1,164 research outputs found
The X-ray Luminosity Function of Nearby Rich and Poor Clusters of Galaxies: A Cosmological Probe
In this letter, we present a new determination of the local (z<0.09) X-ray
luminosity function (XLF) using a large, statistical sample of 294 Abell
clusters and the ROSAT All-Sky-Survey. Given our large sample size, we have
reduced errors by a factor of two for L(X)(0.5-2keV)>10^43 ergs/sec. We combine
our data with previous work in order to explore possible constraints imposed by
the shape of the XLF on cosmological models. A set of currently viable
cosmologies is used to construct theoretical XLFs assuming Lx is proportional
to M^p and a sigma_8-Omega_0 constraint (from Viana & Liddle 1996) based on the
local X-ray temperature function. We fit these models to our observed XLF and
verify that the simplest adiabatic, analytic scaling relation (e.g. Kaiser
1986) disagrees strongly with observations. If we assume that clusters can be
described by the pre-heated, constant core-entropy models of Evrard & Henry
(1991) then the observed XLF is consistent only with 0.1 < Omega_0 < 0.4 if the
energy per unit mass in galaxies is roughly equal to the gas energy (ie if
beta=1). (abridged)Comment: 4 pages, 2 figures, accepted for publication in ApJ Letters. uses
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Spectral functions of isoscalar scalar and isovector electromagnetic form factors of the nucleon at two-loop order
We calculate the imaginary parts of the isoscalar scalar and isovector
electromagnetic form factors of the nucleon up to two-loop order in chiral
perturbation theory. Particular attention is paid on the correct behavior of Im
and Im at the two-pion threshold
in connection with the non-relativistic 1/M-expansion. We recover the
well-known strong enhancement near threshold originating from the nearby
anomalous singularity at . In the
case of the scalar spectral function Im one finds a significant
improvement in comparison to the lowest order one-loop result. Higher order
-rescattering effects are however still necessary to close a remaining
20%-gap to the empirical scalar spectral function. The isovector electric and
magnetic spectral functions Im get additionally enhanced near
threshold by the two-pion-loop contributions. After supplementing their
two-loop results by a phenomenological -meson exchange term one can
reproduce the empirical isovector electric and magnetic spectral functions
fairly well.Comment: 10 pages, 6 figures, submitted to Physical Review
Particular concerns with regard to the Rotterdam Rules
Resumen: A medida que el proceso de fi rma de las Reglas de Rotterdam va tomando cuerpo, también cobran fuerza las voces discordantes. Este artículo o manifi esto recoge la opinión crítica colectiva de un grupo de nueve destacados especialistas en Derecho marítimo de distintas partes del mundo, pertenecientes a los sectores académico y profesional. El artículo analiza con brevedad y precisión los rasgos más destacados de las Reglas de Rotterdam, particularmente aquéllos que, a juicio de los firmantes, meritan mayor debate y crítica. La conclusión a la que llegan los miembros de este grupo de juristas es que las Reglas de Rotterdam no vienen sino a añadir más complejidad a la actual regulación internacional del transporte marítimo y multimodal. El artículo finaliza con una propuesta de alternativas que permitan aprovechar lo mejor de la regulación vigente y abrir las puertas a una actualización y complementación de dicha regulación.
Palabras clave: Reglas, Rotterdam, Crítica, Alternativas.
Abstract: As the Rotterdam Rules signature process gains momentum, strong dissenting opinions are also starting to be heard. This article or manifesto sums up the collective critical voice of nine worldwide leading shipping lawyers and professors. It provides a short and precise analysis of the Rotterdam Rules main features from the point of view of those issues which the authors fi nd unworthy of praise. And their conclusion is that the Rotterdam Rules simply just add up more complexity to the present shipping and multimodal international regulation. The article closes with a quest for alternatives aimed to get the best of what we already have and opens the gate to proposals based on the updating and complementation of the regulation in force today.
