Influence of the lattice topography on a three-dimensional, controllable Brownian motor

We study the influence of the lattice topography and the coupling between motion in different directions, for a three-dimensional Brownian motor based on cold atoms in a double optical lattice. Due to controllable relative spatial phases between the lattices, our Brownian motor can induce drifts in arbitrary directions. Since the lattices couple the different directions, the relation between the phase shifts and the directionality of the induced drift is non trivial. Here is therefore this relation investigated experimentally by systematically varying the relative spatial phase in two dimensions, while monitoring the vertically induced drift and the temperature. A relative spatial phase range of 2pi x 2pi is covered. We show that a drift, controllable both in speed and direction, can be achieved, by varying the phase both parallel and perpendicular to the direction of the measured induced drift. The experimental results are qualitatively reproduced by numerical simulations of a simplified, classical model of the system

A nonadiabatic semi-classical method for dynamics of atoms in optical lattices

We develop a semi-classical method to simulate the motion of atoms in a dissipative optical lattice. Our method treats the internal states of the atom quantum mechanically, including all nonadiabatic couplings, while position and momentum are treated as classical variables. We test our method in the one-dimensional case. Excellent agreement with fully quantum mechanical simulations is found. Our results are much more accurate than those of earlier semi-classical methods based on the adiabatic approximation.Comment: 7 pages, 5 figures, submitted to European Physical Journal

Spatially dependent Rabi oscillations: an approach to sub-diffraction-limited CARS microscopy

We present a theoretical investigation of coherent anti-Stokes Raman scattering (CARS) that is modulated by periodically depleting the ground state population through Rabi oscillations driven by an additional control laser. We find that such a process generates optical sidebands in the CARS spectrum and that the frequency of the sidebands depends on the intensity of the control laser light field. We show that analyzing the sideband frequency upon scanning the beams across the sample allows one to spatially resolve emitter positions where a spatial resolution of 65 nm, which is well below the diffraction-limit, can be obtained

Demonstration of a controllable three-dimensional Brownian motor in symmetric potentials

We demonstrate a Brownian motor, based on cold atoms in optical lattices, where isotropic random fluctuations are rectified in order to induce controlled atomic motion in arbitrary directions. In contrast to earlier demonstrations of ratchet effects, our Brownian motor operates in potentials that are spatially and temporally symmetric, but where spatiotemporal symmetry is broken by a phase shift between the potentials and asymmetric transfer rates between them. The Brownian motor is demonstrated in three dimensions and the noise-induced drift is controllable in our system.Comment: 5 pages, 4 figure

\Lambda-buildings and base change functors

We prove an analog of the base change functor of \Lambda-trees in the setting of generalized affine buildings. The proof is mainly based on local and global combinatorics of the associated spherical buildings. As an application we obtain that the class of generalized affine building is closed under ultracones and asymptotic cones. Other applications involve a complex of groups decompositions and fixed point theorems for certain classes of generalized affine buildings.Comment: revised version, 29 pages, to appear in Geom. Dedicat

Rapid and quantitative detection of homologous and non-homologous recombination events using three oligonucleotide MLPA

Embryonic stem (ES) cell technology allows modification of the mouse germline from large deletions and insertions to single nucleotide substitutions by homologous recombination. Identification of these rare events demands an accurate and fast detection method. Current methods for detection rely on Southern blotting and/or conventional PCR. Both the techniques have major drawbacks, Southern blotting is time-consuming and PCR can generate false positives. As an alternative, we here demonstrate a novel approach of Multiplex Ligation-dependent Probe Amplification (MLPA) as a quick, quantitative and reliable method for the detection of homologous, non-homologous and incomplete recombination events in ES cell clones. We have adapted MLPA to detect homologous recombinants in ES cell clones targeted with two different constructs: one introduces a single nucleotide change in the PCNA gene and the other allows for a conditional inactivation of the wild-type PCNA allele. By using MLPA probes consisting of three oligonucleotides we were able to simultaneously detect and quantify both wild-type and mutant alleles

Perancangan Dan Pengembangan Aplikasi E-transmobile Berbasis Wap Portal Menggunakan Gprs – General Packet Radio Service

Pada makalah ini, akan dipaparkan perancangan dan pengembangan aplikasi sistem transaksi online dengan menggunakan handphone berbasis wap portal dengan pemanfaatan fasilitas General Packet Radio Service (GPRS). Aplikasi tersebut dinamakan e-TransMobile. Aplikasi ini dirancang untuk pengembangan aplikasi berbasis Local Area Network yang ada saat ini, dengan perluasan jangkauan aliran data sehingga informasi transaksi suatu Perusahaan tidak lagi dibatasi oleh ruang dan waktu melalui media handphone. Aplikasi ini terdiri dari interaksi client-server, dimana interaksi ini merupakan bagian yang dijalankan pihak internal Perusahaan. Serta interaksi piranti teknologi komputer dengan handphone, yang bertindak sebagai penampung data dan piranti transaksi. Terdapat empat komponen yang digunakan yaitu basis data, graphic interface mobile, web interface, dan relasi data. Aplikasi e-TransMobile dibangun dengan menggunakan perangkat lunak MySqlServer 2005, Visual Studio 2005, Macromedia Flash Profesional 8 dan Adobe Photoshop CS 3. Transaksi yang ditampung meliputi informasi penjualan, pembelian, status pembayaran, stok barang serta data konsumen. Metode pendekatan yang digunakan adalah pendekatan media on-line melalui interface handphone yang terhubung dengan server Perusahaan dimana aliran data ditujukan pada pihak internal Perusahaan yang berkepentingan pada informasi yang diberikan. Maksud dari proses perancangan dan pengembangan aplikasi e-TransMobile yang dilakukan adalah informasi transaksi diharapkan dapat memberikan informasi yang lebih cepat, akurat dan relevan untuk mencapai keefisienan dan keefektifan kinerja Perusahaan. Sistem informasi ini dimaksudkan agar Perusahaan akan lebih dapat mengoptimalkan sistem transaksi serta dapat memperluas jangkauan pemasaran

Detoxification in rehabilitation in England: effective continuity of care or unhappy bedfellows?

There is evidence that residential detoxification alone does not provide satisfactory treatment outcomes and that outcomes are significantly enhanced when clients completing residential detoxification attend rehabilitation services (Gossop, Marsden, Stewart, & Rolfe, 1999; Ghodse, Reynolds, Baldacchino, et al., 2002). One way of increasing the likelihood of this continuity of treatment is by providing detoxification and rehabilitation within the same treatment facility to prevent drop-out, while the client awaits a rehabilitation bed or in the transition process. However, there is little research evidence available on the facilities that offer both medical detoxification and residential rehabilitation. The current study compares self-reported treatment provision in 87 residential rehabilitation services in England, 34 of whom (39.1%) reported that they offered detoxification services within their treatment programmes. Although there were no differences in self-reported treatment philosophies, residential rehabilitation services that offered detoxification were typically of shorter duration overall, had significantly more beds and reported offering more group work than residential rehabilitation services that did not offer detoxification. Outcomes were also different, with twice as many clients discharged on disciplinary grounds from residential rehabilitation services without detoxification facilities. The paper questions the UK classification of residential drug treatment services as either detoxification or rehabilitation and suggests the need for greater research focus on the aims, processes and outcomes of this group of treatment providers