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Search Results: 1 - 10 of 219520 matches for " C. Packham "
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Canaricam: capabilities and current status
C. Packham,C. M. Telesco
Revista mexicana de astronomía y astrofísica , 2007,
Abstract: La Universidad de Florida ha desarrollado una c amara vers atil del IR medio para el Gran Telescopio de Canarias de 10.4-m. El instrumento CanariCam utiliza un solo detector de silic on dopado con ars enico de 320 249 pixeles, enfriado a menos de 10K. CanariCam estar a listo para observaciones de primera luz en el GTC, ofreciendo capacidad de obtener im agenes limitada por difracci on mediante un juego extenso de ltros, espectroscop a de resoluci on baja y moderada, un modo coronogr a co y, por primera vez en longitudes de onda del infrarrojo medio, un modo de polar metro de doble haz. Describimos brevemente el instrumento y presentamos pruebas recientes de laboratorio del instrumento.
A mid-IR survey of local AGN with GTC/CanariCam
A. Alonso-Herrero,C. Packham
Physics , 2012,
Abstract: We describe a mid-infrared (MIR) survey of local AGN to be conducted with the CanariCam instrument on the Gran Telescopio Canarias (GTC). We will obtain MIR imaging and spectroscopy of a sample of ~100 AGN covering six orders of magnitude in AGN luminosity, and including different AGN classes (e.g., LINERs, Seyfert 1s and 2s, QSO). The main goals are: (1) to test unification of Type 1 and Type 2 AGN, (2) to study the star formation activity around AGN, and (3) to explore the role of the dusty torus in low-luminosity AGN.
CanariCam: The Multi-Mode Mid-IR Instrument for the GTC
C. Packham,C. M. Telesco,J. H. Hough,C. Ftaclas
Revista mexicana de astronomía y astrofísica , 2005,
Abstract:
Spatially-resolved mid-infrared spectroscopy of IC 5063
S. Young,C. Packham,C. M. Telesco,J. T. Radomski
Revista mexicana de astronomía y astrofísica , 2007,
Abstract: N-band spectroscopy of the radio strong Seyfert 2 active galaxy IC 5063 (z=0.0110) was obtained using Gemini South in conjunc- tion with the Thermal-Region Camera Spec- trograph (T-ReCS; Telesco et al. 1998). T- ReCS uses a Raytheon 320x240 pixel SiAs IBC array, at a plate scale of 0.08900 pixel-1. The observations were conducted on the nights of UT 2005 July 7 and 9 using the standard chop-nod technique to remove the time-variable sky background, telescope ther- mal emission, and the so-called 1/f detector noise. A 0.6700 wide slit was used aligned along the position angle of the radio axis at 305o(Morganti et al. 1998) and close to the extended narrow line emission region (ENLR) axis at 303_(Colina et al. 1991). The total on- source integration time was 1212 seconds.
Gemini Mid-IR Polarimetry of NGC 1068
R. E. Mason,C. Packham,S. Young,R. S. Fisher
Revista mexicana de astronomía y astrofísica , 2008,
Abstract:
Mid-ir emission from the nucleus of centaurus a
J. T. Radomski,C. Packham,N. A. Levenson,E. Perlman
Revista mexicana de astronomía y astrofísica , 2007,
Abstract: We present high spatial resolution mid-IR images of the nuclear region of Centaurus A. Images were obtained at 8.8 um, N-band (10.5uem), and 18.3um using the mid-IR in- strument T-ReCS on Gemini South, a pro- genitor to CanariCam on the Gran Telescopio Canarias (GTC).
Influence of Adult Height on Rheumatoid Arthritis: Association with Disease Activity, Impairment of Joint Function and Overall Disability
Ying Chen, Zanzhe Yu, Jonathan C. Packham, Derek L. Mattey
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0064862
Abstract: Objectives To investigate whether normal variation of adult height is associated with clinical characteristics in rheumatoid arthritis (RA), including disease activity (DAS28), impairment of joint function (mechanical joint score, MJS) and overall disability (health assessment questionnaire, HAQ). Methods A cohort (134 males, 287 females) of consecutively recruited RA patients of Northern European origin was studied. Height, weight and demographic information were obtained. A core set of disease measurements, including DAS28, MJS and HAQ, were recorded at baseline, 12 and 24 months. Other clinical variables (e.g. disease duration, IgM rheumatoid factor, antibodies to cyclic citrullinated peptide, C-reactive protein, erythrocyte sedimentation rate) were recorded at baseline. Socioeconomic status, smoking status, comorbid condition, other autoimmune conditions and drug therapy were also recorded. Associations were analyzed using univariate statistics and multivariate linear regression models. Mediation tests were also carried out for evaluating the relationship between gender, height and disease measures. Results In males, height was inversely associated with DAS28, MJS and HAQ (at baseline and over 24 months) independent of other factors (e.g. weight, body mass index, age, disease duration, osteoporosis, autoantibodies, erosive disease, joint replacement, steroid use, smoking status, socioeconomic status and comorbid disease). In females, a similar trend was seen but the relationships were non significant. In the whole population, the association of female gender with more active disease and poor function disappeared after adjustment for height. Mediation analysis indicated that height served as a full mediator in the relationship of gender with disease activity and overall disability. Confirmation of these findings was demonstrated in a second RA population (n = 288). Conclusion Adult height is inversely associated with disease activity, impairment of joint function and overall disability in RA, particularly in males. The association of female sex with more severe disease activity and disability appears to be mediated by smaller stature.
