bluuebunny/crossref_metadata_2025_split huggingface dataset:
Removing redundant arguments automatically
Authors: ALPUENTE M. , ESCOBAR S. , LUCAS S. 
Published: February 2007

AbstractThe application of automatic transformation processes during the formal development and optimization of programs can introduce encumbrances in the generated code that programmers usually (or presumably) do not write. An example is the introduction of redundant arguments in the functions defined in the program. Redundancy of a parameter means that replacing it by any expression does not change the result. In this work, we provide methods for the analysis and elimination of redundant arguments in term rewriting systems as a model for the programs that can be written in more sophisticated languages. On the basis of the uselessness of redundant arguments, we also propose an erasure procedure which may avoid wasteful computations while still preserving the semantics (under ascertained conditions). A prototype implementation of these methods has been undertaken, which demonstrates the practicality of our approach.
Demand analysis with partial predicates
Authors: MARIÑO JULIO , HERRANZ ÁNGEL , MORENO-NAVARRO JUAN JOSÉ 
Published: February 2007

AbstractTo alleviate the inefficiencies caused by the interaction of the logic and functional sides, integrated languages may take advantage ofdemandinformation, i.e. knowing in advance which computations are needed and, to which extent, in a particular context. This work studiesdemand analysis– which is closely related tobackwards strictness analysis– in a semantic framework ofpartial predicates, which in turn are constructive realizations of ideals in a domain. This will allow us to give a concise, unified presentation of demand analysis, to relate it to other analyses based on abstract interpretation or strictness logics, some hints for the implementation, and, more important, to prove the soundness of our analysis based ondemand equations. There are also some innovative results. One of them is that a set constraint-based analysis has been derived in a stepwise manner using ideas taken from the area of program transformation. The other one is the possibility of using program transformation itself to perform the analysis, specially in those domains of properties where algorithms based on constraint solving are too weak.
Eccentric treatment for patellar tendinopathy: a prospective randomised short-term pilot study of two rehabilitation protocols
Authors: Frohm Anna , Saartok Tönu , Halvorsen Kjartan , Renström Per 
Published: February 2007

Objective:To compare the efficacy and safety of two eccentric rehabilitation protocols for patients with symptomatic patellar tendinopathy. A new eccentric overload training device was compared with the present standard eccentric rehabilitation programme on a decline board.Design:Prospective, randomised clinical trial.Setting:Sports rehabilitation clinic, university sports laboratory, supplemented with home exercises.Patients:20 competitive and recreational athletes, all with clinical diagnosis of patellar tendinopathy, verified by MRI or ultrasound imaging.Interventions:A 12-week rehabilitation period, either with bilateral eccentric overload strength training using the Bromsman device twice a week or with unilateral eccentric body load training using a decline board twice a week, supplemented with daily home exercises.Outcome measures:The primary outcome was pain and function, assessed by the Swedish Victorian Institute of Sport Assessment for Patella (VISA-P) score. Secondary outcome measures were isokinetic muscle torque, dynamic function and muscle flexibility, as well as pain level estimations using visual analogue scale (VAS). Side effects were registered.Results:Both treatment groups improved in the short term according to the VISA-P scores during the 12-week rehabilitation period. However, there were no significant differences between the groups in terms of pain and function. After a 3-month rehabilitation period, most patients could be regarded as improved enough to be able to return to training and sports. No serious side effects were detected in either group.Conclusion:In patients with patellar tendinopathy pain, two-legged eccentric overload training twice per week, using the new device (Bromsman), was as efficient and safe as the present standard daily eccentric one-legged rehabilitation-training regimen using a decline board.
Automated external defibrillators in Washington State high schools
Authors: Rothmier Justin D , Drezner Jonathan A , Harmon Kimberly G 
Published: February 2007

