bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of the Roll Plate Method to the Sonication Method To Diagnose Catheter Colonization and Bacteremia in Patients with Long-Term Tunnelled Catheters: a Randomized Prospective Study
Authors: Slobbe Lennert , el Barzouhi Abdelilah , Boersma Eric , Rijnders Bart J. A. 
Published: January 2009

ABSTRACT

Diagnosing catheter-related bloodstream infection (CRBSI) still often involves tip culture. The conventional method is the semiquantitative roll plate method. However, the use of a quantitative sonication technique could have additional value, as it may detect endoluminal microorganisms more easily. Because endoluminal infection tends to occur in long-term central venous catheters, we compared both techniques for patients with long-term tunnelled catheters. For 313 consecutive Hickman catheter tips from 279 hematological patients, colonization detection rates were compared by performing both techniques in a random order, using conventional detection cutoffs. Additionally, for the subgroup of patients with clinical suspicion of CRBSI (
n
= 89), the diagnostic values of both techniques were compared. The overall tip colonization rate was 25%. For each technique, the detection rate tended to be better if that technique was performed first. The diagnostic performance for the subgroup of patients with clinical suspicion of CRBSI was limited and not different for both methods. Sensitivity and specificity were 45% and 84%, respectively, for sonication versus 35% and 90%, respectively, for the roll plate technique. The fact that 35 of 40 patients with CRBSI received antimicrobial therapy before catheter removal and tip culture, in an attempt to salvage the catheter, may partly explain this poor performance. No differences were observed when catheters were stratified according to in situ time below or above the median of 4 weeks. The sonication culture technique was not better than the roll plate method to diagnose tip colonization or CRBSI in patients with long-term tunnelled catheters.
An exploratory study of the safety, tolerability and bioactivity of a single intravitreal injection of vascular endothelial growth factor Trap-Eye in patients with diabetic macular oedema
Authors: Do D V , Nguyen Q D , Shah S M , Browning D J , Haller J A , Chu K , Yang K , Cedarbaum J M , Vitti R L , Ingerman A , Campochiaro P A 
Published: January 2009

Aim:The aim of the study was to assess the safety and bioactivity of a single intravitreal injection of vascular endothelial growth factor (VEGF) Trap-Eye in subjects with diabetic macular oedema (DMO).Methods:Five subjects with DMO, foveal thickness ⩾250 μm measured by optical coherence tomography (OCT), and best-corrected visual acuity (BCVA) between 20/40 and 20/320, were enrolled. Each participant received a single intravitreal injection of 4.0 mg of VEGF Trap-Eye followed by a 6-week observation period. Outcome measures included safety and biological activity, including changes in BCVA and excess retinal thickness assessed by OCT.Results:Injections of VEGF Trap-Eye were well tolerated with no ocular toxicity. One patient had an unrelated serious adverse event: hospitalisation for cellulitis of the left foot 27 days after injection of VEGF Trap-Eye. Median baseline BCVA was 36 ETDRS letters read at 4 m (not ETDRS visual acuity score; Snellen equivalent: 20/50) and median baseline excess central 1 mm foveal thickness (FTH) was 108 μm. At 4 weeks after injection, the median excess FTH was 59 μm and the median improvement in BCVA was nine letters. At 6 weeks after injection, four of the five patients showed improvement in excess FTH (median 74 μm; 31% reduction from baseline, p = 0.0625) and four of the five showed improvement in BCVA (median improvement of three letters).Conclusions:A single intravitreal injection of 4.0 mg of VEGF Trap-Eye was well tolerated and preliminary evidence of bioactivity was detected. These findings support additional studies investigating multiple injections of VEGF Trap-Eye in patients with DMO.
Analysis of soluble vascular endothelial growth factor receptor-1 secreted from cultured corneal and oral mucosal epithelial cell sheets in vitro
Authors: Kanayama S , Nishida K , Yamato M , Hayashi R , Maeda N , Okano T , Tano Y 
Published: January 2009

