12,841 research outputs found
FIFO Buffers in tie Sauce
International audienceThis paper introduces a new semantics for FIFO buffers (more usually called channels) in a parallel programming language, B(PN)². This semantics is given in terms of M-nets, which form an algebra of labelled high-level Petri nets. The proposed approach makes usage of asynchronous link operator, newly introduced in the algebra of M-nets, and repairs some drawbacks of the previous M-net semantics. Channels are now fully expressible within the algebra (it was not the case), they are significantly smaller (in number of places), and they offer several other advantages
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Children's acquisition of science terms: does fast mapping work?
About the book: This proceedings contains 99 selected papers from the 8th Conference of the International Association for the Study of Child Language (IASCL) held in Donostia-San Sebastián in the Spanish Basque Country in July 1999. The proceedings includes the plenary addresses by Jean-Paul Bronckart, Brian MacWhinney, and Miquel Siguan. The other 96 papers are organized into sections on bilingualism, discourse, phonology, language disorders, lexicon, morphology, syntax, and signed languages. Several of these sections include symposia with introductions as well as individual papers
Detoxification in rehabilitation in England: effective continuity of care or unhappy bedfellows?
There is evidence that residential detoxification alone does not provide satisfactory treatment outcomes and that outcomes are significantly enhanced when clients completing residential detoxification attend rehabilitation services (Gossop, Marsden, Stewart, & Rolfe, 1999; Ghodse, Reynolds, Baldacchino, et al., 2002). One way of increasing the likelihood of this continuity of treatment is by providing detoxification and rehabilitation within the same treatment facility to prevent drop-out, while the client awaits a rehabilitation bed or in the transition process. However, there is little research evidence available on the facilities that offer both medical detoxification and residential rehabilitation. The current study compares self-reported treatment provision in 87 residential rehabilitation services in England, 34 of whom (39.1%) reported that they offered detoxification services within their treatment programmes. Although there were no differences in self-reported treatment philosophies, residential rehabilitation services that offered detoxification were typically of shorter duration overall, had significantly more beds and reported offering more group work than residential rehabilitation services that did not offer detoxification. Outcomes were also different, with twice as many clients discharged on disciplinary grounds from residential rehabilitation services without detoxification facilities. The paper questions the UK classification of residential drug treatment services as either detoxification or rehabilitation and suggests the need for greater research focus on the aims, processes and outcomes of this group of treatment providers
The final two redshifts for radio sources from the equatorial BRL sample
Best, Rottgering and Lehnert (1999, 2000a) defined a new sample of powerful
radio sources from the Molonglo Reference Catalogue, for which redshifts were
compiled or measured for 177 of the 178 objects. For the final object,
MRC1059-010 (3C249), the host galaxy is here identified using near-infrared
imaging, and the redshift is determined from VLT spectroscopy. For one other
object in the sample, MRC0320+053 (4C05.14), the literature redshift has been
questioned: new spectroscopic observations of this object are presented,
deriving a corrected redshift. With these two results, the spectroscopic
completeness of this sample is now 100%.
