bluuebunny/crossref_metadata_2025_split huggingface dataset:
Facile Synthesis of Trifluoromethyl-substituted Enynes: Remarkable Reactivity and Stereoselectivity of Tributyl(3,3,3-trifluoropropynyl)stannane in Carbostannylation of Alkynes
Authors: Shimizu Masaki , Jiang Guofang , Murai Masahito , Takeda Youhei , Nakao Yoshiaki , Hiyama Tamejiro , Shirakawa Eiji 
Published: November 2005

Abstract
Carbostannylation of alkynes with tributyl(3,3,3-trifluoropropynyl)stannane is found to proceed at room temperature in a syn-manner, giving rise to the corresponding CF3-substituted enynes as a single stereoisomer in good yields. Both terminal and, CF3- or RO2C-substituted internal alkynes are applicable to the addition reaction. Synthetic applications of the adduct are also demonstrated.
Calorimetric and Spectroscopic Studies of Water Adsorption onto Alkaline Earth Fluorides
Authors: Mori Toshinori , Kuroda Yasushige , Kumashiro Ryotaro , Hirata Koji , Toyota Hidehiro , Nagao Mahiko 
Published: November 2005

Interactions between the surfaces of alkaline earth fluorides (CaF2, SrF2 and BaF2) and water molecules were investigated by calorimetric and spectroscopic methods. The exposed surfaces of the alkaline earth fluoride samples, with which the (100) crystalline plane is mainly associated, were found to be fully covered with strongly adsorbed water molecules, resulting in characteristic IR bands at 3684, 2561, 1947 and 1000 cm−1, respectively. This surface was homogeneous towards further water adsorption. The strongly adsorbed water molecules were almost completely desorbed from the surface on evacuating the sample up to 473 K. The heat of immersion in water also increased with increasing pretreatment temperature; this may be attributed to surface rehydration of the alkaline earth fluorides. The state of the surface changed drastically as the pretreatment temperature was increased and stabilized towards incoming water molecules. Thus, the surface formed after evacuation at temperatures greater than 473 K was resistant to hydration even after immersion in water at room temperature. This surface was relatively heterogeneous towards water adsorption, although it behaved homogeneously towards argon adsorption. These facts indicate that strongly adsorbed water molecules appear to be somewhat specific towards the adsorption of further incoming water molecules. The adsorption properties of the (100) plane of alkaline earth fluorides towards water and argon molecules depend strongly on both the electrostatic field strength and the extent of rehydration of the alkaline earth fluoride surface.
Sorption and Direct Electrochemistry of Mitochondrial Cytochrome C on Hematite Surfaces
Authors: Khare Nidhi , Eggleston Carrick M. , Lovelace David M. 
Published: November 2005

AbstractThe interaction of cytochromes (heme proteins) with mineral surfaces is important from an environmental perspective (e.g. heavy metal remediation and reductive dehalogenation reactions), for designing biosensors and bioanalytical systems, and for emerging photovoltaic applications. In addition, the cytochrome studied here shares properties with some cytochromes from Fe-reducing bacteria and its general behavior sheds light on how other cytochromes might behave during Fe(III) reduction. The objectives of this study were to characterize the direct electrochemistry and sorption mechanism of horse heart ferricytochrome c (a mitochondrial cytochrome referred to as Hcc) on hematite surfaces as a function of pH, time of sorption and ionic strength. Hcc sorption on hematite mainly occurs between pH 8 and 10, the pH range in which hematite surfaces and Hcc are oppositely charged. Calculated net attractive forces correspond closely with the pH range of peak sorption, suggesting that sorption is mainly electrostatically controlled. Hcc sorption with ionic strength is consistent with this conclusion. The pH-dependent conformation of Hcc sorbed on hematite appears to be different from that in solution as indicated by UV-visible spectroscopy and its more negative reduction potential compared to native Hcc. Sorption kinetics were rapid and pH-independent across the pH range 3–10 with slow conformational changes occurring at >60 h. Our results suggest that the electrostatic attraction of the cytochrome towards the surface orient the cytochrome for favorable electron transfer between the heme group of the cytochrome and hematite.
Aids mortality and the mobility of children in Kwazulu Natal, South Africa
Authors: Ford Kathleen , Hosegood Victoria 
Published: November 2005

