bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heart rate variability parameters of myxomatous mitral valve disease in dogs with and without heart failure obtained using 24‐hour Holter electrocardiography
Authors: Oliveira M. S. , Muzzi R. A. L. , Araújo R. B. , Muzzi L. A. L. , Ferreira D. F. , Nogueira R. , Silva E. F. 
Published: May 2012

Time‐domain heart rate variability (HRV) parameters and the correlation between echocardiography and Holter examinations in dogs with myxomatous mitral valve disease (MMVD) were determined. Holter examination was also performed at different time frames: an entire 24‐hour period, a four‐hour period during sleep, and a four‐hour period while awake. Ten healthy (control group) and 28 MMVD dogs, 15 with and 13 without heart failure, were evaluated. The SDANN (sd of the mean normal RR intervals for all five‐minute segments during 24‐hour Holter) and pNN 50 (percentage of differences between adjacent normal RR intervals that are >50 ms computed over 24‐hour Holter) variables were significantly lower in the dogs with MMVD heart failure. The differences in HRV between the groups were only detected during the 24‐hour evaluation period (P < 0.05). There were high correlations (canonical analysis) between Holter and echocardiography examinations when considering pNN 50 , SDANN, and LA/AO (left atrial to aortic root ratio) (r = 0.92; P < 0.05), indicating that both are important in evaluating MMVD dogs. SDANN and pNN 50 are measures of parasympathetic control of the heart, and thus, it is possible to infer that the MMVD dogs exhibit parasympathetic withdrawal during the development of heart failure.
Residual effects of Mycobacterium avium infection on susceptibility of sheep to copper toxicity and efficacy of treatment with tetrathiomolybdate
Authors: Suttle N. F. 
Published: May 2012

Posthaemolytic copper poisoning (post‐HCP) in one of six, one‐year‐old, uninfected sheep (group O) on a Mycobacterium avium experiment prompted an evaluation of copper status and hepatotoxicity in 17 surviving cohorts. Group O had higher mean plasma Cu and δ‐glutamyl transferase (GGT) activity and more variable bile acid (BA) concentrations and glutamate dehydrogenase activities (GDH) than two groups infected with M avium soon after birth. Ammonium tetrathiomolybdate (TTM; 3 x 1.7 mg/kg LW) was given subcutaneously over seven days and the pelleted, complete diet replaced by hay, low in copper. Plasma BA immediately declined and was followed by GDH, but erythrocyte superoxide dismutase activity (ESOD) became severely inhibited and took 18 days to recover. Plasma BA and GDH rose sharply after 18 days in uninfected sheep and they became hypercupraemic. TTM treatment was repeated from day 42 and had removed all group differences by day 110 but only after further inhibition of ESOD. M avium infections probably lessened the severity of pre‐HCP by reducing copper retention but may predispose grazing livestock to hypocupraemia. The capacity of TTM to reduce liver Cu has probably been overestimated and side effects on cuproenzyme activity underestimated.
An experimental study of how variation in deer density affects vegetation and songbird assemblages of recently harvested boreal forests
Authors: Cardinal Etienne , Martin Jean-Louis , Tremblay Jean-Pierre , Côté Steeve D. 
Published: May 2012

Intense browsing by abundant large herbivores can threaten the ecological integrity of ecosystems by inducing modifications in the structure and composition of vegetation that trigger trophic cascades affecting plant and animal communities. We investigated the relationships between density of white-tailed deer ( Odocoileus virginianus (Zimmermann, 1780)), forest succession after clear-cut, and songbird communities on Anticosti Island, Quebec, Canada. We hypothesized that lower deer densities would alter the trajectory of forest succession after clear-cutting and lead to a rapid recovery of habitat attributes favorable to songbirds associated with a dense complex shrub layer. Six years after establishing a controlled browsing experiment (0, 7.5, 15, and >27 deer·km–2) in recent clearcuts, reducing deer densities ≤7.5 deer·km–2initiated the restoration of balsam fir ( Abies balsamea (L.) Mill.) forests and increased the regeneration of paper birch ( Betula papyrifera Marshall). Increasing birch ground cover from 10% to 20% increased songbird total abundance, species richness, and diversity by 17%, 39%, and 31%, respectively. Alder Flycatcher (Empidonax alnorum Brewster, 1895) was only present at ≤7.5 deer·km–2and strongly associated with birch regeneration. The regeneration of browse-resistant plants such as white spruce ( Picea glauca (Moench) Voss) in some areas at high deer density favored the maintenance of many shrub-dependent songbirds but also species usually associated with forest canopy. Active management of deer populations in Canadian harvested boreal forests will mitigate losses in vegetation and songbirds caused by over-browsing.
Variation in reproductive success of male and female Columbian ground squirrels (Urocitellus columbianus)
Authors: Jones Philip H. , Van Zant Jeffrey L. , Dobson F. Stephen 
Published: May 2012

