Modeling Uric Acid Kidney Stones Disease in D. melanogaster using RNAi and Dietary Modulation

In humans, the major predictor for gout and forming uric acid kidney stones is elevated uric acid in the serum and urine respectively. It is known that uric acid is an end metabolite of purine degradation in humans, but in other species from D. melanogaster to lower apes, uric acid can be further metabolized by urate oxidase into readily excreted allantoin. We hypothesize that if urate oxidase enzyme activity and dietary purine are both critical in uric acid kidney stone formation, then urate oxidase knockdown in combination with dietary purine supplementation will increase uric acid and induce uric acid kidney stone formation in D. melanogaster. Initially, we confirmed urate oxidase knockdown and then elevation of uric acid as a consequence. We then confirmed uric acid kidney stones formed as a consequence of urate oxidase knocked down and a high purine diet. Next, we tested compounds used to treat gout or uric acid kidney stones in humans using our model. We found that allopurinol and potassium citrate reduced uric acid kidney stone formation in our model. We then tested whether compounds predicted to reduce uric acid and uric acid kidney stones in humans, but not currently used as treatments, can reduce uric acid kidney stone formation in our model. We found that methotrexate, hydrochlorothiazide, and l-lysine were effective at reducing uric acid kidney stone formation. Lastly, we ran a medium throughput screen of 117 natural compounds for inhibitors of uric acid kidney stone formation using our model and found seven inhibitors

T-Duality For String in Horava-Lifshitz Gravity

We continue our study of the Lorentz breaking string theories. These theories are defined as string theory with modified Hamiltonian constraint which breaks the Lorentz symmetry of target space-time. We analyze properties of this theory in the target space-time that possesses isometry along one direction. We also derive the T-duality rules for Lorentz breaking string theories and show that they are the same as that of Buscher's T-duality for the relativistic strings.Comment: 17 pages, references adde

Qualitätsmanagementsysteme und ihre Anwendung auf Serviceeinrichtungen der WGL

"Der Arbeitsbericht gibt einen Überblick über häufig verwendete Begriffe und Konzepte im Bereich von Qualitätsmanagementsystemen. Neben der Normenfamilie ISO 9000 - 9004 sowie Total Quality Management (TQM) werden spezielle Maßnahmen wie Benchmarking und Re-Engineering angesprochen sowie Probleme der Anwendung dieser Systeme im Bereich von Forschungs- und Serviceeinrichtungen diskutiert. Auf die Evaluation und die geplanten Maßnahmen zur Qualitätssicherung im Rahmen der Institute der Wissenschaftsgemeinschaft Gottfried Wilhelm Leibniz (WGL) und die Besonderheiten von Serviceeinrichtungen wird eingegangen." (Autorenreferat

Light-like noncommutativity and duality from open strings/branes

In this paper we perform some non-trivial tests for the recently obtained open membrane/D-brane metrics and `generalized' noncommutativity parameters using Dp/NS5/M5-branes which have been deformed by light-like fields. The results obtained give further evidence that these open membrane/D-brane metrics and `generalized' noncommutativity parameters are correct. Further, we use the open brane data and supergravity duals to obtain more information about non-gravitational theories with light-like noncommutativity, or `generalized' light-like noncommutativity. In particular, we investigate various duality relations (strong coupling limits). In the light-like case we also comment on the relation between open membrane data (open membrane metric etc.) in six dimensions and open string data in five dimensions. Finally, we investigate the strong coupling limit (high energy limit) of five dimensional NCYM with \Theta^{12}=\Theta^{34}. In particular, we find that this NCYM theory can be UV completed by a DLCQ compactification of M-theory.Comment: 24 pages, Latex. v2:Comments and references added. v3:Version published in JHE

The Lemaitre Model and the Generalisation of the Cosmic Mass

We consider the spherically symmetric metric with a comoving perfect fluid and non-zero pressure -- the Lemaitre metric -- and present it in the form of a calculational algorithm. We use it to review the definition of mass, and to look at the apparent horizon relations on the observer's past null cone. We show that the introduction of pressure makes it difficult to separate the mass from other physical parameters in an invariant way. Under the usual mass definition, the apparent horizon relation, that relates the diameter distance to the cosmic mass, remains the same as in the Lemaitre-Tolman case.Comment: latex, 16 pages, Revision has minor changes due to referee's comments

Protons in near earth orbit

The proton spectrum in the kinetic energy range 0.1 to 200 GeV was measured by the Alpha Magnetic Spectrometer (AMS) during space shuttle flight STS-91 at an altitude of 380 km. Above the geomagnetic cutoff the observed spectrum is parameterized by a power law. Below the geomagnetic cutoff a substantial second spectrum was observed concentrated at equatorial latitudes with a flux ~ 70 m^-2 sec^-1 sr^-1. Most of these second spectrum protons follow a complicated trajectory and originate from a restricted geographic region.Comment: 19 pages, Latex, 7 .eps figure

Search for antihelium in cosmic rays

The Alpha Magnetic Spectrometer (AMS) was flown on the space shuttle Discovery during flight STS-91 in a 51.7 degree orbit at altitudes between 320 and 390 km. A total of 2.86 * 10^6 helium nuclei were observed in the rigidity range 1 to 140 GV. No antihelium nuclei were detected at any rigidity. An upper limit on the flux ratio of antihelium to helium of < 1.1 * 10^-6 is obtained.Comment: 18 pages, Latex, 9 .eps figure

A Study of Cosmic Ray Secondaries Induced by the Mir Space Station Using AMS-01

The Alpha Magnetic Spectrometer (AMS-02) is a high energy particle physics experiment that will study cosmic rays in the $\sim 100 \mathrm{MeV}$ to $1 \mathrm{TeV}$ range and will be installed on the International Space Station (ISS) for at least 3 years. A first version of AMS-02, AMS-01, flew aboard the space shuttle \emph{Discovery} from June 2 to June 12, 1998, and collected $10^8$ cosmic ray triggers. Part of the \emph{Mir} space station was within the AMS-01 field of view during the four day \emph{Mir} docking phase of this flight. We have reconstructed an image of this part of the \emph{Mir} space station using secondary $\pi^-$ and $\mu^-$ emissions from primary cosmic rays interacting with \emph{Mir}. This is the first time this reconstruction was performed in AMS-01, and it is important for understanding potential backgrounds during the 3 year AMS-02 mission.Comment: To be submitted to NIM B Added material requested by referee. Minor stylistic and grammer change