bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adenosine reduces the reverse mode of the Na+/Ca2+exchanger in ferret cardiac fibres
Authors: Hleihel W. , Lafoux A. , Ouaini N. , Huchet-Cadiou C. 
Published: March 2008

The aim of this study was to investigate the effects of adenosine on reverse mode Na+/Ca2+exchange. In intact ferret cardiac trabeculae, Na+-free contractures were investigated after treating preparations with ryanodine, a sarcoplasmic reticulum Ca2+-channel inhibitor, and thapsigargin, a sarcoplasmic reticulum Ca2+-pump inhibitor added to suppress the sarcoplasmic reticulum function. The effects of adenosine (50–100 nmol/L), adenosine deaminase (ADA, 0.1–0.5 U/L), the A1and A2Areceptor agonists CCPA (3–100 nmol/L) and CGS 21680 (25–100 nmol/L), and the A1and A2Areceptor antagonists DPCPX (25 nmol/L) and ZM 241385 (25 nmol/L) were tested on Na+-free contractures. The application of adenosine (50–100 nmol/L) had no significant effect on the characteristics of the Na+-free contractures. However, the results show that treatment with ADA (0.3 U/L), adenosine (≥50 nmol/L) and CCPA, a specific A1receptor agonist (3–100 nmol/L), all reduced the Na+-free contracture amplitude. In the presence of ADA, the effects of adenosine and CCPA were also reduced by a specific antagonist of A1receptors (DPCPX, 25 nmol/L). Furthermore, adenosine, ADA, and CCPA did not affect the properties of the contractile apparatus in Triton-skinned fibres. It is therefore proposed that endogenous adenosine reduced the reverse mode of the Na+/Ca2+exchanger by acting on A1receptors present in the sarcolemmal membrane.
Overexpression of Gsα compensates for myocyte loss in diabetic cardiomyopathyPresented in part at the American Heart Association meeting, New Orleans, Louisiana, November 2004.
Authors: Malhotra Ashwani , Kang Barinder P.S. , Vashistha Himanshu , Yadav Virender S. , Meggs Leonard G. 
Published: March 2008

The stimulatory G protein Gsα transmits signals from activated β-adrenergic receptors via the cyclic AMP–PKA pathway, targeting the key regulatory protein phospholamban. We hypothesized that mice with intrinsic activation of cardiac Gsα are resistant to the development of the diabetic cardiomyopathy phenotype. Accordingly, streptozotocin (STZ)-diabetes mellitus was induced in genetically engineered mice with cardiac-specific Gsα overexpression and in nontransgenic (NTG) littermates. At 8 weeks, Gsα diabetic mice showed no impairment of LV contractility nor increase in myocyte apoptosis, whereas NTG diabetic mice showed a 30% decrease in +dP/dt and –dP/dt with sustained (3-fold) myocyte loss by apoptosis. To assess the level of myocardial reactive oxygen species, we measured malondialdehyde, a surrogate marker of oxidative stress, which was increased in the hearts of NTG and Gsα diabetic mice. In addition, chronic hyperglycemia also increased the activity of catalase and superoxide dismutase in the hearts of NTG and Gsα diabetic mice. Hearts of NTG diabetic mice, but not Gsα mice, showed increased expression of proapoptosis Bax, downregulation in Bcl2, and an increase in the Bax/Bcl2 ratio. Hearts of NTG diabetic mice showed 60% reduction in phosphorylation at the critical Ser16 residue of phospholamban, whereas phosphorylation at Ser16 was restored in hearts of Gsα-diabetic mice. We conclude that cardiac-specific overexpression of Gsα compensates for the loss of cardiac function in diabetes mellitus.
Stable carbon and nitrogen isotope values in teeth of Steller sea lions: age of weaning and the impact of the 1975–1976 regime shift in the North Pacific Ocean
Authors: York A. E. , Thomason J. R. , Sinclair E. H. , Hobson K. A. 
Published: March 2008

