448 research outputs found
Post 'Celtic Tiger' Ireland, Silver Vigilantes and Public Sociology: Protesting Against Global Neoliberalisation
It is not just publicly funded universities that are facing a cold and hard future in the aftershock of the 2008 global banking crisis. Nations, such as Ireland, are similarly affected as states seek to appease 'the markets' and cover private banks' losses at the public's expense. As this wave of neoliberalisation, or market fundamentalism, proceeds we may ask: what is the role of sociology? Drawing from an exploratory study of financial activism, notably silver vigilantism and the Crash JP Morgan Campaign, this paper endorses global public sociology among threatened publics. As per Michael Burawoy's calls for public sociology, this entails promoting reflexive knowledge and democratic dialogue in the defence of civil society. After outlining the core tenets, strengths and weaknesses of silver vigilantism, the role of public sociology and the need for further research are underscored as the economic crisis continues in post 'Celtic Tiger' Ireland and beyond.Public Sociology; Neoliberalisation; Money; Protest; the Internet
Media, ‘Fat Panic’ and Public Pedagogy:Mapping Contested Terrain
Discourses regarding a ‘global obesity crisis’ and alternative frames (e.g. weight-inclusive approaches to health) have proliferated through various media of communication. These media range from traditional print and visual formats (e.g. newspapers and television shows) to digital media (e.g. Twitter, Facebook, YouTube), which enable different publics to produce, and not just consume, text, images and other data relating to the body. Reflecting a sociological understanding of educational practices as extending beyond formal schooling, mediated obesity discourse and counter-movements have also been conceptualised as public pedagogies, which instruct people how to relate to their own and other's bodies, health and subjectivities. This article examines what is critically known about various media at a time when governments and agencies are reinvigorating the global war on obesity, with populations being ‘advised’ to become and remain conscientious weight watchers. In conclusion, the article underscores the salience of social studies of the media when seeking to rethink obesity, incorporating critical reference to moral panic theory and the need to better understand what media can ‘do’ as enactments of public pedagogy.</p
Toward a better understanding of tool wear effect through a comparison between experiments and SPH numerical modelling of machining hard materials
The aim of this study is to improve the general understanding of tungsten carbide (WC–Co) tool wear under dry machining of the hard-to-cut titanium alloy Ti6Al4V. The chosen approach includes experimental and numerical tests. The experimental part is designed to identify wear mechanisms using cutting force measurements, scanning electron microscope observations and optical profilometer analysis. Machining tests were conducted in the orthogonal cutting framework and showed a strong evolution of the cutting forces and the chip profiles with tool wear. Then, a numerical method has been used in order to model the machining process with both new and worn tools. The use of smoothed particle hydrodynamics model (SPH model) as a numerical tool for a better understanding of the chip formation with worn tools is a key aspect of this work. The redicted chip morphology and the cutting force evolution with respect to the tool wear are qualitatively compared with experimental trends. The chip formation mechanisms during dry cutting process are shown to be quite dependent from the worn tool geometry. These mechanisms explain the high variation of the experimental and numerical feed force between new and worn tools
Newtonian Hydrodynamics of the Coalescence of Black Holes with Neutron Stars I: Tidally locked binaries with a stiff equation of state
We present a detailed study of the hydrodynamical interactions in a Newtonian
black hole-neutron star binary during the last stages of inspiral. We consider
close binaries which are tidally locked, use a stiff equation of state (with an
adiabatic index Gamma=3) throughout, and explore the effect of different
initial mass ratios on the evolution of the system. We calculate the
gravitational radiation signal in the quadrupole approximation. Our
calculations are carried out using a Smooth Particle Hydrodynamics (SPH) code.Comment: Replaces previous version which had figures separate from the text of
the paper. Now 47 pages long with 19 embedded figures (the figures are the
same, they were renumbered) Uses aaspp4.st
The Dynamical Evolution of Black Hole-Neutron Star Binaries in General Relativity: Simulations of Tidal Disruption
We calculate the first dynamical evolutions of merging black hole-neutron
star binaries that construct the combined black hole-neutron star spacetime in
a general relativistic framework. We treat the metric in the conformal flatness
approximation, and assume that the black hole mass is sufficiently large
compared to that of the neutron star so that the black hole remains fixed in
space. Using a spheroidal spectral methods solver, we solve the resulting field
equations for a neutron star orbiting a Schwarzschild black hole. The matter is
evolved using a relativistic, Lagrangian, smoothed particle hydrodynamics (SPH)
treatment. We take as our initial data recent quasiequilibrium models for
synchronized neutron star polytropes generated as solutions of the conformal
thin-sandwich (CTS) decomposition of the Einstein field equations. We are able
to construct from these models relaxed SPH configurations whose profiles show
good agreement with CTS solutions. Our adiabatic evolution calculations for
neutron stars with low compactness show that mass transfer, when it begins
while the neutron star orbit is still outside the innermost stable circular
orbit, is more unstable than is typically predicted by analytical formalisms.
