The channels of technology acquisition in commercial firms, and the NASA dissemination program

Technology acquisition in commercial firms, and NASA dissemination progra

A Randomised, Blinded, Placebo-Controlled, Dose Escalation Study of the Tolerability and Efficacy of Filgrastim for Haemopoietic Stem Cell Mobilisation in Patients With Severe Active Rheumatoid Arthritis

Autologous haemopoietic stem cell transplantation (HSCT) represents a potential therapy for severe rheumatoid arthritis (RA). As a prelude to clinical trails, the safety and efficacy of haemopoietic stem cell (HSC) mobilisation required investigation as colony-stimulating factors (CSFs) have been reported to flare RA. A double-blind, randomised placebo-controlled dose escalation study was performed. Two cohorts of eight patients fulfilling strict eligibility criteria for severe active RA (age median 40 years, range 24-60 years; median disease duration 10.5 years, range 2-18 years) received filgrastim (r-Hu-methionyl granulocyte(G)-(SF) at 5 and 10 microg/kg/day, randomised in a 5:3 ratio with placebo. Patients were unblinded on the fifth day of treatment and those randomised to filgrastim underwent cell harvesting (leukapheresis) daily until 2 X 10^6/kg CD34+ cells (haemopoietic stem and progenitor cells) were obtained. Patients were assessed by clinical and laboratory parameters before, during and after filgrastim administration. RA flare was defined as an increase of 30% or more in two of the following parameters: tender joint count, swollen joint count or pain score. Efficacy was assessed by quantitation of CD34+ cells and CFU-GM. One patient in the 5 microg/kg/day group and two patients in the 10 microg/kg/day group fulfilled criteria for RA flare, although this did not preclude successful stem cell collection. Median changes in swollen and tender joint counts were not supportive of filgrastim consistently causing exacerbation of disease, but administration of filgrastim at 10 microg/kg/day was associated with rises in median C-reactive protein and median rheumatoid factor compared with placebo. Other adverse events were well recognised for filgrastim and included bone pain (80%) and increases in alkaline phosphatase (four-fold) and lactate dehydrogenase (two-fold). With respect to efficacy, filgrastim at 10 microg/kg/day was more efficient with all patients (n = 5) achieving target CD34+ cell counts with a single leukapheresis (median = 2.8, range = 2.3-4.8 X 10^6/kg, median CFU-GM = 22.1, range = 4.2-102.9 X 10^4/kg), whereas 1-3 leukaphereses were necessary to achieve the target yield using 5 microg/kg/day. We conclude that filgrastim may be administered to patients with severe active RA for effective stem cell mobilisation. Flare of RA occurs in a minority of patients and is more likely with 10 than 5 microg/kg/day. However, on balance, 10 microg/kg/day remains the dose of choice in view of more efficient CD34+ cell mobilisation

Electron-phonon interactions on a single-branch quantum Hall edge

We consider the effect of electron-phonon interactions on edge states in quantum Hall systems with a single edge branch. The presence of electron-phonon interactions modifies the single-particle propagator for general quantum Hall edges, and, in particular, destroys the Fermi liquid even at integer filling. The effect of the electron-phonon interactions may be detected experimentally in the AC conductance or in the tunneling conductance between integer quantum Hall edges.Comment: 9 pages (revtex) + one postscript file with 2 figures. A complete postscript file with all figures + text (5 pages) is available from http://FY.CHALMERS.SE/~eggert/fqh.ps or by request from [email protected]

Boundary interactions changing operators and dynamical correlations in quantum impurity problems

Recent developments have made possible the computation of equilibrium dynamical correlators in quantum impurity problems. In many situations however, one is rather interested in correlators subject to a non equilibrium initial preparation; this is the case for instance for the occupation probability $P(t)$ in the double well problem of dissipative quantum mechanics (DQM). We show in this paper how to handle this situation in the framework of integrable quantum field theories by introducing ``boundary interactions changing operators''. We determine the properties of these operators by using an axiomatic approach similar in spirit to what is done for form-factors. This allows us to obtain new exact results for $P(t)$; for instance, we find that that at large times (or small $g$), the leading behaviour for g < 1/2} is $P(t)\propto e^{-\Gamma t}\cos\Omega t$, with the universal ratio. $\Omega/\Gamma = \cot {\pi g}/{2(1-g)}$.Comment: 4 pages, revte

Quasi-Andreev reflection in inhomogeneous Luttinger liquids

Reflection of charge excitations at the step in the interaction strength in a Luttinger liquid can be of the Andreev type, even if the interactions are purely repulsive. The region with stronger repulsion plays the role of a normal metal in a normal-metal /superconductor junction, whereas the region with weaker repulsion plays the role of a superconductor. It is shown that this quasi-Andreev reflection leads to a number of proximity-like effects, including the local enhancement (suppression) of superconducting fluctuations on the quasi-normal (quasi-superconducting) side of the step, significant modification of the local density of states, as well as others. The observable consequences of these proximity effects are analyzed for the case of single- and two-particle tunneling from a normal-metal or superconducting tip into an inhomogeneous Luttinger-liquid wire.Comment: 5 pages, 2 figures (eps

Movement patterns of forest elephants (Loxodonta cyclotis Matschie, 1900) in the Odzala-Kokoua National Park, Republic of Congo