We measured δ15N and δ13C values and tooth width from the first 4 years’ dentinal growth layer groups (GLGs) in the teeth of 113 female Steller sea lions ( Eumetopias jubatus (Schreber, 1776)) born between 1960 and 1983, a period that included a large population decrease and a climate regime shift. A linear discriminant analysis on the δ13C and δ15N values estimated 60% of Steller sea lions were weaned in their 1st year, 30% in their 2nd year, and 8% in their 3rd year. GLG-1 was wider in “weaned” animals than those still “nursing” in their 2nd year, suggesting that faster growing pups weaned earlier. Except during the regime shift, the average age at weaning increased and the size of GLG-1 in weaned animals decreased. We suggest that during the regime shift a greater proportion of pups which survived (to have their teeth sampled for this study) grew faster and were weaned by the end of their 1st year. We hypothesize that the long-term weaning age increase and growth rate decrease are consistent with a change in relative mortality of weaned pups and those that continued to nurse, possibly caused by a reduction in available resources, characterized as a switch from a “live-fast” to a “live-slow” life history.
Male sperm whale (Physeter macrocephalus) coda production and coda-type usage depend on the presence of conspecifics and the behavioural context
Authors: Frantzis Alexandros , Alexiadou Paraskevi 
Published: March 2008

Sperm whale ( Physeter macrocephalus L., 1758 (= Physeter catodon L., 1758)) codas serve a communication function, but the message they carry remains unknown. Very few codas and extremely few coda types are available from males. For 7 years we studied the coda occurrence and the coda types produced by 15 males in different behavioural and encounter contexts. Of the 67 encounters, 615 codas were produced by nonsolitary males. Codas occurred in 60% of the nonsolitary encounters and 36% of the dive cycles. Four hundred and ninety codas have been categorized into 8 coda families and 25 distinctive coda types. Both the coda type used and the dive cycle phase in which codas occurred strongly depended on the behavioural context. This is the first time that coda types have been associated with particular behavioural contexts. The “Three plus” family coda types were mainly used by ascending or descending whales in feeding dive cycles. The “Regular” and “Progressive” families were used almost exclusively by interacting whales. The “Root” coda family was used exclusively at surface, mainly in altered dive cycles. The coda types used in these three behavioural contexts seem to carry different messages and are proposed to be named “dive cycle codas”, “social codas”, and “alarm codas”, respectively.
Discrimination of carbon and nitrogen isotopes from milk to serum and vibrissae in Alaska Steller sea lions (Eumetopias jubatus)
Authors: Stegall Vicki K. , Farley Sean D. , Rea Lorrie D. , Pitcher Kenneth W. , Rye Robert O. , Kester Cynthia L. , Stricker Craig A. , Bern Carleton R. 
Published: March 2008

Knowledge of diet–tissue stable isotope discrimination is required to properly interpret stable isotope values and to identify possible diet shifts, such as might be expected from nursing through weaning. This study compared δ13C and δ15Ν οf paired serum and vibrissal roots with those of ingested milk (n = 52) from free-ranging Steller sea lion ( Eumetopias jubatus (Schreber, 1776)) pups (1–11 months) and juveniles (14–27 months) to estimate diet–tissue discrimination. Mean 15N enrichment from ingested milk to serum was 2.1‰ ± 0.6‰ and δ15Ν at the root of the vibrissae (representing current growth) were not significantly different from serum values. Milk was enriched for mean 13C by 5.0‰ ± 1.0‰ and 7.3‰ ± 1.2‰ relative to serum and vibrissal roots, respectively, which was due to the presence of 13C-depleted lipids in milk. This was confirmed by lipid extraction from a subset of milk and serum samples, resulting in a 5.8‰ ± 1.0‰ change only in milk. This study established that vibrissal roots and serum are reflective of a milk diet with approximately 2.0‰ 15N enrichment, and vibrissal roots reflect serum and lipid-extracted milk values with approximately 2.0‰ 13C enrichment. These discrimination factors are important to establish for stable isotope studies assessing diet shifts.
THE BIFURCATION STRUCTURE OF FIRING PATTERN TRANSITIONS IN THE CHAY NEURONAL PACEMAKER MODEL
Authors: YANG ZHUOQIN , LU QISHAO 
Published: March 2008

