University of Arizona

About: University of Arizona is a education organization based out in Tucson, Arizona, United States. It is known for research contribution in the topics: Population & Galaxy. The organization has 63805 authors who have published 155998 publications receiving 6854915 citations. The organization is also known as: UA & U of A.

A Comparative Review of Generic Quality-of-Life Instruments

Abstract: The assessment of health-related quality of life (HR-QOL) is an essential element of healthcare evaluation Hundreds of generic and specific HR-QOL instruments have been developed Generic HR-QOL instruments are designed to be applicable across a wide range of populations and interventions Specific HR-QOL measures are designed to be relevant to particular interventions or in certain subpopulations (eg individuals with rheumatoid arthritis) This review examines 7 generic HR-QOL instruments: (i) the Medical Outcomes Study 36-Item Short Form (SF-36) health survey; (ii) the Nottingham Health Profile (NHP); (iii) the Sickness Impact Profile (SIP); (iv) the Dartmouth Primary care Cooperative Information Project (COOP) Charts; (v) the Quality of Well-Being (QWB) Scale; (vi) the Health Utilities Index (HUI); and (vii) the EuroQol Instrument (EQ-5D) These instruments were selected because they are commonly used and/or cited in the English language literature The 6 characteristics of an instrument addressed by this review are: (i) conceptual and measurement model; (ii) reliability; (iii) validity; (iv) respondent and administrative burden; (v) alternative forms; and (vi) cultural and language adaptations Of the instruments reviewed, the SF-36 health survey is the most commonly used HR-QOL measure It was developed as a short-form measure of functioning and well-being in the Medical Outcomes Study The Dartmouth COOP Charts were designed to be used in everyday clinical practice to provide immediate feedback to clinicians about the health status of their patients The NHP was developed to reflect lay rather than professional perceptions of health The SIP was constructed as a measure of sickness in relation to impact on behaviour The QWB, HUI and EQ-5D are preference-based measures designed to summarise HR-QOL in a single number ranging from 0 to 1 We found that there are no uniformly ‘worst’or ‘best’ performing instruments The decision to use one over another, to use a combination of 2 or more, to use a profile and/or a preference-based measure or to use a generic measure along with a targeted measure will be driven by the purpose of the measurment In addition, the choice will depend on a variety of factors including the characteristics of the population (eg age, health status, language/culture) and the environment in which the measurement is undertaken (eg clinical trial, routine physician visit) We provide our summary of the level of evidence in the literature regarding each instrument’s characteristics based on the review criteria The potential user of these instruments should base their instrument selection decision on the characteristics that are most relevant to their particular HR-QOL measurment needs

Measuring the Baryon Acoustic Oscillation scale using the Sloan Digital Sky Survey and 2dF Galaxy Redshift Survey

Abstract: We introduce a method to constrain general cosmological models using Baryon Acoustic Oscillation (BAO) distance measurements from galaxy samples covering different redshift ranges, and apply this method to analyse samples drawn from the Sloan Digital Sky Survey (SDSS) and 2dF Galaxy Redshift Survey (2dFGRS). BAOs are detected in the clustering of the combined 2dFGRS and SDSS main galaxy samples, and measure the distance–redshift relation at z= 0.2. BAOs in the clustering of the SDSS luminous red galaxies measure the distance–redshift relation at z= 0.35. The observed scales of the BAOs calculated from these samples and from the combined sample are jointly analysed using estimates of the correlated errors, to constrain the form of the distance measure DV(z) ≡[(1 +z)2D2Acz/H(z)]1/3. Here DA is the angular diameter distance, and H(z) is the Hubble parameter. This gives rs/DV(0.2) = 0.1980 ± 0.0058 and rs/DV(0.35) = 0.1094 ± 0.0033 (1σ errors), with a correlation coefficient of 0.39, where rs is the comoving sound horizon scale at recombination. Matching the BAOs to have the same measured scale at all redshifts then gives DV(0.35)/DV(0.2) = 1.812 ± 0.060. The recovered ratio is roughly consistent with that predicted by the higher redshift Supernova Legacy Survey (SNLS) supernova data for Λ cold dark matter cosmologies, but does require slightly stronger cosmological acceleration at a low redshift. If we force the cosmological model to be flat with constant w, then we find Ωm= 0.249 ± 0.018 and w=−1.004 ± 0.089 after combining with the SNLS data, and including the WMAP measurement of the apparent acoustic horizon angle in the cosmic microwave background.