Background:In clinical trials, eyes transplanted with cultured oral mucosal epithelial cell sheets have shown increased neovascularisation compared with eyes treated with cultured corneal epithelial cell sheets. As reported recently, soluble vascular endothelial growth factor receptor-1 (soluble VEGFr-1) is a main factor to maintain a corneal avascularity.Aim:To investigate soluble VEGFr-1 of cultured corneal epithelial cells (CCE) and cultured oral mucosal epithelial cells (COE) in vitro.Methods:Rabbit corneal and oral mucosal epithelial cells were co-cultured with mitomycin C-treated NIH/3T3 cells on culture plates. After CCE and COE were multilayered, culture medium was replaced by basal medium and incubated. Protein secretion of soluble VEGFr-1 was assessed in conditioned medium from CCE and COE by ELISA. Angiogenic potential was examined by invasion, migration assays with human umbilical vein endothelial cells (HUVECs) in addition to recombinant soluble VEGFr-1.Results:CCE secreted a significantly higher amount of soluble VEGFr-1 than did COE. Recombinant soluble VEGFr-1 significantly suppressed HUVEC migration induced by COE, without suppression in CCE. In conclusion, these findings suggest that low protein levels of soluble VEGFr-1 may lead to corneal neovascularisation after COE sheet transplantation.
Ethical aspects of research into Alzheimer disease. A European Delphi Study focused on genetic and non-genetic research
Authors: van der Vorm A , Vernooij-Dassen M J F J , Kehoe P G , Rikkert M G M Olde , van Leeuwen E , Dekkers W J M 
Published: January 2009

Background:Although genetic research into Alzheimer disease (AD) is increasing, the ethical aspects of this kind of research and the differences between ethical issues related to genetic and non-genetic research into AD have not yet received much attention.Objectives:(1) To identify and compare the five ethical issues considered most important by surveyed expert panellists in non-genetic and genetic AD research and (2) to compare our empirical findings with ethical issues in genetic research in general as described in the literature.Method:A modified Delphi study in two roundsResults:Genetic and non-genetic research into AD generated an approximately equal number of topics with a considerable overlap. Different priorities in the ethics of both types of research were found. Genetic research raised new topics such as “confidentiality of genetic information” and “implications of research for relatives” which changes the impact and application of existing ethical topics such as “informed consent” and is judged to have more impact on both individuals and society. A difference with the results of more theoretical approaches on ethical aspects related to AD research was also found.Conclusions:Different priorities are given to ethical issues in genetic and non-genetic research. These arise partly because genetic research causes unique and new questions, mostly related to the position of family members and the status of and access to genetic information. Differences found between the results of our empirical study and the more theoretical literature, suggest an additional value for empirical research in medical ethics.
Comparison of High-Cloud Characteristics as Estimated by Selected Spaceborne Observations and Ground-Based Lidar Datasets
Authors: Plana-Fattori Artemio , Brogniez Gérard , Chervet Patrick , Haeffelin Martial , Lado-Bordowsky Olga , Morille Yohann , Parol Frédéric , Pelon Jacques , Roblin Antoine , Sèze Geneviève , Stubenrauch Claudia 
Published: January 2009

