The Properties of Field Elliptical Galaxies at Intermediate Redshift. I: Empirical Scaling Laws

We present measurements of the Fundamental Plane (FP) parameters (the effective radius, the mean effective surface brightness, and the central velocity dispersion) of six field elliptical galaxies at intermediate redshift. The imaging is taken from the Medium Deep Survey of the Hubble Space Telescope, while the kinematical data are obtained from long-slit spectroscopy using the 3.6-m ESO telescope. The Fundamental Plane appears well defined in the field even at redshift $\approx$ 0.3. The data show a shift in the FP zero point with respect to the local relation, possibly indicating modest evolution, consistent with the result found for intermediate redshift cluster samples. The FP slopes derived for our field data, plus other cluster ellipticals at intermediate redshift taken from the literature, differ from the local ones, but are still consistent with the interpretation of the FP as a result of homology, of the virial theorem and of the existence of a relation between luminosity and mass, $L \propto M^{\eta}$. We also derive the surface brightness vs. effective radius relation for nine galaxies with redshift up to $z \approx0.6$, and data from the literature; the evolution that can be inferred is consistent with what is found using the FP.Comment: 17 pages, including 9 figures, MNRAS, accepte

Saturation properties and incompressibility of nuclear matter: A consistent determination from nuclear masses

Starting with a two-body effective nucleon-nucleon interaction, it is shown that the infinite nuclear matter model of atomic nuclei is more appropriate than the conventional Bethe-Weizsacker like mass formulae to extract saturation properties of nuclear matter from nuclear masses. In particular, the saturation density thus obtained agrees with that of electron scattering data and the Hartree-Fock calculations. For the first time using nuclear mass formula, the radius constant $r_0$=1.138 fm and binding energy per nucleon $a_v$ = -16.11 MeV, corresponding to the infinite nuclear matter, are consistently obtained from the same source. An important offshoot of this study is the determination of nuclear matter incompressibility $K_{\infty}$ to be 288$\pm$ 28 MeV using the same source of nuclear masses as input.Comment: 14 latex pages, five figures available on request ( to appear in Phy. Rev. C

Amyotrophic lateral sclerosis-associated mutant SOD1 inhibits anterograde axonal transport of mitochondria by reducing Miro1 levels

Defective axonal transport is an early neuropathological feature of amyotrophic lateral sclerosis (ALS). We have previously shown that ALS-associated mutations in Cu/Zn superoxide dismutase 1 (SOD1) impair axonal transport of mitochondria in motor neurons isolated from SOD1 G93A transgenic mice and in ALS mutant SOD1 transfected cortical neurons, but the underlying mechanisms remained unresolved. The outer mitochondrial membrane protein mitochondrial Rho GTPase 1 (Miro1) is a master regulator of mitochondrial axonal transport in response to cytosolic calcium (Ca2+) levels ([Ca2+]c) and mitochondrial damage. Ca2+ binding to Miro1 halts mitochondrial transport by modifying its interaction with kinesin-1 whereas mitochondrial damage induces Phosphatase and Tensin homolog (PTEN)-induced putative kinase 1 (PINK1) and Parkin-dependent degradation of Miro1 and consequently stops transport. To identify the mechanism underlying impaired axonal transport of mitochondria in SOD1-related ALS we investigated [Ca2+]c and Miro1 levels in ALS mutant SOD1 expressing neurons. We found that expression of ALS mutant SOD1 reduced the level of endogenous Miro1 but did not affect [Ca2+]c. ALS mutant SOD1 induced reductions in Miro1 levels were Parkin dependent. Moreover, both overexpression of Miro1 and ablation of PINK1 rescued the mitochondrial axonal transport deficit in ALS mutant SOD1-expressing cortical and motor neurons. Together these results provide evidence that ALS mutant SOD1 inhibits axonal transport of mitochondria by inducing PINK1/Parkin-dependent Miro1 degradation

Structural operational semantics for stochastic and weighted transition systems

We introduce weighted GSOS, a general syntactic framework to specify well-behaved transition systems where transitions are equipped with weights coming from a commutative monoid. We prove that weighted bisimilarity is a congruence on systems defined by weighted GSOS specifications. We illustrate the flexibility of the framework by instantiating it to handle some special cases, most notably that of stochastic transition systems. Through examples we provide weighted-GSOS definitions for common stochastic operators in the literature

