60 research outputs found

    Recent progress on the manipulation of single atoms in optical tweezers for quantum computing

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    This paper summarizes our recent progress towards using single rubidium atoms trapped in an optical tweezer to encode quantum information. We demonstrate single qubit rotations on this system and measure the coherence of the qubit. We move the quantum bit over distances of tens of microns and show that the coherence is reserved. We also transfer a qubit atom between two tweezers and show no loss of coherence. Finally, we describe our progress towards conditional entanglement of two atoms by photon emission and two-photon interferences.Comment: Proceedings of the ICOLS07 conferenc

    Ray chaos in optical cavities based upon standard laser mirrors

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    We present a composite optical cavity made of standard laser mirrors; the cavity consists of a suitable combination of stable and unstable cavities. In spite of its very open nature the composite cavity shows ray chaos, which may be either soft or hard, depending on the cavity configuration. This opens a new, convenient route for experimental studies of the quantum aspects of a chaotic wave field.Comment: 4 pages, 3 figures, 1 tabl

    Experimental observation of wave chaos in a conventional optical resonator

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    Quantum Matter and Optic

    Atom chip for BEC interferometry

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    We have fabricated and tested an atom chip that operates as a matter wave interferometer. In this communication we describe the fabrication of the chip by ion-beam milling of gold evaporated onto a silicon substrate. We present data on the quality of the wires, on the current density that can be reached in the wires and on the smoothness of the magnetic traps that are formed. We demonstrate the operation of the interferometer, showing that we can coherently split and recombine a Bose–Einstein condensate with good phase stability

    Just Click Here : A Brief Glance at Absurd Electronic Contracts and the Law Failing to Protect Consumers

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    As e-commerce explodes around the world, consumers’ rights have been left behind. Before the completion of virtually every transaction on the Internet, the onus is placed on consumers to read and agree to an onslaught of terms and conditions. Often hidden in the middle of this extremely lengthy list of terms are massive exemption and limitation of liability clauses that deny consumers most if not all of their rights as “equal” trading partners. The common law principle that all onerous clauses in a contract need to be brought to the attention of the consumer for them to be binding seems to have been lost with the invention of the “click here to agree” button for signing online contracts. As the courts in Canada have not provided clear guidance on this issue thus far, other means must be pursued in order to protect consumers from the near-tyrannical control of unencumbered electronic standard form contracts in e-commerce. This paper will describe the principle of sufficiency of notice as it applies to paper contracts, and then contrast it with the newer jurisprudence that has refused to apply the principle to electronic contracts. The reasons for the refusal will be explored, followed by an examination of why the principle of sufficiency of notice needs to be applied and strengthened to respond to the increasingly onerous provisions hidden in electronic contracts. Finally, some other options for achieving the goal of consumer protection from hidden onerous clauses will be briefly explored. These other options include introducing stiffer consumer protection legislation domestically, the creation of international treaties, developing voluntary standards of contracting, and relying on Internet self-regulation

    Decisions at the data border : discretion, discernment and security

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    Amidst a widespread turn to data analysis and automated screening in security contexts, the question of how decisions are made at the interface of embodied humans and algorithmic processes becomes pressing. This article is concerned with the production of security decisions at the data border. It makes two contributions. It first presents qualitative fieldwork conducted amongst data processors at a European smart border targeting centre and, second, traces a largely obscured cultural history of discretion as means of reflecting on the politics of contemporary data-led decisionmaking. Discretion is an important concept in contemporary administrative contexts, referring to a decision about the (non-)application of a rule in contexts of public power and authority. Its etymon, discretio, however, referred historically to spiritual and visual discernment, as well as prudence and humility. I present the history of discretion to make two arguments: 1) decisionmaking at the data border is an uncertain visual practice oriented to seeing and authorizing what is there and 2) discretion in contemporary data-led contexts revises the conventional ethical relationship between general and particular that has always been intrinsic to discretion. My overall point is that contemporary debates about judgement in automated security decisions are the most recent manifestation of long-standing tensions between rule and judgement, authorization and uncertainty

    Proteasome inhibitors in acute leukemia

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    Proteasome inhibition has been recognized as a novel treatment modality in hematologic malignancies. Initially, the reversible proteasome inhibitor bortezomib demonstrated efficacy in multiple myeloma (MM), which supported its approval for relapsed and refractory MM in 2003. Later on, carfilzomib, a next-generation irreversible proteasome inhibitor was approved by the US FDA in July 2012 for relapsed/refractory MM. Currently, several other proteasome inhibitors are undergoing preclinical and clinical evaluation. The successes of proteasome inhibitors in MM are now being translated to other hematologic malignancies, including acute leukemia. The first clinical studies with bortezomib in leukemia revealed promising clinical activity, particularly when combined with conventional chemotherapeutics. In this review the position of proteasome inhibitors in acute leukemia treatment is summarized and discussed. Special focus is also attributed to immunoproteasome inhibitors. As a future perspective, it is anticipated that proteasome inhibitors may prove to be of added value in therapeutic interventions for acute leukemia

    Monoclonal antibody PAL-E specific for endothelium

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    A monoclonal antibody, PAL-E, is described that is specific for endothelial cells. The monoclonal antibody, an IgG2a, markedly stains endothelium of capillaries, medium-sized and small veins, and venules in frozen sections of human and some animal tissues tested. It reacts not at all or only weakly with endothelium of large, medium-sized, and small arteries, arterioles, and large veins and does not stain the endothelial lining of lymphatic vessels and sinus histiocytes. The cellular staining pattern and tissue staining were different from those obtained with antifactor VIII R:AG antiserum and Ulex europaeus I lectin. Blocking experiments indicated that these three reagents recognize different endothelial binding sites. Therefore, PAL-E is a new staining reagent for endothelium in frozen sections. Based on immunoelectronmicroscopic observations, the antigenic determinant recognized by PAL-E is associated with endothelial vesicle
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