This dynamical mass loss is found to be the driving force in determining the
subsequent evolution of the binary orbit and the neutron star, which typically
disrupts completely within a few orbital periods. The majority of the mass
transferred onto the black hole is accreted promptly; a significant fraction
(~30%) of the mass is shed outward as well, some of which will become
gravitationally unbound and ejected completely from the system. The remaining
portion forms an accretion disk around the black hole, and could provide the
energy source for short-duration gamma ray bursts.Comment: 32 pages, 16 figures, 2 tables, RevTeX, accepted by PR
Unveiling the Circumstellar Envelope and Disk: A Sub-Arcsecond Survey of Circumstellar Structures
We present the results of a 2.7 mm continuum interferometric survey of 24
young stellar objects in 11 fields. The target objects range from deeply
embedded Class 0 sources to optical T Tauri sources. This is the first
sub-arcsecond survey of the 2.7 mm dust continuum emission from young, embedded
stellar systems. The images show a diversity of structure and complexity. The
optically visible T Tauri stars (DG Tauri, HL Tauri, GG Tauri,and GM Aurigae)
have continuum emission dominated by compact, less than 1", circumstellar
disks. The more embedded near-infrared sources (SVS13 and L1551 IRS5) have
continuum emission that is extended and compact. The embedded sources (L1448
IRS3, NGC1333 IRAS2, NGC1333 IRAS4, VLA1623, and IRAS 16293-2422) have
continuum emission dominated by the extended envelope, typically more than 85%.
In fact, in many of the deeply embedded systems it is difficult to uniquely
isolate the disk emission component from the envelope extending inward to AU
size scales. All of the target embedded objects are in multiple systems with
separations on scales of 30" or less. Based on the system separation, we place
the objects into three categories: separate envelope (separation > 6500 AU),
common envelope (separation 150-3000 AU), and common disk (separation < 100
AU). These three groups can be linked with fragmentation events during the star
formation process: separate envelopes from prompt initial fragmentation and the
separate collapse of a loosely condensed cloud, common envelopes from
fragmentation of a moderately centrally condensed spherical system, and common
disk from fragmentation of a high angular momentum circumstellar disk.Comment: 47 Pages, 18 Figures, ApJ accepte
Coincident, 100 kpc-scale damped Lyman alpha absorption towards a binary QSO: how large are galaxies at z ~ 3?
