Engineering geology of the London clay in the London and Hampshire basins

Imperial Users onl

Quantum imaging of spin states in optical lattices

We investigate imaging of the spatial spin distribution of atoms in optical lattices using non-resonant light scattering. We demonstrate how scattering spatially correlated light from the atoms can result in spin state images with enhanced spatial resolution. Furthermore, we show how using spatially correlated light can lead to direct measurement of the spatial correlations of the atomic spin distribution

Submarine Cable Security and International Law

In this article the revolution in fiber optic submarine cable communications is placed in context with the world’s growing dependence upon critical submarine cable infrastructure. Emphasis is placed on the development of international law designed to protect submarine cables and in particular those articles in the United Nations Law of the Sea Convention that foster and safeguard the freedom to lay and repair submarine cables. Special focus is applied to the status of international submarine telecommunication cables in cases of intentional actions that damage or destroy them and the State practice and customary international law that generally classifies submarine cables as legitimate military targets by belligerents. The article highlights the importance of increasing submarine route diversity and amending the SUA conventions to provide protection to international submarine cable systems. The concept and need of allowing cable ships to be exempt from belligerent attack in wartime is also analyzed

International Submarine Cables and Biodiversity of Areas Beyond National Jurisdiction

In International Submarine Cables and Biodiversity of Areas Beyond National Jurisdiction, Douglas R. Burnett and Lionel Carter closely examine the relationship between trans-oceanic submarine cables and biodiversity in areas beyond national jurisdiction. Readership: All practitioners and academics interested in submarine cables, International Law of the Sea, and marine biodiversity law

Evolution of an ancient protein function involved in organized multicellularity in animals.

To form and maintain organized tissues, multicellular organisms orient their mitotic spindles relative to neighboring cells. A molecular complex scaffolded by the GK protein-interaction domain (GKPID) mediates spindle orientation in diverse animal taxa by linking microtubule motor proteins to a marker protein on the cell cortex localized by external cues. Here we illuminate how this complex evolved and commandeered control of spindle orientation from a more ancient mechanism. The complex was assembled through a series of molecular exploitation events, one of which - the evolution of GKPID's capacity to bind the cortical marker protein - can be recapitulated by reintroducing a single historical substitution into the reconstructed ancestral GKPID. This change revealed and repurposed an ancient molecular surface that previously had a radically different function. We show how the physical simplicity of this binding interface enabled the evolution of a new protein function now essential to the biological complexity of many animals

Xenopus tropicalis allurin: Expression, purification, and characterization of a sperm chemoattractant that exhibits cross-species activity

AbstractPreviously we reported the identification of the first vertebrate sperm chemoattractant, allurin, in the frog Xenopus laevis (Xl) and demonstrated that it was a member of the CRISP family of proteins. Here we report identification, purification, and characterization of Xenopus tropicalis (Xt) allurin, a homologous protein in X. tropicalis. “Egg water” as well as purified allurin from both species exhibit efficient cross-species sperm chemoattractant activity. Western blots show that Xt egg water contains a single anti-allurin cross-reactive protein whose molecular weight (20,497 Da by MALDI MS) agrees well with the molecular weight of the hypothetical gene product for a newly recognized “Crisp A” gene in the X. tropicalis genome. A recombinant form of the protein, expressed in 3T3 cells, exhibits chemoattraction for both Xt and Xl sperm and cross reacts with anti-allurin antibodies. Examination of Crisp protein expression in the Xt oviduct using RT-PCR showed that of five documented Xt Crisp genes (Crisps 2, 3, LD1, LD2 and A) only Crisp A was expressed. In contrast, Crisp 2, Crisp 3, Crisp LD1, and Crisp LD2, but not Crisp A, were all found to be expressed in the Xt testes while subsets of Crisp proteins where expressed in the Xt ovary. These data suggest that Crisp proteins in amphibians may play multiple roles in sperm production, maturation and guidance just as they are thought to in mammals indicating that Crisp protein involvement in reproduction may not be limited to mammals