bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Cautionary Note on the Use of Nonparametric Bootstrap for Estimating Uncertainties in Extreme-Value Models
Authors: Kyselý Jan 
Published: June 2008

AbstractThe parametric and nonparametric approaches to the bootstrap are compared as to their performance in estimating uncertainties in extreme-value models. Simulation experiments make use of several combinations of true and fitted probability distributions utilized in climatological and hydrological applications. The results demonstrate that for small to moderate sample sizes the nonparametric bootstrap should be interpreted with caution because it leads to confidence intervals that are too narrow and underestimate the real uncertainties involved in the frequency models. Although the parametric bootstrap yields confidence intervals that are slightly too liberal as well, it improves the uncertainty estimates in most examined cases, even under conditions in which an incorrect parametric model is adopted for the data. Differences among three examined types of bootstrap confidence intervals (percentile, bootstrap t, and bias corrected and accelerated) are usually smaller in comparison with those between the parametric and nonparametric versions of bootstrap. It is concluded that the parametric bootstrap should be preferred whenever inferences are based on small to moderate sample sizes (n ≤ 60) and a suitable model for the data is known or can be assumed, including applications to confidence intervals related to extremes in global and regional climate model projections.
Fast Lidar and Radar Multiple-Scattering Models. Part I: Small-Angle Scattering Using the Photon Variance–Covariance Method
Authors: Hogan Robin J. 
Published: June 2008

Abstract
A fast, approximate method is described for the calculation of the intensity of multiply scattered lidar returns from clouds. At each range gate it characterizes the outgoing photon distribution by its spatial variance, the variance of photon direction, and the covariance of photon direction and position. The result is that for an N-point profile the calculation is O(N) efficient yet it implicitly includes all orders of scattering, in contrast with the O(Nm/m!) efficiency of models that explicitly consider each scattering order separately for truncation at m-order scattering. It is also shown how the shape of the scattering phase function near 180° may be taken into account for both liquid water droplets and ice particles. The model considers only multiple scattering due to small-angle forward-scattering events, which is suitable for most ground-based and airborne lidars because of their small footprint on the cloud. For spaceborne lidar, it must be used in combination with the wide-angle multiple scattering model described in Part II of this two-part paper.
Controls of Global-Mean Precipitation Increases in Global Warming GCM Experiments
Authors: Stephens Graeme L. , Ellis Todd D. 
Published: June 2008

Abstract
This paper examines the controls on global precipitation that are evident in the transient experiments conducted using coupled climate models collected for the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4). The change in precipitation, water vapor, clouds, and radiative heating of the atmosphere evident in the 1% increase in carbon dioxide until doubled (1pctto2x) scenario is examined. As noted in other studies, the ensemble-mean changes in water vapor as carbon dioxide is doubled occur at a rate similar to that predicted by the Clausius–Clapeyron relationship. The ratio of global changes in precipitation to global changes in water vapor offers some insight on how readily increased water vapor is converted into precipitation in modeled climate change. This ratio ɛ is introduced in this paper as a gross indicator of the global precipitation efficiency under global warming.
The main findings of this paper are threefold. First, increases in the global precipitation track increase atmospheric radiative energy loss and the ratio of precipitation sensitivity to water vapor sensitivity is primarily determined by changes to this atmospheric column energy loss. A reference limit to this ratio is introduced as the rate at which the emission of radiation from the clear-sky atmosphere increases as water vapor increases. It is shown that the derived efficiency based on the simple ratio of precipitation to water vapor sensitivities of models in fact closely matches the sensitivity derived from simple energy balance arguments involving changes to water vapor emission alone. Second, although the rate of increase of clear-sky emission is the dominant factor in the change to the energy balance of the atmosphere, there are two important and offsetting processes that contribute to ɛ in the model simulations studied: One involves a negative feedback through cloud radiative heating that acts to reduce the efficiency; the other is the global reduction in sensible heating that counteracts the effects of the cloud feedback and increases the efficiency. These counteracting feedbacks only apply on the global scale. Third, the negative cloud radiative heating feedback occurs through reductions of cloud amount in the middle troposphere, defined as the layer between 680 and 440 hPa, and by slight global cloud decreases in the lower troposphere. These changes act in a manner to expose the warmer atmosphere below to high clouds, thus resulting in a net warming of the atmospheric column by clouds and a negative feedback on the precipitation.
Observed and CAM3 GCM Sea Surface Wind Speed Distributions: Characterization, Comparison, and Bias Reduction
Authors: Capps Scott B. , Zender Charles S. 
Published: June 2008