Abstract
The characterization of high clouds as performed from selected spaceborne observations is assessed in this article by employing a number of worldwide ground-based lidar multiyear datasets as reference. Among the latter, the ground lidar observations conducted at Lannion, Bretagne (48.7°N, 3.5°W), and Palaiseau, near Paris [the Site Instrumental de Recherche par Télédétection Atmosphérique (SIRTA) observatory: 48.7°N, 2.2°E], both in France, are discussed in detail. High-cloud altitude statistics at these two sites were found to be similar. Optical thicknesses disagree, and possible reasons were analyzed. Despite the variety of instruments, observation strategies, and methods of analysis employed by different lidar groups, high-cloud optical thicknesses from the Geoscience Laser Altimeter System (GLAS) on board the Ice, Cloud and land Elevation Satellite (ICESat) were found to be consistent on the latitude band 40°–60°N. Respective high-cloud altitudes agree within 1 km with respect to those from ground lidars at Lannion and Palaiseau; such a finding remains to be verified under other synoptic regimes. Mean altitudes of high clouds from Lannion and Palaiseau ground lidars were compared with altitudes of thin cirrus from the Television and Infrared Observation Satellite (TIROS) Operational Vertical Sounder (TOVS) Path-B 8-yr climatology for a common range of optical thicknesses (0.1–1.4). Over both sites, the annual altitude distribution of thin high clouds from TOVS Path-B is asymmetric, with a peak around 8–9.5 km, whereas the distribution of high clouds retrieved from ground lidars seems symmetric with a peak around 9.5–11.5 km. Additional efforts in standardizing ground lidar observation and processing methods, and in merging high-cloud statistics from complementary measuring platforms, are recommended.
Detection and Attribution of Streamflow Timing Changes to Climate Change in the Western United States
Authors: Hidalgo H. G. , Das T. , Dettinger M. D. , Cayan D. R. , Pierce D. W. , Barnett T. P. , Bala G. , Mirin A. , Wood A. W. , Bonfils C. , Santer B. D. , Nozawa T. 
Published: January 2009

Abstract
This article applies formal detection and attribution techniques to investigate the nature of observed shifts in the timing of streamflow in the western United States. Previous studies have shown that the snow hydrology of the western United States has changed in the second half of the twentieth century. Such changes manifest themselves in the form of more rain and less snow, in reductions in the snow water contents, and in earlier snowmelt and associated advances in streamflow “center” timing (the day in the “water-year” on average when half the water-year flow at a point has passed). However, with one exception over a more limited domain, no other study has attempted to formally attribute these changes to anthropogenic increases of greenhouse gases in the atmosphere. Using the observations together with a set of global climate model simulations and a hydrologic model (applied to three major hydrological regions of the western United States—the California region, the upper Colorado River basin, and the Columbia River basin), it is found that the observed trends toward earlier “center” timing of snowmelt-driven streamflows in the western United States since 1950 are detectably different from natural variability (significant at the p &lt; 0.05 level). Furthermore, the nonnatural parts of these changes can be attributed confidently to climate changes induced by anthropogenic greenhouse gases, aerosols, ozone, and land use. The signal from the Columbia dominates the analysis, and it is the only basin that showed a detectable signal when the analysis was performed on individual basins. It should be noted that although climate change is an important signal, other climatic processes have also contributed to the hydrologic variability of large basins in the western United States.
Variations of U.S. Regional Precipitation and Simulations by the NCEP CFS: Focus on the Southwest
Authors: Yang Song , Jiang Yundi , Zheng Dawei , Higgins R. Wayne , Zhang Qin , Kousky Vernon E. , Wen Min 
Published: January 2009

Abstract
Variations of U.S. regional precipitation in both observations and free-run experiments with the NCEP Climate Forecast System (CFS) are investigated. The seasonality of precipitation over the continental United States and the time–frequency characteristics of precipitation over the Southwest (SW) are the focus. The differences in precipitation variation among different model resolutions are also analyzed.
The spatial distribution of U.S. precipitation is characterized by high values over the East and the West Coasts, especially over the Gulf Coast and southeast states, and low values elsewhere except over the SW in summer. A large annual cycle of precipitation occurs over the SW, northern plains, and the West Coast. Overall, the CFS captures the above features reasonably well, except for the SW. However, it overestimates the precipitation over the western United States, except the SW in summer, and underestimates the precipitation over the central South, except in springtime. It also overestimates (underestimates) the precipitation seasonality over the intermountain area and Gulf Coast states (SW, West Coast, and northern Midwest). The model using T126 resolution captures the observed features more realistically than at the lower T62 resolution over a large part of the United States.
The variability of observed SW precipitation is characterized by a large annual cycle, followed by a semiannual cycle, and the oscillating signals on annual, semiannual, and interannual time scales account for 41% of the total precipitation variability. However, the CFS, at both T62 and T126 resolution, fails in capturing the above feature. The variability of SW precipitation in the CFS is much less periodic. The annual oscillation of model precipitation is much weaker than that observed and it is even much weaker than the simulated semiannual oscillation. The weakly simulated annual cycle is attributed by the unrealistic precipitation simulations of all seasons, especially spring and summer. On the annual time scale, the CFS fails in simulating the relationship between the SW precipitation and the basinwide sea surface temperature (SST) and the overlying atmospheric circulation. On the semiannual time scale, the model exaggerates the response of the regional precipitation to the variations of SST and atmospheric circulation over the tropics and western Atlantic, including the Gulf of Mexico. This study also demonstrates a challenge for the next-generation CFS, at T126 resolution, to predict the variability of North American monsoon climate.
Vertical Mixing in the Ocean and Its Impact on the Coupled Ocean–Atmosphere System in the Eastern Tropical Pacific*
Authors: Richards Kelvin J. , Xie Shang-Ping , Miyama Toru 
Published: January 2009

