Jorella Andrews

A pulsed-laser microbeam at 532 nm wavelength and a laser-induced optical trap at 1064 nm wavelength have been successively combined to dissect and manipulate chromosomes in live newt lung epithelial cells. These preliminary experimental results demonstrated that chromosome fragments dissected by laser microbeam surgery, regardless of their size, could be easily pulled or rotated by optical forces when positioned at the periphery of the mitotic spindle. In addition, chromosome arms which were not subjected to laser microsurgery also could be moved with the optical tweezers at the spindle periphery. In our previous study on rat kangaroo kidney cells, this degree of facility in manipulating chromosome movement was not possible, most likely due to the close proximity of the intermediate filament 'cage' to the spindle. It is concluded herein that optical scissors and tweezers can be used in combination to study the interaction of chromosomes with the mitotic spindle in cells where the peripheral regions of the spindle are unobstructed by intermediate filaments. This can be performed on newt cells, where the diameter of the cage can be substantially larger than the diameter of the spindle.

Using an image taken by Reuters' photographer Nicky Loh during the 2009 earthquake in Sumatra, this article rethinks in positive terms the experience of being captivated by photographs, including `disaster' photographs that are often described as problematically spectacularizing. In order to do this I bring together two propositions, that of the photograph as a uniquely articulated prosthetic stare on the one hand, and as an inorganic but powerful `agent' or `actor' on the other. My main theoretical resources come from Donna Haraway's well-known 1988 essay `Situated knowledges' and Maurice Merleau-Ponty's 1961 essay `Eye and mind'