Abstract
Climatological surface wind speed probability density functions (PDFs) estimated from observations are characterized and used to evaluate, for the first time, contemporaneous wind PDFs predicted by a GCM. The observations include NASA’s global Quick Scatterometer (QuikSCAT) dataset, the NCEP/Department of Energy Global Reanalysis 2 (NCEP-2) 6-hourly reanalysis, and the Tropical Atmosphere Ocean (TAO)/Triangle Trans-Ocean Buoy Network (TRITON) moored buoy data, all from 2000 to 2005. Wind speed mean, 90th percentile, standard deviation, and Weibull shape parameter climatologies are constructed from these data. New features that emerge from the analysis include the identification of a stationary pattern to the wind speed variance in the equatorial Pacific. Interestingly, a distinct wind speed shape anomaly migrates with the ITCZ across this stationary background.
The GCM despite its coarser spatial and temporal resolution predicts wind speed PDFs in general agreement with observations. Relative to QuikSCAT, the NCAR Community Atmosphere Model, version 3 (CAM3) GCM has a globally averaged positive mean wind speed bias of about 0.2 m s−1 originating primarily within the trades and Southern Hemisphere storm track. Global standard deviation biases are largest in the winter hemisphere storm tracks. The largest shape biases occur along the equatorial peripheries of the Northern Hemisphere and southern Indian Ocean anticyclones. Year-round negative shape and mean wind speed biases persist along the ITCZ. The GCM’s overactive tropical convection and slight subtropical anticyclone displacement contribute to positive mean speed, standard deviation, and shape trade biases.
Surface heat and energy fluxes depend nonlinearly on wind speed magnitude, are sensitive to the tails of the wind distribution, and hence vary significantly on spatiotemporal scales not resolved by GCMs. Limited computing resources force the use of coarse-resolution GCMs, which do not resolve finer-scale wind speed fluctuations. Rather, surface fluxes are determined from the mean wind speed computed by averaging spatially and temporally over subgrid-scale features. Some surface flux routines account for gustiness during low mean winds resulting from thermally driven convection. The authors hypothesize that GCMs systematically underestimate surface momentum flux nonlinearities and that this biases surface wind predictions most in regions of strong winds with high variability. To test this, climate simulations that account for surface fluxes due to subgrid-scale GCM winds are performed. This significantly improves climatological surface wind speed statistics, particularly in the Southern Hemisphere storm track, consistent with the hypothesis. These wind speed improvements can be attributed to a reduction in GCM sea level pressure biases throughout the globe.
Sensitivity of Numerical Simulation of Early Rapid Intensification of Hurricane Emily (2005) to Cloud Microphysical and Planetary Boundary Layer Parameterizations
Authors: Li Xuanli , Pu Zhaoxia 
Published: June 2008

Abstract
An advanced research version of the Weather Research and Forecasting (ARW) Model is used to simulate the early rapid intensification of Hurricane Emily (2005) using grids nested to high resolution (3 km). A series of numerical simulations is conducted to examine the sensitivity of the simulation to available cloud microphysical (CM) and planetary boundary layer (PBL) parameterization schemes. Results indicate that the numerical simulations of the early rapid intensification of Hurricane Emily are very sensitive to the choice of CM and PBL schemes in the ARW model. Specifically, with different CM schemes, the simulated minimum central sea level pressure (MSLP) varies by up to 29 hPa, and the use of various PBL schemes has resulted in differences in the simulated MSLP of up to 19 hPa during the 30-h forecast period. Physical processes associated with the above sensitivities are investigated. It is found that the magnitude of the environmental vertical wind shear is not well correlated with simulated hurricane intensities. In contrast, the eyewall convective heating distributions and the latent heat flux and high equivalent potential temperature (θe) feeding from the ocean surface are directly associated with the simulated intensities. Consistent with recognized facts, higher latent heat release in stronger eyewall convection, stronger surface energy, and high θe air feeding from the ocean surface into the hurricane eyewall are evident in the more enhanced convection and intense storms. The sensitivity studies in this paper also indicate that the contributions from the CM and PBL processes can only partially explain the slow intensification in the ARW simulations. Simulation at 1-km grid resolution shows a slight improvement in Emily’s intensity forecast, implying that the higher resolution is somewhat helpful, but still not enough to cause the model to reproduce the real intensity of the hurricane.
Future Issues in Adult Education: A Review of the Literature of the Seventies
Authors: Hoare Carol H. 
Published: June 2008