Abstract
The zonal and meridional asymmetries in the eastern tropical Pacific (the eastern equatorial cold tongue and the northern intertropical convergence zone) are key aspects of the region that are strongly influenced by ocean–atmosphere interactions. Here the authors investigate the impact of vertical mixing in the ocean on these asymmetries, employing a coupled ocean–atmosphere regional model. Results highlight the need to study the impact of processes such as vertical mixing in the context of the coupled system.
Changes to the vertical mixing in the ocean are found to produce large changes in the state of the system, which include changes to the surface properties of the ocean, the ocean currents, the surface wind field, and clouds and precipitation in the atmosphere. Much of the strength of the impact is through interactions between the ocean and atmosphere. Increasing ocean mixing has an opposite effect on the zonal and meridional asymmetries. The zonal asymmetry is increased (i.e., a colder eastern equatorial cold tongue and increased easterly winds), whereas the meridional asymmetry is decreased (a reduced north–south temperature difference and reduced southerlies), with the impact being enhanced by the Bjerknes and wind–evaporation–sea surface temperature feedbacks.
Water mass transformations are analyzed by consideration of the diapynic fluxes. Although the general character of the diapycnic transport remains relatively unchanged with a change in ocean mixing, there are changes to the magnitude and location of the transport in density space. Oceanic vertical mixing impacts the balance of terms contributing to the heating of the ocean surface mixed layer. With reduced mixing the advection of heat plays an increased role in areas such as the far eastern tropical Pacific and under the intertropical convergence zone.
Seasonal Predictability of European Discharge: NAO and Hydrological Response Time
Authors: Bierkens M. F. P. , van Beek L. P. H. 
Published: January 2009

Abstract
In this paper the skill of seasonal prediction of river discharge and how this skill varies between the branches of European rivers across Europe is assessed. A prediction system of seasonal (winter and summer) discharge is evaluated using 1) predictions of the average North Atlantic Oscillation (NAO) index for the coming winter based on May SST anomalies of the North Atlantic; 2) a global-scale hydrological model; and 3) 40-yr European Centre for Medium-Range Weather Forecasts Re-Analysis (ERA-40) data. The skill of seasonal discharge predictions is investigated with a numerical experiment. Also Europe-wide patterns of predictive skill are related to the use of NAO-based seasonal weather prediction, the hydrological properties of the river basin, and a correct assessment of initial hydrological states. These patterns, which are also corroborated by observations, show that in many parts of Europe the skill of predicting winter discharge can, in theory, be quite large. However, this achieved skill mainly comes from knowing the correct initial conditions of the hydrological system (i.e., groundwater, surface water, soil water storage of the basin) rather than from the use of NAO-based seasonal weather prediction. These factors are equally important for predicting subsequent summer discharge.
A Modeling and Observational Framework for Diagnosing Local Land–Atmosphere Coupling on Diurnal Time Scales
Authors: Santanello Joseph A. , Peters-Lidard Christa D. , Kumar Sujay V. , Alonge Charles , Tao Wei-Kuo 
Published: January 2009

