bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cost-effectiveness of a new combined immunosuppressive and anti-infectious regimen in kidney transplantation
Authors: Wasserfallen Jean-Blaise , Kast-Brückner Mira , Manuel Oriol , Venetz Jean-Pierre , Meylan Pascal R. A. , Pascual Manuel 
Published: July 2008

Objectives:The aims of this study were to assess the 1-year cost-effectiveness of a new combined immunosuppressive and anti-infectious regimen in kidney transplantation to prevent both rejection and infectious complications.Methods:Patients (pts) transplanted from January 2000 to March 2003 (Group A) and treated with a conventional protocol were compared with pts submitted to a combined regimen including universal cytomegalovirus (CMV) prophylaxis between April 2003 and July 2005 (Group B). Costs were computed from the hospital accounting system for hospital stays, and official tariffs for outpatient visits. Patients with incomplete costs data were excluded from analysis.Results:Fifty-three patients were analyzed in Group A, and 60 in Group B. Baseline characteristics including CMV serostatus were not significantly different between the two groups. Over 12 months after transplantation, acute rejections decreased from 41.5 percent in Group A to 6.7 percent in Group B (p&lt; .001), and CMV infections from 47 percent to 15 percent (p&lt; .001). Overall, readmissions decreased from 68 percent to 55 percent (p= .160), and average hospital days from 28 ± 19 to 20 ± 11 days (p&lt; .007). The average number of outpatient visits decreased from 49 ± 10 to 39 ± 8 (p&lt; .001). Average 1-year immunosuppressive and CMV prophylaxis costs (per patient) increased from CHF20,402 ± 7,273 to 27,375 ± 6,063 (p&lt; .001), graft rejection costs decreased from CHF4,595 ± 10,182 to 650 ± 3,167 (p= .005), CMV treatment costs from CHF2,270 ± 6,161 to 101 ± 326 (p= .008), and outpatient visits costs from CHF8,466 ± 1’721 to 6,749 ± 1,159 (p&lt; .001). Altogether, 1-year treatment costs decreased from CHF39’957 ± 16,573 to 36,204 ± 6,901 (p= .115).Conclusions: The new combined regimen administered in Group B was significantly more effective, and its additional costs were more than offset by savings associated with complications avoidance.
Comparison of three instruments assessing the quality of economic evaluations: A practical exercise on economic evaluations of the surgical treatment of obesity
Authors: Gerkens Sophie , Crott Ralph , Cleemput Irina , Thissen Jean-Paul , Closon Marie-Christine , Horsmans Yves , Beguin Claire 
Published: July 2008

Objectives:The increasing use of full economic evaluations has led to the development of various instruments to assess their quality. The purpose of this study was to compare the frequently usedBritish Medical Journal(BMJ) check-list and two new instruments: the Consensus Health Economic Criteria (CHEC) list and the Quality of Health Economic Studies (QHES) instrument. The analysis was based on a practical exercise on economic evaluations of the surgical treatment of obesity.Methods:The quality of nine selected studies was assessed independently by two health economists. To compare instruments, the Spearman rank correlation coefficient was calculated for each assessor. Moreover, the test–retest reliability for each instrument was assessed with the intraclass correlation coefficient (ICC) (3,1). Finally, the inter-rater agreement for each instrument was estimated at two levels: comparison of the total score of each article by the ICC(2,1) and comparison of results per item by kappa values.Results:The Spearman's rank correlation coefficient between instruments was usually high (rho &gt; 0.70). Furthermore, test–retest reliability was good for every instruments, that is, 0.98 (95 percent CI, 0.86–0.99) for the BMJ check-list, 0.97 (95 percent CI, 0.73–0.98) for the CHEC list, and 0.95 (95 percent CI, 0.75–0.99) for the QHES instrument. However, inter-rater agreement was poor (kappa &lt; 0.40 for most items and ICC(2,1) ≤ 0.5).Conclusions:The study shows that the results of the quality assessment of economic evaluations are not so much influenced by the instrument used but more by the assessor. Therefore, quality assessments should be performed by at least two independent experts and final scoring based on consensus.
Analysis of the quality of clinical practice guidelines on established ischemic stroke
Authors: Navarro Puerto Ma Asunción , Ibarluzea Iñaki Gutiérrez , Ruiz Oscar Guzmán , Alvarez Francisco Moniche , Herreros Rocío Gómez , Pintiado Ruth Engelhardt , Dominguez Antonio Reyes , León Ignacio Marín 
Published: July 2008

