bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Gas hold‐up model for slurry bubble columns
Authors: Chilekar Vinit P. , Singh Chattarbir , Schaaf John van der , Kuster Ben F. M. , Schouten Jaap C. 
Published: June 2007

AbstractA phenomenological model of the gas bubble hold‐up in slurry bubble columns is presented. The slurry moves upward in the core of the column and downward in the annulus, resembling the riser and downer of an air‐lift loop reactor, respectively. The model virtually divides the column in a riser and a downer. The cross‐sectional areas of the riser and the downer are experimentally found to be approximately equal. A macroscopic momentum balance over the riser and downer gives the liquid circulation velocity. The gas bubble hold‐up is modeled for two size classes: small and large. In the homogeneous regime only small gas bubbles are present. Above the regime transition velocity the churn‐turbulent regime exists, characterized by the presence of small and large gas bubbles. High speed video imaging shows that the gas flow up to the regime transition velocity generates small gas bubbles and that the gas flow in excess of the regime transition velocity generates large gas bubbles. Small gas bubbles are present in the riser and in the downer and have a constant slip velocity. The Wallis drift‐flux model describes the small gas bubble hold‐up in the riser and in the downer. Large gas bubbles are only present in the riser. The rise velocity of the large gas bubbles is the sum of the liquid velocity and the slip velocity according to the Davies‐Taylor equation. The large gas bubble hold‐up is obtained from the volume of gas flowing in large gas bubbles and the rise velocity of the large gas bubbles. For a given column diameter, column height, regime transition velocity, and physical properties of a gas–liquid system, the model predicts the total gas hold‐up, the hold‐up of the small and the large gas bubbles, and the average superficial liquid velocity in the riser and in the downer. Two parameters in the model are determined from experiments in a 29‐cm ID bubble column: the ratio of the small gas bubble hold‐up in the downer to that in the riser, and the energy dissipation at the top and bottom of the column. The model describes the gas hold‐up and liquid velocity data from literature with these parameter values within an error of 6%. The model shows that there is no effect of scale on the gas hold‐up for columns larger than 15 cm in diameter. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Continuous coating of discrete areas of a flexible web
Authors: Bower C. L. , Simister E. A. , Bonnist E. , Paul K. , Pightling N. , Blake T. D. 
Published: June 2007

AbstractThe use of surface energy (wettability) contrast to direct liquid into designated areas, so that flexible substrates can be coated with a discrete pattern in a continuous, roll‐to‐roll manner is described. The method makes use of a substrate prepatterned with lyophilic and lyophobic regions. When this substrate is over‐coated with the target liquid, the liquid withdraws from the lyophobic areas and collects on the lyophilic ones. The surface‐energy pattern and the liquid can be applied by a variety of different methods, but we have focused on printing the patterns by flexography and slide coating the target liquid. A benefit of the technique is that coatings of subsequent layers with the same pattern are self‐aligned with the previous layer, since they are directed by the same surface energy pattern. The capability is also demonstrated to perform simultaneous multi‐layer patterned coating in a single‐pass operation. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Hypermethylation of the p15INK4B gene promoter in B‐chronic lymphocytic leukemia
Authors: Papageorgiou Sotirios G. , Lambropoulos Stefanos , Pappa Vassiliki , Economopoulou Christina , Kontsioti Frinta , Papageorgiou Efstathios , Tsirigotis Panagiotis , Dervenoulas John , Economopoulos Theofanis 
Published: June 2007

