bluuebunny/crossref_metadata_2025_split huggingface dataset:
Finding starting points for Markov chain Monte Carlo analysis of genetic data from large and complex pedigrees
Authors: Luo Yuqun , Lin Shili 
Published: June 2003

AbstractGenetic data from founder populations are advantageous for studies of complex traits that are often plagued by the problem of genetic heterogeneity. However, the desire to analyze large and complex pedigrees that often arise from such populations, coupled with the need to handle many linked and highly polymorphic loci simultaneously, poses challenges to current standard approaches. A viable alternative to solving such problems is via Markov chain Monte Carlo (MCMC) procedures, where a Markov chain, defined on the state space of a latent variable (e.g., genotypic configuration or inheritance vector), is constructed. However, finding starting points for the Markov chains is a difficult problem when the pedigree is not single‐locus peelable; methods proposed in the literature have not yielded completely satisfactory solutions. We propose a generalization of the heated Gibbs sampler with relaxed penetrances (HGRP) of Lin et al., ([1993] IMA J. Math. Appl. Med. Biol. 10:1–17) to search for starting points. HGRP guarantees that a starting point will be found if there is no error in the data, but the chain usually needs to be run for a long time if the pedigree is extremely large and complex. By introducing a forcing step, the current algorithm substantially reduces the state space, and hence effectively speeds up the process of finding a starting point. Our algorithm also has a built‐in preprocessing procedure for Mendelian error detection. The algorithm has been applied to both simulated and real data on two large and complex Hutterite pedigrees under many settings, and good results are obtained. The algorithm has been implemented in a user‐friendly package called START. Genet Epidemiol 25:14–24, 2003. © 2003 Wiley‐Liss, Inc.
Testing linkage and Gene × Environment interaction: Comparison of different affected sib‐pair methods
Authors: Dizier M.H. , Selinger‐Leneman H. , Genin E. 
Published: June 2003

AbstractThe aim of this study was to compare, under different models of gene‐environment (G × E) interaction, the power to detect linkage and G × E interaction of different tests using affected sib‐pairs. Methods considered were: 1) the maximum likelihood lod‐score (MLS), based on the distribution of parental alleles identical by descent (IBD) in affected sibs; 2) the sum of the MLS (sMLS) calculated in affected sib‐pairs with 2, 1, or 0 sibs exposed; 3) the predivided sample test (PST), which compares the IBD distribution between affected sib‐pairs with 2, 1, or 0 sibs exposed; 4) the triangle test statistic (TTS), which uses the IBD distribution among discordant affected sib‐pairs (one exposed, one unexposed); and 5) the mean interaction test (MIT), based on the regression of the proportion of alleles shared IBD among affected sib‐pairs on the exposure among sib‐pairs. The MLS, sMLS, and MIT allow detection of linkage. However, the sMLS and MIT account for a possible G × E interaction without testing it. In contrast, the PST and the TTS allow detection of both linkage and G × E interaction. Results showed that when exposure cancels the effect of the gene, or changes the direction of this effect (i.e., the protective allele becomes the risk allele), the PST, sMLS, and MIT may provide, under some models, greater power to detect linkage than the MLS. Under models where exposure changes the direction of the effect of the gene, the TTS test may also be more powerful than the other tests accounting for G × E interaction. Under the other models, the MLS remains the most powerful test to detect linkage. However, only the PST and TTS allow the detection of G × E interaction. Genet Epidemiol 25:73–79, 2003. © 2003 Wiley‐Liss, Inc.
Genetic association tests for family data with missing parental genotypes: A comparison
Authors: Whittemore Alice S. , Halpern Jerry 
Published: June 2003

