Central aspects of skew translation quadrangles, I

Except for the Hermitian buildings $\mathcal{H}(4,q^2)$, up to a combination of duality, translation duality or Payne integration, every known finite building of type $\mathbb{B}_2$ satisfies a set of general synthetic properties, usually put together in the term "skew translation generalized quadrangle" (STGQ). In this series of papers, we classify finite skew translation generalized quadrangles. In the first installment of the series, as corollaries of the machinery we develop in the present paper, (a) we obtain the surprising result that any skew translation quadrangle of odd order $(s,s)$ is a symplectic quadrangle; (b) we determine all skew translation quadrangles with distinct elation groups (a problem posed by Payne in a less general setting); (c) we develop a structure theory for root-elations of skew translation quadrangles which will also be used in further parts, and which essentially tells us that a very general class of skew translation quadrangles admits the theoretical maximal number of root-elations for each member, and hence all members are "central" (the main property needed to control STGQs, as which will be shown throughout); (d) we solve the Main Parameter Conjecture for a class of STGQs containing the class of the previous item, and which conjecturally coincides with the class of all STGQs.Comment: 66 pages; submitted (December 2013

Unextendible mutually unbiased bases (after Mandayam, Bandyopadhyay, Grassl and Wootters)

We consider questions posed in a recent paper of Mandayam et al. (2014) on the nature of unextendible mutually unbiased bases. We describe a conceptual framework to study these questions, using a connection proved by the author in Thas (2009) between the set of nonidentity generalized Pauli operators on the Hilbert space of N d-level quantum systems, d a prime, and the geometry of non-degenerate alternating bilinear forms of rank N over finite fields F d We then supply alternative and short proofs of results obtained in Mandayam et al. (2014), as well as new general bounds for the problems considered in loc. cit. In this setting, we also solve Conjecture 1 of Mandayam et al. (2014) and speculate on variations of this conjecture

South Kivu: identity, territory, and power in the eastern Congo

This Usalama report by Koen Vlassenroot outlines the historical dynamics behind the armed movements in South Kivu, focusing on the period before and leading up to the First Congo War. The province of South Kivu has been at the heart of the conflict in the eastern DRC. Since the end of the Second Congo War (1998–2003), the province’s potential to cause broader regional destabilization has decreased, but violent local conflicts have multiplied, fuelled by political opportunism and local struggles over land and power. The report concentrates on sources of local conflict but argues that these can only be understood when also concentrating on wider political, social, economic, and demographic processes at both national and regional levels

The fate of William Whewell’s four palætiological domains : a comparative study

In 1847, the British polymath William Whewell pointed out that the sciences for which he, in 1837, had coined the term “palætiological” have much in common and that they may reflect light upon each other by being treated together. This recommendation is here put into practice in a specific way, to wit, not by comparing the palaetiological sciences that Whewell distinguished himself but by comparing the general historical development of the scientific study of the four broad palætiological domains that he enumerated in 1847: the solar system, the Earth, its vegetable and animal creation, and man. For wide and various as their subjects are, it will be found that [the palætiological sciences] have all certain principles, maxims, and rules of procedure in common; and thus may reflect light upon each other by being treated together. William Whewell ( 1847 , 1, p. 640

Middle and late Holocene vegetation and landscape evolution of the Scheldt estuary : a palynological study of a peat deposit from Doel (Belgium)

Local and regional environmental conditions for the south-eastern Scheldt estuary during the middle and late Holocene period have been reconstructed based on pollen analysis, loss-on-ignition and radiocarbon dating of a sediment core from Doe (N-Belgium) and the comparison with existing data from other sites from the same region. Postglacial relative sea level rise resulted in the formation of alder carr vegetation in the lower parts of the landscape from c. 7640 cal BP onwards. The vegetation succession was weakly influenced by the deposition of tidal clay deposits between c. 6550 and 5650 a cal BP and eventually culminated in the development of an oligotrophic bog. Peat accumulation seems to have ceased between c. 2030 and 1220 a cal BP, well before it was covered by marine sediments in the late Middle Ages

Reformist hagiography : the life of St Roding of Beaulieu and the struggle for power in early eleventh-Century Lotharingia

This paper explores an example of ‘reformist’ hagiographic production in early eleventh-century Lotharingia by focusing on the Life of St Roding of Beaulieu, a small monastery in the diocese of Verdun. Until recently, this text was interpreted exclusively in terms of the scant information it provides on this institution’s early medieval history and in terms of its ideological message regarding monastic discipline and leadership. By integrating the redaction of this text into the then-current regional geography and political context, this paper proposes a new approach to its interpretation and to the understanding of Beaulieu’s ‘monastic reform’ in general. Close analysis of the narrative reveals that its redaction was inspired by specific issues relating to local and regional politics in the mid-1010s, and that parts of the institution’s recent history were allegorically veiled behind the portrayal of Roding. However, rapid changes in power relationships rendered those aspects of the text outdated within a few years. This raises significant questions regarding the long-term relevance of such hidden stories and the degree to which their various ideological, political and other messages remained accessible to medieval audiences

The beginnings of a monastic reformer : the younger years of Poppo of Stavelot (Lotharingia, 978-1020)

This paper investigates the underlying mechanisms and different contexts which played a decisive role in the advancement of the pre-abbatial monastic careers of adult converts living in the eleventh century. Whereas most studies on these individuals have focused primarily on their abbatial careers, this article will consider the years preceding their attaining an influential monastic leadership position. Based upon the case of Poppo of Stavelot, traditionally regarded as one of the principal proponents of monastic reform in early-eleventh-century Lotharingia, this paper argues that the key factor leading up to a person’s nomination as abbot was not so much his religious reputation, extraordinary character, or even the result of his accumulated experience. Rather, the evolution of an individual’s pre-abbatial career depended to a large extent on how his social identity was perceived by others, as well as on the confrontation between his social capital and the concrete and short-term political context of the time