Anisotropic Bose-Einstein condensates and completely integrable dynamical systems

A Gaussian ansatz for the wave function of two-dimensional harmonically trapped anisotropic Bose-Einstein condensates is shown to lead, via a variational procedure, to a coupled system of two second-order, nonlinear ordinary differential equations. This dynamical system is shown to be in the general class of Ermakov systems. Complete integrability of the resulting Ermakov system is proven. Using the exact solution, collapse of the condensate is analyzed in detail. Time-dependence of the trapping potential is allowed

Sydney Conservatorium of Music Postgraduate Handbook 2009

In stage III breast carcinoma, metastasized disease needs to be determined. In the past, conventional imaging by liver ultrasound, chest X-ray and bone scintigraphy was the work-up of choice. Recently, FDG-PET/CT was found to have additional value, but clinicians are hesitant to introduce this technique. We present three patients in whom FDG-PET/CT was applied. A 61-year-old woman with stage III breast carcinoma after conventional work-up was upstaged to stage IV breast carcinoma by FDG-PET/CT, upon which her treatment was changed. A 55-year-old woman suspected of stage IV breast carcinoma after conventional imaging was downstaged to stage III after FDG-PET/CT. Her treatment was changed as well. In a 78-year-old woman with recurrent breast carcinoma, the diagnostic certainty of stage III breast carcinoma was increased by FDG-PET/CT. We conclude that FDG-PET/CT is valuable for adequately diagnosing metastases in patients with stage III breast carcinoma and can replace conventional imaging

Theory for the excitation spectrum of High-T$_c superconductors : quasiparticle dispersion and shadows of the Fermi surface

Using a new method for the solution of the FLEX-equations, which allows the determination of the self energy $\Sigma_{\bf k}(\omega)$ of the $2D$ Hubbard model on the real frequency axis, we calculate the doping dependence of the quasi-particle excitations of High-T$_c$ superconductors. We obtain new results for the shadows of the Fermi surface, their dependence on the deformation of the quasi particle dispersion, an anomalous $\omega$-dependence of ${\rm Im}\Sigma_{\bf k}(\omega)$ and a related violation of the Luttinger theorem. This sheds new light on the influence of short range magnetic order on the low energy excitations and its significance for photoemission experiments.Comment: 4 pages (REVTeX) with 3 figure

Characterization of the arcD Arginine:Ornithine Exchanger of Pseudomonas aeruginosa. Localization in the Cytoplasmic Membrane and a Topological Model

The arcDABC operon of Pseudomonas aeruginosa encodes the enzymes of the arginine deiminase pathway and is induced by oxygen limitation. The arcD gene specifies a 53-kDa protein with arginine: ornithine exchange activity. The ArcD protein of P. aeruginosa, like the LysI lysine transporter of Corynebacterium glutamicum, has 13 hydrophobic regions which could span the cytoplasmic membrane. Fusion of a Caa (colicin A) epitope to the N-terminal part of ArcD permitted the localization, by immunoblotting, of the hybrid protein in the inner membrane of P. aeruginosa. Fusion of PhoA (alkaline phosphatase) to the very C terminus of ArcD produced another hybrid protein, which exhibited PhoA activity. Both ArcD hybrid proteins retained arginine transport activity and served to support a topological model which proposes that the N terminus is oriented toward the cytoplasm and the C terminus faces the periplasm. Further ArcD-PhoA fusions were consistent with this model. When the Caa epitope was fused to a C-terminal ArcD fragment consisting of only 5 hydrophobic domains, the resulting hybrid protein could be recovered intact from the inner membrane, suggesting that the C-terminal part of ArcD contains sufficient information for insertion into the membrane. This study illustrates the utility of the Caa epitope to tag membrane proteins

Using Satellite Data To Improve Land Value Estimations In Bolivia

Precise land valuation is necessary for an efficient allocation of resources at the private level, and territorial planning and provision of public good at the government level. This information can be obtained from real data transactions in limited areas where they occurred, leaving the rest of the land valuation depending on precise estimation models. These estimation models may use sold land characteristics to forecast the value of land with similar characteristics, by using existing data (i.e. returns on land, productivity, surface, soil maps, precipitation data, land use constraints by law, etc.). In many low and middle-income countries this data is scarce, limiting the possibility of developing these models. This information gap may be filled using satellite data. This study uses average biomass production estimations based on satellite data as a proxy for fertility. By using biomass production estimates for Bolivia over a period of 6 years, together with administrative land transaction data and geographical maps including precipitation, average temperature, slope, distance to closest road, to closed local and national markets, we are able to significantly improve previous land price models. This improvement allowed us to develop a land price index to inform farmers about current price trends and expected sale price for their own land

Amplitude and phase representation of quantum invariants for the time dependent harmonic oscillator

The correspondence between classical and quantum invariants is established. The Ermakov Lewis quantum invariant of the time dependent harmonic oscillator is translated from the coordinate and momentum operators into amplitude and phase operators. In doing so, Turski's phase operator as well as Susskind-Glogower operators are generalized to the time dependent harmonic oscillator case. A quantum derivation of the Manley-Rowe relations is shown as an example