AbstractWe consider three tests for genetic association in data from nuclear families (the Family‐Based Association Test (FBAT) test proposed by Rabinowitz and Laird ([2000] Hum. Hered. 50:211–223), a second test proposed by Rabinowitz ([2002] J. Am. Stat. Assoc. 97:742–758), and the Family Genotype Analysis Program (FGAP) nonfounder or partial score test proposed by Clayton ([1999] Am. J. Hum. Genet. 65:1170–1177) and Whittemore and Tu ([2000] Am. J. Hum. Genet. 66:1329–1340)). We show that each test statistic arises from the efficient score of the family data as the solution to a set of constraints on its null expectation. Moreover, the FBAT and Rabinowitz tests (but not the FGAP test) are locally the most powerful among all tests satisfying their constraints. We used simulations to examine how the three tests perform in situations when their assumptions are violated and the number of families is not huge. We found that the FBAT test tended to have less power than the other two tests, particularly when applied to families in whom all offspring were affected. The Rabinowitz and FGAP tests performed similarly, although the latter tended to extract more information from families containing one typed parent. While none of the tests showed good power to detect rare, recessively acting genes, the Rabinowitz test with a sample variance estimate performed particularly poorly in this case. However, the Rabinowitz test with a model‐based variance had power comparable to that of the FGAP test, and more accurate type I error rates. We conclude that for the situations we considered, the Rabinowitz test with model‐based variance has good power without forfeiting robustness against misspecification of parental genotype probabilities. However, its utility is limited by the lack of a simple algorithm to apply it to families with varying structures and phenotypes. Genet Epidemiol 25:80–91, 2003. © 2003 Wiley‐Liss, Inc.
Assessing accuracy in linkage analysis by means of confidence regions
Authors: Hössjer Ola 
Published: June 2003

AbstractWhen statistical linkage to a certain chromosomal region has been found, it is of interest to develop methods quantifying the accuracy with which the disease locus can be mapped. In this paper, we investigate the performance of three different types of confidence regions, with asymptotically correct coverage probability as the number of pedigrees grows. Our setup is that of a saturated map of marker data. We allow for arbitrary combinations of pedigree structures, and treat various kinds of genetic models (e.g. binary and quantitative phenotypes) in a unified way. The linkage scores are weighted sums of the individual family scores, with NPL and lod scores as special cases. We show that the expected length of the confidence region is inversely proportional to the slope‐to‐noise ratio, or equivalently, inversely proportional to the product of the square of the noncentrality parameter and a certain normalized slope‐to‐noise ratio. Our investigations reveal that maximal expected linkage scores can be quite different from estimation‐based performance criteria based on expected length of confidence regions. The main reason is that there is no simple relationship between peak height and peak slope of the mean linkage score. One application of our results is planning of linkage studies: given a certain genetic model, we can approximate the number of pedigrees needed to obtain a confidence region with given coverage probability and expected length. Genet Epidemiol 25:59–72, 2003. © 2003 Wiley‐Liss, Inc.
Linkage analysis with sequential imputation
Authors: Skrivanek Zachary , Lin Shili , Irwin Mark 
Published: June 2003

AbstractMultilocus calculations, using all available information on all pedigree members, are important for linkage analysis. Exact calculation methods in linkage analysis are limited in either the number of loci or the number of pedigree members they can handle. In this article, we propose a Monte Carlo method for linkage analysis based on sequential imputation. Unlike exact methods, sequential imputation can handle large pedigrees with a moderate number of loci in its current implementation. This Monte Carlo method is an application of importance sampling, in which we sequentially impute ordered genotypes locus by locus, and then impute inheritance vectors conditioned on these genotypes. The resulting inheritance vectors, together with the importance sampling weights, are used to derive a consistent estimator of any linkage statistic of interest. The linkage statistic can be parametric or nonparametric; we focus on nonparametric linkage statistics. We demonstrate that accurate estimates can be achieved within a reasonable computing time. A simulation study illustrates the potential gain in power using our method for multilocus linkage analysis with large pedigrees. We simulated data at six markers under three models. We analyzed them using both sequential imputation and GENEHUNTER. GENEHUNTER had to drop between 38–54% of pedigree members, whereas our method was able to use all pedigree members. The power gains of using all pedigree members were substantial under 2 of the 3 models. We implemented sequential imputation for multilocus linkage analysis in a user‐friendly software package called SIMPLE. Genet Epidemiol 25:25–35, 2003. © 2003 Wiley‐Liss, Inc.
Heat transport characteristics of flexible looped heat pipe under micro‐gravity condition
Authors: Ogushi Tetsurou , Yao Akira , Xu Jason J. , Masumoto Hiromitsu , Kawaji Masahiro 
Published: June 2003