AbstractThe p15 gene is a putative tumor suppressor gene that encodes a member of the cyclin dependent kinase inhibitors. Inactivation of p15 by promoter hypermethylation has been postulated as a possible way by which tumor suppressor genes are inactivated in cancer. In this study, we examined the methylation status of the p15 gene promoter in 34 patients with B‐Chronic Lymphocytic Leukemia (B‐CLL), by the Methylation‐Specific Polymerase Chain Reaction. Selective methylation of the p15 gene promoter was found in 4/34 cases (11.8%). According to Rai staging, the four patients with methylated p15 were staged on diagnosis as: 1 on Stage 0, 1 in Stage I, 1 in Stage III, and 1 in Stage IV. Our results suggest that methylation of the p15 gene promoter can be detected in a small subset of B‐CLL patients, at all stages of the disease. Am. J. Hematol., 2007. © 2007 Wiley‐Liss, Inc.
Polymorphic Alu insertions in five North‐West Italian populations
Authors: Santovito A. , Selvaggi A. , Cervella P. , Castellano S. , Bigatti M. P. , Sella G. , Delpero M. 
Published: June 2007

AbstractWe analyzed the frequencies of eight human polymorphic Alu insertion loci in population samples from five towns in North‐West Italy: Postua, Cavaglià, Biella, Torino, and Genova. All loci under scrutiny were found to be polymorphic in all samples, with the two exceptions of locus A25 in Postua, which was fixed for the absence of the Alu element, and APO in Genova, where the Alu insertion was fixed. Heterozigosity values were highly variable in all loci. FST values for all loci indicate that most of the variability is found within populations, while between population variability is lower. In the multidimensional scaling (MDS) analysis plot, the studied populations are separated from the main group represented by European populations. The Postua sample is set apart also from neighboring towns as Cavaglià and Biella, confirming previous observations of the demographic isolation of this population. Am. J. Hum. Biol. 19:589–592, 2007. © 2007 Wiley‐Liss, Inc.
BMI, income, and social capital in a native Amazonian society: Interaction between relative and community variables
Authors: Brabec Marek , Godoy Ricardo , Reyes‐García Victoria , Leonard William R. 
Published: June 2007

AbstractResearchers have shown interest in the relation between (a) social capital and individual income and (b) the individual health of people of industrial nations. The socioeconomic complexity of industrial nations makes it difficult to arrive at firm conclusions. We circumvent the obstacle by using data from a small‐scale rural society of foragers‐farmers in the Bolivian Amazon (Tsimane'). We examine the interactions between the outcome (BMI) and relative income, relative social capital, village income, and village social capital. We test three hypotheses: people in villages with more social capital should have higher BMI, the positive association between social capital and BMI will be more marked among the less well‐off, and better‐off people who display generosity will have higher BMI than better‐off people who do not. On the methodological side we show the importance of: focusing on relative measures of income and social capital, estimating interaction between community and relative measures of income and social capital, and showing results through contour plots that summarize the relation between BMI and pairs of explanatory variables. On the substantive side we find evidence that village social capital and village income complement each other and are associated with higher BMI, the rich who are stingy have lower BMI than the rich who display generosity, and increase in village income might reduce individual incentives to invest in social capital. We explore interactions between explanatory variables and their influence on BMI, and end by recommending the use of an experimental research design to obtain unbiased estimates of causal effects. Am. J. Hum. Biol. 19:459–474, 2007. © 2007 Wiley‐Liss, Inc.
Multiple mortality optima due to heterogeneity in the birth cohort: A continuous model of birth weight by gestational age‐specific infant mortality
Authors: Fang Fu , Stratton Howard , Gage Timothy B. 
Published: June 2007

