bluuebunny/crossref_metadata_2025_split huggingface dataset:
The State of Diabetes Care Provided to Medicare Beneficiaries Living in Rural America
Authors: Weingarten Joseph P. , Brittman Susan , Hu Wenrong , Przybyszewski Chris , Hammond Judith M. , FitzGerald Dawn 
Published: September 2006

ABSTRACT:
Context: Diabetes poses a growing health burden in the United States, but much of the research to date has been at the state and local level. Purpose: To present a national profile of diabetes care provided to Medicare beneficiaries living in urban, semirural, and rural communities. Methods: Medicare beneficiaries with diabetes aged 18‐75 were identified from Part A and Part B claims data from 1999 to 2001. A composite of 3 diabetes care indicators was assessed (annual hemoglobin A1c test, biennial lipid profile, and biennial eye examination). Findings: Over 77% had a hemoglobin A1c test, 74% a lipid profile, and 69% an eye examination. Patterns of care were considerably different across the urban‐rural continuum at the state, Census division, and regional levels. States in the northern and eastern portions of the country had higher indicator rates for rural than for urban residents. States in the South had much lower rates for rural residents than their urban counterparts. Despite these within‐state differences, across‐state comparisons found that several states tended to have low indicator rates in every level of the urban‐rural continuum. A common feature of these states was the relatively high concentration of nonwhite beneficiaries. For example, southern states had much higher concentrations of nonwhite beneficiaries relative to other areas in the country and demonstrated low rates in every level of the urban‐rural continuum. Conclusions: Urban‐rural quality of care differences may be a function not just of geography but also of the presence of a large nonwhite population.
Idiopathic epilepsy in dogs: owners’ perspectives on management with phenobarbitone and/or potassium bromide
Authors: Chang Y. , Mellor D. J. , Anderson T. J. 
Published: September 2006

Objectives:To explore seizure management from the perspective of the owners of dogs with idiopathic epilepsy.Methods:Questionnaires were mailed to owners of 29 dogs under management for suspected or diagnosed idiopathic epilepsy through the clinics of the Small Animal Hospital of the University of Glasgow Veterinary School, using either phenobarbitone or potassium bromide alone or in combination.Results:The postal survey had an 86 per cent response rate. Analysis of the responses demonstrated that “the dog’s quality of life”, “adequate seizure frequency” and “acceptable side effects of antiepileptic drugs” were the three greatest concerns for owners; 52 per cent of owners strongly agreed that the seizure management for their dog was adequate, though the seizure frequency reported varied within this group; the majority of owners did not consider the administration of medication a nuisance. However, approximately 60 per cent of owners reported that caring for an epileptic dog had an effect on the organisation of their free time, though this was not dependent on perception of seizure control. Opinions as to the value of further diagnostic procedures, in particular intracranial imaging, were significantly affected by having pet health insurance.ClinicalSignificance:From the owners’ perspective, adequacy of seizure control is determined by the balance between “the dog’s quality of life”, “adequate seizure frequency” and “acceptable side effects of antiepileptic drugs”. A frequency of less than one seizure every three months is associated with the perception by owners of adequate seizure control.
Indirect Impact of Atmospheric Aerosols in Idealized Simulations of Convective–Radiative Quasi Equilibrium
Authors: Grabowski Wojciech W. 
Published: September 2006

