An anatomico physiological principle governing the direction of the gastro intestinal mucosal folds during life

ArticleThe original publication is available at http://www.samj.org.zaThe mucosa, being the innermost layer of the gastro intestinal tract, is intimately concerned with digestion and absorption, and, presumably, also with the transport of intestinal contents. In anatomical, physiological and motility studies, possible movements of the mucosa and its folds are neither considered nor investigated. Dogmatic statements about the direction of the folds are often made. Radiologists have long been aware of mucosal movements, but after the fundamental work of Forssell, no further views have been put forward. Radiological procedures have been used to investigate the normal, macroscopic, physiological movements of mucosal folds. A general rule follows. Normally, when the intestine is filled, but inactive, the folds are circular; when the walls contract, the folds change in direction, to become longitudinal. This phenomenon is confirmed by in vivo baboon studies and elucidated by wire spirals. It is seen to be an inherent characteristic of 'peristaltic' and 'segmental' contractions. In this manner longitudinal mucosal furrows are formed simultaneously with the contraction wave of the walls, thus facilitating transit. Were this not so, peristalsis would be an ineffective mechanism, with contraction waves acting against the resistance of circular folds.Publishers’ versio

#MustFall–TheEvent: Rights, Student Activism and the Transformation of South African Universities in University on the Border: Crisis of Authority and Precarity

In this chapter, we read the 2015-2016 #MustFall movement as an “event” in Badiou’s sense of the word. Employing Badiou’s (2005, 2013) interpretive scheme, we suggest that the #MustFall movement fractured the appearance of regularity of the South African higher education landscape to such an extent that it can be considered the kind of ‘event’ that Badiou defines as “something that brings to light a possibility that was invisible or even unthinkable. [It] is, in a certain way, merely a proposition. It proposes something to us” (Badiou, 2013:9-10). Reflecting on a long-term research project on ‘transformative student citizenship’ that started in 2011, we argue that the #MustFall movement’s contemporary emergence and forms of political action that disrupted the functioning of the social order can be perceived as a demand for ‘retreating’ rights. We suggest that the ‘event’ breaks with established power’s control over what should or should not be considered possible. While established power institutes and sustains this distinction through the use of state apparatus and capital, the ‘event’ extracts the possible from the impossible: “the ‘event’, for its part, will transform what has been declared impossible into a possibility” (Badiou, 2013:11). Though much work needs to be done within the realm of what is pragmatically possible, the case for a free, ‘decolonised’ higher education system has most certainly been snatched from the realm of the impossible. We tentatively explore what possibilities are proposed by #MustFall–TheEvent. For this chapter, #MustFall–TheEvent will designate the protests prior, during and after the 2015-2016 student ‘uprising’. This ‘uprising’ nearly brought the country to a standstill and temporarily disrupted the appearance of social stability. Mainly peaceful, productive and unsettling, the protests were also accompanied by violence, damage to property, intimidation and bullying across a wide spectrum, and political opportunism and proprietary inclinations of all sorts. Our analysis here does not make any judgements in these regards, nor will it attempt to provide an explanatory historical interpretation. These matters are well-traversed in a large number of opinion pieces as well as substantial studies such as Free Fall: Why South African Universities are in a Race against Time (Ray, 2016) and Fees Must Fall: Student Revolt, Decolonisation and Governance in South Africa (Booysen, 2016). Instead, we make a modest attempt at formulating the possibilities that have been opened up by #MustFall–TheEvent. To do so, we briefly provide a context for positioning student politics and protests within broader societal processes. We then proceed to read the #MustFall movements as a Badioun ‘event’, followed by an exploration of #MustFall–TheEvent as an instance for ‘retreating’ rights. In conclusion, we contemplate the implications of our analysis for the discourse on social justice

Symmetry of Brans-Dicke gravity as a novel solution-generating technique

A symmetry of Brans-Dicke gravity in (electro) vacuo or in the presence of conformally invariant matter is presented and used as a solution-generating technique starting from a known solution as a seed. This novel technique is applied to generate, as examples, new spatially homogeneous and isotropic cosmologies, a 3-parameter family of spherical time-dependent spacetimes conformal to a Campanelli-Lousto geometry, and a family of cylindrically symmetric geometries.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [BIDEB-2219]; Namik Kemal UniversityNamik Kemal University; Natural Sciences and Engineering Research Council of CanadaNatural Sciences and Engineering Research Council of Canada (NSERC)CGIAR [201603803]We are grateful to Nathalie Deruelle for a discussion and to a referee for useful comments. D. K. C. thanks the Scientific and Technological Research Council of Turkey (TUBITAK) for a postdoctoral fellowship through the Programme BIDEB-2219 and Namik Kemal University for support. V. F. is supported by the Natural Sciences and Engineering Research Council of Canada (Grant No. 201603803), and all authors thank Bishop's University

Quantum secret sharing with qudit graph states

We present a unified formalism for threshold quantum secret sharing using graph states of systems with prime dimension. We construct protocols for three varieties of secret sharing: with classical and quantum secrets shared between parties over both classical and quantum channels.Comment: 13 pages, 12 figures. v2: Corrected to reflect imperfections of (n,n) QQ protocol. Also changed notation from $(n,m)$ to $(k,n)$, corrected typos, updated references, shortened introduction. v3: Updated acknowledgement

Mediating the GM Foods Debate: Lessons from the Enduring Conflict Framework

Critics of the commercialization of Genetically Modified (GM) foods in Canada and the United States oppose the economic and political forces that create and approve the technology: the industry that develops it and the governments that approve its use. The conventional narrative pits the concerned public, labeled anti-GM, against the pro-GM interests of industry supported by business-friendly governments. Based on this binary view of the interests and motivations of stakeholders, conflict betwee

New Protocols and Lower Bound for Quantum Secret Sharing with Graph States

We introduce a new family of quantum secret sharing protocols with limited quantum resources which extends the protocols proposed by Markham and Sanders and by Broadbent, Chouha, and Tapp. Parametrized by a graph G and a subset of its vertices A, the protocol consists in: (i) encoding the quantum secret into the corresponding graph state by acting on the qubits in A; (ii) use a classical encoding to ensure the existence of a threshold. These new protocols realize ((k,n)) quantum secret sharing i.e., any set of at least k players among n can reconstruct the quantum secret, whereas any set of less than k players has no information about the secret. In the particular case where the secret is encoded on all the qubits, we explore the values of k for which there exists a graph such that the corresponding protocol realizes a ((k,n)) secret sharing. We show that for any threshold k> n-n^{0.68} there exists a graph allowing a ((k,n)) protocol. On the other hand, we prove that for any k< 79n/156 there is no graph G allowing a ((k,n)) protocol. As a consequence there exists n_0 such that the protocols introduced by Markham and Sanders admit no threshold k when the secret is encoded on all the qubits and n>n_0

Conceptual Model Interoperability: a Metamodel-driven Approach

Linking, integrating, or converting conceptual data models represented in different modelling languages is a common aspect in the design and maintenance of complex information systems. While such languages seem similar, they are known to be distinct and no unifying framework exists that respects all of their language features in either model transformations or inter-model assertions to relate them. We aim to address this issue using an approach where the rules are enhanced with a logic-based metamodel. We present the main approach and some essential metamodel-driven rules for the static, structural, components of ER, EER, UML v2.4.1, ORM, and ORM2. The transformations for model elements and patterns are used with the metamodel to verify correctness of inter-model assertions across models in different languages