Abstract
This paper examines the effect of parental death on the mobility of 39,163 children aged 0–17 in rural KwaZulu Natal, South Africa, in 2000 and 2001. Parental mortality from all causes prior to and during follow-up increased the risk of a child moving by nearly two times after we controlled for the age and gender of the child and household characteristics. However, in the follow-up period, child mobility following maternal deaths from AIDS was lower than child mobility following maternal deaths from other causes. Younger children, boys, and children whose mothers or fathers were resident members of the children’s households were also less likely to move.
Familial obesity as a proxy for omitted variables in the obesity-mortality relationship
Authors: Gronniger J. Timothy 
Published: November 2005

Abstract
In a conventional survival analysis of a sample of the U.S. population in 1971–1974, the association between mortality and obesity is compared with the analogous risk from the presence of an obese person in a household. The two factors have similar risk profiles, with a hazard ratio of 1.44 for nonmorbid obesity and 1.48 for nonmorbid familial obesity in one sample. If “familial obesity” cannot directly affect personal longevity, and if shared factors determine both personal and familial obesity, the mortality risk of family and actual personal obesity is similarly overstated. This false positive in the estimated risk arises from correlations among obesity and unobserved environmental, behavioral, or genetic factors.
Temporal and spatial variation in age-specific net migration in the United States
Authors: Johnson Kenneth M. , Voss Paul R. , Hammer Roger B. , Fuguitt Glenn V. , Mcniven Scott 
Published: November 2005

AbstractAs fertility differences in the United States diminish, population redistribution trends are increasingly dependent on migration. This research used newly developed county-level age-specific net migration estimates for the 1990s, supplemented with longitudinal age-specific migration data spanning the prior 40 years, to ascertain whether there are clear longitudinal trends in age-specific net migration and to determine if there is spatial clustering in the migration patterns. The analysis confirmed the continuation into the 1990s of distinct net migration “signature patterns” for most types of counties, although there was temporal variation in the overall volume of migration across the five decades. A spatial autocorrelation analysis revealed large, geographically contiguous regions of net in-migration (in particular, Florida and the Southwest) and geographically contiguous regions of net out-migration (the Great Plains, in particular) that persisted over time. Yet the patterns of spatial concentration and fragmentation over time in these migration data demonstrate the relevance of this “neighborhood” approach to understanding spatiotemporal change in migration.
Did fertility go up after the oklahoma city bombing? An analysis of births in metropolitan counties in Oklahoma, 1990–1999
Authors: Rodgers Joseph Lee , John Craig A. St. , Coleman Ronnie 
Published: November 2005

Abstract
Political and sociocultural events (e.g., Brown v. Board of Education in 1954 and the German reunification in 1989) and natural disasters (e.g., Hurricane Hugo in 1989) can affect fertility. In our research, we addressed the question of whether the Oklahoma City bombing in April 1995, a man-made disaster, influenced fertility patterns in Oklahoma. We defined three theoretical orientations—replacement theory, community influence theory, and terror management theory—that motivate a general expectation of birth increases, with different predictions emerging from time and geographic considerations. We used two different empirical methodologies. First, we fitted dummy-variable regression models to monthly birth data from 1990 to 1999 in metropolitan counties. We used birth counts to frame the problem and general fertility rates to address the problem formally. These analyses were organized within two design structures: a control-group interrupted time-series design and a difference-in-differences design. In these analyses, Oklahoma County showed an interpretable, consistent, and significant increase in births. Second, we used graphical smoothing models to display these effects visually. In combination, these methods provide compelling support for a fertility response to the Oklahoma City bombing. Certain parts of each theory helped us organize and understand the pattern of results.
The influence of network mortality experience on nonnumeric response concerning expected family size: Evidence from a Nepalese mountain village
Authors: Sandberg John 
Published: November 2005