Unique Decomposition of Processes

AbstractIn this paper, we examine questions about the prime decomposability of processes, where we define a process to be prime whenever it cannot be decomposed into nontrivial components.We show that any finite process can be uniquely decomposed into prime processes with respect to bisimulation equivalence, and demonstrate counterexamples to such a result for both failures (testing) equivalence and trace equivalence.Although we show that prime decompositions cannot exist for arbitrary infinite processes, we motivate but leave as open a conjecture on the unique decomposability of a wide subclass of infinite behaviours

Ultrasonic Attenuation in the Vortex State of d-wave Superconductors

We calculate the low temperature quasi-particle contribution to the ultrasonic attenuation rate in the mixed state of d-wave superconductors. Our calculation is performed within the semi-classical approximation using quasi-particle energies that are Doppler shifted, with respect to their values in the Meissner phase, by the supercurrent associated with the vortices. We find that the attenuation at low temperatures and at fields $H_{c1} \leq H \ll H_{c2}$ has a temperature independent contribution which is proportional to $\surd H$ where $H$ is the applied magnetic field. We indicate how our result in combination with the zero-field result for ultrasonic attenuation can be used to calculate one of the parameters $v_F$, $H_{c2}$ or $\xi$ given the values for any two of them.Comment: 10 pages, RevTeX, submitted to Physica

Mirroring everyday clinical practice in clinical trial design: a new concept to improve the external validity of randomized double-blind placebo-controlled trials in the pharmacological treatment of major depression

Background: Randomized, double-blind, placebo-controlled trials constitute the gold standard in clinical research when testing the efficacy of new psychopharmacological interventions in the treatment of major depression. However, the blinded use of placebo has been found to influence clinical trial outcomes and may bias patient selection. Discussion: To improve clinical trial design in major depression so as to reflect clinical practice more closely we propose to present patients with a balanced view of the benefits of study participation irrespective of their assignment to placebo or active treatment. In addition every participant should be given the option to finally receive the active medication. A research agenda is outlined to evaluate the impact of the proposed changes on the efficacy of the drug to be evaluated and on the demographic and clinical characteristics of the enrollment fraction with regard to its representativeness of the eligible population. Summary: We propose a list of measures to be taken to improve the external validity of double-blind, placebocontrolled trials in major depression. The recommended changes to clinical trial design may also be relevant for other psychiatric as well as medical disorders in which expectations regarding treatment outcome may affect the outcome itself

A Calculus for Orchestration of Web Services

Service-oriented computing, an emerging paradigm for distributed computing based on the use of services, is calling for the development of tools and techniques to build safe and trustworthy systems, and to analyse their behaviour. Therefore, many researchers have proposed to use process calculi, a cornerstone of current foundational research on specification and analysis of concurrent, reactive, and distributed systems. In this paper, we follow this approach and introduce CWS, a process calculus expressly designed for specifying and combining service-oriented applications, while modelling their dynamic behaviour. We show that CWS can model all the phases of the life cycle of service-oriented applications, such as publication, discovery, negotiation, orchestration, deployment, reconfiguration and execution. We illustrate the specification style that CWS supports by means of a large case study from the automotive domain and a number of more specific examples drawn from it

Reply To "comment On 'photoionization Of Helium Atoms Irradiated With Intense Vacuum Ultraviolet Free-electron Laser Light. Part I. Experimental Study Of Multiphoton And Single-photon Processes'"

