The Sunyaev-Zeldovich Effect at 1 and 2 mm towards ROSAT Clusters

An observing campaign was devoted to the search for the Sunyaev-Zeldovich (S-Z) effect towards X-ray ROSAT Clusters in the millimetric spectral domain. A double channel (1.2 and 2 {\it mm}) photometer was installed at the focus of the 15m Swedish ESO Submillimeter Telescope (SEST) in Chile in september 1994 and 1995 and observations of the targets S1077, A2744, S295 and RXJ0658-5557 were gathered. Detections were found for A2744 at 1 {\it mm} and in both channels (at 1.2 and 2 {\it mm}) towards RXJ0658-5557. For the first time there is evidence for the S-Z enhancement and both the latter and the decrement were detected on the same source. We discuss astrophysical and systematic effects which could give origin to these signals.Comment: 6 pg Latex file (style file included) including 1 ps figure, XVIth Moriond Astrophysics Meeting "The Anisotropies of the Cosmic Microwave Background", Les Arcs, Savoie-France, March 16-23 199

A Deep VLA survey at 20cm of the ISO ELAIS survey regions

We have used the Very Large Array(VLA) in C configuration to carry out a sensitive 20cm radio survey of regions of sky that have been surveyed in the Far Infra-Red over the wavelength range 5-200 microns with ISO as part of the European Large Area ISO Survey(ELAIS). As usual in surveys based on a relatively small number of overlapping VLA pointings the flux limit varies over the area surveyed. The survey has a flux limit that varies from a 5$\sigma$ limit of 0.135mJy over an area of 0.12deg$^2$ to a 5$\sigma$ limit of 1.15mJy or better over the whole region covered of 4.22 deg$^2$. In this paper we present the radio catalogue of 867 sources. These regions of sky have previously been surveyed to shallow flux limits at 20cm with the VLA as part of the VLA D configuration NVSS(FWHM=45 arcsec) and VLA B configuration FIRST(FWHM=5 arcsec) surveys. We have carried out a a detailed comparison of the reliability of our own survey and these two independent surveys in order to assess the reliability and completeness of each survey.Comment: 19 pages, 24 figures, submitted to MNRAS, also available in http://www.ast.cam.ac.uk/~ciliegi/elais/paper

Building Orientation and Heat Treatments Effect on the Pseudoelastic Properties of NiTi Produced by LPBF

NiTi dominates the market of shape memory materials due to its optimal combination of mechanical, functional, and biocompatibility properties, which enabled its use for several applications, in particular for the biomedical and the aerospace sectors. However, due to its poor machinability, NiTi is a challenging material from the manufacturing standpoint. Therefore, in the last years, researchers have focused on the production of NiTi components by additive manufacturing processes, which also enable the manufacturing of complex shape parts that cannot be produced with conventional methods. The aim of this study is to provide insights on the optimization of the functional performances of NiTi produced by Laser Powder Bed Fusion, leveraging on the building orientation and post-processing heat treatments. Uniaxial mechanical tests have been performed in tension and compression, and the influence of heat treatments and building orientation on the mechanical behavior of pseudoelastic NiTi has been evaluated. Different heat treatment schedules have been evaluated, leading to transformation strains up to 2.7% in tension and 4.6% in compression. This study confirms that Laser Powder Bed Fusion is a promising additive manufacturing technology for the production of net-shape and near defect-free NiTi components, exhibiting remarkable functional properties

The Voices of History: theorising the interpersonal semantics of historical discourses