AbstractThis article investigates the effects of sociometric network members’ self-reported experiences with infant mortality on nonnumeric responses regarding expected family size among women in a small Nepalese community. The hypotheses tested include (1) that uncertainty about child survival, measured as average infant mortality across social networks, increases the likelihood of a non numeric response and (2) that this effect will be stronger when there is less variance in infant mortality experience within women’s networks. The results suggest that nonnumeric response may be related to uncertainty about mortality derived through social learning.
Trends in educational assortative marriage from 1940 to 2003
Authors: Schwartz Christine R. , Mare Robert D. 
Published: November 2005

AbstractThis paper reports trends in educational assortative marriage from 1940 to 2003 in the United States. Analyses of census and Current Population Survey data show that educational homogamy decreased from 1940 to 1960 but increased from 1960 to 2003. From 1960 to the early 1970s, increases in educational homogamy were generated by decreasing intermarriage among groups of relatively well-educated persons. College graduates, in particular, were increasingly likely to marry each other rather than those with less education. Beginning in the early 1970s, however, continued increases in the odds of educational homogamy were generated by decreases in intermarriage at both ends of the education distribution. Most striking is the decline in the odds that those with very low levels of education marry up. Intermarriage between college graduates and those with “some college” continued to decline but at a more gradual pace. As intermarriage declined at the extremes of the education distribution, intermarriage among those in the middle portion of the distribution increased. These trends, which are similar for a broad cross section of married couples and for newlyweds, are consistent with a growing social divide between those with very low levels of education and those with more education in the United States.
Do conditional cash transfers influence migration? A study using experimental data from the Mexican progresa program
Authors: Stecklov Guy , Winters Paul , Stampini Marco , Davis Benjamin 
Published: November 2005

AbstractPrior research on Mexican migration has shown that social networks and economic incentives play an important role in determining migration outcomes. We use experimental data from PROGRESA, Mexico’s primary poverty-reduction program, to evaluate the effects of conditional cash transfers on migration both domestically and to the United States. Our study complements a growing body of literature aimed at overcoming longstanding hurdles to the establishment of causal validity in empirical studies of migration. Analysis based on the data collected before and after the program’s onset shows that conditional transfers reduce U.S. migration but not domestic migration. The data also enable us to explore the role of existing family and community migration networks. The results show that migration networks strongly influence migration, but that the effect of conditional transfers on migration is apparently not mediated by existing migration network structures. Our results suggest that conditional transfers may be helpful in managing rural out-migration, particularly to the United States.
The relationship between childbearing and transitions from marriage and cohabitation in Britain
Authors: Steele Fiona , Kallis Constantinos , Goldstein Harvey , Joshi Heather 
Published: November 2005

Abstract
In this article, we describe a general framework for the analysis of correlated event histories, with an application to a study of partnership transitions and fertility among a cohort of British women. Using a multilevel, multistate competing-risks model, we examine the relationship between prior fertility outcomes (the presence and characteristics of children and current pregnancy) and the dissolution of marital and cohabiting unions and movements from cohabitation to marriage. Using a simultaneous-equations model, we model these partnership transitions jointly with fertility, allowing for correlation between the unobserved woman-level characteristics that affect each process. The analysis is based on the partnership and birth histories that were collected for the 1958 birth cohort (National Child Development Study) aged 16–42. The findings indicate that preschool children have a stabilizing effect on their parents’ partnership, whether married or cohabiting, but the effect is weaker for older children. There is also evidence that although pregnancy precipitates marriage among cohabitors, the odds of marriage decline to prepregnancy levels following a birth.
Changes in women’s postmarital employment in Japan and Taiwan
Authors: Yu Wei-Hsin 
Published: November 2005