The adult education and related literature was reviewed for the decade of 1970 in order to delineate the predominant future issues that emerge from that period. Based on conference proceedings, surveys, action-inquiry forums, investigations and informed opinion, the predominant program areas that included significant future issues were those of education for work and leisure, education for aging, health education, continuing professional education, education for social and civic responsibility, education for personal adaptation, education for functional competency and education for teachers of adults. Substantive issues also emerged regarding future delivery modalities. Reflected throughout was a view of adult learning ventures as potential vehicles for solving complex individual and social problems. The following conclusions were drawn: (1) Denial of the deleterious effects of change is apparent; (2) A consideration of global issues, as appropriate content for adult education intervention, is limited; (3) Although new roles for adult learning programs and professionals were forecast, there is a notable absence of specific strategies for meeting the educational needs projected during the seventies.
Characteristics of Adult Education Research Reported At the Adult Education Research Conference, 1971-1980
Authors: Long Huey B. 
Published: June 2008

The investigator analyzed the abstracts of all research papers and classified them according to predetermined criteria following the work of Long and Agyekum. Findings indicate that 355 papers were presented by 347 different individuals including faculty from 83 post-secondary education institutions in the U.S.A. and 13 Canadian Colleges and Universities. Some 65 individuals made two or more presentations during the period. Nine different types of research papers were presented; 55 percent of the papers were based on descriptive research procedures. Four different kinds of descriptive research data collection procedures were identified and analyzed. Ten kinds of content were reported; 28% of the papers reported on research that focused on program areas and 24% of the papers were concerned with program planning and administration. The categories of program areas, program planning and administration and adult education as a field of study accounted for 68% of the papers, by content. Representatives from seven higher education institutions accounted for 127 papers. Four of these institutions are from the U.S.A. and three are from Canada. The University of Wisconsin at Madison is the leading institution according to number of papers and individuals. Other analyses and conclusions are reported.
Determining The Importance of Community-Wide Adult Education Needs1
Authors: Kemerer Richard W. , Schroeder Wayne L. 
Published: June 2008

The purpose of this research was to develop and test an explicit set of procedures for determining the relative importance of community-wide needs in adult education. Two dimensions of meaning of the term importance were conceptualized: qualitative which refers to the values placed on certain broad goals and needs relating to those goals, and quantitative which refers to the amount of magnitude of need in the community. The procedures developed ultimately result in clusters of needs assigned priority according to their qualitative and quantitative importance. Results revealed a .80 Spearman rank correlation between two sets of rankings derived through use of the procedures. This value is significant at the .01 level. The data suggest that the procedures may provide a reliable way to integrate both the qualitative and the quantitative bases for judging importance.
Stable Halodilithiosilanes: Synthesis and Reactivity of TsiXSiLi2 (X = Br and Cl)
Authors: Lee Myong Euy , Lim Young Mook , Son Joo Young , Seo Won Guk 
Published: June 2008

Abstract
The stable bromodilithiosilane at room temperature was synthesized in 86% yield by the reduction of the corresponding tribromo[tris(trimethylsilyl)methyl]silane with lithium naphthalenide.
Synthesis and Electroluminescent Properties of New Amorphous Cyclohexyl- and Hexyl-substituted Ter(9,9-dialkylfluorene)s
Authors: Lim Eunhee , Jung Byung-Jun , Kim Sung Min , Kim Bong Ok , Shim Hong-Ku 
Published: June 2008