The imbalanced reproductive success of polygynous mammals results in sexual selection on male traits like body size. Males and females might have more balanced reproductive success under polygynandry, where both sexes mate multiply. Using 4 years of microsatellite DNA analyses of paternity and known maternity, we investigated variation in reproductive success of Columbian ground squirrels, Urocitellus columbianus (Ord, 1815); a species with multiple mating by both sexes and multiple paternity of litters. We asked whether male reproductive success was more variable than that of females under this mating system. The overall percentage of confirmed paternity was 61.4% of 339 offspring. The mean rate of multiple paternity in litters with known fathers was 72.4% (n = 29 litters). Estimated mean reproductive success of males (10.27 offspring) was about thrice that of females (3.11 offspring). Even after this difference was taken into account statistically, males were about three times as variable in reproductive success as females (coefficients of variation = 77.84% and 26.74%, respectively). The Bateman gradient (regression slope of offspring production on number of successful mates) was significantly greater for males (βM = 1.44) than females (βF = 0.28). Thus, under a polygynandrous mating system, males exhibited greater variation in reproductive success than females.
Growth and maturity of a terrestrial ectotherm near its northern distributional limit: does latitude matter?
Authors: Tuttle Krysia N. , Gregory Patrick T. 
Published: May 2012

High-latitude environments are challenging for terrestrial ectotherms because short and cool active seasons generally limit the time available for foraging and growth, thereby negatively influencing life-history variables such as growth rate and age at maturity and ultimately, via fitness differences, their evolution. Many species show latitudinal clines in life-history traits, including growth rate and body size. We estimated growth curves of Plains Garter Snakes ( Thamnophis radix (Baird and Girard, 1853)) near the northern limit of the species’ range in central Alberta and compared our findings to similar estimates for more southerly populations. Despite a short growing season, female T. radix at Miquelon Lake grew rapidly, reaching maturity in 1 or 2 years, similar to southern populations, and attained greater maximum sizes than snakes in southern populations. Overall, growth in this high-latitude population is comparable with what is seen in other conspecific populations. Possible reasons for lack of marked latitudinal effect include longer days at high latitudes, highly productive aquatic habitats for foraging, effective thermoregulation, reduced competition, and (or) countergradient variation in growth rate.
Tumor-Associated Macrophages in Pediatric Classical Hodgkin Lymphoma: Association with Epstein-Barr Virus, Lymphocyte Subsets, and Prognostic Impact
Authors: Barros Mário Henrique M. , Hassan Rocio , Niedobitek Gerald 
Published: May 2012