Objectives:To catalogue and comparatively assess the quality of Clinical Practice Guidelines (CPG) for ischemic stroke taking into account format and development methodology.Methods:We performed a comprehensive, systematic bibliographic search of CPGs addressing the management of ischemic stroke. We designed a sensitive strategy, using methodological filters in the following databases: Medline, IME and Lilacs, National Guidelines Clearinghouse, National electronic Library for Health, NICE, Guidelines International Network (GIN), Canadian Medical Association Infobase, development groups such as Scottish Intercollegiate Guidelines Network (SIGN), New Zealand Guidelines Group (NZGG), Agency for Healthcare Research and Quality (AHRQ), Ministry of Health Singapore, Institute for Clinical Systems Improvement (ICSI); and scientific societies: American Heart Association, American Medical Association, Royal College of Physicians London. We included all CPGs published in English, French, Italian, Portuguese, or Spanish from 1999 to 2005 and excluded those CPGs whose scope was primary prevention and rehabilitation from ischemic stroke. Four researchers independently assessed the structure and methodologies followed in drafting the CPGs using the Changing Professional Practice (CPP) and Appraisal of Guidelines Research &amp; Evaluation (AGREE) instruments.Results:We retrieved 117 documents; following application of exclusion criteria, twenty-seven CPGs were appraised. With regard to methodological quality (using the AGREE instrument), the domains that scored highest were “Scope and purpose” and “Clarity and presentation.” The lowest scoring domains were “Stakeholder involvement,” “Rigor of development,” and “Applicability.” Most guidelines received an overall score of “would not recommend” (77.8 percent). Finally, based on the CPP instrument, most of the CPGs evaluated were aimed at secondary care and did not provide updating procedures.Conclusions:The overall quality of the CPGs published for ischemic stroke management did not have minimum methodological quality. Quality improvement has been observed in more recent CPGs and may be due to the publication of new tools such as the AGREE or CPP instruments, as well as international initiatives for CPG improvement.
Appropriateness of healthcare interventions: Concepts and scoping of the published literature
Authors: Sanmartin Claudia , Murphy Kellie , Choptain Nicole , Conner-Spady Barbara , McLaren Lindsay , Bohm Eric , Dunbar Michael J. , Sanmugasunderam Suren , De Coster Carolyn , McGurran John , Lorenzetti Diane L. , Noseworthy Tom 
Published: July 2008

Objectives:This report is a scoping review of the literature with the objective of identifying definitions, conceptual models and frameworks, as well as the methods and range of perspectives, for determining appropriateness in the context of healthcare delivery.Methods:To lay groundwork for future, intervention-specific research on appropriateness, this work was carried out as a scoping review of published literature since 1966. Two reviewers, with two screens using inclusion/exclusion criteria based on the objective, focused the research and articles chosen for review.Results:The first screen examined 2,829 abstracts/titles, with the second screen examining 124 full articles, leaving 37 articles deemed highly relevant for data extraction and interpretation. Appropriateness is defined largely in terms of net clinical benefit to the average patient and varies by service and setting. The most widely used method to assess appropriateness of healthcare services is the RAND/UCLA Model. There are many related concepts such as medical necessity and small-areas variation.Conclusions:A broader approach to determining appropriateness for healthcare interventions is possible and would involve clinical, patient and societal perspectives.
Empirical comparison of subgroup effects in conventional and individual patient data meta-analyses
Authors: Koopman Laura , van der Heijden Geert J. M. G. , Hoes Arno W. , Grobbee Diederick E. , Rovers Maroeska M. 
Published: July 2008

