Quantum phases of electric dipole ensembles in atom chips

We present how a phase factor is generated when an electric dipole moves along a closed trajectory inside a magnetic field gradient. The similarity of this situation with charged particles in a magnetic field can be employed to simulate condensed matter models, such as the quantum Hall effect and chiral spin Hamiltonians, with ultra cold atoms integrated on atom chips. To illustrate this we consider a triangular configuration of a two dimensional optical lattice, where the chiral spin Hamiltonian $\vec{\sigma}_i \cdot \vec{\sigma}_j \times \vec{\sigma}_k$ can be generated between any three neighbours on a lattice yielding an experimentally implementable chiral ground state.Comment: 4 pages, 2 figures, REVTEX. Title slightly changed and conclusions extende

Persistent spin and mass currents and Aharonov-Casher effect

Spin-orbit interaction produces persistent spin and mass currents in the ring via the Aharonov-Casher effect. The experiment in $^3He-A_1$ phase, in which this effect leads to the excitation of mass and spin supercurrent is proposed.Comment: 10 page

Topological phase due to electric dipole moment and magnetic monopole interaction

We show that there is an anologous Aharonov-Casher effect on a neutral particle with electric dipole moment interacting with a magnetic filed produced by magnetic monopoles.Comment: 8 page

Correspondences and Quantum Description of Aharonov-Bohm and Aharonov-Casher Effects

We establish systematic consolidation of the Aharonov-Bohm and Aharonov-Casher effects including their scalar counterparts. Their formal correspondences in acquiring topological phases are revealed on the basis of the gauge symmetry in non-simply connected spaces and the adiabatic condition for the state of magnetic dipoles. In addition, investigation of basic two-body interactions between an electric charge and a magnetic dipole clarifies their appropriate relative motions and discloses physical interrelations between the effects. Based on the two-body interaction, we also construct an exact microscopic description of the Aharonov-Bohm effect, where all the elements are treated on equal footing, i.e., magnetic dipoles are described quantum-mechanically and electromagnetic fields are quantized. This microscopic analysis not only confirms the conventional (semiclassical) results and the topological nature but also allows one to explore the fluctuation effects due to the precession of the magnetic dipoles with the adiabatic condition relaxed

WEIRD Testbeds with Fixed and Mobile WiMAX Technology for User Applications, Telemedicine and Monitoring of Impervious Areas

Wireless Metropolitan Area Networks based on IEEE 802.16d/e standards are soon to be deployed in several countries. However, there is lack of published literature with results from actual test¬beds. This paper introduces the work done in the EU Sixth Framework Programme Project WEIRD to design and set up WiMAX testbeds in four EU countries. We describe the method¬ology followed, detail our implementation and present results from the testbeds, as deployed in the first phase of WEIRD. The testbeds are used to demonstrate how WiMAX technology can be used to extend the connectivity of the pan-European data com¬munications network (GEANT2) to isolated and impervious ar¬eas and, furthermore, to assure end-to-end quality of service to novel applications

Landau Analog Levels for Dipoles in the Noncommutative Space and Phase Space

In the present contribution we investigate the Landau analog energy quantization for neutral particles, that possesses a nonzero permanent magnetic and electric dipole moments, in the presence of an homogeneous electric and magnetic external fields in the context of the noncommutative quantum mechanics. Also, we analyze the Landau--Aharonov--Casher and Landau--He--McKellar--Wilkens quantization due to noncommutative quantum dynamics of magnetic and electric dipoles in the presence of an external electric and magnetic fields and the energy spectrum and the eigenfunctions are obtained. Furthermore, we have analyzed Landau quantization analogs in the noncommutative phase space, and we obtain also the energy spectrum and the eigenfunctions in this context.Comment: 20 pages, references adde

WEIRD Testbeds with Fixed and Mobile WiMAX Technology for User Applications, Telemedicine and Monitoring of Impervious Areas

Wireless Metropolitan Area Networks based on IEEE 802.16d/e standards are soon to be deployed in several countries. However, there is lack of published literature with results from actual test¬beds. This paper introduces the work done in the EU Sixth Framework Programme Project WEIRD to design and set up WiMAX testbeds in four EU countries. We describe the method¬ology followed, detail our implementation and present results from the testbeds, as deployed in the first phase of WEIRD. The testbeds are used to demonstrate how WiMAX technology can be used to extend the connectivity of the pan-European data com¬munications network (GEANT2) to isolated and impervious ar¬eas and, furthermore, to assure end-to-end quality of service to novel applications.SIGARCH, Create-NetPublishedInnsbruck, Austria1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attiveope