AbstractResearch on female labor-force participation has not fully explained why economic development has different effects on married women’s employment continuity across societies. I use life-history data from nationally representative samples of women in Japan and Taiwan to examine the divergence in women’s patterns of labor-force exit in these two countries during the postwar period. The findings reveal that the effects of family demands, occupation, firm size, and employment sector on women’s exit rates differed substantially between Japan and Taiwan. Taken together, these factors account for the different trends in married women’s employment during this period. I argue that the cross-national differences in the predictors of women’s labor-force withdrawal reflect the extent of incompatibility between work and family responsibilities for married women in these two societies.
Relative Influences of Crossing Over and Gene Conversion on the Pattern of Linkage Disequilibrium in Arabidopsis thaliana
Authors: Plagnol Vincent , Padhukasahasram Badri , Wall Jeffrey D , Marjoram Paul , Nordborg Magnus 
Published: November 2005

Abstract
In this article we infer the rates of gene conversion and crossing over in Arabidopsis thaliana from population genetic data. Our data set is a genomewide survey consisting of 1347 fragments of length 600 bp sequenced in 96 accessions. It has several orders of magnitude more markers than any previous nonhuman study. This allows for more accurate inference as well as a detailed comparison between theoretical expectations and observations. Our methodology is specifically set to account for deviations such as recurrent mutations or a skewed frequency spectrum. We found that even if some components of the model clearly do not fit, the pattern of LD conforms to theoretical expectations quite well. The ratio of gene conversion to crossing over is estimated to be around one. We also find evidence for fine-scale variations of the crossing-over rate.
Genetic Addiction: Selfish Gene's Strategy for Symbiosis in the Genome
Authors: Mochizuki Atsushi , Yahara Koji , Kobayashi Ichizo , Iwasa Yoh 
Published: November 2005

Abstract
The evolution and maintenance of the phenomenon of postsegregational host killing or genetic addiction are paradoxical. In this phenomenon, a gene complex, once established in a genome, programs death of a host cell that has eliminated it. The intact form of the gene complex would survive in other members of the host population. It is controversial as to why these genetic elements are maintained, due to the lethal effects of host killing, or perhaps some other properties are beneficial to the host. We analyzed their population dynamics by analytical methods and computer simulations. Genetic addiction turned out to be advantageous to the gene complex in the presence of a competitor genetic element. The advantage is, however, limited in a population without spatial structure, such as that in a well-mixed liquid culture. In contrast, in a structured habitat, such as the surface of a solid medium, the addiction gene complex can increase in frequency, irrespective of its initial density. Our demonstration that genomes can evolve through acquisition of addiction genes has implications for the general question of how a genome can evolve as a community of potentially selfish genes.
Constructing the Parental Linkage Phase and the Genetic Map Over Distances &lt;1 cM Using Pooled Haploid DNA
Authors: Gasbarra Dario , Sillanpää Mikko J 
Published: November 2005

AbstractA new statistical approach for construction of the genetic linkage map and estimation of the parental linkage phase based on allele frequency data from pooled gametic (sperm or egg) samples is introduced. This method can be applied for estimation of recombination fractions (over distances &lt;1 cM) and ordering of large numbers (even hundreds) of closely linked markers. This method should be extremely useful in species with a long generation interval and a large genome size such as in dairy cattle or in forest trees; the conifer species have haploid tissues available in megagametophytes. According to Mendelian expectation, two parental alleles should occur in gametes in 1:1 proportions, if segregation distortion does not occur. However, due to mere sampling variation, the observed proportions may deviate from their expected value in practice. These deviations and their dependence along the chromosome can provide information on the parental linkage phase and on the genetic linkage map. Usefulness of the method is illustrated with simulations. The role of segregation distortion as a source of these deviations is also discussed. The software implementing this method is freely available for research purposes from the authors.
Estimating Selection on Nonsynonymous Mutations
Authors: Loewe Laurence , Charlesworth Brian , Bartolomé Carolina , Nöel Véronique 
Published: November 2005