AbstractPurpose: Tumor-infiltrating macrophages are associated with adverse outcome in adult classical Hodgkin lymphoma (cHL). We have previously shown age-related changes in the lymphocyte composition of pediatric cHL. We therefore hypothesized that the number, function, and prognostic impact of macrophages in pediatric cHL would be different from adult cases.Experimental Design: We analyzed the number of macrophages and dendritic cells (DC) in the tumor microenvironment of pediatric cHL by immunohistochemistry. Results were analyzed in context of age, histologic characteristics, Epstein-Barr virus (EBV) status, clinical follow-up, and our previous study of T-cell populations in these cases.Results: One hundred cHL cases were studied, including 69% nodular sclerosis and 23% mixed cellularity cases. A total of 44.8% of cases were EBV-positive. Patients ≤10 years displayed more CD14+ cells (P = 0.025). In comparison with nodular sclerosis, mixed cellularity was characterized by higher numbers of CD14+, (P = 0.003) and CD163+ cells (P = 0.027). EBV+ cases exhibited higher numbers of CD14+ (P &lt; 0.0005), CD68+ (P = 0.005), and CD163+ cells (P = 0.02). CD68-positive cells did not display an effect on outcome. Worse overall survival was observed in cases with CD163/CD8 ratio ≥2 (P = 0.007). High numbers of CD163+ cells were associated with worse progression-free survival (PFS; P = 0.015). Furthermore, high numbers of CD163+ and granzyme B+ cells were associated with worse PFS in EBV-negative (P = 0.005) but not in EBV-positive cases.Conclusion: Our results suggest that macrophage composition in pediatric cHL is distinct from adults. Functional status of macrophages and their value as prognostic indicators in pediatric cHL may depend on EBV status. Clin Cancer Res; 18(14); 3762–71. ©2012 AACR.
A Randomized, Double-Blind, Active-Controlled Phase 2 Trial to Evaluate a Novel Selective and Reversible Intravenous and Oral P2Y
12
Inhibitor Elinogrel Versus Clopidogrel in Patients Undergoing Nonurgent Percutaneous Coronary Intervention
Authors: Welsh Robert C. , Rao Sunil V. , Zeymer Uwe , Thompson Vivian P. , Huber Kurt , Kochman Janusz , McClure Matthew W. , Gretler Daniel D. , Bhatt Deepak L. , Gibson C. Michael , Angiolillo Dominick J. , Gurbel Paul A. , Berdan Lisa G. , Paynter Gayle , Leonardi Sergio , Madan Mina , French William J. , Harrington Robert A. 
Published: May 2012

Background—

We evaluated the safety, efficacy, and tolerability of elinogrel, a competitive, reversible intravenous and oral P2Y
12
inhibitor that does not require metabolic activation, in patients undergoing nonurgent percutaneous coronary intervention.

Methods and Results—
In a randomized, double-blind, dose-ranging phase 2b trial, 652 patients received either 300 or 600 mg of clopidogrel pre-percutaneous coronary intervention followed by 75 mg daily or 80 or 120 mg of IV elinogrel followed by 50, 100, or 150 mg oral elinogrel twice daily. Numerous exploratory safety and efficacy end points were assessed and, as such, had no prespecified primary end point, and the study was not powered to conclusively evaluate its objectives. Thrombolysis in myocardial infarction combined bleeding was increased with elinogrel (hazard ratio, 1.98; 95% confidence interval, 1.10 to 3.57), related largely to increased bleeding requiring medical attention (elinogrel 47/408 [11.5%] versus clopidogrel 13/208 [6.3%]) and occurring primarily at the percutaneous coronary intervention access site. Efficacy end points and postprocedure cardiac enzyme were similar, but there was a nonsignificant higher frequency of periprocedural myocardial infarctions in the elinogrel arms (OR, 1.59; 95% confidence interval, 0.79 to 3.48). There was an increased incidence of dyspnea (elinogrel 50/408 [12.3%] versus clopidogrel 8/208 [3.8%]) and transaminase elevation (alanine transferase/aspartate transferase >3× the upper limit of normal; elinogrel 18/408 [4.4%] versus clopidogrel 2/208 [1.0%]) in the elinogrel arms, but there were no cases of heart block, bradycardia, hypotension, or liver failure.

Conclusions—
In patients undergoing nonurgent percutaneous coronary intervention and in comparison with clopidogrel, intravenous and oral elinogrel therapy did not significantly increase thrombolysis in myocardial infarction major or minor bleeding, although bleeding requiring medical attention was more common. The significance of these findings will need to be more definitively determined in future Phase 3 studies.

Clinical Trial Registration—

URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT00751231.
Comparison of Hyperemic Efficacy Between Central and Peripheral Venous Adenosine Infusion for Fractional Flow Reserve Measurement
Authors: Seo Myung-Ki , Koo Bon-Kwon , Kim Ji-Hyun , Shin Dong-Ho , Yang Han-Mo , Park Kyung-Woo , Lee Hae-Young , Kang Hyun-Jae , Kim Hyo-Soo , Oh Byung-Hee , Park Young-Bae 
Published: May 2012

Background—
Maximal hyperemia is a prerequisite for the accurate measurement of fractional flow reserve (FFR). Although continuous infusion of adenosine via the femoral vein is considered to be the gold standard, this requires an additional invasive procedure for femoral vein access and is difficult to use during transradial coronary catheterization. We performed this prospective study to evaluate the feasibility and efficacy of peripheral intravenous infusion of adenosine for FFR measurement.