Abstract
This paper discusses a cloud-resolving modeling study concerning the impact of warm-rain microphysics on convective–radiative quasi equilibrium with fixed surface characteristics and prescribed solar input, both mimicking the mean conditions on earth. Two limits of the concentration of cloud droplets, either 100 cm−3 (referred to as “pristine”) or 1000 cm−3 (referred to as “polluted”), are considered. In addition, three formulations of the effective radius of water droplets in diluted cloudy volumes are used, corresponding to the homogeneous, intermediate, and extremely inhomogeneous mixing scenarios. The assumed concentration of cloud droplets, together with the assumed mixing scenario, affects the local value of the effective radius of cloud droplets (the first indirect aerosol effect, also known as the Twomey effect) and the transfer of cloud water into drizzle and rain, which can affect the mean cloudiness and the hydrologic cycle (the second indirect effect).
The convective–radiative quasi equilibrium mimics the estimates of globally and annually averaged water and energy fluxes across the earth’s atmosphere to within less than 10 W m−2. As on earth, the model cloudiness is dominated by shallow convection. It is found that the impact of warm microphysics is dominated by the first indirect effect, whereas the second indirect effect has a smaller impact. The assumed droplet concentration and mixing scenario impact the mean “planetary” albedo and, thus, the amount of solar energy reaching the surface, with all other components of atmospheric energy and water budgets virtually the same in all simulations. The weak second indirect effect highlights the difference between the impact of cloud microphysics on a single cloud and the impact on an ensemble of clouds, with only the latter including the feedbacks between clouds and their environment. The formulation of the effective radius in the diluted cloudy volumes turns out to be of critical importance, with the amount of solar energy reaching the surface being the same in the pristine case assuming the homogeneous mixing scenario and in the polluted case with the extremely inhomogeneous mixing. This result emphasizes the essential role of poorly understood microphysical transformations within diluted convective clouds, which strongly impact the magnitude of the first indirect (Twomey) effect. Implications for future research in this area are discussed.
Optimal Forcing Patterns for Coupled Models of ENSO
Authors: Moore Andrew M. , Zavala-Garay Javier , Tang Youmin , Kleeman Richard , Weaver Anthony T. , Vialard Jérôme , Sahami Kamran , Anderson David L. T. , Fisher Michael 
Published: September 2006

Abstract
The optimal forcing patterns for El Niño–Southern Oscillation (ENSO) are examined for a hierarchy of hybrid coupled models using generalized stability theory. Specifically two cases are considered: one where the forcing is stochastic in time, and one where the forcing is time independent. The optimal forcing patterns in these two cases are described by the stochastic optimals and forcing singular vectors, respectively. The spectrum of stochastic optimals for each model was found to be dominated by a single pattern. In addition, the dominant stochastic optimal structure is remarkably similar to the forcing singular vector, and to the dominant singular vectors computed in a previous related study using a subset of the same models. This suggests that irrespective of whether the forcing is in the form of an impulse, is time invariant, or is stochastic in nature, the optimal excitation for the eigenmode that describes ENSO in each model is the same. The optimal forcing pattern, however, does vary from model to model, and depends on air–sea interaction processes.
Estimates of the stochastic component of forcing were obtained from atmospheric analyses and the projection of the dominant optimal forcing pattern from each model onto this component of the forcing was computed. It was found that each of the optimal forcing patterns identified may be present in nature and all are equally likely. The existence of a dominant optimal forcing pattern is explored in terms of the effective dimension of the coupled system using the method of balanced truncation, and was found to be O(1) for the models used here. The implications of this important result for ENSO prediction and predictability are discussed.
Atmospheric Teleconnection over Eurasia Induced by Aerosol Radiative Forcing during Boreal Spring
Authors: Kim Maeng-Ki , Lau William K. M. , Chin Mian , Kim Kyu-Myong , Sud Y. C. , Walker Greg K. 
Published: September 2006

