664 research outputs found

    Interferometric imaging of the high-redshift radio galaxy, 4C60.07: An SMA, Spitzer and VLA study reveals a binary AGN/starburst

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    ‘The definitive version is available at www3.interscience.wiley.com '. Copyright Blackwell / RAS. DOI: 10.1111/j.1365-2966.2008.13811.xPeer reviewe

    Effect of Al substitution on the magnetocaloric properties of La(Fe SiAl)

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    Here we study the influence of Al doping on the magnetization, heat capacity, and entropy change of La(FeSiAl ) where x = 0, 0.048, and 0.081. When x = 0, the system shows a remarkably sharp heat capacity feature associated with spin fluctuations coincident with, but quite distinct from the latent heat spike of the first order paramagnetic to ferromagnetic phase transition. With the addition of Al the magnetic and calorimetric features become more distributed in field, suggesting that Al adds disorder to the system. For both finite x compositions studied here, the latent heat disappears and the transition can be classified as second order. Although the entropy change associated with the transition is reduced once Al is substituted for Si, the adiabatic temperature change, ΔT is still significant. In La(Fe [Al) the balance between changes in the field dependence of the heat capacity with respect to overall ΔT gain is highlighted, showing that a small amount of Al doping clearly offers some advantage for application

    Adaptation and validation of an existing bottom-up model for simulating temporal and inter-dwelling variations of residential appliance and lighting demands

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    The design and analysis of community-scale energy systems and incentives is a non-trivial task. The challenge of such undertakings is the well-documented uncertainty of building occupant behaviours. This is especially true in the residential sector, where occupants are given more freedom of activity compared to work environments. Further complicating matters is the dearth of available measured data. Building performance simulation tools are one approach to community energy analysis, however such tools often lack realistic models for occupant-driven demands, such as appliance and lighting (AL) loads. For community-scale analysis, such AL models must also be able to capture the temporal and inter-dwelling variation to achieve realistic estimates of aggregate electrical demand. This work adapts the existing Centre for Renewable Energy Systems Technology (CREST) residential energy model to simulate Canadian residential AL demands. The focus of the analysis is to determine if the daily, seasonal, and inter-dwelling variation of AL demands estimated by the CREST model is realistic. An in-sample validation is conducted on the model using 22 high-resolution measured AL demand profiles from dwellings located in Ottawa, Canada. The adapted CREST model is shown to broadly capture the variation of AL demand variations observed in the measured data, however seasonal variation in daily AL demand behaviour was found to be under-estimated by the model. The average and variance of daily load factors was found to be similar between measured and modelled. The model was found to under-predict the daily coincidence factors of aggregated demands, although the variance of coincident factors was shown to be similar between measured and modelled. A stochastic baseload input developed for

    Systematic model behavior of adsorption on flat surfaces

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    A low density film on a flat surface is described by an expansion involving the first four virial coefficients. The first coefficient (alone) yields the Henry's law regime, while the next three correct for the effects of interactions. The results permit exploration of the idea of universal adsorption behavior, which is compared with experimental data for a number of systems

    Systematic review of economic evaluations and cost analyses of guideline implementation strategies

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    Objectives To appraise the quality of economic studies undertaken as part of evaluations of guideline implementation strategies; determine their resources use; and recommend methods to improve future studies. Methods Systematic review of economic studies undertaken alongside robust study designs of clinical guideline implementation strategies published (1966-1998). Studies assessed against the BMJ economic evaluations guidelines for each stage of the guideline process (guideline development, implementation and treatment). Results 235 studies were identified, 63 reported some information on cost. Only 3 studies provided evidence that their guideline was effective and efficient. 38 reported the treatment costs only, 12 implementation and treatment costs, 11 implementation costs alone, and two guideline development, implementation and treatment costs. No study gave reasonably complete information on costs. Conclusions Very few satisfactory economic evaluations of guideline implementation strategies have been performed. Current evaluations have numerous methodological defects and rarely consider all relevant costs and benefits. Future evaluations should focus on evaluating the implementation of evidence based guidelines. Keywords: Cost-effectiveness analysis, physician (or health care professional) behaviour, practice guidelines, quality improvement, systematic review.Peer reviewedAuthor versio

    MTBVAC vaccination protects rhesus macaques against aerosol challenge with M. tuberculosis and induces immune signatures analogous to those observed in clinical studies