Background:The placement of automated external defibrillators (AEDs) in schools and public sporting venues is a growing national trend.Objective:To determine the prevalence and use of AEDs in Washington State high schools and to examine the existing emergency preparedness for sudden cardiac arrest (SCA).Design:Cross-sectional survey.Setting:High schools in Washington State.Participants:The principal at each high school in the Washington Interscholastic Activities Association (n = 407) was invited to complete a web-based questionnaire using the National Registry for AED Use in Sports (http://www.AEDSPORTS.com).Main outcome measurements:The primary outcome measures studied included AED prevalence and location, funding for AEDs, AED training of school personnel, coordination of AED placement with local emergency response agencies, and prior AED use.Results:118 schools completed the survey (29% response rate). 64 (54%) of the schools have at least one AED on school grounds (mean 1.6, range 1–4). The likelihood of AED placement increased with larger school size (p = 0.044). 60% of AEDs were funded by donations, 27% by the school district and 11% by the school or athletic department itself. Coaches (78%) were the most likely to receive AED training, followed by administrators (72%), school nurses (70%) and teachers (48%). Only 25% of schools coordinated the implementation of AEDs with an outside medical agency and only 6% of schools coordinated with the local emergency medical system. One school reported having used an AED previously to treat SCA in a basketball official who survived after a single shock. The estimated probability of AED use to treat SCA was 1 in 154 schools per year.Conclusions:Over half of Washington State high schools have an AED on school grounds. AED use occurred in <1% of schools annually and was effective in the treatment of SCA. Funding of AED programmes was mostly through private donations, with little coordination with local emergency response teams. Significant improvement is needed in structuring emergency response plans and training targeted rescuers for an SCA in the high-school setting.
Seasonal Dependence of the MJO–ENSO Relationship
Authors: Hendon Harry H. , Wheeler Matthew C. , Zhang Chidong 
Published: February 2007

AbstractObservations of the development of recent El Niño events suggest a pivotal role for the Madden–Julian oscillation (MJO). Previous attempts to uncover a systematic relationship between MJO activity and the El Niño–Southern Oscillation (ENSO), however, have yielded conflicting results. In this study the MJO–ENSO relationship is stratified by season, and the focus is on MJO activity in the equatorial western Pacific. The results demonstrate that MJO activity in late boreal spring leads El Niño in the subsequent autumn–winter for the period 1979–2005. Spring is the season when MJO activity is least asymmetric with respect to the equator and displays the most sensitivity to SST variations at the eastern edge of the warm pool. Enhanced MJO activity in the western Pacific in spring is associated with an eastward-expanded warm pool and low-frequency westerly surface zonal wind anomalies. These sustained westerly anomalies in the western Pacific are hypothesized to project favorably onto a developing El Niño in spring.
Cloud Cover over the South Pole from Visual Observations, Satellite Retrievals, and Surface-Based Infrared Radiation Measurements
Authors: Town Michael S. , Walden Von P. , Warren Stephen G. 
Published: February 2007

Abstract
Estimates of cloud cover over the South Pole are presented from five different data sources: routine visual observations (1957–2004; Cvis), surface-based spectral infrared (IR) data (2001; CPAERI), surface-based broadband IR data (1994–2003; Cpyr), the Extended Advanced Very High Resolution Radiometer (AVHRR) Polar Pathfinder (APP-x) dataset (1994–99; CAPP-x), and the International Satellite Cloud Climatology Project (ISCCP) dataset (1994–2003; CISCCP). The seasonal cycle of cloud cover is found to range from 45%–50% during the short summer to a relatively constant 55%–65% during the winter. Relationships between Cpyr and 2-m temperature, 10-m wind speed and direction, and longwave radiation are investigated. It is shown that clouds warm the surface in all seasons, 0.5–1 K during summer and 3–4 K during winter. The annual longwave cloud radiative forcing is 18 W m−2 for downwelling radiation and 10 W m−2 for net radiation. The cloud cover datasets are intercompared during the time periods in which they overlap. The nighttime bias of Cvis is worse than previously suspected, by approximately −20%; CISCCP shows some skill during the polar day, while CAPP-x shows some skill at night. The polar cloud masks for the satellite data reviewed here are not yet accurate enough to reliably derive surface or cloud properties over the East Antarctic Plateau. The best surface-based source of cloud cover in terms of the combination of accuracy and length of record is determined to be Cpyr. The use of the Cpyr dataset for further tests of satellite retrievals and for tests of polar models is recommended.
Dynamics of the Extratropical Response to a Tropical Atlantic SST Anomaly
Authors: Li Shuanglin , Robinson Walter A. , Hoerling Martin P. , Weickmann Klaus M. 
Published: February 2007