AbstractThis paper presents the heat transport performance of a flexible looped heat pipe (FLHP) with the working fluid of ammonium under micro‐gravity condition. The evaporator of the FLHP has two coaxial wicks. The outer wick is made of PTFE with 1.2µm pore diameter and the inner one is made of polyethylene with 12µm pore diameter. The inside surface of the inner wick is axially grooved. The core of the inner wick is used as liquid reservoir so that reliability of the operation can be enhanced. The experiment revealed that the FLHP performed normally under micro‐gravity condition and had the predicted capillary limit. The FLHP showed good temperature control ability and was like a VCHP in the range of 150 to 240 W heat transfer rate. Liquid behavior observed in the visual module ensured the normal operation of the second wick and inner axial grooves under micro‐gravity condition. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(5): 381–390, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.10092
Flashing characteristics in a pipe downstream from a depressurizing tank and temperature fluctuation characteristics at a mixing tee junction with cold water injection
Authors: Shiina Koji , Takahashi Shirou , Asada Yukihiro 
Published: June 2003

AbstractThe flashing characteristics in a pipe downstream from a depressurizing tank were experimentally and analytically investigated on the basis of the transient test and two‐phase flow analysis. The following conclusions were obtained. (1) When the pressure margin of the pump inlet side and the distance to obtain an isothermal condition were sufficient, flashing phenomena did not occur in spite of the decreasing pressure. (2) When the ratio of the cold water injection flow rate to the hot water flow rate Mc/Mh increased, the peak distance of the water temperature fluctuation moved from L/D = 1 to 0, and the maximum water temperature fluctuation ratio was about 40% of the temperature difference between hot and cold water near the mixing tee junction. Because no problem occurred regarding the pipe material thermal fatigue, reliability of the mixing tee junction was assured. (3) Due to suppression of flashing phenomena of the mixing pipe system, the decision diagram on the flashing occurrence was obtained from the test and the analytical results, taking into consideration three factors: the depressurizing ratio in the tank; the cold water injection flow rate due to remaining subcooling; and the delay time of thermal mixing. The simplified analytical equation was used to decrease the cold water injection flow rate by the optimized pipe length between the mixing tee junction and the drain pump. The cold water injection flow rate was minimized when the pipe length was about 15 to 20 times the pipe inner diameter. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(5): 411–429, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.10096
Enhancement of shell side forced convective heat transfer in the shell tube‐type heat exchanger using thin plate‐type supports
Authors: Shiina Koji , Nakamura Shozo , Matsumura Seiichi 
Published: June 2003

AbstractThe shell side heat transfer and pressure drop in counterflowing water were experimentally investigated on the basis of the overall heat transfer coefficient. The investigation was intended to identify ways to get higher performance for the cooler in a BWR nuclear power plant. The following three conclusions were reached in the study. (1) Predicted performance of the heat exchanger, using the overall heat transfer coefficient based on the outside area of the tube Ko, indicated an enhancement by 92% compared with the measured performance of the conventional segmental baffle‐type heat exchanger. (2) The tube side pressure drop ΔPt=20 kPa and the shell side pressure drop ΔPs=70 kPa were obtained, and were within the allowable value ΔPa=80 kPa. The shell side pressure drop of the low‐pressure drop spacer could be decreased by 20% as compared with that of the standard spacer. (3) The enhancement constant of the shell side heat transfer using the low‐pressure drop spacer was about 1.2 times as large as that of the standard spacer, regardless of the pumping power. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(5): 455–471, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.10097
Effect of fins on forced convection heat transfer around a tube
Authors: Hashizume Kenichi , Matsue Takahiro , Sueoka Yoshiaki 
Published: June 2003