AbstractLand–atmosphere interactions play a critical role in determining the diurnal evolution of both planetary boundary layer (PBL) and land surface temperature and moisture states. The degree of coupling between the land surface and PBL in numerical weather prediction and climate models remains largely unexplored and undiagnosed because of the complex interactions and feedbacks present across a range of scales. Furthermore, uncoupled systems or experiments [e.g., the Project for the Intercomparison of Land-Surface Parameterization Schemes (PILPS)] may lead to inaccurate water and energy cycle process understanding by neglecting feedback processes such as PBL-top entrainment. In this study, a framework for diagnosing local land–atmosphere coupling is presented using a coupled mesoscale model with a suite of PBL and land surface model (LSM) options along with observations during field experiments in the U.S. Southern Great Plains. Specifically, the Weather Research and Forecasting Model (WRF) has been coupled to the Land Information System (LIS), which provides a flexible and high-resolution representation and initialization of land surface physics and states. Within this framework, the coupling established by each pairing of the available PBL schemes in WRF with the LSMs in LIS is evaluated in terms of the diurnal temperature and humidity evolution in the mixed layer. The coevolution of these variables and the convective PBL are sensitive to and, in fact, integrative of the dominant processes that govern the PBL budget, which are synthesized through the use of mixing diagrams. Results show how the sensitivity of land–atmosphere interactions to the specific choice of PBL scheme and LSM varies across surface moisture regimes and can be quantified and evaluated against observations. As such, this methodology provides a potential pathway to study factors controlling local land–atmosphere coupling (LoCo) using the LIS–WRF system, which will serve as a test bed for future experiments to evaluate coupling diagnostics within the community.
A Geometry-Based Approach to Identifying Cloud Shadows in the VIIRS Cloud Mask Algorithm for NPOESS
Authors: Hutchison Keith D. , Mahoney Robert L. , Vermote Eric F. , Kopp Thomas J. , Jackson John M. , Sei Alain , Iisager Barbara D. 
Published: January 2009

Abstract
A geometry-based approach is presented to identify cloud shadows using an automated cloud classification algorithm developed for the National Polar-orbiting Operational Environmental Satellite System (NPOESS) program. These new procedures exploit both the cloud confidence and cloud phase intermediate products generated by the Visible/Infrared Imager/Radiometer Suite (VIIRS) cloud mask (VCM) algorithm. The procedures have been tested and found to accurately detect cloud shadows in global datasets collected by NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) sensor and are applied over both land and ocean background conditions. These new procedures represent a marked departure from those used in the heritage MODIS cloud mask algorithm, which utilizes spectral signatures in an attempt to identify cloud shadows. However, they more closely follow those developed to identify cloud shadows in the MODIS Surface Reflectance (MOD09) data product. Significant differences were necessary in the implementation of the MOD09 procedures to meet NPOESS latency requirements in the VCM algorithm. In this paper, the geometry-based approach used to predict cloud shadows is presented, differences are highlighted between the heritage MOD09 algorithm and new VIIRS cloud shadow algorithm, and results are shown for both these algorithms plus cloud shadows generated by the spectral-based approach. The comparisons show that the geometry-based procedures produce cloud shadows far superior to those predicted with the spectral procedures. In addition, the new VCM procedures predict cloud shadows that agree well with those found in the MOD09 product while significantly reducing the execution time as required to meet the operational time constraints of the NPOESS system.
Fast k-Nearest-Neighbors Calculation for Interpolation of Radar Reflectivity Field*
Authors: Gao Feng 
Published: January 2009

Abstract
To efficiently implement the interpolation methods (e.g., Shepard’s method and its variants) for the radar reflectivity field, a fast method that calculates the k-nearest-neighbor nodes (sampling points in radar volume scan) of the interpolated point (grid point) is described and proved. Several geometric propositions of radar volume scan on which the method is based are suggested and proved. Finally, the computational cost of the method is analyzed. The method is fast enough for real-time applications.