Methods and Results—

Seventy-one patients were prospectively enrolled, and FFR was measured using a 0.014-inch coronary pressure wire. Hyperemic efficacy of adenosine was compared among intracoronary bolus injection and continuous IV infusion (140 μg/min/kg) via the femoral and via the forearm vein. In 20 patients, hyperemic mean transit time and index of microcirculatory resistance were also measured. Mean FFR after bolus administration of adenosine was 0.81±0.10. As compared with femoral vein infusion (FFR: 0.80±0.10), hyperemic efficacy of forearm vein infusion of adenosine (FFR: 0.80±0.11) was not inferior (
P
for noninferiority=0.01). The number of functionally significant stenoses (FFR <0.75) was also not different between the 2 methods (femoral vein versus forearm vein; 17 (25.0%) versus 17 (25.0%),
P
=1.0). Both hyperemic mean transit time and index of microcirculatory resistance were not different between the 2 routes of adenosine infusion. Additional bolus injection of adenosine during IV infusion did not improve the hyperemic efficacy but increased the risk of atrioventricular block.

Conclusions—
This study suggests that continuous intravenous infusion of adenosine via the forearm vein is a convenient and effective way to induce steady-state hyperemia for invasive physiological measurements.

Clinical Trial Registration—

URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT01070420.
Sustained Ventricular Tachycardia and Ventricular Fibrillation Complicating Non–ST-Segment–Elevation Acute Coronary Syndromes
Authors: Piccini Jonathan P. , White Jennifer A. , Mehta Rajendra H. , Lokhnygina Yuliya , Al-Khatib Sana M. , Tricoci Pierluigi , Pollack Charles V. , Montalescot Gilles , Van de Werf Frans , Gibson C. Michael , Giugliano Robert P. , Califf Robert M. , Harrington Robert A. , Newby L. Kristin 
Published: May 2012

Background—
Ventricular arrhythmias remain a lethal complication of acute coronary syndromes (ACS). However, the incidence and prognosis of sustained ventricular tachycardia/ventricular fibrillation (VT/VF) in contemporary non–ST-segment–elevation (NSTE) ACS populations are not well described.

Methods and Results—

We examined the incidence of VT/VF and subsequent survival among 9211 patients enrolled in the Early Glycoprotein IIb/IIIa Inhibition in NSTE ACS (EARLY ACS) trial. The cumulative incidence of VT/VF was 1.5% (n=141); 0.6% (n=55) had VT/VF ≤48 hours after enrollment, and 0.9% (n=86) had VT/VF >48 hours after enrollment. Patients with VT/VF more frequently had prior heart failure, an ejection fraction <30%, and triple-vessel coronary artery disease. Predictors of sustained VT/VF were similar regardless of the timing of VT/VF (≤48 versus >48 hours). Patients with VT/VF ≤48 hours after enrollment had higher 30-day mortality than those who did not have VT/VF ≤48 hours (13.0% versus 2.2%; adjusted odds ratio, 6.73; 95% confidence interval, 2.68–16.9). The increased risk of death associated with VT/VF ≤48 hours persisted at 1 year. The risk of mortality, relative to patients without VT/VF, was greater for patients with VT/VF >48 hours (hazard ratio, 20.70; 95% confidence interval, 15.39–27.85) than for those with earlier VT/VF (hazard ratio, 7.45; 95% confidence interval, 4.60–12.08;
P
=0.0003). The frequency of arrhythmic death was higher in patients with VT/VF than in those without VT/VF (26.4% versus 6.9%).

Conclusions—
Sustained VT/VF is infrequent after NSTE ACS but is as likely to occur after 48 hours as within the first 48 hours. The marked increase in all-cause death among NSTE ACS patients with both early and late sustained VT/VF raises important considerations for aggressive monitoring beyond 48 hours and interventions to prevent arrhythmic death in these patients.