Abstract
The direct effects of aerosols on global and regional climate during boreal spring are investigated based on numerical simulations with the NASA Global Modeling and Assimilation Office finite-volume general circulation model (fvGCM) with Microphyics of Clouds with the Relaxed–Arakawa Schubert Scheme (McRAS), using aerosol forcing functions derived from the Goddard Ozone Chemistry Aerosol Radiation and Transport model (GOCART).
The authors find that anomalous atmospheric heat sources induced by absorbing aerosols (dust and black carbon) excite a planetary-scale teleconnection pattern in sea level pressure, temperature, and geopotential height spanning North Africa through Eurasia to the North Pacific. Surface cooling due to direct effects of aerosols is found in the vicinity and downstream of the aerosol source regions, that is, South Asia, East Asia, and northern and western Africa. Significant atmospheric heating is found in regions with large loading of dust (over northern Africa and the Middle East) and black carbon (over Southeast Asia). Paradoxically, the most pronounced feature in aerosol-induced surface temperature is an east–west dipole anomaly with strong cooling over the Caspian Sea and warming over central and northeastern Asia, where aerosol concentrations are low. Analyses of circulation anomalies show that the dipole anomaly is a part of an atmospheric teleconnection pattern driven by atmospheric heating anomalies induced by absorbing aerosols in the source regions, but the influence was conveyed globally through barotropic energy dispersion and sustained by feedback processes associated with the regional circulations.
The surface temperature signature associated with the aerosol-induced teleconnection bears striking resemblance to the spatial pattern of observed long-term trend in surface temperature over Eurasia. Additionally, the boreal spring wave train pattern is similar to that reported by Fukutomi et al. associated with the boreal summer precipitation seesaw between eastern and western Siberia. The results of this study raise the possibility that global aerosol forcing during boreal spring may play an important role in spawning atmospheric teleconnections that affect regional and global climates.
The Impact of Tropical Atlantic Freshwater Fluxes on the North Atlantic Meridional Overturning Circulation
Authors: Spence J. Paul , Weaver Andrew J. 
Published: September 2006

Abstract
The influence of ENSO-related changes in the Atlantic-to-Pacific freshwater budget on the North Atlantic meridional overturning is examined using the University of Victoria (UVic) Earth System Climate Model. The initial analysis of freshwater fluxes in the 50-yr NCEP–NCAR (NCEP50) reanalysis product and Global Precipitation Climatology Project (GPCP) dataset reveals that the transport of water vapor out of the tropical Atlantic drainage basin is enhanced during El Niño phases and reduced during La Niña phases; a one standard deviation in the Southern Oscillation index alters the tropical Atlantic freshwater balance by about 0.09 Sv (Sv ≡ 106 m3 s−1). A weaker link with ENSO is found in the 40-yr ECMWF Re-Analysis (ERA-40), although its usefulness is severely limited by a strong and spurious trend in tropical precipitation. Model results suggest that tropical Atlantic salinity anomalies generated with the frequency and amplitude of ENSO tend not to impact deep-water formation as they are diluted en route to the North Atlantic. Lower frequency, decadal time-scale anomalies, however, do have an impact, albeit weak, on the rate of North Atlantic Deep Water formation. In addition, and contrary to earlier results, it is found that even a shift of the tropical Atlantic freshwater balance toward permanent El Niño conditions only slightly mitigates the transient reduction of North Atlantic Deep Water formation associated with the increase of anthropogenic greenhouse gases. Taken together, the results suggest that the poleward propagation of salinity anomalies from the tropical Atlantic, associated with changes in ENSO, should not be considered a significant mechanism for the variability of the North Atlantic meridional overturning in the present and foreseeable future climate.
Global Climate and Ocean Circulation on an Aquaplanet Ocean–Atmosphere General Circulation Model
Authors: Smith Robin S. , Dubois Clotilde , Marotzke Jochem 
Published: September 2006