Key words: Rules, Rotterdam, Critical, Alternatives
A Blue Print for a Worldwide Multimodal Regime
Resumen: En el nº 2 de 2010 de CDT se publicó un manifiesto del llamado “Grupo de los 9” titulado “Particular concerns with regard to the Rotterdam Rules” en el que estos destacados profesores y juristas expresaban sus dudas acerca de este nuevo instrumento internacional. Este Grupo ofrece ahora un nuevo manifiesto que supone un paso adelante en el que se indica que a pesar de la innegable necesidad de poner al día las Reglas de La Haya-Visby, y de las aportaciones efectuadas en tal sentido por las Reglas de Rótterdam, las perspectivas de éxito de estas últimas se ven ensombrecidas por su pretensión de extenderse más allá de lo que en puridad debía ser su objeto, el transporte marítimo, para convertirse en el texto de referencia para el transporte multimodal que cuente con una fase marítima. Lejos de contribuir a un verdadero y efectivo régimen unificado de la multimodalidad, plantea nuevas dudas a la hora de determinar qué régimen, de entro los existentes para cada tipo de transporte, debe ser de aplicación en cada caso. Mientras tanto, parece que para conseguir los objetivos referidos al transporte marítimo de las Reglas de Rótterdam habría bastado con la introducción de Protocolos a las Reglas de La Haya-Visby, dejando que lo concerniente al transporte multimodal continuara por la senda establecida a tal efecto por el CMR, cuyo sistema quizás debiera traspasar las fronteras europeas con el impulso de las diferentes instituciones internacionales. Palabras clave: Reglas de Rotterdam, transporte multimodal, transporte marítimo, Reglas de La Haya-Visby, CMR. Abstract: In the issue n. 2 of 2010 of CDT it was published a manifesto of the so-called “Group of the 9” under the title of “Particular concerns with regard to the Rotterdam Rules” where these renowned scholars and attorneys expressed their doubts about this new international legal instrument. The Group offers now a new manifesto providing a step further whereby they indicate that notwithstanding the undeniable necessity to update the Hague-Visby Rules and the contributions carried out in this direction by the Rotterdam Rules, success expectations of the latter rules are hindered because of the aim to expand the scope of application beyond their object in strict sense, namely maritime transport, so as to become the text of reference as for every multimodal transport that includes a sea leg. Far from contributing to a real and effective multimodal unified regime, new doubts arise when determining which regime, of all those for each type of transport, shall apply in each case. In any event, it seems that in order to reach the objectives appointed to by the Rotterdam Rules, introducing Protocols to the Hague-Visby Rules would have been good enough, whereas all that related to multimodal transport continues by the CMR established paths, a system which should trespass European borders with the help of different international institutions. Key words: Rotterdam Rules, multimodal transport, maritime transport, Hague-Visby Rules, CMR
The First VLBI Detection of a Spiral DRAGN Core
The existence of spiral DRAGNs challenges standard galaxy formation theories.
We present the first observation of 0313192, the archetypal spiral DRAGN, at
VLBI resolutions. Spiral DRAGNs are Double Radio Sources Associated with
Galactic Nuclei (DRAGNs) that are hosted by spiral galaxies. 0313192 is an
edge-on spiral galaxy that appears to host a 360 kpc double-lobed radio source.
The core of this galaxy is clearly detected at L, S, and X-bands using the
VLBA, signifying an ongoing active nucleus in the galaxy. This rules out the
possibility that the spiral DRAGN is merely a chance alignment. The radio core
has LW Hz. Radio components are
detected to the South-West of the core, but there are no detections of a
counterjet. Assuming a symmetric, relativistic jet, we estimate an upper limit
to the inclination angle of degrees. The VLBI-detected
radio jet components are extremely well-aligned with the larger-scale radio
source suggesting little to no jet disruption or interaction with the ISM of
the host galaxy.Comment: 6 pages, 4 figure
Clinical translation of a click-labeled 18F-octreotate radioligand for imaging neuroendocrine tumors
© 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc. We conducted the first-in-human study of 18F-fluoroethyl triazole [Tyr3] octreotate (18F-FET-βAG-TOCA) in patients with neuroendocrine tumors (NETs) to evaluate biodistribution, dosimetry, and safety. Despite advances in clinical imaging, detection and quantification of NET activity remains a challenge, with no universally accepted imaging standard. Methods: Nine patients were enrolled. Eight patients had sporadic NETs, and 1 had multiple endocrine neoplasia type 1 syndrome. Patients received 137-163 MBq (mean ± SD, 155.7 ± 8 MBq) of 18F-FET-βAG-TOCA. Safety data were obtained during and 24 h after radioligand administration. Patients underwent detailed wholebody PET/CT multibed scanning over 4 h with sampling of venous bloods for radioactivity and radioactive