Abstract
Previous atmospheric general circulation model (AGCM) experiments revealed that atmospheric responses to a tropical Atlantic sea surface temperature anomaly (SSTA) were asymmetric with respect to the sign of the SSTA. A positive SSTA produced a south–north dipole in geopotential heights, much like the North Atlantic Oscillation (NAO), while a negative SSTA yielded an eastward-propagating wave train, with the northern lobe of the NAO absent.
Here these height responses are decomposed into components that are symmetric or antisymmetric with respect to the sign of the SSTA. The symmetric, or notionally linear, component is a nearly south–north dipole projecting on the NAO, while the antisymmetric, or notionally nonlinear, component is a different dipole. Experiments with a diagnostic linear baroclinic model (LBM) suggest that both components are maintained primarily by transient-eddy forcing. Dynamical mechanisms for the formation of the two components are explored using the LBM and a nonlinear barotropic vorticity equation model (BVM). Transient-eddy feedback is sufficient to explain the linear response. The NAO-like linear response occurs when the initial heating induces transient-eddy forcing in the exit of the Atlantic jet. The structure of the background absolute vorticity in this region is such that this transient-eddy forcing induces a nearly north–south dipole in anomalous geopotential heights. When the nonlinear self-interaction of this transient-induced low-frequency perturbation is included in the BVM, the dipole axis tilts to the east or west, resulting in a response that is nonlinear about the sign of the forcing.
Climate Response to External Sources of Freshwater: North Atlantic versus the Southern Ocean
Authors: Stouffer Ronald J. , Seidov Dan , Haupt Bernd J. 
Published: February 2007

Abstract
The response of an atmosphere–ocean general circulation model (AOGCM) to perturbations of freshwater fluxes across the sea surface in the North Atlantic and Southern Ocean is investigated. The purpose of this study is to investigate aspects of the so-called bipolar seesaw where one hemisphere warms and the other cools and vice versa due to changes in the ocean meridional overturning. The experimental design is idealized where 1 Sv (1 Sv ≡ 106 m3 s−1) of freshwater is added to the ocean surface for 100 model years and then removed. In one case, the freshwater perturbation is located in the Atlantic Ocean from 50° to 70°N. In the second case, it is located south of 60°S in the Southern Ocean.
In the case where the North Atlantic surface waters are freshened, the Atlantic thermohaline circulation (THC) and associated northward oceanic heat transport weaken. In the Antarctic surface freshening case, the Atlantic THC is mainly unchanged with a slight weakening toward the end of the integration. This weakening is associated with the spreading of the fresh sea surface anomaly from the Southern Ocean into the rest of the World Ocean. There are two mechanisms that may be responsible for such weakening of the Atlantic THC. First is that the sea surface salinity (SSS) contrast between the North Atlantic and North Pacific is reduced. And, second, when freshwater from the Southern Ocean reaches the high latitudes of the North Atlantic Ocean, it hinders the sinking of the surface waters, leading to the weakening of the THC.
The spreading of the fresh SSS anomaly from the Southern Ocean into the surface waters worldwide was not seen in earlier experiments. Given the geography and climatology of the Southern Hemisphere where the climatological surface winds push the surface waters northward away from the Antarctic continent, it seems likely that the spreading of the fresh surface water anomaly could occur in the real world.
A remarkable symmetry between the two freshwater perturbation experiments in the surface air temperature (SAT) response can be seen. In both cases, the hemisphere with the freshwater perturbation cools, while the opposite hemisphere warms slightly. In the zonally averaged SAT figures, both the magnitude and the pattern of the anomalies look similar between the two cases. The oceanic response, on the other hand, is very different for the two freshwater cases, as noted above for the spreading of the SSS anomaly and the associated THC response.
If the differences between the atmospheric and oceanic responses apply to the real world, then the interpretation of paleodata may need to be revisited. To arrive at a correct interpretation, it matters whether or not the evidence is mainly of atmospheric or oceanic origin. Also, given the sensitivity of the results to the exact details of the freshwater perturbation locations, especially in the Southern Hemisphere, a more realistic scenario must be constructed to explore these questions.
The Influence of ENSO on the Generation of Decadal Variability in the North Pacific*
Authors: An Soon-Il , Kug Jong-Seong , Timmermann Axel , Kang In-Sik , Timm Oliver 
Published: February 2007

