Non-Descender and All-Cap Arabic Writing

Contrary to the common belief of Arabic language users that the Arabic writing system has descenders as an inherent quality, some historical examples demonstrate that there were some artistic attempts to create non-descender, all-cap calligraphic systems, but they have never been studied as a phenomenon. This article draws attention to the existence of these examples, and analyses and classifies them according to their form.

The article begins with an analysis of the current Arabic writing system in terms of descenders, differentiating between artistic and functional writing, defining the need for harmonious balance in artistic writing, and demonstrating that descenders do disrupt the balance in Arabic writing, which could be considered as an ascender-system.

Then, historical examples of the non-descender system are introduced, categorised into four visual stages, and the descender handling for each stage is described; all-capital letter examples are then introduced.

Finally, some historical texts describing the beauty of calligraphy in this specific system of writing are analysed.

Abbreviations: MET: The Metropolitan Museum of Art, www.metmuseum.org; LACMA: The Los Angeles County Museum of Art, www.lacma.org; No. : Accession Number     

塔克拉玛干沙漠北缘地表反照率特征及参数化研究

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The geometry of linearly and quadratically constrained optimization problems for signal processing and communications

Constrained minimization problems considered in this paper arise in the design of beamformers for radar, sonar, and wireless communications, and in the design of precoders and equalizers for digital communications. The problem is to minimize a quadratic form under a set of linear or quadratic constraints. We present solutions to these problems and establish a connection between them. A majorization result for matrix trace and Poincare's separation theorem play key roles in establishing the connection. We show that our solutions can be formulated as generalized sidelobe cancellers (GSCs), which tie our constrained minimizations to linear minimum mean-squared error (LMMSE) estimations. We then express our solutions in terms of oblique projection matrices and establish the geometry of our constrained minimizations.     

Differential subordination and superordination of analytic functions defined by the Dziok-Srivastava linear operator

Differential subordination and superordination results are obtained for analytic functions in the open unit disk which are associated with the Dziok-Srivastava linear operator. These results are obtained by investigating appropriate classes of admissible functions. Sandwich-type results are also obtained.     

The three facets of knowledge: A critique of the practice-based learning theory

The community of practice learning theory (Lave and Wenger, 1991) can be credited with establishing the social basis of learning, viewing it as occurring through participation in social practices and activities. However, it remains silent on the cognitive content of what is learned by participants in a community of practice. Nor does it address explicitly the role of individuals in the knowing process. Individuals are merely depicted in terms of a desire to belong to a community, progressing from a peripheral participation position to a more central one. The aim of the present paper is to assess the contribution of Lave and Wenger's (1991) practice theory for educational and other learning social settings. In a schooling context, for instance, Lave and Wenger's (1991) account of learning would imply that what students learn at school is how to relate and belong to the school community. By reducing learning and knowing to participation, and by displacing cognition from individuals to anonymous practices, the practice-based epistemology ignores the significant corpus of content knowledge (such as curriculums) and ascribes too passive a role to individuals and glosses over their differentiated access to resources for changing practices and their differentiated efforts in their social and cognitive development. The present paper suggests an approach to knowledge that takes into account the various facets of knowledge, that is, knowledge as knowledge-productive practices, as content, and as relation to a knowing subject, at the same time preserving the sociality of knowledge and learning.     

Oxidatively Damaged DNA: A Possible Antigenic Stimulus for Cancer Autoantibodies

Reactive oxygen species (ROS) are cytotoxic at higher concentration resulting in cell death, mutations, chromosomal aberrations or carcinogenesis. In this study DNA was modified by singlet oxygen and superoxide anion radicals generated by illumination of riboflavin under 365 nm UV-light. The modified DNA induced high titre antibodies in experimental animals. In enzyme immunoassay, serum antibodies from cancer patients (n = 34) showed a higher recognition of the modified DNA, as compared to the native form. This was further confirmed by the gel-shift assay. Immune IgG were used as a probe to detect oxidative lesions in the DNA of cancer patients. DNA isolated from lymphocytes of cancer patients proved to be an appreciable inhibitor of the experimentally induced antibodies against the ROS-DNA. This indicates the presence of oxidative lesions in the DNA obtained from cancer patients. The results show that ROS induced oxidative damage to DNA in cancer patients generate neo-epitopes that are alien for the immune system, resulting in autoantibody formation.     

A study of cross-national collaborative research: reflecting on experience in Pakistan

This paper seeks to offer insights into the complexities involved in cross-national collaborative research. It identifies and provides an account of the various issues running through the research process, whilst at the same time derives principles upon which such work should be based. Key narratives were identified by highlighting a number of critical incidents. These narratives were related to issues of ownership, trust, and power, whilst in the course of theorising the research process itself, the metaphors of voice and crossing borders were found to be profoundly empowering and transformative. The complexities of working cross-nationally in the research group, understanding roles, clarifying professional frames and ethical values, at the same time as creating and maintaining a context for effective partnership and participation, made managing and sustaining the research process challenging.