metabolite quantification. Regions of interest were defined to derive individual and mean organ residence times; effective dose was calculated with OLINDA 1.1. Results: All patients tolerated 18F-FET-βAG-TOCA with no adverse events. Over 60% parent radioligand was present in plasma at 60 min. High tumor (primary and metastases)-to-background contrast images were observed. Physiologic distribution was seen in the pituitary, salivary glands, thyroid, and spleen, with low background distribution in the liver, an organ in which metastases commonly occur. The organs receiving highest absorbed dose were the gallbladder, spleen, stomach, liver, kidneys, and bladder. The calculated effective dose over all subjects (mean ± SD) was 0.029 ± 0.004 mSv/MBq. Conclusion: The favorable safety, imaging, and dosimetric profile makes 18F-FET-βAGTOCA a promising candidate radioligand for staging and management of NETs. Clinical studies in an expanded cohort are ongoing to clinically qualify this agent
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A semantic sensor web for environmental decision support applications
Sensing devices are increasingly being deployed to monitor the physical world around us. One class of application for which sensor data is pertinent is environmental decision support systems, e.g., flood emergency response. For these applications, the sensor readings need to be put in context by integrating them with other sources of data about the surrounding environment. Traditional systems for predicting and detecting floods rely on methods that need significant human resources. In this paper we describe a semantic sensor web architecture for integrating multiple heterogeneous datasets, including live and historic sensor data, databases, and map layers. The architecture provides mechanisms for discovering datasets, defining integrated views over them, continuously receiving data in real-time, and visualising on screen and interacting with the data. Our approach makes extensive use of web service standards for querying and accessing data, and semantic technologies to discover and integrate datasets. We demonstrate the use of our semantic sensor web architecture in the context of a flood response planning web application that uses data from sensor networks monitoring the sea-state around the coast of England
The novel choline kinase inhibitor ICL-CCIC-0019 reprograms cellular metabolism and inhibits cancer cell growth
The glycerophospholipid phosphatidylcholine is the most abundant phospholipid species of eukaryotic membranes and essential for structural integrity and signaling function of cell membranes required for cancer cell growth. Inhibition of choline kinase alpha (CHKA), the first committed step to phosphatidylcholine synthesis, by the selective small-molecule ICL-CCIC-0019, potently suppressed growth of a panel of 60 cancer cell lines with median GI50 of 1.12 μM and inhibited tumor xenograft growth in mice. ICL-CCIC-0019 decreased phosphocholine levels and the fraction of labeled choline in lipids, and induced G1 arrest, endoplasmic reticulum stress and apoptosis. Changes in phosphocholine cellular levels following treatment could be detected non-invasively in tumor xenografts by [18F]-fluoromethyl-[1,2–2H4]-choline positron emission tomography. Herein, we reveal a previously unappreciated effect of choline metabolism on mitochondria function. Comparative metabolomics demonstrated that phosphatidylcholine pathway inhibition leads to a metabolically stressed phenotype analogous to mitochondria toxin treatment but without reactive oxygen species activation. Drug treatment decreased mitochondria function with associated reduction of citrate synthase expression and AMPK activation. Glucose and acetate uptake were increased in an attempt to overcome the metabolic stress. This study indicates that choline pathway pharmacological inhibition critically affects the metabolic function of the cell beyond reduced synthesis of phospholipids
Symmetry-breaking Effects for Polariton Condensates in Double-Well Potentials
We study the existence, stability, and dynamics of symmetric and anti-symmetric states of quasi-one-dimensional polariton condensates in double-well potentials, in the presence of nonresonant pumping and nonlinear damping. Some prototypical features of the system, such as the bifurcation of asymmetric solutions, are similar to the Hamiltonian analog of the double-well system considered in the realm of atomic condensates. Nevertheless, there are also some nontrivial differences including, e.g., the unstable nature of both the parent and the daughter branch emerging in the relevant pitchfork bifurcation for slightly larger values of atom numbers. Another interesting feature that does not appear in the atomic condensate case is that the bifurcation for attractive interactions is slightly sub-critical instead of supercritical. These conclusions of the bifurcation analysis are corroborated by direct numerical simulations examining the dynamics of the system in the unstable regime.MICINN (Spain) project FIS2008- 0484
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