AbstractEffect of fins on heat transfer around a tube was investigated experimentally. A test tube of 30 mm diameter was installed in a test section of an open‐type wind tunnel as a single tube, or as a center tube in a single tube row and in a tube bundle of staggered layout. Fins made of paper were put on the test tube having certain fin spacing. It was clarified from the experiment that the local heat transfer coefficient around the tube degrades with decreasing fin spacing, especially on the downstream side of the tube, and the minimum fin spacing where the effect of the fin begins to appear is the largest for the single tube and the smallest for the tube bundle. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(5): 445–454, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.10098
Prediction of critical heat flux on natural convective boiling in vertical short‐thick tube submerged in saturated liquid
Authors: Liu Zhen‐Hua 
Published: June 2003

AbstractAn experimental and semitheoretical study was carried out for the critical heat flux (CHF) on natural convective boiling in uniformly heated vertical short‐thick tubes and vertical short‐thick annular tubes submerged in saturated liquids. By adapting a mathematical dealing method based on the theoretical formulas of CHF of both the natural convective boiling in vertical narrow‐long tubes and the pool boiling, a simple semitheoretical formula was derived. The new formula expands the prediction range of CHF from pool boiling of vertical plates to very long vertical tubes and agrees well with the data of the tubes, annular tubes submerged in water or other liquids under various pressure conditions. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(5): 402–410, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.10103
Study on kinetics of desulfurization reaction by cao particles
Authors: Yan Y. , Peng X.F. , Fu G.G. , Wang B.X. 
Published: June 2003

AbstractIn this paper, TGA was employed in the desulfurization reaction with different CaO particles to investigate the dynamical behavior and the effect of particle size. The changing grain model was revised to describe the reaction kinetics characteristic. The effect of temperature on the reaction was analyzed using scanning electron microscope (SEM) photos of CaO particles. The diffusion coefficient of SO2 in the product layer and the chemical reaction rate constant were acquired through comparison between TGA experimental data and the reaction dynamics equations. It was found that the diffusion coefficient of SO2 in the product layer was proportional to some power of the particle radius and the CaO particles can be depicted by fractal geometry. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(5): 391–401, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.10108
A theoretical study of evaporative heat transfer in high‐velocity two‐phase flow of air–water in a small vertical tube
Authors: Yi Jie , Liu Zhen‐Hua , Wang Jing 
Published: June 2003

AbstractA theoretical study was performed to investigate the evaporative heat transfer of high‐velocity two‐phase flow of air–water in a small vertical tube under both heating conditions of constant wall temperature and constant heat flux. A simplified two‐phase flow boundary layer model was used to evaluate the evaporative heat transfer characteristics of the annular two‐phase flow. The analytical results show that the gravitational force, the gas–liquid surface tension force, and the inertial force are much smaller than the frictional force and hence can be neglected for a small tube. The evaporative heat transfer characteristics of the small tube with constant wall temperature are quite close to those of the small tube with constant heat flux. The mechanism of the heat transfer enhancement is the forced convective evaporation on the surface of the thin liquid film. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(5): 430–444, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.10110
Reinforced concrete structures – shall concrete remain the dominating means of corrosion prevention?
Authors: Rostam S. 
Published: June 2003

AbstractThe acknowledged serious deterioration of reinforced concrete structures due to chloride induced corrosion has been the main fuel for research and development of very dense and impermeable concrete, so‐called high performance concrete (HPC). This development has dominated concrete research up through the 80'ies and 90'ies. The results have technically been successful. However, the practical use of such concretes on site have often posed serious difficulties, resulting in at times very low performance concrete structures although HPC was specified. The discrepancy between concrete quality reached in the laboratory, what is being specified in the design and what can realistically be achieved on site is seldom in balance. Alternative means of more or less reliable means of corrosion prevention, often based on organic materials, have during recent years been developed to protect our inorganic concrete and reinforcement. However, a highly reliable means of corrosion prevention has been the introduction of stainless steel reinforcement, which is available with dimensions and strengths directly interchangeable with ordinary carbon steel reinforcement. It has been proven that stainless steel and carbon steel can be in metallic contact when cast into concrete, without causing galvanic corrosion. This seems, for the present, to be like an unexpectedly simple and highly reliable solution to the corrosion problems. As exemplified, this technology is rapidly gaining momentum in highly corrosive environments – and concretes being much more robust to execution can now take over from HPC.
Evolution of reinforcement corrosion due to climatic variations
Authors: Andrade C. , Castillo A. 
Published: June 2003