Different transitions of neuronal firing patterns are explored by the combination of experimental results, numerical simulation and bifurcation analysis. Three types of firing sequences with respect to extracellular calcium concentration ([ Ca 2+] o ) were observed in experiments on neural pacemakers. In accordance with them, the corresponding transitions of neuronal firing patterns are surveyed by standard bifurcation analysis of the Chay model, where λn corresponds to different nerve fibers and VC is the dynamical parameter. The results are listed in this paper. Firstly, it is obtained that the transitions of periodic firing patterns from period-1 bursting to period-1 spiking without any bifurcation, from period-1 to -2 to -1 through a pair of period-doubling bifurcations and from period-1 to -2 to -1 through two pairs of period-doubling bifurcations. Secondly, one supercritical and two subcritical period-doubling bursting sequences with different appearances lead to chaos, respectively. Then the former transits directly to an inverse supercritical period-doubling spiking sequence via chaos, and the latter transit to it through the period-adding bursting sequences from period-1 to -3 and from -1 to -5 with chaotic bursting, respectively. Thirdly, we reveal the true nature of period-adding bursting sequence without chaotic bursting. Every periodic bursting is closely related to two period-doubling bifurcations of the corresponding periodic spiking, except for period-1 bursting appearing via Hopf bifurcation and disappearing via period-doubling bifurcation. As a consequence, the period-adding bursting sequence without chaotic bursting has a compound structure of elementary bifurcations with transitions from spiking to bursting. Thus period-adding bifurcation without chaos cannot be regarded as a new elementary bifurcation.
Estimating Seasonal Changes in Volumetric Soil Water Content at Landscape Scales in a Savanna Ecosystem Using Two-Dimensional Resistivity Profiling
Authors: Garcia-Montiel Diana C. , Coe Michael T. , Cruz Meyr P. , Ferreira Joice N. , da Silva Euzebio M. , Davidson Eric A. 
Published: March 2008

Abstract
Water distributed in deep soil reservoirs is an important factor determining the ecosystem structure of water-limited environments, such as the seasonal tropical savannas of South America. In this study a two-dimensional (2D) geoelectrical profiling technique was employed to estimate seasonal dynamics of soil water content to 10-m depth along transects of 275 m in savanna vegetation during the period between 2002 and 2006. Methods were developed to convert resistivity values along these 2D resistivity profiles into volumetric water content (VWC) by soil depth. The 2D resistivity profiles revealed the following soil and aquifer structure characterizing the underground environment: 0–4 m of permanently unsaturated and seasonally droughty soil, less severely dry unsaturated soil at about 4–7 m, nearly permanently saturated soil between 7 and 10 m, mostly impermeable saprolite interspaced with fresh bedrock of parent material at about 10–30 m, and a region of highly conductive water-saturated material at 30 m and below. Considerable spatial variation of these relative depths is clearly demonstrated along the transects. Temporal dynamics in VWC indicate that the active zone of water uptake is predominantly at 0–7 m, and follows the seasonal cycles of precipitation and evapotranspiration. Uptake from below 7 m may have been critical for a short period near the beginning of the rainy season, although the seasonal variations in VWC in the 7–10-m layer are relatively small and lag the surface water recharge for about 6 months. Calculations using a simple 1-box water balance model indicate that average total runoff was 15–25 mm month−1 in the wet season and about 6–9 mm month−1 in the dry season. Modeled ET was about 75–85 mm month−1 in the wet season and 20–25 mm month−1 in the dry season. Variation in basal area and tree density along one transect was positively correlated with VWC of the 0–3-m and 0–7-m soil depths, respectively, during the wettest months. These multitemporal measurements demonstrate that the along-transect spatial differences in soil moisture are quasi-permanent and influence vegetation structure at the scale of tens to hundreds of meters.
Derivation of Effective Aerodynamic Surface Roughness in Urban Areas from Airborne Lidar Terrain Data
Authors: Holland Donald E. , Berglund Judith A. , Spruce Joseph P. , McKellip Rodney D. 
Published: March 2008