‘The individual consumer, the learner of history, is offered an impressive array of discursive products geared to catch his or her attention, to persuade him or her of the truth of whatever message is transmitted’ (Blanco and Rosa 1997: 197. In this article I examine these discursive products from the perspective of ‘voice’. I do this as a way of bringing to conscious attention the strategies that historians use in order to persuade and position the ‘consumer’. ‘Voice’ in recent systemic linguistic theorizing refers to distinctive configurations of APPRAISAL choices. Within the domain of history, research to date has identified three main configurations or voices—‘recorder’, ‘interpreter’, and ‘adjudicator’. Central to the research reported on in this article is Martin’s APPRAISAL framework (Martin 1997, 2000). APPRAISAL 1 systems are the semantic resources used to negotiate emotions, judgments, and valuations. In this article I will examine how choices from these systems vary in ways that are systematic — different history texts speak with different ‘voices’. These voices, I argue, are a key rhetorical strategy in history discourse. Different combinations of APPRAISAL resources are drawn on to negotiate the heteroglossic positions of their audiences. As such they are a key resource for both the professional and apprentice historian in their assessment of interpretations of the past

Stomatin-like Protein 2 Links Mitochondria to T-Cell Receptor Signalosomes at the Immunological Synapse and Enhances T-Cell Activation

T cell activation through the antigen receptor (TCR) requires sustained signalling from microclusters in the peripheral region of the immunological synapse (IS). The bioenergetics of such prolonged signaling have been linked to the redistribution of mitochondria to the IS. Here, we report that stomatin-like protein-2 (SLP-2) plays an important role in this process by bridging polarized mitochondria to these signaling TCR microclusters or signalosomes in the IS in a polymerized actin-dependent manner. In this way, SLP-2 helps to sustain TCR-dependent signalling and enhances T cell activation

The European Large Area ISO Survey II: mid-infrared extragalactic source counts

We present preliminary source counts at 6.7um and 15um from the Preliminary Analysis of the European Large Area ISO survey, with limiting flux densities of \~2mJy at 15um & ~1mJy at 6.7um. We separate the stellar contribution from the extragalactic using identifications with APM sources made with the likelihood ratio technique. We quantify the completeness & reliability of our source extraction using (a) repeated observations over small areas, (b) cross-IDs with stars of known spectral type, (c) detections of the PSF wings around bright sources, (d) comparison with independent algorithms. Flux calibration at 15um was performed using stellar IDs; the calibration does not agree with the pre-flight estimates, probably due to effects of detector hysteresis and photometric aperture correction. The 6.7um extragalactic counts are broadly reproduced in the Pearson & Rowan-Robinson model, but the Franceschini et al. (1997) model underpredicts the observed source density by ~0.5-1 dex, though the photometry at 6.7um is still preliminary. At 15um the extragalactic counts are in excellent agreement with the predictions of the Pearson & Rowan-Robinson (1996), Franceschini et al. (1994), Guiderdoni et al. (1997) and the evolving models of Xu et al. (1998), over 7 orders of magnitude in 15um flux density. The counts agree with other estimates from the ISOCAM instrument at overlapping flux densities (Elbaz et al. 1999), provided a consistent flux calibration is used. Luminosity evolution at a rate of (1+z)^3, incorporating mid-IR spectral features, provides a better fit to the 15um differential counts than (1+z)^4 density evolution. No-evolution models are excluded, and implying that below around 10mJy at 15um the source counts become dominated by an evolving cosmological population of dust-shrouded starbursts and/or active galaxies.Comment: MNRAS in press. 14 pages, uses BoxedEPS (included). For more information on the ELAIS project see http://athena.ph.ic.ac.uk

Vanishing Fe 3d orbital moments in single-crystalline magnetite

We show detailed magnetic absorption spectroscopy results of an in situ cleaved high quality single crystal of magnetite. In addition the experimental setup was carefully optimized to reduce drift, self absorption, and offset phenomena as far as possible. In strong contradiction to recently published data, our observed orbital moments are nearly vanishing and the spin moments are quite close to the integer values proposed by theory. This very important issue supports the half metallic full spin polarized picture of magnetite.Comment: 7 pages, 4 figure

Ice Dragon: A Mission to Address Science and Human Exploration Objectives on Mars

We present a mission concept where a SpaceX Dragon capsule lands a payload on Mars that samples ground ice to search for evidence of life, assess hazards to future human missions, and demonstrate use of Martian resources