We report coincident damped Lyman alpha (DLA) and sub-DLA absorption at z =
2.66 and z = 2.94 towards the z ~ 3 13.8 arcsecond separation binary quasar
SDSS 1116+4118 AB. At the redshifts of the absorbers, this angular separation
corresponds to a proper transverse separation of ~ 110 kpc. A third absorber, a
sub-DLA at z = 2.47, is detected towards SDSS 1116+4118 B, but no corresponding
high column density absorber is present towards SDSS 1116+4118 A. We use high
resolution galaxy simulations and a clustering analysis to interpret the
coincident absorption and its implications for galaxy structure at z ~ 3. We
conclude that the common absorption in the two lines of sight is unlikely to
arise from a single galaxy, or a galaxy plus satellite system, and is more
feasibly explained by a group of two or more galaxies with separations ~ 100
kpc. The impact of these findings on single line of sight observations is also
discussed; we show that abundances of DLAs may be affected by up to a few
tenths of a dex by line of sight DLA blending. From a Keck ESI spectrum of the
two quasars, we measure metal column densities for all five absorbers and
determine abundances for the three absorbers with log N(HI) > 20. For the two
highest N(HI) absorbers, we determine high levels of metal enrichment,
corresponding to 1/3 and 1/5 solar. These metallicities are amongst the highest
measured for DLAs at any redshift and are consistent with values measured in
Lyman break galaxies at 2 < z < 3. For the DLA at z = 2.94 we also infer an
approximately solar ratio of alpha-to-Fe peak elements from [S/Zn] = +0.05, and
measure an upper limit for the molecular fraction in this particular line of
sight of log f(H_2)< -5.5.Comment: Accepted for publication in MNRAS. Full resolution simulation images
available in pdf copy of the manuscript at
http://www.astro.uvic.ca/~sara/1116.pd
Transgenic expression of the dicotyledonous pattern recognition receptor EFR in rice leads to ligand-dependent activation of defense responses
Plant plasma membrane localized pattern recognition receptors (PRRs) detect extracellular pathogen-associated molecules. PRRs such as Arabidopsis EFR and rice XA21 are taxonomically restricted and are absent from most plant genomes. Here we show that rice plants expressing EFR or the chimeric receptor EFR::XA21, containing the EFR ectodomain and the XA21 intracellular domain, sense both Escherichia coli- and Xanthomonas oryzae pv. oryzae (Xoo)-derived elf18 peptides at sub-nanomolar concentrations. Treatment of EFR and EFR::XA21 rice leaf tissue with elf18 leads to MAP kinase activation, reactive oxygen production and defense gene expression. Although expression of EFR does not lead to robust enhanced resistance to fully virulent Xoo isolates, it does lead to quantitatively enhanced resistance to weakly virulent Xoo isolates. EFR interacts with OsSERK2 and the XA21 binding protein 24 (XB24), two key components of the rice XA21-mediated immune response. Rice-EFR plants silenced for OsSERK2, or overexpressing rice XB24 are compromised in elf18-induced reactive oxygen production and defense gene expression indicating that these proteins are also important for EFR-mediated signaling in transgenic rice. Taken together, our results demonstrate the potential feasibility of enhancing disease resistance in rice and possibly other monocotyledonous crop species by expression of dicotyledonous PRRs. Our results also suggest that Arabidopsis EFR utilizes at least a subset of the known endogenous rice XA21 signaling components
Control of star formation by supersonic turbulence
Understanding the formation of stars in galaxies is central to much of modern
astrophysics. For several decades it has been thought that stellar birth is
primarily controlled by the interplay between gravity and magnetostatic
support, modulated by ambipolar diffusion. Recently, however, both
observational and numerical work has begun to suggest that support by
supersonic turbulence rather than magnetic fields controls star formation. In
this review we outline a new theory of star formation relying on the control by
turbulence. We demonstrate that although supersonic turbulence can provide
global support, it nevertheless produces density enhancements that allow local
collapse. Inefficient, isolated star formation is a hallmark of turbulent
support, while efficient, clustered star formation occurs in its absence. The
consequences of this theory are then explored for both local star formation and
galactic scale star formation. (ABSTRACT ABBREVIATED)Comment: Invited review for "Reviews of Modern Physics", 87 pages including 28
figures, in pres
Metabolic inactivation of estrogens in breast tissue by UDP-glucuronosyltransferase enzymes: an overview
The breast tissue is the site of major metabolic conversions of estradiol (E(2)) mediated by specific cytochromes P450 hydroxylations and methylation by catechol-O-methytransferase. In addition to E(2 )itself, recent findings highlight the significance of 4-hydroxylated estrogen metabolites as chemical mediators and their link to breast cancer development and progression, whereas, in opposition, 2-methoxylated estrogens appear to be protective. Recent data also indicate that breast tissue possesses enzymatic machinery to inactivate and eliminate E(2 )and its oxidized and methoxylated metabolites through conjugation catalyzed by UDP-glucuronosyltransferases (UGTs), which involves the covalent addition of glucuronic acid. In opposition to other metabolic pathways of estrogen, the UGT-mediated process leads to the formation of glucuronides that are devoid of biologic activity and are readily excreted from the tissue into the circulation. This review addresses the most recent findings on the identification of UGT enzymes that are responsible for the glucuronidation of E(2 )and its metabolites, and evidence regarding their potential role in breast cancer
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