Abstract
An automated technique was developed that uses only airborne lidar terrain data to derive the necessary parameters for calculation of effective aerodynamic surface roughness in urban areas. The technique provides parameters for geometric models that have been used over the past 40+ years by automatically deriving the relevant geometry, orientation, and spacing of buildings and trees. In its prototypical form, this technique subsequently calculates an effective surface roughness for 1-km2 parcels of land for each of five geometric models. The user can define several constraints to guide processing based on a priori knowledge of the urban area or lidar data characteristics. Any given wind direction (or range of directions) can be selected to simulate conditions of variable wind flow and the impact on effective surface roughness. The operation, capabilities, and limitations of the technique were demonstrated using lidar terrain data from Broward County, Florida.
Precipitation Recycling Variability and Ecoclimatological Stability—A Study Using NARR Data. Part I: Central U.S. Plains Ecoregion
Authors: Dominguez Francina , Kumar Praveen 
Published: March 2008

Abstract
Precipitation recycling is one of the key mechanisms linking the land surface and atmospheric dynamics. This work explores the physical mechanisms that modulate precipitation recycling variability at the daily-to-intraseasonal time scales in the central U.S. plains ecoregion using a set of land–atmosphere variables derived from the North American Regional Reanalysis dataset. Recycling estimates are performed using the Dynamic Recycling Model, which allows for analysis at shorter time scales than the previous bulk recycling models.
In the central U.S. plains ecoregion local evapotranspiration only becomes an important contributor to precipitation when moisture of advective origin, the largest contributor to precipitation, diminishes. Consequently, the recycling ratio is negatively correlated to precipitation. The dominant mechanism is a negative feedback, which ensures that, even when precipitation is low, evapotranspiration continues to feed moisture into the overlying atmosphere and contribute to rainfall. Consequently, in the central U.S. plains, precipitation recycling acts as a mechanism for ecoclimatological stability through local negative feedbacks. Additionally, the zonal and meridional winds and moisture fluxes were also found to be important drivers of recycling variability. As winds decrease, the air has more time to traverse the region and capture moisture of evaporative origin. Evapotranspiration variability is not an important driver for recycling ratio variability in the central U.S. plains. Only during the extremely dry 1988 summer drought, when soil moisture storage was depleted, did the recycling ratio variability closely follow evapotranspiration.
Ensemble Precipitation and Water-Level Forecasts for Anticipatory Water-System Control
Authors: Jan van Andel Schalk , Price Roland K. , Lobbrecht Arnold H. , van Kruiningen Frans , Mureau Robert 
Published: March 2008

Abstract
A method is presented for testing weather forecast products for applications in anticipatory water-system control. The applicability of the ensemble prediction system (EPS) of the ECMWF is tested for flood control in a regional water system in the Netherlands. By performing long-term verification analyses, a full range of probability-threshold-based decision rules to apply anticipatory control actions is evaluated in terms of hits (correct alerts), missed events, and false alarms. The analysis includes forecast horizons from 3 to 9 days for extreme precipitation events and extreme water-level events. The water-level forecasts are prepared by feeding each member of the ECMWF EPS precipitation ensemble into a deterministic water-system control model. The current operational strategy is modeled to forecast when the routine operational control will not be sufficient to prevent high water levels, and therefore anticipatory control actions are needed. The results show that ECMWF EPS precipitation forecasts contain useful information for regional water-system control in the Netherlands. All critical events during the analysis period were forecasted. The applied analysis method allows water managers to define decision rules, on the basis of requirements, in terms of forecast horizon, safety, and allowable costs of adverse effects of false alarms.
Explicit Forecasts of Winter Precipitation Using an Improved Bulk Microphysics Scheme. Part II: Implementation of a New Snow Parameterization
Authors: Thompson Gregory , Field Paul R. , Rasmussen Roy M. , Hall William D. 
Published: March 2008