Abstract
A low-resolution coupled ocean–atmosphere general circulation model (OAGCM) is used to study the characteristics of the large-scale ocean circulation and its climatic impacts in a series of global coupled aquaplanet experiments. Three configurations, designed to produce fundamentally different ocean circulation regimes, are considered. The first has no obstruction to zonal flow, the second contains a low barrier that blocks zonal flow in the ocean at all latitudes, creating a single enclosed basin, while the third contains a gap in the barrier to allow circumglobal flow at high southern latitudes.
Warm greenhouse climates with a global average air surface temperature of around 27°C result in all cases. Equator-to-pole temperature gradients are shallower than that of a current climate simulation. While changes in the land configuration cause regional changes in temperature, winds, and rainfall, heat transports within the system are little affected. Inhibition of all ocean transport on the aquaplanet leads to a reduction in global mean surface temperature of 8°C, along with a sharpening of the meridional temperature gradient. This results from a reduction in global atmospheric water vapor content and an increase in tropical albedo, both of which act to reduce global surface temperatures.
Fitting a simple radiative model to the atmospheric characteristics of the OAGCM solutions suggests that a simpler atmosphere model, with radiative parameters chosen a priori based on the changing surface configuration, would have produced qualitatively different results. This implies that studies with reduced complexity atmospheres need to be guided by more complex OAGCM results on a case-by-case basis.
Is the Thermohaline Circulation Changing?
Authors: Latif M. , Böning C. , Willebrand J. , Biastoch A. , Dengg J. , Keenlyside N. , Schweckendiek U. , Madec G. 
Published: September 2006

Abstract
Analyses of ocean observations and model simulations suggest that there have been considerable changes in the thermohaline circulation (THC) during the last century. These changes are likely to be the result of natural multidecadal climate variability and are driven by low-frequency variations of the North Atlantic Oscillation (NAO) through changes in Labrador Sea convection. Indications of a sustained THC weakening are not seen during the last few decades. Instead, a strengthening since the 1980s is observed. The combined assessment of ocean hydrography data and model results indicates that the expected anthropogenic weakening of the THC will remain within the range of natural variability during the next several decades.
Low-Frequency Variations of Surface Temperature in Observations and Simulations
Authors: DelSole Timothy 
Published: September 2006

Abstract
This paper documents the low-frequency (i.e., decadal) variations of surface temperature for the period 1899–1998 in observations, and in simulations conducted as part of the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4). The space–time structure of low-frequency variations is extracted using optimal persistence analysis, which is a technique that linearly decomposes a vector time series into a set of uncorrelated components, ordered such that the first component maximizes the decorrelation time, the second maximizes the decorrelation time subject to being uncorrelated with the first, and so on. The results suggests that only the first two optimal persistence patterns (OPPs) in the observation-based record are statistically distinguishable from white noise. These two components can reproduce the spatial structure of local linear trends over various multidecadal periods, indicating that they give an efficient representation of the observed change in surface temperature. In contrast, most simulations suggest the existence of a single physically significant OPP, all with qualitatively similar time series but each with somewhat different spatial structure. The leading OPP computed from the full model grid is surprisingly consistent with the leading OPP computed from the observation-based grid with missing data masked out, suggesting that the observation-based grid does not pose a serious barrier to extracting the dominant low-frequency variations in the global climate system. The regions in which the leading optimal persistence patterns agree in their predictions of warming coincides with the regions in which warming has in fact been observed to occur.
Contributions of Wind Forcing and Surface Heating to Interannual Sea Level Variations in the Atlantic Ocean
Authors: Cabanes Cécile , Huck Thierry , Colin de Verdière Alain 
Published: September 2006

Abstract
Interannual sea surface height variations in the Atlantic Ocean are examined from 10 years of high-precision altimeter data in light of simple mechanisms that describe the ocean response to atmospheric forcing: 1) local steric changes due to surface buoyancy forcing and a local response to wind stress via Ekman pumping and 2) baroclinic and barotropic oceanic adjustment via propagating Rossby waves and quasi-steady Sverdrup balance, respectively. The relevance of these simple mechanisms in explaining interannual sea level variability in the whole Atlantic Ocean is investigated. It is shown that, in various regions, a large part of the interannual sea level variability is related to local response to heat flux changes (more than 50% in the eastern North Atlantic). Except in a few places, a local response to wind stress forcing is less successful in explaining sea surface height observations. In this case, it is necessary to consider large-scale oceanic adjustments: the first baroclinic mode forced by wind stress explains about 70% of interannual sea level variations in the latitude band 18°–20°N. A quasi-steady barotropic Sverdrup response is observed between 40° and 50°N.
A Multithickness Sea Ice Model Accounting for Sliding Friction
Authors: Wilchinsky Alexander V. , Feltham Daniel L. , Miller Paul A. 
Published: September 2006