Abstract
This diagnostic study explores the generation of decadal variability in the North Pacific resulting from the asymmetry of the El Niño–Southern Oscillation phenomenon and the nonlinearity of the atmospheric tropical–extratropical teleconnection. Nonlinear regression analysis of the North Pacific sea surface temperatures and atmospheric fields with respect to the ENSO index reveals that the main teleconnection centers shift between El Niño and La Niña years. This asymmetry in the ENSO response, together with the skewed probabilistic distribution of ENSO itself, may contribute to the generation of the long-term decadal variability of sea surface temperatures in the extratropical North Pacific. It is argued that this hypothesis may explain the significant variance of the observed Pacific decadal oscillation in the extratropics.
Multi-Instrument Comparison of Top-of-Atmosphere Reflected Solar Radiation
Authors: Loeb Norman G. , Wielicki Bruce A. , Su Wenying , Loukachine Konstantin , Sun Wenbo , Wong Takmeng , Priestley Kory J. , Matthews Grant , Miller Walter F. , Davies R. 
Published: February 2007

Abstract
Observations from the Clouds and the Earth’s Radiant Energy System (CERES), Moderate Resolution Imaging Spectroradiometer (MODIS), Multiangle Imaging Spectroradiometer (MISR), and Sea-Viewing Wide-Field-of-View Sensor (SeaWiFS) between 2000 and 2005 are analyzed in order to determine if these data are meeting climate accuracy goals recently established by the climate community. The focus is primarily on top-of-atmosphere (TOA) reflected solar radiances and radiative fluxes. Direct comparisons of nadir radiances from CERES, MODIS, and MISR aboard the Terra satellite reveal that the measurements from these instruments exhibit a year-to-year relative stability of better than 1%, with no systematic change with time. By comparison, the climate requirement for the stability of visible radiometer measurements is 1% decade−1. When tropical ocean monthly anomalies in shortwave (SW) TOA radiative fluxes from CERES on Terra are compared with anomalies in Photosynthetically Active Radiation (PAR) from SeaWiFS—an instrument whose radiance stability is better than 0.07% during its first six years in orbit—the two are strongly anticorrelated. After scaling the SeaWiFS anomalies by a constant factor given by the slope of the regression line fit between CERES and SeaWiFS anomalies, the standard deviation in the difference between monthly anomalies from the two records is only 0.2 W m−2, and the difference in their trend lines is only 0.02 ± 0.3 W m−2 decade−1, approximately within the 0.3 W m−2 decade−1 stability requirement for climate accuracy. For both the Tropics and globe, CERES Terra SW TOA fluxes show no trend between March 2000 and June 2005. Significant differences are found between SW TOA flux trends from CERES Terra and CERES Aqua between August 2002 and March 2005. This discrepancy is due to uncertainties in the adjustment factors used to account for degradation of the CERES Aqua optics during hemispheric scan mode operations. Comparisons of SW TOA flux between CERES Terra and the International Satellite Cloud Climatology Project (ISCCP) radiative flux profile dataset (FD) RadFlux product show good agreement in monthly anomalies between January 2002 and December 2004, and poor agreement prior to this period. Commonly used statistical tools applied to the CERES Terra data reveal that in order to detect a statistically significant trend of magnitude 0.3 W m−2 decade−1 in global SW TOA flux, approximately 10 to 15 yr of data are needed. This assumes that CERES Terra instrument calibration remains highly stable, long-term climate variability remains constant, and the Terra spacecraft has enough fuel to last 15 yr.
Global Distribution of Tropical Deep Convection: Different Perspectives from TRMM Infrared and Radar Data
Authors: Liu Chuntao , Zipser Edward J. , Nesbitt Stephen W. 
Published: February 2007