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    A single intradermal vaccination with MTBVAC given to adult rhesus macaques was well tolerated and conferred a significant improvement in outcome following aerosol exposure to M. tuberculosis compared to that provided by a single BCG vaccination. Vaccination with MTBVAC resulted in a significant reduction in M. tuberculosis infection-induced disease pathology measured using in vivo medical imaging, in gross pathology lesion counts and pathology scores recorded at necropsy, the frequency and severity of pulmonary granulomas and the frequency of recovery of viable M. tuberculosis from extrapulmonary tissues following challenge. The immune profiles induced following immunisation with MTBVAC reflect those identified in human clinical trials of MTBVAC. Evaluation of MTBVAC- and TB peptide-pool-specific T-cell cytokine production revealed a predominantly Th1 response from poly- (IFN-Âż+TNF-a+IL2+) and multi-(IFN-Âż+TNF-a+) functional CD4 T cells, while only low levels of Th22, Th17 and cytokine-producing CD8 T-cell populations were detected together with low-level, but significant, increases in CFP10-specific IFN-Âż secreting cells. In this report, we describe concordance between immune profiles measured in clinical trials and a macaque pre-clinical study demonstrating significantly improved outcome after M. tuberculosis challenge as evidence to support the continued development of MTBVAC as an effective prophylactic vaccine for TB vaccination campaigns

    Food availability, energetic constraints and reproductive development in a wild seasonally breeding songbird

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    1. In many organisms, food availability is a proximate cue that synchronizes seasonal development of the reproductive system with optimal environmental conditions. Growth of the gonads and secondary sexual characteristics is orchestrated by the hypothalamic–pituitary–gonadal (HPG) axis. However, our understanding of the physiological mechanisms by which food availability modulates activity of the HPG axis is limited. 2. It is thought that many factors, including energetic status, modulate seasonal reproductive activation. We tested the hypothesis that food availability modulates the activity of the HPG axis in a songbird. Specifically, we food‐restricted captive adult male Abert's Towhees Melozone aberti for 2 or 4 weeks during photoinduced reproductive development. A third group (control) received ad libitum food throughout. We measured multiple aspects of the reproductive system including endocrine activity of all three levels of the HPG axis [i.e. hypothalamic gonadotropin‐releasing hormone‐I (GnRH‐I), plasma luteinizing hormone (LH) and testosterone (T)], and gonad morphology. Furthermore, because gonadotropin‐inhibitory hormone (GnIH) and neuropeptide Y (NPY; a potent orexigenic peptide) potentially integrate information on food availability into seasonal reproductive development, we also measured the brain levels of these peptides. 3. At the hypothalamic level, we detected no effect of food restriction on immunoreactive (ir) GnRH‐I, but the duration of food restriction was inversely related to the size of ir‐GnIH perikarya. Furthermore, the number of ir‐NPY cells was higher in food‐restricted than control birds. Food restriction did not influence photoinduced testicular growth, but decreased plasma LH and T, and width of the cloacal protuberance, an androgen‐sensitive secondary sexual characteristic. Returning birds to ad libitum food availability had no effect on plasma LH or T, but caused the cloacal protuberance to rapidly increase in size to that of ad libitum‐fed birds. 4. Our results support the tenet that food availability modulates photoinduced reproductive activation. However, they also suggest that this modulation is complex and depends upon the level of the HPG axis considered. At the hypothalamic level, our results are consistent with a role for the GnIH and NPY systems in integrating information on energetic status. There also appears to be a role for endocrine function at the anterior pituitary gland and testicular levels in modulating reproductive development in the light of energetic status and independently of testicular growth

    Event-by-Event Fluctuations in Particle Multiplicities and Transverse Energy Produced in 158.A GeV Pb+Pb collisions

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    Event-by-event fluctuations in the multiplicities of charged particles and photons, and the total transverse energy in 158⋅A\cdot A GeV Pb+Pb collisions are studied for a wide range of centralities. For narrow centrality bins the multiplicity and transverse energy distributions are found to be near perfect Gaussians. The effect of detector acceptance on the multiplicity fluctuations has been studied and demonstrated to follow statistical considerations. The centrality dependence of the charged particle multiplicity fluctuations in the measured data has been found to agree reasonably well with those obtained from a participant model. However for photons the multiplicity fluctuations has been found to be lower compared to those obtained from a participant model. The multiplicity and transverse energy fluctuations have also been compared to those obtained from the VENUS event generator.Comment: To appear in Physical Review C; changes : more detailed discussion on errors and few figures modifie

    Study of the B^0 Semileptonic Decay Spectrum at the Upsilon(4S) Resonance

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    We have made a first measurement of the lepton momentum spectrum in a sample of events enriched in neutral B's through a partial reconstruction of B0 --> D*- l+ nu. This spectrum, measured with 2.38 fb**-1 of data collected at the Upsilon(4S) resonance by the CLEO II detector, is compared directly to the inclusive lepton spectrum from all Upsilon(4S) events in the same data set. These two spectra are consistent with having the same shape above 1.5 GeV/c. From the two spectra and two other CLEO measurements, we obtain the B0 and B+ semileptonic branching fractions, b0 and b+, their ratio, and the production ratio f+-/f00 of B+ and B0 pairs at the Upsilon(4S). We report b+/b0=0.950 (+0.117-0.080) +- 0.091, b0 = (10.78 +- 0.60 +- 0.69)%, and b+ = (10.25 +- 0.57 +- 0.65)%. b+/b0 is equivalent to the ratio of charged to neutral B lifetimes, tau+/tau0.Comment: 14 page, postscript file also available at http://w4.lns.cornell.edu/public/CLN
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