Dirac-Foldy term and the electromagnetic polarizability of the neutron

We reconsider the Dirac-Foldy contribution $\mu^2/m$ to the neutron electric polarizability. Using a Dirac equation approach to neutron-nucleus scattering, we review the definitions of Compton continuum ($\bar{\alpha}$), classical static ($\alpha^n_E$), and Schr\"{o}dinger ($\alpha_{Sch}$) polarizabilities and discuss in some detail their relationship. The latter $\alpha_{Sch}$ is the value of the neutron electric polarizability as obtained from an analysis using the Schr\"{o}dinger equation. We find in particular $\alpha_{Sch} = \bar{\alpha} - \mu^2/m$ , where $\mu$ is the magnitude of the magnetic moment of a neutron of mass $m$. However, we argue that the static polarizability $\alpha^n_E$ is correctly defined in the rest frame of the particle, leading to the conclusion that twice the Dirac-Foldy contribution should be added to $\alpha_{Sch}$ to obtain the static polarizability $\alpha^n_E$.Comment: 11 pages, RevTeX, to appear in Physical Review

Low recurrence rate after surgery for dermatofibrosarcoma protuberans

BACKGROUND Dermatofibrosarcoma protuberans (DFSP) is a rare sarcoma with a propensity for local recurrence. Treatments with wide excision, Mohs surgery, and other approaches have been reported with widely variable local control rates. The objective of this study was to review the experience with a multidisciplinary approach employing wide excision and Mohs surgery selectively in the treatment of patients with DFSP at a single academic institution over the past 10 years. METHODS The records of 62 patients with 63 DFSP tumors who underwent wide excision, Mohs surgery, or a multidisciplinary combination approach from January 1991 to December 2000 were reviewed retrospectively. Primary endpoints included the ability to extirpate the DFSP lesion completely, the tumor recurrence rate, and the need for skin grafts or local tissue flaps. Additional objectives included defining surgical practice patterns at the authors' institution. RESULTS Sixty-three DFSP lesions were removed from 62 patients. At a median follow-up of 4.4 years, no local or distant recurrences were detected in any patient. Forty-three lesions were treated with wide local excision, 11 lesions were treated with Mohs surgery, and 9 lesions were treated with a combination approach. Ninety-five percent of lesions that were approached initially with wide local excision were cleared histologically. Two patients (5%) received postoperative radiation for positive margins after undergoing maximal excision. Eighty-five percent of lesions that were approached initially with Mohs surgery were cleared histologically. The remaining 15% of lesions subsequently were cleared surgically with a wide excision. DFSP lesions that were approached initially with Mohs surgery tended to be smaller. Patients with head and neck lesions most often underwent Mohs surgery or were treated with a multidisciplinary combination approach (87%). CONCLUSIONS Wide local excision with careful pathologic analysis of margins was found to have a very low recurrence rate and was used for the majority of patients with DFSP lesions at the authors' institution. Wide local excision, Mohs surgery, and a multidisciplinary combination approach, selected based on both tumor and patient factors, were capable of achieving very high local control rates in the treatment of DFSP. The evolution of a multidisciplinary approach has provided a level of expertise that no single individual could achieve for the treatment of the full spectrum of DFSP lesions at the authors' institution. Cancer 2004;100:1008–16. © 2004 American Cancer Society.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34385/1/20051_ftp.pd

Induction of microRNAs, mir-155, mir-222, mir-424 and mir-503, promotes monocytic differentiation through combinatorial regulation

Acute myeloid leukemia (AML) involves a block in terminal differentiation of the myeloid lineage and uncontrolled proliferation of a progenitor state. Using phorbol myristate acetate (PMA), it is possible to overcome this block in THP-1 cells (an M5-AML containing the MLL-MLLT3 fusion), resulting in differentiation to an adherent monocytic phenotype. As part of FANTOM4, we used microarrays to identify 23 microRNAs that are regulated by PMA. We identify four PMA-induced micro- RNAs (mir-155, mir-222, mir-424 and mir-503) that when overexpressed cause cell-cycle arrest and partial differentiation and when used in combination induce additional changes not seen by any individual microRNA. We further characterize these prodifferentiative microRNAs and show that mir-155 and mir-222 induce G2 arrest and apoptosis, respectively. We find mir-424 and mir-503 are derived from a polycistronic precursor mir-424-503 that is under repression by the MLL-MLLT3 leukemogenic fusion. Both of these microRNAs directly target cell-cycle regulators and induce G1 cell-cycle arrest when overexpressed in THP-1. We also find that the pro-differentiative mir-424 and mir-503 downregulate the anti-differentiative mir-9 by targeting a site in its primary transcript. Our study highlights the combinatorial effects of multiple microRNAs within cellular systems.Comment: 45 pages 5 figure