Ben Marais (1909-1999): The influences on and heritage of a South African Prophet during two periods of transformation

University of Pretoria / Dissertation / Department of Church History and Church Policy / Advised by Prof J W Hofmeyr

Nutrition or Detoxification: Why Bats Visit Mineral Licks of the Amazonian Rainforest

Many animals in the tropics of Africa, Asia and South America regularly visit so-called salt or mineral licks to consume clay or drink clay-saturated water. Whether this behavior is used to supplement diets with locally limited nutrients or to buffer the effects of toxic secondary plant compounds remains unclear. In the Amazonian rainforest, pregnant and lactating bats are frequently observed and captured at mineral licks. We measured the nitrogen isotope ratio in wing tissue of omnivorous short-tailed fruit bats, Carollia perspicillata, and in an obligate fruit-eating bat, Artibeus obscurus, captured at mineral licks and at control sites in the rainforest. Carollia perspicillata with a plant-dominated diet were more often captured at mineral licks than individuals with an insect-dominated diet, although insects were more mineral depleted than fruits. In contrast, nitrogen isotope ratios of A. obscurus did not differ between individuals captured at mineral lick versus control sites. We conclude that pregnant and lactating fruit-eating bats do not visit mineral licks principally for minerals, but instead to buffer the effects of secondary plant compounds that they ingest in large quantities during periods of high energy demand. These findings have potential implications for the role of mineral licks for mammals in general, including humans.

Peace and Peacemaking in Paul Against the Backdrop of Greco-Roman Conceptions of Peace

Peace in the ancient world has been studied primarily from the perspective of pacifism and questions related to war and peace. This study employs a socio-historical method to determine how peace was understood in itself, not just with respect to war. It demonstrates that the Greco-Roman world viewed peace as brief periods of tranquility in an existence where conflict was the norm, while Paul regarded peace as the norm and conflict as an intrusive aberration. Through a historical and literary survey of Greco-Roman thought and culture, this study shows that myth, legend, religion, education, philosophy, and science created and perpetuated the idea that conflict was necessary for existence. Wars were fought to attain peace, which meant periods of calm, quiet, and security with respect to the gods, one's inner self, nature, others who are insiders, and others who are outsiders. Despite the desirability of peace, genuine peace was seldom experienced, and even then, only briefly, as underlying enmity persisted without resolution. While Paul supports the prevailing conception of peace as tranquility and felicity in relation to God, self, nature, and others, he differs as to the origin, attainment, and maintenance of peace. In Paul, peace originates in God and is graciously given to those who are justified and reconciled to God through Jesus Christ. God removes the enmity caused by sin and provides the indwelling Spirit to empower believers to think and behave in ways that promote and maintain peace. This study also examines how three social dynamics (honor-shame, patron-client, friendship-enmity) affect Paul's approach to conflict resolution with Philemon and Onesimus, Euodia and Syntyche, believers who are prosecuting one another in civil courts, and Peter. Rather than giving specific procedures for resolving conflict, Paul reinforces the believer's new identity in Christ and the implications of God's grace, love, and peace upon their thoughts, words, and behavior toward one another. Paul uses these three social dynamics to encourage believers in the right direction, but their ultimate accountability is to God. The study concludes with four strategic principles for educating the church and developing an atmosphere and attitude within the church for peacemaking.

Christian Witness on the Plateau Vivarais-Lignon: Narrative, Nonviolence, and the Formation of Character

This dissertation analyzes the theological and ethical convictions that led the people of the Plateau Vivarais-Lignon to shelter thousands of refugees between 1939 and 1945. It does so by examining the themes of narrative identity, hospitality, character formation, nonviolence, and the contextual witness of church tradition. Though a number of studies have been published about the rescue activity in this region of France during World War II, none have thoroughly analyzed the theological nature of this activity. Using the Plateau Vivarais-Lignon as a case study in theological ethics, the dissertation draws on historical sources as well as the work of contemporary theologians and ethicists to understand, interpret, and analyze the witness of this community. After situating its rescue and resistance work within the Huguenot narrative of persecution and exile, I examine the theological convictions of the Reformed pastor of Le Chambon-sur-Lignon, André Trocmé, who played a key role in making the Plateau a place of refuge during the Holocaust. The study highlights the importance of narrative in the actions of this community and discusses the relationship between narrative, character, and ethics. It then examines the nonviolent commitments of key leaders of the rescue effort, using this analysis as a springboard to engage in broader theological reflection about the ethics of nonviolence. After examining the radical hospitality practiced on the Plateau in light of biblical narratives and Reformed history, I investigate the counter-cultural nature of Christian hospitality. The study concludes by analyzing the nature and witness of the church in light of the legacy of the Plateau Vivarais-Lignon. The dissertation suggests that increased academic and ecclesial attention be given to the relationship between narrative and character, the counter-cultural shape of Christian hospitality, and the active nature of nonviolence. It presents an in-depth analysis of the theological and ethical convictions of the people of the Plateau Vivarais-Lignon, arguing that their witness has ongoing significance for communities of faith as they grapple with how to form disciples, relate to the wider society, welcome strangers, and communicate God's shalom in a world of violence.

Modeling the Possible Influences of Eye Movements on the Refinement of Cortical Direction Selectivity

The second-order statistics of neural activity was examined in a model of the cat LGN and V1 during free-viewing of natural images. In the model, the specific patterns of thalamocortical activity required for a Bebbian maturation of direction-selective cells in VI were found during the periods of visual fixation, when small eye movements occurred, but not when natural images were examined in the absence of fixational eye movements. In addition, simulations of stroboscopic reming that replicated the abnormal pattern of eye movements observed in kittens chronically exposed to stroboscopic illumination produced results consistent with the reported loss of direction selectivity and preservation of orientation selectivity. These results suggest the involvement of the oculomotor activity of visual fixation in the maturation of cortical direction selectivity.