We do not agree with the conclusion of the Comment by Charalambidis questioning our observation of two-photon ionization of helium by intense radiation with 13 eV photons from a vuv free-electron laser. Two-photon ionization is clearly established by the detection of low-energy photoelectrons at ∼1.7 eV, which agrees very well with the expected energy for a two-photon ionization process. © 2006 The American Physical Society.743Laarmann, T., De Castro, A.R.B., Schulz, J., Wabnitz, H., Möller, T., (2005) Phys. Rev. A, 72, p. 023409. , PLRAAN. 1050-2947. 10.1103/PhysRevA.72.023409Ayvazyan, V., Baboi, N., Bohnet, I., Brinkmann, R., Castellano, M., Castro, P., Catani, L., Zapfe, K., (2002) Phys. Rev. Lett., 88, p. 104802. , PRLTAO. 0031-9007. 10.1103/PhysRevLett.88.104802Ayvazyan, V., Baboi, N., Bähr, J., Balandin, V., Beutner, B., Brandt, A., Bohnet, I., Schreiber H, -J., (2006) Eur. Phys. J. D, 37, p. 297. , EPJDF6. 1434-6060. 10.1140/epjd/e2005-00308-1Wabnitz, H., Bittner, L., De Castro, A.R.B., Döhrmann, R., Gürtler, P., Laarmann, T., Laasch, W., Yurkov, M., (2002) Nature (London), 420, p. 482. , NATUAS. 0028-0836. 10.1038/nature01197Laarmann, T., De Castro, A.R.B., Gürtler, P., Laasch, W., Schulz, J., Wabnitz, H., Möller, T., (2004) Phys. Rev. Lett., 92, p. 143401. , PRLTAO. 0031-9007. 10.1103/PhysRevLett.92.143401Laarmann, T., Rusek, M., Wabnitz, H., Schulz, J., De Castro, A.R.B., Gürtler, P., Laasch, W., Möller, T., (2005) Phys. Rev. Lett., 95, p. 063402. , PRLTAO. 0031-9007. 10.1103/PhysRevLett.95.063402Wabnitz, H., De Castro, A.R.B., Gürtler, P., Laarmann, T., Laasch, W., Schulz, J., Möller, T., (2005) Phys. Rev. Lett., 94, p. 023001. , PRLTAO. 0031-9007. 10.1103/PhysRevLett.94.023001Santra, R., Greene, C.H., (2004) Phys. Rev. A, 70, p. 053401. , PLRAAN 1050-2947 10.1103/PhysRevA.70.053401Tzallas, P., Charalambidis, D., Papadogiannis, N.A., Witte, K., Tsakiris, G.D., (2003) Nature (London), 426, p. 267. , NATUAS 0028-0836 10.1038/nature02091Papadogiannis, N.A., Nikolopoulos, L.A.A., Charalambidis, D., Tsakiris, G.D., Tzallas, P., Witte, K., (2003) Appl. Phys. B, 76, p. 721. , APDOEM 0946-2171Papadogiannis, N.A., Nikolopoulos, L.A.A., Charalambidis, D., Tsakiris, G.D., Tzallas, P., Witte, K., (2003) Phys. Rev. Lett., 90, p. 133902. , PRLTAO 0031-9007 10.1103/PhysRevLett.90.133902De Castro, A.R.B., Laarmann, T., Schulz, J., Wabnitz, H., Möller, T., (2005) Phys. Rev. A, 72, p. 023410. , PLRAAN. 1050-2947. 10.1103/PhysRevA.72.02341

Investigation of persistent coherent structures along the Southern Brazilian Shelf

Dentre as diferentes influências que a hidrodinâmica da plataforma continental sul brasileira sofre, uma de destaque é a pluma de água proveniente da Lagoa dos Patos, gerando no seu entorno uma região com elevada complexidade na dinâmica do escoamento. Além disto, ventos sazonais, sinóticos e variáveis, bem como as condições das correntes costeiras levam a padrões alternantes de escoamentos. Deste modo, foram investigadas ocorrências de estruturas coerentes persistentes neste ambiente. Para tal fim, foi utilizada uma metodologia numérica capaz de descrever as principais características fluidodinâmicas durante um ano climatológico. O código aberto de elementos finitos Telemac-Mascaret foi aplicado no domínio tridimensional, juntamente com o modelo k-épsilon para a descrição dos efeitos turbulentos. Estruturas persistentes de elevada turbulência foram identificadas na área de estudo, as quais ocorrem como perturbações de curvatura definidas por altas taxas de produção e dissipação turbulenta. Como resultado, há um aumento local na mistura entre porções de fluido, caracterizado por um fluxo ascendente. Este fenômeno pode ser atribuído as irregularidades na topografia do leito, associado as tensões de cisalhamento provocadas pela ação do vento. Os resultados obtidos por modelagem numérica contribuíram para aumentar a informação disponível sobre as estruturas de circulação nesta região.The freshwater-influenced region of the Patos Lagoon discharge to the Southern Brazilian Shelf (SBS) is a region of complex fluid dynamics. Seasoning and synoptic variable winds and coastal current conditions create an alternating flow pattern. The aim of this paper was to investigate the occurrence of persistent coherent structures in this environment. A numerical approach was chosen to describe the main hydrodynamic features of the region during a climatological year. The open-source finite-element code TelemacMascaret was applied to the three-dimensional domain. In addition the two-equation k-epsilon model described the turbulence mechanisms. The presence of persistent high-turbulent structures was identified within the study area. These occur as a strong curvilinear disturbance characterized by higher turbulent production and dissipation rates, which increase local mixture. As a result, upward circulation flow was observed, which may be due to irregularities in bottom topography associated with wind-induced stress forces. These results increase the information about the circulation structures of the study area by means of numerical modelling analysis