An HST Morphological Survey of Faint EROs
David G. Gilbank,Ian Smail,R. J. Ivison,C. Packham
Physics , 2003, DOI: 10.1111/j.1365-2966.2003.07153.x
Abstract: We present the results from a survey for Extremely Red Objects (EROs) in deep, high resolution optical images taken from the Hubble Space Telescope (HST) Medium Deep Survey. We have surveyed 35 deep F814W HST/WFPC2 fields in the near-infrared to a typical depth of K~20. From a total area of 206 arcmin^2 and to a limit of K=20.0 we identify 224 EROs ((1.14+/-0.08) arcmin^-2) with (I_{814}-K)=>4.0 and 83 ((0.41+/-0.05) arcmin^-2) with (I_{814}-K)=>5.0. We find that the slope of the number counts of the (I_{814}-K)=>4.0 EROs flattens beyond K~19, in line with results from previous surveys, and the typical colours of the EROs become redder beyond the break magnitude. We morphologically classify our ERO sample using visual and quantitative schemes and find that 35% of our sample exhibit clear disk components, 15% are disturbed or irregular, a further 30% are either spheroidal or compact and the remaining 20% are unclassifiable. Using a quantitative measure of morphology, we find that the ERO morphological distribution evolves across the break in their counts, such that low concentration (disk-like) galaxies decline. We relate the morphological and colour information for our EROs and conclude that those EROs morphologically classified as bulges do indeed possess SEDs consistent with passive stellar populations; while EROs with dusty star-forming SEDs are mostly associated with disk-like and peculiar galaxies. However, ~30% of disk EROs reside in the passive region of I/J/K colour-colour space. These could be either genuinely passive systems, lower redshift contaminants to the high-z ERO population, or systems with composite star-forming and passive SEDs.
Results of high-spatial resolution mid-ir imaging of NGC7172
J. J. Schaefer,C. Packham,J. T. Radomski,C. M. Telesco
Revista mexicana de astronomía y astrofísica , 2007,
Abstract: We present results from an analysis of high- spatial resolution images of the Seyfert 2 galaxy NGC 7172, as observed by T-ReCS on Gemini South at 10.4 microns. We model the IR SED of this AGN using our observations and archival data. We find that a best fit model describes the observed SED with a reddened stellar population and 2 thermal components.
Interaction between smoking and functional polymorphism in the TGFB1 gene is associated with ischaemic heart disease and myocardial infarction in patients with rheumatoid arthritis: a cross-sectional study
Ying Chen, Peter T Dawes, Jon C Packham, Derek L Mattey
Arthritis Research & Therapy , 2012, DOI: 10.1186/ar3804
Abstract: PCR-based assays were used to determine the genotypes of TGFB1 SNPs including TGFB1-509 C/T (rs1800469, in the promoter region), +868 T/C (rs1800470, in exon 1) and +913 G/C (rs1800471, in exon 1) in 414 subjects with established RA. Genotyping for the +868 SNP was also carried out on a second study population of RA patients (n = 259) with early disease. Serum levels of TGF-beta1 were measured using a commercial ELISA kit. Smoking history and IHD/MI status were obtained on each patient. Associations with IHD/MI were assessed using contingency tables and logistic regression analyses.The heterozygous genotype of TGFB+868 was associated with an increased risk of IHD (OR 2.14, 95% CI 1.30 - 3.55) and MI (OR 2.42, 95% CI 1.30-4.50), compared to the homozygous genotypes combined. Smoking was an independent risk for IHD and MI, and evidence of interaction between smoking and TGFB+868 was found. Multivariate analyses indicated that the strongest associations with IHD and MI were due to the combined effect of the TGFB1+868 TC genotype and smoking (OR 2.75, 95% CI 1.59-4.75; and OR 2.58 95% CI 1.33-4.99, respectively), independent of other cardiovascular risk factors. The association of the +868 TC genotype and evidence of +868 TC-smoking interaction with IHD were replicated in a second population of RA patients with early disease. Serum TGF-beta1 levels were not associated with TGFB1 genetic variations, smoking or IHD/MI status.Interaction between smoking and polymorphism in the TGFB1 gene may influence the risk of IHD and MI in patients with RA.The excess risk of cardiovascular disease (CVD) associated with rheumatoid arthritis (RA) has long been recognized [1-4]. Among cardiovascular (CV) conditions, ischaemic heart disease (IHD), usually due to coronary artery disease (CAD), is the most common comorbidity in RA. A higher incidence of CAD in patients with RA in comparison with control subjects has been reported, and patients with RA are more likely to experience unrecogniz
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