Abstract
A multithickness sea ice model explicitly accounting for the ridging and sliding friction contributions to sea ice stress is developed. Both ridging and sliding contributions depend on the deformation type through functions adopted from the Ukita and Moritz kinematic model of floe interaction. In contrast to most previous work, the ice strength of a uniform ice sheet of constant ice thickness is taken to be proportional to the ice thickness raised to the 3/2 power, as is revealed in discrete element simulations by Hopkins. The new multithickness sea ice model for sea ice stress has been implemented into the Los Alamos “CICE” sea ice model code and is shown to improve agreement between model predictions and observed spatial distribution of sea ice thickness in the Arctic.
Aegean Sea Water Masses during the Early Stages of the Eastern Mediterranean Climatic Transient (1988–90)
Authors: Gertman I. , Pinardi N. , Popov Y. , Hecht A. 
Published: September 2006

Abstract
The Aegean water masses and circulation structure are studied via two large-scale surveys performed during the late winters of 1988 and 1990 by the R/V Yakov Gakkel of the former Soviet Union. The analysis of these data sheds light on the mechanisms of water mass formation in the Aegean Sea that triggered the outflow of Cretan Deep Water (CDW) from the Cretan Sea into the abyssal basins of the eastern Mediterranean Sea (the so-called Eastern Mediterranean Transient). It is found that the central Aegean Basin is the site of the formation of Aegean Intermediate Water, which slides southward and, depending on their density, renews either the intermediate or the deep water of the Cretan Sea. During the winter of 1988, the Cretan Sea waters were renewed mainly at intermediate levels, while during the winter of 1990 it was mainly the volume of CDW that increased. This Aegean water mass redistribution and formation process in 1990 differed from that in 1988 in two major aspects: (i) during the winter of 1990 the position of the front between the Black Sea Water and the Levantine Surface Water was displaced farther north than during the winter of 1988 and (ii) heavier waters were formed in 1990 as a result of enhanced lateral advection of salty Levantine Surface Water that enriched the intermediate waters with salt. In 1990 the 29.2 isopycnal rose to the surface of the central basin and a large volume of CDW filled the Cretan Basin. It is found that, already in 1988, the 29.2 isopycnal surface, which we assume is the lowest density of the CDW, was shallower than the Kassos Strait sill and thus CDW egressed into the Eastern Mediterranean.
Decadal Variability in the Large-Scale Sea Surface Height Field of the South Pacific Ocean: Observations and Causes
Authors: Qiu Bo , Chen Shuiming 
Published: September 2006

Abstract
Large-scale sea surface height (SSH) changes in the extraequatorial South Pacific Ocean are investigated using satellite altimetry data of the past 12 yr. The decadal SSH signals in the 1990s were dominated by an increasing trend in the 30°–50°S band and a decreasing trend in the central South Pacific Ocean poleward of 50°S. In recent years since 2002 there has been a reversal in both of these trends. Spatially varying low-frequency SSH signals are also found in the tropical region of 10°–25°S where the decadal SSH trend is negative in the eastern basin, but positive in the western basin. To clarify the causes for these observed spatially varying SSH signals, a 1½-layer reduced-gravity model that includes the wind-driven baroclinic Rossby wave dynamics and the responses forced by SSH changes along the South American coast was adopted. The model hindcasts the spatially varying decadal trends in the midlatitude and the eastern tropical regions well. Accumulation of the wind-forced SSH anomalies along Rossby wave characteristics is found to be important for both previously reported long-term trends and their reversals in recent years. The boundary forcing associated with the time-varying SSH signals along the South American coast is crucial for understanding the observed SSH signals of all time scales in the eastern tropical South Pacific basin, but it has little impact upon the midlatitude interior SSH signals.