[Otros] Les éléphants de forêt d'Afrique (Loxodonta cyclotis Matschie, 1900) sont des ingénieurs en écologie qui jouent un rôle fondamental dans la dynamique de la végétation. L'espèce constitue une préoccupation immédiate pour la conservation, mais elle est relativement peu étudiée. Pour combler cette lacune de connaissances, nous avons étudié les facteurs de déplacements quotidiens (déplacements linéaires) des éléphants de forêt ¿ caractérisés par un ensemble de variables géographiques, météorologiques et anthropiques ¿ dans le Parc National d'Odzala¿Kokoua, en République du Congo. Concrètement, nous avons utilisé la forêt d'arbres décisionnels pour modéliser et démêler les principaux facteurs environnementaux régissant les déplacements de six éléphants de forêt, équipés de colliers GPS et suivis pendant 16 mois. Les résultats ont montré que les femelles se déplaçaient plus loin que les mâles, tandis que la présence de routes ou d¿établissements humains perturbait le comportement des éléphants, ce qui accélérait les déplacements. Les éléphants de forêt se déplaçaient plus rapidement dans les cours d¿eau et dans les forêts dont le sous¿bois était dominé par les forêts de Marantaceae et les bais, mais se déplaçait plus lentement dans les savanes. Enfin, les zones inondables ¿ characterisées par l¿altitude et les précipitations accumulées ¿ et les températures plus élevées empêchaient des déplacements plus longs. Nous espérons que ces résultats amélioreront les connaissances sur les mouvements des espèces à travers différents habitats, ce qui serait bénéfique pour la gestion de leur conservation.[EN] African forest elephants (Loxodonta cyclotis Matschie, 1900) are ecological engineers that play a fundamental role in vegetation dynamics. The species is of immediate conservation concern, yet it is relatively understudied. To narrow this knowledge gap, we studied the drivers of daily movement patterns (linear displacements) of forest elephants¿characterised by a set of geographical, meteorological and anthropogenic variables¿in the Odzala¿Kokoua National Park, Republic of Congo. Explicitly, we used conditional random forest to model and disentangle the main environmental factors governing the displacements of six forest elephants,fitted with GPS collars and tracked over 16 months. Results indicated that females moved further distances than males, while the presence of roads or human settlements disrupted elephant behaviour resulting in faster displacements. Forest elephants moved faster along watercourses and through forest with understory dominated by Marantaceae forests and bais, but moved slower in savannahs. Finally, flood¿prone areas¿described by elevation and accumulated precipitation¿and higher temperatures prevented longer displacements. We expect these results to improve the knowledge on the species movements through different habitats, which would benefit its conservation management.The fieldwork was financed by African Parks. We are grateful to the Congolese wildlife authorities (Ministère de l'Économie Forestière et de l'Environnement) for the permission to carry out this study, and we are deeply indebted to the director of the OKNP and to the conservation, wildlife monitoring and research manager, Erik Marav, respectively, for their continued support during our study. We are particularly grateful to Dr. Mike Kock, veterinarian, for collaring the elephants and to the field tracking team. We are also grateful to Séan Cahill for the useful comments and English correction that helped improve this manuscript. 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Quantum Phase Transition in a Resonant Level Coupled to Interacting Leads

An interacting one-dimensional electron system, the Luttinger liquid, is distinct from the "conventional" Fermi liquids formed by interacting electrons in two and three dimensions. Some of its most spectacular properties are revealed in the process of electron tunneling: as a function of the applied bias or temperature the tunneling current demonstrates a non-trivial power-law suppression. Here, we create a system which emulates tunneling in a Luttinger liquid, by controlling the interaction of the tunneling electron with its environment. We further replace a single tunneling barrier with a double-barrier resonant level structure and investigate resonant tunneling between Luttinger liquids. For the first time, we observe perfect transparency of the resonant level embedded in the interacting environment, while the width of the resonance tends to zero. We argue that this unique behavior results from many-body physics of interacting electrons and signals the presence of a quantum phase transition (QPT). In our samples many parameters, including the interaction strength, can be precisely controlled; thus, we have created an attractive model system for studying quantum critical phenomena in general. Our work therefore has broadly reaching implications for understanding QPTs in more complex systems, such as cold atoms and strongly correlated bulk materials.Comment: 11 pages total (main text + supplementary

QHE of Bilayer Systems in the Presence of Tunneling -- ν=1/q\nu=1/q case --

Transport properties of bilayer quantum Hall systems at $\nu=1/q$, where $q$ is an odd integer, are investigated. The edge theory is used for the investigation, since tunneling between the two layers is assumed to occur on the edge of the sample because of the bulk incompressibility. It is shown that in the case of the independent Laughlin state tunneling is irrelevant when $\nu<1/2$ in the low temperature and long wave length limit. The temperature dependence of two-terminal conductance of the system in which only one of the two layers is contacted with electrode is discussed.Comment: 5 page

Resonance in a Tomonaga-Luttinger liquid

We study a homogeneous Tomonaga-Luttinger liquid with backscattering potential. A perturbative computation of the conductance at and near resonance is given. We find that the backscattering of one electron dominates that of two electrons for an interaction parameter $K\geq 1/3$ and that the resonance point depends on temperature. Our results may be relevant for recent experiments on shot-noise in FQHE, where the charge 1/3 and not $2*1/3$ is measured on resonance.Comment: 15 pages, three Figures. v2: Definite version, Citations added, presentation improved. To appear in Phys. Rev. B, Rapid Co