AbstractConcrete moisture is the most significant parameter with respect to its durability, however the data on moisture content in real‐size structures are scarce in contrast to the numerous literature published on laboratory experiments. The majority of laboratory tests have been performed in chambers with controlled hydrothermal regime, in general to enable the concrete to reach equilibrium and steady‐state conditions. However, real weather induces permanent non‐steady state situations due to the evolution of temperature and climatic events as snowing or raining.Present paper discusses the effect of climatic events on the hydrothermal performance of concrete and their influence on reinforcement corrosion process. Concerning the moisture level, the degree of saturation, SW, and not the internal relative humidity has been identified to be the controlling parameter of the corrosion process. The psychometric chart and the SW‐RH plots are very suitable to study the hydrothermal behaviour. With respect to the corrosion parameters, corrosion potential, resistivity and corrosion rates, they are very influenced by temperature in a complex manner. The temperature is the main factor influencing the degree of saturation in sheltered conditions while rain and snow are so, in unsheltered ones. In opposition, however, what can be expected, climates with higher temperatures are less aggressive than colder ones, except when rain periods are produced during the hotter periods.
Zum rückseitigen kathodischen Korrosionsschutz einseitig korrodierender Stahlbetonbauteile – Modellversuche und numerische Berechnungen
Authors: Raupach M. , Warkus J. 
Published: June 2003

AbstractDer kathodische Korrosionsschutz ist ein weltweit verbreitetes Verfahren zum Schutz korrosionsgefährdeter Bewehrung in Stahlbetonbauteilen. Dabei wird durch eine äußere Spannung, die zwischen der Bewehrung und einer inerten Anode angelegt wird oder über galvanische Anoden, ihr elektrochemisches Potential in negative Bereiche verschoben, in denen der Stahl kathodisch reagiert. Bei einseitig unzugänglichen Bauteilen (Stützwände, Tunnel, etc.) oder unter Abdichtungen ist es aus baupraktischen Überlegungen oft wünschenswert, die Anode an der abgewandten Seite der gefährdeten Lage anzubringen. In diesem Zusammenhang soll durch am Institut für Bauforschung der RWTH Aachen zur Zeit laufende Untersuchungen der Fragestellung nachgegangen werden, ob ein Schutz der abgewandten Lage möglich ist oder durch die Abschirmung der näher an der Anode liegenden Bewehrung verhindert wird. Erste Ergebnisse aus diesen Untersuchungen zeigen, dass der Schutz von der Rückseite unter bestimmten Bedingungen möglich ist. Weiterhin wird überprüft, ob durch geeignete numerische Modellierungen das Verhalten der Probekörper unter variablen Randbedingungen berechnet werden kann.
Langzeitverhalten feuerverzinkter Bewehrungsbänder für Bewehrte Erde Bauwerke
Authors: Nürnberger U. 
Published: June 2003

AbstractBei Bewehrte Erde Bauwerken sind • durch die Wahl spezifischer nichtbindiger Böden, • durch Maßnahmen zur Verhinderung des Eindringens von Fremdsalzen • und durch die Wahl einer mind. 100 μm dicken Zinkschicht Maßnahmen getroffen worden, die einen langjährigen Korrosionsschutz der Bewehrungsbänder sicherstellen. Es ist nahezu auszuschließen, daß es in baupraktisch relevanten Zeiträumen zu einem korrosionsbedingten Versagen der Bänder kommt.