Abstract
The distribution of mutational effects on fitness is of fundamental importance for many aspects of evolution. We develop two methods for characterizing the fitness effects of deleterious, nonsynonymous mutations, using polymorphism data from two related species. These methods also provide estimates of the proportion of amino acid substitutions that are selectively favorable, when combined with data on between-species sequence divergence. The methods are applicable to species with different effective population sizes, but that share the same distribution of mutational effects. The first, simpler, method assumes that diversity for all nonneutral mutations is given by the value under mutation-selection balance, while the second method allows for stronger effects of genetic drift and yields estimates of the parameters of the probability distribution of mutational effects. We apply these methods to data on populations of Drosophila miranda and D. pseudoobscura and find evidence for the presence of deleterious nonsynonymous mutations, mostly with small heterozygous selection coefficients (a mean of the order of 10−5 for segregating variants). A leptokurtic gamma distribution of mutational effects with a shape parameter between 0.1 and 1 can explain observed diversities, in the absence of a separate class of completely neutral nonsynonymous mutations. We also describe a simple approximate method for estimating the harmonic mean selection coefficient from diversity data on a single species.
Approximate Bayesian Inference Reveals Evidence for a Recent, Severe Bottleneck in a Netherlands Population of Drosophila melanogaster
Authors: Thornton Kevin , Andolfatto Peter 
Published: November 2005

Abstract
Genome-wide nucleotide variation in non-African populations of Drosophila melanogaster is a subset of variation found in East sub-Saharan African populations, suggesting a bottleneck in the history of the former. We implement an approximate Bayesian approach to infer the timing, duration, and severity of this putative bottleneck and ask whether this inferred model is sufficient to account for patterns of variability observed at 115 loci scattered across the X chromosome. We estimate a recent bottleneck 0.006Ne generations ago, somewhat further in the past than suggested by biogeographical evidence. Using various proposed statistical tests, we find that this bottleneck model is able to predict the majority of observed features of diversity and linkage disequilibrium in the data. Thus, while precise estimates of bottleneck parameters (like inferences of selection) are sensitive to model assumptions, our results imply that it may be unnecessary to invoke frequent selective sweeps associated with the dispersal of D. melanogaster from Africa to explain patterns of variability in non-African populations.
Primate Chaperones Hsc70 (Constitutive) and Hsp70 (Induced) Differ Functionally in Supporting Growth and Prion Propagation in Saccharomyces cerevisiae
Authors: Tutar Yusuf , Song Youtao , Masison Daniel C 
Published: November 2005

Abstract
Hsp70's are highly conserved essential protein chaperones that assist protein folding and prevent protein aggregation. They have modular structures consisting of ATPase, substrate-binding, and C-terminal domains. Substrate binding and release is regulated by ATP hydrolysis and nucleotide exchange, which in turn are regulated by cochaperones. Eukaryotes have constitutive (Hsc70) and stress-inducible (iHsp70) isoforms, but their functions have not been systematically compared. Using a yeast system to evaluate heterologous Hsp70's we find that primate Hsc70 supported growth but iHsp70 did not. Plant Hsc70 and iHsp70 counterparts behaved similarly, implying evolutionary conservation of this distinction. Swapping yeast and primate Hsp70 domains showed that (i) the Hsc70–iHsp70 distinction resided in the ATPase domain, (ii) substrate-binding domains of Hsp70's within and across species functioned similarly regarding growth, (iii) C-terminal domain function was important for growth, and (iv) Hsp70 functions important for cell growth and prion propagation were separable. Enzymatic analysis uncovered a correlation between substrate affinity and prion phenotype and showed that ATPase and protein-folding activities were generally similar. Our data support a view that intrinsic activities of Hsp70 isoforms are comparable, and functional differences in vivo lie mainly in complex interactions of Hsp70 with cochaperones.