Abstract
Cold cloud features (CCFs) are defined by grouping six full years of Tropical Rainfall Measuring Mission (TRMM) infrared pixels with brightness temperature at 10.8-μm wavelength (TB11) less than or equal to 210 and 235 K. Then the precipitation radar (PR)-observed precipitation area and reflectivity profiles inside CCFs are summarized and compared with the area and minimum temperature of the CCFs. Comparing the radar with the infrared data, significant regional differences are found, quantified, and used to describe regional differences in selected properties of deep convective systems in the Tropics. Inside 4 million CCFs, 35% (57%) of cold cloud area with TB11 ≤ 235 K (210 K) have rain detected by the PR near the surface. Only ∼1% of the area of TB11 ≤ 210 K have 20 dBZ reaching 14 km. CCFs colder than 210 K occur most frequently over the west Pacific Ocean, but 20-dBZ echoes extending above 10 km in this region are disproportionately rare by comparison to many continental regions. Ratios of PR-detected raining area to area of TB11 ≤ 235 K are higher over central Africa, Argentina, and India than over tropical oceans. After applying these ratios to the climatological Global Precipitation Index (GPI) tropical rainfall estimates, the regional distribution is more consistent with the rainfall retrieval from the PR. This suggests that the discrepancy between GPI- and PR-retrieved rainfall can be partly explained with the nonraining anvil. Categorization of CCFs based on the minimum TB11, size of CCFs, and 20-dBZ heights demonstrates that 20-dBZ echoes above 17 km occur most frequently over land, while the coldest clouds occur most frequently over the west Pacific. The vertical distances between the cloud-top heights determined from TB11 and PR 20-dBZ echo-top heights are smaller over land than over ocean and may be considered as another proxy for convective intensity.
The Predictability of Extratropical Storm Tracks and the Sensitivity of Their Prediction to the Observing System
Authors: Froude Lizzie S. R. , Bengtsson Lennart , Hodges Kevin I. 
Published: February 2007

Abstract
A new method for assessing forecast skill and predictability that involves the identification and tracking of extratropical cyclones has been developed and implemented to obtain detailed information about the prediction of cyclones that cannot be obtained from more conventional analysis methodologies. The cyclones were identified and tracked along the forecast trajectories, and statistics were generated to determine the rate at which the position and intensity of the forecasted storms diverge from the analyzed tracks as a function of forecast lead time. The results show a higher level of skill in predicting the position of extratropical cyclones than the intensity. They also show that there is potential to improve the skill in predicting the position by 1–1.5 days and the intensity by 2–3 days, via improvements to the forecast model. Further analysis shows that forecasted storms move at a slower speed than analyzed storms on average and that there is a larger error in the predicted amplitudes of intense storms than the weaker storms. The results also show that some storms can be predicted up to 3 days before they are identified as an 850-hPa vorticity center in the analyses. In general, the results show a higher level of skill in the Northern Hemisphere (NH) than the Southern Hemisphere (SH); however, the rapid growth of NH winter storms is not very well predicted. The impact that observations of different types have on the prediction of the extratropical cyclones has also been explored, using forecasts integrated from analyses that were constructed from reduced observing systems. A terrestrial, satellite, and surface-based system were investigated and the results showed that the predictive skill of the terrestrial system was superior to the satellite system in the NH. Further analysis showed that the satellite system was not very good at predicting the growth of the storms. In the SH the terrestrial system has significantly less skill than the satellite system, highlighting the dominance of satellite observations in this hemisphere. The surface system has very poor predictive skill in both hemispheres.