Objectives:Individual patient data (IPD) meta-analyses have been proposed as a major improvement in meta-analytic methods to study subgroup effects. Subgroup effects of conventional and IPD meta-analyses using identical data have not been compared. Our objective is to compare such subgroup effects using the data of six trials (n= 1,643) on the effectiveness of antibiotics in children with acute otitis media (AOM).Methods:Effects (relative risks, risk differences [RD], and their confidence intervals [CI]) of antibiotics in subgroups of children with AOM resulting from (i) conventional meta-analysis using summary statistics derived from published data (CMA), (ii) two-stage approach to IPD meta-analysis using summary statistics derived from IPD (IPDMA-2), and (iii) one-stage approach to IPD meta-analysis where IPD is pooled into a single data set (IPDMA-1) were compared.Results:In the conventional meta-analysis, only two of the six studies were included, because only these reported on relevant subgroup effects. The conventional meta-analysis showed larger (age &lt; 2 years) or smaller (age ≥ 2 years) subgroup effects and wider CIs than both IPD meta-analyses (age &lt; 2 years: RDCMA-21 percent, RDIPDMA-1-16 percent, RDIPDMA-2-15 percent; age ≥2 years: RDCMA-5 percent, RDIPDMA-1-11 percent, RDIPDMA-2-11 percent). The most important reason for these discrepant results is that the two studies included in the conventional meta-analysis reported outcomes that were different both from each other and from the IPD meta-analyses.Conclusions:This empirical example shows that conventional meta-analyses do not allow proper subgroup analyses, whereas IPD meta-analyses produce more accurate subgroup effects. We also found no differences between the one- and two-stage meta-analytic approaches.
A criterion for a monomial in P(3) to be hit
Authors: JANFADA A. S. 
Published: July 2008

AbstractLet P(n) = [x1, . . ., xn] = ⊕d≥0Pd(n) be the polynomial algebra viewed as a graded left module over the Steenrod algebra at the prime 2. The grading is by the degree of the homogeneous polynomials Pd(n) of degree d in the n variables x1, . . ., xn. The algebra P(n) realizes the cohomology of the product of n copies of infinite real projective space. We recall that a homogeneous element f of grading d in a graded left -module M is hit if there is a finite sum f = ΣiSqi(hi), called a hit equation, where the pre-images hi ∈ M have grading strictly less than d and the Sqi, called the Steenrod squares, generate . One of the important parts of the hit problem is to check whether a given polynomial in M is hit or not. In this article we study this problem in the 3-variable case.
Incorporating hypothalamic–pituitary–adrenal axis measures into preventive interventions for adolescent depression: Are we there yet?
Authors: Adam Emma K. , Sutton Jonathan M. , Doane Leah D. , Mineka Susan 
Published: July 2008

AbstractAltered functioning of the hypothalamic–pituitary–adrenal (HPA) axis is a robust correlate of major depression in adults, and to a lesser extent, in adolescents. Premorbid differences in HPA axis function have been found to prospectively predict the onset of adolescent depression. To what extent might our knowledge of HPA axis function in adolescents with, or at risk for, depression, help guide efforts to prevent depression in this age group? We review evidence regarding the role of the HPA axis in the development of adolescent depression, and examine whether and which HPA axis measures might be useful in guiding prevention efforts as (a) as a criterion by which to select youth at risk for depression, (b) as a predictor of which youth will be most responsive to prevention efforts, and (c) as an indicator of whether prevention/intervention efforts are working. We conclude that our current understanding of the HPA axis, and its measurement, in adolescent depression are not sufficiently precise to be of immediate practical use in improving prevention efforts. Incorporating HPA axis measures into prevention studies, however, would be immensely useful in clarifying the role of the HPA axis in adolescent depression, such that future prevention efforts might more confidently rely on HPA axis information.
Adenosine dysfunction in astrogliosis: cause for seizure generation?
Authors: Li Tianfu , Quan Lan Jing , Fredholm Bertil B. , Simon Roger P. , Boison Detlev 
Published: July 2008