Abstract
A series of ter(9,9-dialkylfluorene)s (TFs) containing cyclohexyl and hexyl side groups has been synthesized via the Suzuki coupling reaction. Their chemical structures were characterized by 1H NMR and 13C NMR. All TFs were soluble in common organic solvents and showed good thermal stability up to 400 °C. In particular, T(CHC)F composed of two 9,9-bis(cyclohexylmethyl)fluorenes and one dihexylfluorene showed improved thermal stability over T(HHH)F and was found to be amorphous, unlikely with T(CCC)F. A light-emitting diode device fabricated with an ITO/2-TNATA/NPB/TFs/Alq3/Liq/Al configuration exhibited blue light emission with EL maxima at 450 nm and EL efficiency of 1.1 cd/A.
A Relationship between Molecular Orientation and Current–Voltage Characteristics in Poly(3-hexylthiophene) Thin Film
Authors: Komino Takeshi , Tajima Hiroyuki , Matsuda Masaki 
Published: June 2008

Abstract
Simultaneous measurement of molecular orientation and current as a function of voltage has been conducted. Molecular orientation was measured using the polarization dependence of intramolecular electronic transition. In ITO/poly(3-hexylthiophene)/Al structure, it was found that the molecular orientation change assists the hysteretic current–voltage (J–V) characteristics. The result indicates that this measuring method can be useful in investigating the effects of molecular orientation change on unusual J–V characteristics.
An Onium Salt-catalyzed Direct Polycondensation of Lactic Acid
Authors: Iwahashi Hisako , Oka Tatsuya , Abiko Atsushi 
Published: June 2008

Abstract
Poly(l-lactic acid) of Mw≈160000 (PDI = 1.6) was produced by direct polycondensation of water-containing lactic acid using triphenylphosphonium triflate as a catalyst.
Chiral Bead-like Trimer of Tris(2,4-pentanedionato)ruthenium(III)
Authors: Sato Hisako , Kameda Jun , Fukuda Yutaka , Haga Masa-aki , Yamagishi Akihiko 
Published: June 2008

Abstract
A chiral tri-nuclear metal complex, ΔΔΔ- or ΛΛΛ-[Ru(acac)2(taet)Ru(acac)(taet)Ru(acac)2] (acac = acetylacetonato and taet = tetraacetylethanato), was prepared and its monolayer behavior was investigated, leading to the conclusion that the bead-like character of the trimer was an essential factor in achieving stable two-dimensional molecular packing.
Maternal Psychological Adjustment and Knowledge of Infant Development as Predictors of Home Safety Practices in Rural Low-Income Communities
Authors: Zolotor Adam J. , Burchinal Margaret , Skinner Debra , Rosenthal Marjorie ,   and the Key Family Life Project Investigators
Published: June 2008

BACKGROUND. Unintentional injury is the leading cause of death among toddlers in the United States. Toddlers spend the majority of time at home, and the use of recommended safety practices can prevent many injuries.
OBJECTIVE. Maternal psychological adjustment and understanding of child development are thought to influence the implementation of safety practices; however, the extent to which either factor is related has been examined with small samples and without attention to potential confounding. We hypothesize that mothers' use of safety practices will be higher when mothers have more knowledge of development and better psychological adjustment.
METHODS. This study is part of the Family Life Project, a longitudinal birth cohort of children from poor rural communities (n = 1611) and an ethnographic sample (n = 36). Mothers in the birth cohort completed scales to measure knowledge of development, psychological adjustment, and home safety practices. Factor analysis of the safety scale resulted in 4 subscales. Each subscale was predicted from maternal knowledge and adjustment in multivariable regression. Mothers in the ethnographic study described sources of information about home safety, current practices, and barriers.
RESULTS. Analyses indicated that mothers with better psychological adjustment were more likely to implement all of the safety practices, and mothers with more knowledge about development were more likely to minimize subtle hazards and install safety devices. An interaction between maternal adjustment and knowledge suggested that mothers with psychological distress were more likely to install safety devices if they had greater knowledge of development. Mothers reported that health care providers were the primary source of safety information, and barriers to implementation included poverty and lack of stable housing.
CONCLUSIONS. Knowledge of development and better psychological adjustment are associated with improved home safety. Knowledge about development is especially important for mothers with poor mental health. Pediatricians and designers of injury-prevention programs should consider the role of maternal mental health in child safety.
Sleep Patterns and Problems Among Chinese Adolescents
Authors: Liu Xianchen , Zhao Zhongtang , Jia Cunxian , Buysse Daniel J. 
Published: June 2008