Geological records of the Lhasa-Qiangtang and Indo-Asian collisions in the Nima area of central Tibet

Abstract: A geological and geochronologic investigation of the Nima area along the Jurassic–Early Cretaceous Bangong suture of central Tibet (∼32°N, ∼87°E) provides well-dated records of contractional deformation and sedimentation during mid-Cretaceous and mid-Tertiary time. Jurassic to Lower Cretaceous (≤125 Ma) marine sedimentary rocks were transposed, intruded by granitoids, and uplifted above sea level by ca. 118 Ma, the age of the oldest nonmarine strata documented. Younger nonmarine Cretaceous rocks include ca. 110–106 Ma volcanic-bearing strata and Cenomanian red beds and conglomerates. The Jurassic–Cretaceous rocks are unconformably overlain by up to 4000 m of Upper Oligocene to Lower Miocene lacustrine, nearshore lacustrine, and fluvial red-bed deposits. Paleocurrent directions, growth stratal relationships, and a structural restoration of the basin show that Cretaceous–Tertiary nonmarine deposition was coeval with mainly S-directed thrusting in the northern part of the Nima area and N-directed thrusting along the southern margin of the basin. The structural restoration suggests >58 km (>47%) of N–S shortening following Early Cretaceous ocean closure and ∼25 km shortening (∼28%) of Nima basin strata since 26 Ma. Cretaceous magmatism and syncontractional basin development are attributed to northward low-angle subduction of the Neotethyan oceanic lithosphere and Lhasa-Qiangtang continental collision, respectively. Tertiary syncontractional basin development in the Nima area was coeval with that along the Bangong suture in westernmost Tibet and the Indus-Yarlung suture in southern Tibet, suggesting simultaneous, renewed contraction along these sutures during the Oligocene-Miocene. This suture-zone reactivation immediately predated major displacement within the Himalayan Main Central thrust system shear zone, raising the possibility that Tertiary shortening in Tibet and the Himalayas may be interpretable in the context of a mechanically linked, composite orogenic system.

The co-production of science and policy in integrated climate assessments

Abstract: This paper examines the use of interactive models of research in the US regional integrated scientific assessments (RISAS), using as a case study the climate assessment of the Southwest (CLIMAS) It focuses on three components of regional climate assessments: interdisciplinarity, interaction with stakeholders and production of usable knowledge, and on the role of three explanatory variables––the level of ‘fit’ between state of knowledge production and application, disciplinary and personal flexibility, and availability of resources—which affect the co-production of science and policy in the context of integrated assessments It finds that although no single model can fulfill the multitude of goals of such assessments, it is in highly interactive models that the possibilities of higher levels of innovation and related social impact are most likely to occur

An ultraluminous quasar with a twelve-billion-solar-mass black hole at redshift 6.30

Abstract: So far, roughly 40 quasars with redshifts greater than z = 6 have been discovered(1-8) Each quasar contains a black hole with a mass of about one billion solar masses (10(9) M-circle dot)(2,6,7,9-13) The existence of such black holes when the Universe was less than one billion years old presents substantial challenges to theories of the formation and growth of black holes and the coevolution of black holes and galaxies(14) Here we report the discovery of an ultraluminous quasar, SDSS J01001302+2802258, at redshift z = 630 It has an optical and near-infrared luminosity a few times greater than those of previously known z > 6 quasars On the basis of the deep absorption trough(15) on the blue side of the Lyman-alpha emission line in the spectrum, we estimate the proper size of the ionized proximity zone associated with the quasar to be about 26 million light years, larger than found with other z > 61 quasars with lower luminosities(16) We estimate (on the basis of a near-infrared spectrum) that the black hole has a mass of similar to 12 x 10(10) M-circle dot, which is consistent with the 13 x 10(10) M-circle dot derived by assuming an Eddington-limited accretion rate