AbstractEpilepsy is characterized by both neuronal and astroglial dysfunction. The endogenous anticonvulsant adenosine, the level of which is largely controlled by astrocytes, might provide a crucial link between astrocyte and neuron dysfunction in epilepsy. Here we have studied astrogliosis, a hallmark of the epileptic brain, adenosine dysfunction and the emergence of spontaneous seizures in a comprehensive approach that includes a new mouse model of focal epileptogenesis, mutant mice with altered brain levels of adenosine, and mice lacking adenosine A1 receptors. In wild-type mice, following a focal epileptogenesis-precipitating injury, astrogliosis, upregulation of the adenosine-removing astrocytic enzyme adenosine kinase (ADK), and spontaneous seizures coincide in a spatio-temporally restricted manner. Importantly, these spontaneous seizures are mimicked by untreated transgenic mice that either overexpress ADK in brain or lack A1 receptors. Conversely, mice with reduced ADK in the forebrain do not develop either astrogliosis or spontaneous seizures. Our studies define ADK as a crucial upstream regulator of A1 receptor-mediated modulation of neuronal excitability, and support the ADK hypothesis of epileptogenesis in which upregulation of ADK during astrogliosis provides a crucial link between astrocyte and neuron dysfunction in epilepsy. These findings define ADK as rational target for therapeutic intervention.
Technology, complexity and change in agricultural production systems
Authors: Sassenrath G.F. , Heilman P. , Luschei E. , Bennett G.L. , Fitzgerald G. , Klesius P. , Tracy W. , Williford J.R. , Zimba P.V. 
Published: July 2008

AbstractTechnological advances have contributed to impressive yield gains and have greatly altered US agriculture. Selective breeding and directed molecular techniques address biological shortcomings of plants and animals and overcome environmental limitations. Improvements in mechanization, particularly of power sources and harvest equipment, reduce labor requirements and increase productivity and worker safety. Conservation systems, often designed to overcome problems introduced from other technologies, reduce negative impacts on soil and water and improve the environmental sustainability of production systems. Advances in information systems, largely developed in other disciplines and adapted to agriculture, are only beginning to impact US production practices. This paper is the fourth in the series of manuscripts exploring drivers of US agricultural systems. While development of technology is still largely driven by a need to address a problem, adoption is closely linked with other drivers of agricultural systems, most notably social, political and economic. Here, we explore the processes of innovation and adoption of technologies and how they have shaped agriculture. Technologies have increased yield and net output, and have also resulted in decreased control by producers, increased intensification, specialization and complexity of production, greater dependence on non-renewable resources, increased production inputs and hence decreased return, and an enhanced reliance on future technology. Future technologies will need to address emerging issues in land use, decline in work force and societal support of farming, global competition, changing social values in both taste and convenience of food, and increasing concerns for food safety and the environment. The challenge for farmers and researchers is to address these issues and develop technologies that balance the needs of producers with the expectations of society and create economically and environmentally sustainable production systems.
How to form bulges/ellipticals in dark halos as fast as central black holes?
Authors: Zhao Hong Sheng , Xu Bing-Xiao , Wu Xue-Bing 
Published: July 2008

AbstractGravity is nearly a universal constant in the cusp of an NFW galaxy halo. Inside this external field an isothermal gas sphere will collapse and trigger a starburst if above a critical central pressure. Thus formed spheroidal stellar systems have Sersic-profile and satisfy the Faber-Jackson relation. The process is consistent with observed starbursts. We also recover the MBH − σ* relation, if the gas collapse is regulated or resisted by the feedback from radiation from the central BH.
Chemical evolution of bulges at high redshift
Authors: Pipino Antonio , Matteucci Francesca , D'Ercole Annibale 
Published: July 2008

AbstractWe present a new class of hydrodynamical models for the formation of bulges (either massive elliptical galaxies or classical bulges in spirals) in which we implement detailed prescriptions for the chemical evolution of H, He, O and Fe. Our results hint toward an outside-in formation in the context of the supernovae-driven wind scenario. The build-up of the chemical properties of the stellar populations inhabiting the galactic core is very fast. Therefore we predict a non significant evolution of both the mass-metallicity and the mass-[α/Fe] relations after the first 0.5 − 1 Gyr. In this framework we explain how the observed slopes, either positive or negative, in the radial gradient of the mean stellar [α/Fe], and their apparent lack of any correlation with all the other observables, can arise as a consequence of the interplay between star formation and metal-enhanced internal gas flows.
Chemodynamical evolution of galaxies with hypernovae
Authors: Kobayashi Chiaki 
Published: July 2008

AbstractWe simulate the formation and evolution of galaxies with a hydrodynamical model including supernova and hypernova feedback. The large contribution of hypernovae is required from the observed abundance ratios in the Milky Way Galaxy. The hypernova feedback suppress star formation efficiently, which results in the cosmic star formation rate history peaked at z ~ 4. It also drives galactic outflows efficiently in low mass galaxies, and these winds eject heavy elements into the intergalactic medium. The ejected baryon and metal fraction is larger for less massive galaxies, which results in the mass-metallicity relation of galaxies. We also simulate the chemodynamical evolution of the Milky Way Galaxy, and show the difference of the stellar populations in the bulge and disk.
SPH simulations of the chemical evolution of bulges
Authors: Martínez-Serrano F. J. , Domínguez-Tenreiro R. , Mollá M. 
Published: July 2008