New redshifts are also presented for PKS0742+10 from the Wall & Peacock 2.7
GHz catalogue, and PKS1336+003 from the Parkes Selected Regions. PKS0742+10
shows a strong neutral hydrogen absorption feature in its Lyman-alpha emission
profile.Comment: 4 pages. LaTeX. Accepted for publication in MNRA
Deletion of EP4 in S100a4-lineage cells reduces scar tissue formation during early but not later stages of tendon healing
AbstractTendon injuries heal via scar tissue rather than regeneration. This healing response forms adhesions between the flexor tendons in the hand and surrounding tissues, resulting in impaired range of motion and hand function. Mechanistically, inflammation has been strongly linked to adhesion formation, and Prostaglandin E2 (PGE2) is associated with both adhesion formation and tendinopathy. In the present study we tested the hypothesis that deletion of the PGE2 receptor EP4 in S100a4-lineage cells would decrease adhesion formation. S100a4-Cre; EP4flox/flox (EP4cKOS100a4) repairs healed with improved gliding function at day 14, followed by impaired gliding at day 28, relative to wild type. Interestingly, EP4cKOS100a4 resulted in only transient deletion of EP4, suggesting up-regulation of EP4 in an alternative cell population in these mice. Loss of EP4 in Scleraxis-lineage cells did not alter gliding function, suggesting that Scx-lineage cells are not the predominant EP4 expressing population. In contrast, a dramatic increase in α-SMA+, EP4+ double-positive cells were observed in EP4cKOS100a4 suggesting that EP4cKOS100a4 repairs heal with increased infiltration of EP4 expressing α-SMA myofibroblasts, identifying a potential mechanism of late up-regulation of EP4 and impaired gliding function in EP4cKOS100a4 tendon repairs.</jats:p
The cosmic evolution of radio-AGN feedback to z=1
This paper presents the first measurement of the radio luminosity function of
'jet-mode' (radiatively-inefficient) radio-AGN out to z=1, in order to
investigate the cosmic evolution of radio-AGN feedback. Eight radio source
samples are combined to produce a catalogue of 211 radio-loud AGN with
0.5<z<1.0, which are spectroscopically classified into jet-mode and
radiative-mode (radiatively-efficient) AGN classes. Comparing with large
samples of local radio-AGN from the Sloan Digital Sky Survey, the cosmic
evolution of the radio luminosity function of each radio-AGN class is
independently derived. Radiative-mode radio-AGN show an order of magnitude
increase in space density out to z~1 at all luminosities, consistent with these
AGN being fuelled by cold gas. In contrast, the space density of jet-mode
radio-AGN decreases with increasing redshift at low radio luminosities (L_1.4 <
1e24 W/Hz) but increases at higher radio luminosities. Simple models are
developed to explain the observed evolution. In the best-fitting models, the
characteristic space density of jet-mode AGN declines with redshift in
accordance with the declining space density of massive quiescent galaxies,
which fuel them via cooling of gas in their hot haloes. A time delay of 1.5-2
Gyr may be present between the quenching of star formation and the onset of
jet-mode radio-AGN activity. The behaviour at higher radio luminosities can be
explained either by an increasing characteristic luminosity of jet-mode
radio-AGN activity with redshift (roughly as (1+z) cubed) or if the jet-mode
radio-AGN population also includes some contribution of cold-gas-fuelled
sources seen at a time when their accretion rate was low. Higher redshifts
measurements would distinguish between these possibilities.Comment: Accepted for publication in MNRA
Electrically Small Supergain Arrays
The theory, computer simulations, and experimental measurements are presented
for electrically small two-element supergain arrays with near optimal endfire
gains of 7 dB. We show how the difficulties of narrow tolerances, large
mismatches, low radiation efficiencies, and reduced scattering of electrically
small parasitic elements are overcome by using electrically small resonant
antennas as the elements in both separately driven and singly driven
(parasitic) two-element electrically small supergain endfire arrays. Although
rapidly increasing narrow tolerances prevent the practical realization of the
maximum theoretically possible endfire gain of electrically small arrays with
many elements, the theory and preliminary numerical simulations indicate that
near maximum supergains are also achievable in practice for electrically small
arrays with three (and possibly more) resonant elements if the decreasing
bandwidth with increasing number of elements can be tolerated.Comment: 10 pages, 11 figures, submitted to IEEE Transactions on Antennas and
Propagation (December 2006
Effluent charges : good government, but bad business
Includes bibliographical references.In examining current government policy on regulating negative externalities caused by pollution, it becomes obvious that more efficient policies are needed. One such policy, which many economists support, is an effluent charge.
However, the groups who influence government most rarely support effluent charges. In this paper I will cover common economic theory used to support effluent charges, mention some arguments against effluent charges, and finish with their economic affect on business
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