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Unbiased Boolean analysis of public gene expression data for cell cycle gene identification.
Cell proliferation is essential for the development and maintenance of all organisms and is dysregulated in cancer. Using synchronized cells progressing through the cell cycle, pioneering microarray studies defined cell cycle genes based on cyclic variation in their expression. However, the concordance of the small number of synchronized cell studies has been limited, leading to discrepancies in definition of the transcriptionally regulated set of cell cycle genes within and between species. Here we present an informatics approach based on Boolean logic to identify cell cycle genes. This approach used the vast array of publicly available gene expression data sets to query similarity to CCNB1, which encodes the cyclin subunit of the Cdk1-cyclin B complex that triggers the G2-to-M transition. In addition to highlighting conservation of cell cycle genes across large evolutionary distances, this approach identified contexts where well-studied genes known to act during the cell cycle are expressed and potentially acting in nondivision contexts. An accessible web platform enables a detailed exploration of the cell cycle gene lists generated using the Boolean logic approach. The methods employed are straightforward to extend to processes other than the cell cycle
Edge States and Entanglement Entropy
It is known that gauge fields defined on manifolds with spatial boundaries
support states localized at the boundaries. In this paper, we demonstrate how
coarse-graining over these states can lead to an entanglement entropy. In
particular, we show that the entanglement entropy of the ground state for the
quantum Hall effect on a disk exhibits an approximate ``area " law.Comment: 16 pages, minor corrections and futher details adde
Contractual Forms in Islamic Finance Law and Islamic Inv. Co. of the Gulf (Bahamas) Ltd. v. Symphony Gems N.V. & Ors.: A First Impression of Islamic Finance
This Article focuses on the case of Islamic Investment Company of the Gulf (Bahamas) Ltd. v. Symphony Gems N.V. & Others (“Symphony Gems”). Symphony Gems is the first instance where a Western court of law ruled on an Islamic financial transaction. Symphony Gems illuminates the challenges and tensions within the industrial complex of Islamic finance as it seeks to exist and thrive in a commercial reality where the regulatory framework and its associated assumptions (both theoretical as well as those of commercial practice) differ markedly from those of Islamic law and the contemporary Islamic financial industry. The resulting transactions often deviate from the classical modes or forms upon which they are supposed to be based. From a conventional finance perspective, Islamic transactions can be criticized as being anomalous, inefficiently structured and obliquely documented. Symphony Gems arose out of the applicability of an Islamic financial contract known as a murabahah. This Article will explain both the conceptual basis and the contemporary usage of the murabahah contract and, more generally, the challenges of integrating Islamic financial concepts into the Anglo-American legal system that predominates the modern global economy. Murabahah contracts, simply stated, involve the sale of an item, through a middleman, in which the ultimate buyer is aware of the middleman\u27s costs in obtaining the item. As discussed later in this Article, murabahah contracts in contemporary practice closely approximate conventional financing mechanisms, particularly the economics underlying a similarly-profiled conventional commercial financing. This is why murabahah contracts are so popular. Therefore, it is not surprising that the first instance in which a Western court of law has examined and opined upon an Islamic financial contract involves a murabahah sale
Anomalous Defects and Their Quantized Transverse Conductivities
Using a description of defects in solids in terms of three-dimensional
gravity, we study the propagation of electrons in the background of
disclinations and screw dislocations. We study the situations where there are
bound states that are effectively localized on the defect and hence can be
described in terms of an effective 1+1 dimensional field theory for the low
energy excitations. In the case of screw dislocations, we find that these
excitations are chiral and can be described by an effective field theory of
chiral fermions. Fermions of both chirality occur even for a given direction of
the magnetic field. The ``net'' chirality of the system however is not always
the same for a given direction of the magnetic field, but changes from one sign
of the chirality through zero to the other sign as the Fermi momentum or the
magnitude of the magnetic flux is varied. On coupling to an external
electromagnetic field, the latter becomes anomalous, and predicts novel
conduction properties for these materials.Comment: New material added. ReVTeX , 31 pgs., 4 figs.(uses epsf
Novel Edge States in Self-Dual Gravity
In contrast to the Einstein-Hilbert action, the action for self-dual gravity
contains vierbeins. They are eleminated at the level of observables by an
gauge condition implied by the action. We argue that despite
this condition, new "edge" or superselected state vectors corresponding to maps
of the spheres at infinity to arise. They
are characterised by new quantum numbers and they lead to mixed states. For
black holes, they arise both at the horizon and the spatial infinity and may be
relevant for the black hole information paradox. Similar comments can be made
about the Einstein-Palatini action which uses vierbeins.Comment: 15 pages, reference added, some minor notational changes - no changes
in conclusio
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