AbstractWe have implemented a chemical evolution model on the parallel AP3M+SPH DEVA code which we use to perform high resolution simulations of spiral galaxy formation. It includes feedback by SNII and SNIa using the Qij matrix formalism. We also include a diffusion mechanism that spreads newly introduced metals. The gas cooling rate depends on its specific composition. We study the stellar populations of the resulting bulges finding a potential scenario where they seem to be composed of two populations: an old, metal poor, α-enriched population, formed in a multiclump scenario at the beginning of the simulation and a younger one, formed by slow accretion of satellites or gas, possibly from the disk due to instabilities.
The morphology-density relation: a constant of nature
Authors: van der Wel Arjen 
Published: July 2008

AbstractThe Sloan Digital Sky Survey (SDSS) and photometric/spectroscopic surveys of two z ~ 0.8 massive clusters of galaxies and the Chandra Deep Field-South (CDFS) are used to construct volume-limited, stellar mass-selected samples of galaxies at redshifts 0 < z < 1 in a large range of environments. Morphologies are determined visually and with an automated method, using the Sérsic parameter n and a measure of the residual from the Sérsic model fits, called “bumpiness”, to distinguish different morphologies. The agreement between the visual and automated methods is excellent. The fraction of E+S0 galaxies with masses larger than ~ 0.5 M* is 40 − 50% in the field, and > 80% in the clusters, without significant changes with redshift. Therefore, we find that the morphology-density relation (MDR) for galaxies more massive than ~ 0.5 M* has remained constant since at least z ~ 0.8. This implies that galaxy evolution (in terms of mass, star formation, color, morphology, etc.) must happen such that the MDR does not change.
A connection between bulge properties and the bimodality of galaxies
Authors: Drory Niv , Fisher David B. 
Published: July 2008

AbstractThe global colors and structure of galaxies have recently been shown to follow bimodal distributions. Galaxies separate into a “red sequence”, populated prototypically by early-type galaxies, and a “blue cloud”, whose typical objects are late-type disk galaxies. Intermediate-type (Sa-Sbc) galaxies populate both regions. It has been suggested that this bimodality reflects the two-component nature of disk-bulge galaxies. However, it has now been established that there are two types of bulges: “classical bulges” that are dynamically hot systems resembling (little) ellipticals, and “pseudobulges”, dynamically cold, flattened, disk-like structures that could not have formed via violent relaxation. Alas, given the different formation mechanisms of these bulges, the question is whether at types Sa-Sbc, where both bulge types are found, the red-blue dichotomy separates galaxies at some value of disk-to-bulge ratio,B/T, or, whether it separates galaxies of different bulge type, irrespective of theirB/T. In this paper, we identify classical bulges and pseudobulges morphologically with HST images in a sample of nearby galaxies. Detailed surface photometry reveals that: (1) The red – blue dichotomy is a function of bulge type: at the sameB/T, pseudobulges are in globally blue galaxies and classical bulges are in globally red galaxies. (2) Bulge type also predicts where the galaxy lies in other (bimodal) global structural parameters: global Sérsic index and central surface brightness. Hence, the red – blue dichotomy is not due to decreasing bulge prominence alone, and the bulge type of a galaxy carries significance for the galaxy's evolutionary history.
Kinematics of globular cluster systems in galaxy mergers
Authors: Hayward Christopher C. , Cox T. J. , Hernquist Lars 
Published: July 2008

AbstractWe use numerical simulations to study how the spatial distribution and kinematics of globular cluster systems (GCS) are affected by galaxy mergers. Each progenitor galaxy is given a GCS modeled after the Galactic GCS. We then study how a major merger affects the spatial distribution and kinematics of the GCS. Here we present our methodology. Future work will investigate the effects of varying galaxy parameters, merger orbital parameters, and initial GCS number density profile and kinematics. We hope to be able to extract information about the merger history of a galaxy from observations of its GCS spatial distribution and kinematics.