OBJECTIVES. Little is known about sleep patterns and problems in Chinese adolescents. This study was designed to examine sleep/wake patterns and problems and their associations with parent sleep among adolescents in China.
METHODS. This report represents part of an epidemiological study of sleep and health in 6 high schools in Jinan city, China. A total of 1056 adolescents and 838 parents completed a questionnaire in March or April 2005. Participants consisted of 625 boys and 441 girls, 557 seventh-graders (mean age: 13.5 ± 0.6 years) and 509 tenth-graders (mean age: 16.4 ± 0.7 years), and 603 mothers and 235 fathers. Adolescents and parents reported their own sleep/wake patterns and problems.
RESULTS. Average morning rising time (5:56 am vs 8:13 am) and sleep duration (7.5 hours vs 9.4 hours) differed significantly between weekdays and weekends. Compared with seventh-graders, 10th-graders went to bed later and awoke earlier, resulting in ∼1 hour of sleep less. Of the adolescents, 18.8% reported their sleep quality as poor, 26.2% were not satisfied with their sleep, 16.1% had insomnia, and 17.9% had daytime sleepiness. Significant but low adolescent-parent correlations were observed for sleep/wake patterns and perceived sleep quality. Difficulty initiating sleep in adolescents was significantly associated with history of insomnia in mothers and fathers.
CONCLUSIONS. Sleep insufficiency, insomnia, and daytime sleepiness are prevalent in Chinese adolescents. Sleep insufficiency on weekdays may be attributable to earlier morning rising to meet school schedules. Parental history of insomnia is associated with elevated risk for insomnia symptoms in adolescent offspring, although adolescent-parent correlations in sleep/wake patterns are relatively low.
Improved Cognitive Development Among Preterm Infants Attributable to Early Supplementation of Human Milk With Docosahexaenoic Acid and Arachidonic Acid
Authors: Henriksen Christine , Haugholt Kristin , Lindgren Magnus , Aurvåg Anne Karin , Rønnestad Arild , Grønn Morten , Solberg Rønnaug , Moen Atle , Nakstad Britt , Berge Rolf Kristian , Smith Lars , Iversen Per Ole , Drevon Christian André 
Published: June 2008

OBJECTIVE. The objective of our study was to evaluate the effect of supplementation with docosahexaenoic acid and arachidonic acid for human milk-fed preterm infants. The primary end point was cognitive development at 6 months of age.
METHODS. The study was a randomized, double-blind, placebo-controlled study among 141 infants with birth weights of &lt;1500 g. The intervention with 32 mg of docosahexaenoic acid and 31 mg of arachidonic acid per 100 mL of human milk started 1 week after birth and lasted until discharge from the hospital (on average, 9 weeks). Cognitive development was evaluated at 6 months of age by using the Ages and Stages Questionnaire and event-related potentials, a measure of brain correlates related to recognition memory.
RESULTS. There was no difference in adverse events or growth between the 2 groups. At the 6-month follow-up evaluation, the intervention group performed better on the problem-solving subscore, compared with the control group (53.4 vs 49.5 points). There was also a nonsignificant higher total score (221 vs 215 points). The event-related potential data revealed that infants in the intervention group had significantly lower responses after the standard image, compared with the control group (8.6 vs 13.2). There was no difference in responses to novel images.
CONCLUSIONS. Supplementation with docosahexaenoic acid and arachidonic acid for very preterm infants fed human milk in the early neonatal period was associated with better recognition memory and higher problem-solving scores at 6 months.