Clinical Trial Registration—

URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT00089895.
Validation of Satellite-Derived Atmospheric Motion Vectors and Analyses around Tropical Disturbances
Authors: Sears John , Velden Christopher S. 
Published: May 2012

AbstractFields of atmospheric motion vectors (AMVs) are routinely derived by tracking features in sequential geostationary satellite infrared, water vapor, and visible-channel imagery. While AMVs produced operationally by global data centers are routinely evaluated against rawinsondes, there is a relative dearth of validation opportunities over the tropical oceans—in particular, in the vicinity of tropical disturbances when anomalous flow fields and strongly sheared environments commonly exist. A field experiment in 2010 called Pre-Depression Investigation of Cloud-Systems in the Tropics (PREDICT) was conducted in the tropical west Atlantic Ocean and provides an opportunity to evaluate the quality of tropical AMVs and analyses derived from them. The importance of such a verification is threefold: 1) AMVs often provide the only input data for numerical weather prediction (NWP) over cloudy areas of the tropical oceans, 2) NWP data assimilation methods are increasingly reliant on accurate flow-dependent observation-error characteristics, and 3) global tropical analysis and forecast centers often rely on analyses and diagnostic products derived from the AMV fields. In this paper, the authors utilize dropsonde information from high-flying PREDICT aircraft to identify AMV characteristics and to better understand their errors in tropical-disturbance situations. It is found that, in general, the AMV observation errors are close to those identified in global validation studies. However, some distinct characteristics are uncovered in certain regimes associated with tropical disturbances. High-resolution analyses derived from the AMV fields are also examined and are found to be more reflective of anomalous flow fields than the respective Global Forecast System global model analyses.
Application of WRF 3DVAR to Operational Typhoon Prediction in Taiwan: Impact of Outer Loop and Partial Cycling Approaches
Authors: Hsiao Ling-Feng , Chen Der-Song , Kuo Ying-Hwa , Guo Yong-Run , Yeh Tien-Chiang , Hong Jing-Shan , Fong Chin-Tzu , Lee Cheng-Shang 
Published: May 2012

Abstract
In this paper, the impact of outer loop and partial cycling with the Weather Research and Forecasting Model’s (WRF) three-dimensional variational data assimilation system (3DVAR) is evaluated by analyzing 78 forecasts for three typhoons during 2008 for which Taiwan’s Central Weather Bureau (CWB) issued typhoon warnings, including Sinlaku, Hagupit, and Jangmi. The use of both the outer loop and the partial cycling approaches in WRF 3DVAR are found to reduce typhoon track forecast errors by more than 30%, averaged over a 72-h period. The improvement due to the outer loop approach, which can be more than 42%, was particularly significant in the early phase of the forecast. The use of the outer loop allows more observations to be assimilated and produces more accurate analyses. The assimilation of additional nonlinear GPS radio occultation (RO) observations over the western North Pacific Ocean, where traditional observational data are lacking, is particularly useful. With the lack of observations over the tropical and subtropical oceans, the error in the first-guess field (which is based on a 6-h forecast of the previous cycle) will continue to grow in a full-cycling limited-area data assimilation system. Even though the use of partial cycling only shows a slight improvement in typhoon track forecast after 12 h, it has the benefit of suppressing the growth of the systematic model error. A typhoon prediction model using the Advanced Research core of the WRF (WRF-ARW) and the WRF 3DVAR system with outer loop and partial cycling substantially improves the typhoon track forecast. This system, known as Typhoon WRF (TWRF), has been in use by CWB since 2010 for operational typhoon predictions.
Misjudging Their Own Steps
Authors: Zivotofsky Ari Z. , Eldror Ehud , Mandel Roi , Rosenbloom Tova 
Published: May 2012

Objective: The aim of this study was to test whether elderly individuals underestimate the time that it will take them to cross a street by comparing estimated with actual road-crossing time. Background: In many developed countries, elderly people are overrepresented among pedestrian fatalities from motor vehicle accidents. There is surely more than one contributing factor to this phenomenon, and many have been offered. We propose that one additional factor may be that although older people are consciously aware that they no longer walk at the same pace as they once did, they do not take this fact into consideration when planning a street crossing. Method: We compared the ability of young and old pedestrians to estimate the time that it will take them to cross a street, using both prospective and retrospective time estimation. Results: A significant interaction was found between age group and crossing time. Among elderly participants, actual crossing times were significantly longer than both their precrossing estimation and their postcrossing estimation, which did not significantly differ from each other. In contrast, the undergraduate group’s crossing times did not display a significant difference across measurements. Conclusion: This study implies that even if older pedestrians correctly evaluate the road situation, they may nonetheless endanger themselves by underestimating the time that it will take them to cross the street. We suggest that minimizing this effect could be accomplished by educating seniors to the fact that they are not as fast as they once were and that this fact needs to be factored in to street-crossing decisions.