cases of transverse myelitis are related to an underlying autoimmune condition like multiple sclerosis, neuromyelitis optica spectrum disorder (NMOSD), or myelin oligodendrocyte glycoprotein (MOG)-associated disorder.

Ependymomas are glial tumors that arise from the ependymal cells that line the ventricles and the central canal of the spinal cord, mostly located in the fourth ventricle. These tumors commonly affect children aged 1–5 years, though can be found in young adults. Like astrocytomas, ependymomas are graded based on histological characteristics, with grade 1 representing subapendymoma/myxopapillary ependymoma, grade 2 representing ependymoma, and grade 3 representing anaplastic ependymoma.

Acute disseminated encephalomyelitis (ADEM) is a monophasic illness characterized by multifocal CNS inflammation and demyelination that occurs primarily in children below 10 years of age (~80%), though it can occur in teenage years and very rarely in adulthood. In the majority of cases of ADEM, a preceding recent immunological stressor can be identified, usually in the form of a routine vaccination (postvaccinal ADEM) or a childhood illness such as influenza or mononucleosis (post-exanthematous ADEM).

First described by Swiss scientist Charles Bonnet in 1760 in the case of a 90-year-old man with cataracts suffering from complex visual hallucinations in the absence of a psychiatric condition, Charles Bonnet syndrome (CBS) has become a well-known phenomenon of complex visual hallucinations in those with decreased visual acuity. Charles Bonnet syndrome can occur secondary to any disease or condition that decreases visual acuity including diabetic retinopathy, age-related macular degeneration, cerebral infarction, cataracts, glaucoma, optic ischemic or inflammatory disease, or eye trauma. The prevalence of CBS remains relatively undefined; however, it is thought to be between 0.5% and 10% of those with low visual acuity and more common in the elderly. The prevalence, however, is thought to be underestimated due to significant underreporting of visual hallucinations by the affected patient given the stigma of psychiatric illness. The most common cause of CBS is age-related visual acuity loss, particularly macular disease and glaucoma, with the most common age of symptom onset from 70 to 85 years. There is no clear male or female predominance.

By examining transportation, agriculture, animal husbandry, industry, and commerce, this chapter explores the regional division of labor among residents of the landscape trilogy.

Huntington disease (HD) is an autosomal dominant neurodegenerative disease resulting from the trinucleotide repeat expansion of (CAG) sequence on chromosome 4, HTT gene, in exon 1. These CAG trinucleotide repeats (<35 repeats) are seen in individuals without HD, though all individuals with ≥40 CAG repeats develop HD, and those with ≥60 often develop juvenile HD. The average age of onset is 35–45 years.

Much-branched woody shrubs to small trees of spreading to columnar cypress-like form, characterised by abundant slender ascending shoots bearing either spreading leaves or scale leaves. They have freely spreading tips and bunched or solitary long-persistent female cones, each with a basal whorl of sterile scales.

Sturge–Weber syndrome (SWS), also known as encephalofacial angiomatosis, is a neurocutaneous disorder named after English physician William Sturge and dermatologist Frederick Weber, who described its features in detail in 1869. Caused by congenital, nonhereditary (somatic) mosaic mutation of the gene GNAQ, this mutation disrupts vascular development, resulting in areas of abnormal vasculature on the face and intracranially and causing skin discoloration, leptomeningeal angiomatosis, and glaucoma.

The search for extraterrestrial intelligence (SETI) represents a well-known area of astrobiology. This chapter is dedicated to technosignatures, that is, markers produced by extraterrestrial intelligences (ETIs). The famous Drake equation for roughly estimating the number of communicative ETIs is introduced, its various factors are defined, and some of its shortcomings and implications for detecting technosignatures are discussed. Next, the Fermi paradox is delineated: if ETIs are widespread, where are they? Three major classes of solutions to this classic paradox (e.g., we are effectively alone) are considered, along with their accompanying ramifications. After a brief segue into the Kardashev scale for grouping ETIs, the final segment of the chapter categorises the diverse landscape of technosignatures – ranging from artificial radio and optical signals to atmospheric pollutants and waste heat arising from energy harvesting and dissipation – and outlines the current limits derived for the frequency of technosignatures, as well as the anticipated future constraints in this context.

Suggestions of a processual orientation in Collingwood’s thought can be found in certain places in his corpus, but Collingwood is not generally known as a process philosopher. This is likely because the Libellus de Generatione, in which he develops a process-oriented ontology, has long been unavailable and thought lost. While a copy was found and is housed in the Bodleian Library, it was only made publicly available in 2019. This chapter explicates the process ontology developed in the Libellus and contextualizes it in relation to Collingwood’s wider corpus and to early twentieth-century process philosophy. Drawing on Sandra Rosenthal, I argue that Collingwood’s understanding of process is closer to Bergson’s than Whitehead’s, especially in ways that allow for genuine novelty and creation, and in its implications for the metaphysics of time. I then discuss implications of this process ontology for the view of Collingwood as an idealist and for other areas of his philosophy. Finally, I consider whether attributing a processual ontology to Collingwood is in tension with his own view of “metaphysics without ontology.”