Abstract
A new bulk microphysical parameterization (BMP) has been developed for use with the Weather Research and Forecasting (WRF) Model or other mesoscale models. As compared with earlier single-moment BMPs, the new scheme incorporates a large number of improvements to both physical processes and computer coding, and it employs many techniques found in far more sophisticated spectral/bin schemes using lookup tables. Unlike any other BMP, the assumed snow size distribution depends on both ice water content and temperature and is represented as a sum of exponential and gamma distributions. Furthermore, snow assumes a nonspherical shape with a bulk density that varies inversely with diameter as found in observations and in contrast to nearly all other BMPs that assume spherical snow with constant density. The new scheme’s snow category was readily modified to match previous research in sensitivity experiments designed to test the sphericity and distribution shape characteristics. From analysis of four idealized sensitivity experiments, it was determined that the sphericity and constant density assumptions play a major role in producing supercooled liquid water whereas the assumed distribution shape plays a lesser, but nonnegligible, role. Further testing using numerous case studies and comparing model results with in situ and other observations confirmed the results of the idealized experiments and are briefly mentioned herein, but more detailed, microphysical comparisons with observations are found in a companion paper in this series (Part III, forthcoming).
The Temporal Evolution of Convective Indices in Storm-Producing Environments
Authors: Wagner Timothy J. , Feltz Wayne F. , Ackerman Steven A. 
Published: March 2008

Abstract
Temporal changes in stability and shear associated with the development of thunderstorms are quantified using the enhanced temporal resolution of combined Atmospheric Emitted Radiance Interferometer (AERI) thermodynamic profile retrievals and National Oceanic and Atmospheric Administration (NOAA) 404-MHz wind profiler observations. From 1999 to 2003, AERI systems were collocated with NOAA wind profilers at five sites in the southern Great Plains of the United States, creating a near-continuous dataset of atmospheric soundings in both the prestorm and poststorm environments with a temporal resolution of up to 10 min between observations.
Median values for several standard severe weather indices were calculated for tornadic storms and nontornadic supercells. It was found that instability generally increases throughout the preconvective period, reaching a peak roughly 1 h before a tornado forms or a nontornadic supercell forms large hail. Wind shear for both tornadic and nontornadic storms starts to increase roughly 3 h before storm time. However, indices are highly variable between time and space and may not be representative of the environment at large.
Clinical Review : Pediatric and Otologic Aspects of Clinical Research in Cleft Palate
Authors: Paradise Jack L. , Alberti Peter W. R. M. , Bluestone Charles D. , Cheek Donald B. , Lis Edward F. , Stool Sylvan E. 
Published: March 2008

In 1971, the American Speech and Hearing Associa tion, under contract with the National Institute of Dental Reseach, assembled an interdisciplinary commit tee to review the present status of clinical research on cleft lip and palate, and to discuss possible approaches and recommend priorities with respect to filling the gaps in existing knowledge. Between August, 1971 and July, 1972, state-of-the-art workshops were conducted by six subcommittees—concerned, respectively, with etiology and pathogenesis, anatomy and physiology, pediatric and otologic aspects, surgery and physical management, orofacial growth and dentistry, and speech and psy chosocial management. Presented here is the report of the subcommittee concerned with pediatric and otologic aspects. Addi tional information concerning the entire review, includ ing a list of the subcommittees and their chairmen, appears at the end of the article.
A View of Danish Pediatric Care
Authors: Maisel Jerome E. 
Published: March 2008

The Danish social system provides competent, accessible, continuous, and coordinated medical care to the pediatric population. The pediatri cian does not deal with the routine aspects of well-infant and child care but is rather hospital based and acts on consultant to the generalists in his district. The generalist has the primary role in providing health care to the population in a program where everyone is obliged to partici pate and no one is excluded or ineligible for any reason. The American obsession with frequent, periodic examinations for infants, children, and young adults does not exist under the Danish pediatric health system. Hospital emergency rooms are used for truly emergent circum stances and not for episodic care.
Toy Safety in Hospitals—Or Beware of Parents Bearing Gifts
Authors: Frank Donald J. , Drobish Nancy Lloyd 
Published: March 2008

Toys are an indispensable component of play therapy for hospitalized children. They can also be dangerous and may result in catastrophic accidents. Extreme care should be exercised in the purchase of "safe toys" for all infants and children in and out of the hospital. The guidelines of the Bureau of Product Safety of the Federal Drug Administration (FDA) dealing with toy safety can be very helpful for child care professionals as well as parents who purchase toys. An explanation of the additional environmen tal hazards of toys in hospital settings should be an important part of the total in-service training of all personnel who care for infants and children in hospitals. In addition, it might be well for the Division of Product Safety of the FDA to consider criteria for toy safety in hospitals as a separate category in future Bulle tins dealing with this problem.