AbstractBirth weight and gestational age are both important predictors of infant survival. Covariate Density Defined mixture of logistic regressions (CDDmlr), a method that accounts for unobserved heterogeneity, has been applied to birth outcomes using birth weight alone. This paper investigates a CDDmlr model of birth outcomes that includes birth weight and gestational age. Applications to four birth cohorts, composed of all non‐Hispanic singleton African/European American female/male live births in New York State from 1985–1988, are presented. Multiple birth weight by gestational age optimal (minimal) mortalities are observed in the birth weight by gestational age‐specific mortality surface. Multiple optima have not been mentioned in the published literature, but they do appear in some published plots of birth weight by gestational age mortality. It is possible that misreporting of gestational age contributes to this phenomenon, but it cannot completely explain the locations of the local optima. The global optimum is associated with a “normal” fetal development subpopulation, while the local optima are due to a subpopulation that accounts for most low birth weight, intrauterine growth retarded, pre‐term, post‐term, and small for gestational age births, as well as, births with misestimated gestational ages. These two subpopulations have significantly different birth weight by gestational age‐specific mortality surfaces. Consequently, the presence of multiple optima can be attributed to heterogeneity in the birth cohort. Comparisons of CDDmlr based on birth weight by gestational age and birth weight alone might statistically identify births with “erroneous” gestational age. Am. J. Hum. Biol. 19:475–486, 2007. © 2007 Wiley‐Liss, Inc.
Comparison of methods to evaluate changes in relative body mass index in pediatric weight control
Authors: Paluch Rocco A. , Epstein Leonard H. , Roemmich James N. 
Published: June 2007

AbstractOur objective was to compare three BMI‐based adiposity measures to assess change in pediatric weight control: LMS z‐BMI, BMI sympercent, and percent overBMI. Comparison 1 presents changes of +1.0, −1.0, and −2.0 BMI units for 36 hypothetical children (7‐, 11‐, and 15‐year‐old children with BMI values from 19–39 kg/m2). Comparison 2 presents effect sizes over 12 months and the relationship between baseline and change for 140 8–12‐year‐old children with BMI values ranging from 21 to 37 kg/m2. Comparison 1 showed smaller changes in z‐BMI than BMI sympercent or percent overBMI for equal changes in BMI when initial BMI values are greater. Comparison 2 showed similar effect sizes for the three measures, since there is a reduction in both standard deviation and magnitude of LMS z‐BMI values as the BMI values increase. The three measures perform differently when considering the relationship of initial value to change. Initial percent overBMI shows a negative relationship with change, as heavier children show larger changes, LMS z‐BMI shows a positive relationship, as children with lower baseline values show larger changes, and BMI sympercent changes were inconsistently related to baseline BMI sympercent values. Although all three measures result in similar effect sizes when evaluating treatment over time, we conclude that LMS z‐BMI is less appropriate for comparing individuals and percent overBMI is the only measure that shows heavier children have greater change. Am. J. Hum. Biol. 19:487–494, 2007. © 2007 Wiley‐Liss, Inc.
Estimating inbreeding in large, semi‐isolated populations: Effects of varying generation lengths and of migration
Authors: Pattison J.E. 
Published: June 2007

AbstractThe purpose of the study reported here was to investigate two important assumptions used in a recently reported new method of estimating inbreeding in large, relatively isolated populations over historic times. The method, based on modeling the genealogical “paradox,” produces values of Pearl's coefficients, Z, a measure of inbreeding or genealogical coalescence, as a function of time. In this study, the effects on inbreeding of two important assumptions made in earlier studies, namely those of using a constant generation length and of ignoring migration, have been investigated for the population of Britain. First, by relating the median age of women at childbirth to the development level of various societies, the variation of the generation lengths for different periods in historic Britain were estimated. Values of Z for two types of varying generation lengths were then calculated and compared with the case of constant generation length. Second, the population curve for Britain used in earlier studies was modified to obtain the subpopulation at any time during the past two millennia that was descended from the pre‐Roman British Celts. Values of Z for the case with migration were then calculated and compared with the case for no migration. It is shown that these two assumptions may be taken into account if and when required. Both the effect of a varying generation length and the effect of migration on Z were found to be 20–40%, when no known value of inbreeding was used, and 2–5%, when a known value of inbreeding was used. Am. J. Hum. Biol. 19:495–510, 2007. © 2007 Wiley‐Liss, Inc.
Advancing biocultural models by working with communities: A partnership approach
Authors: Schell Lawrence M. , Ravenscroft Julia , Gallo Mia , Denham Melinda 
Published: June 2007

AbstractCulture and human behavior are recognized today as major forces acting on human biological variation around the world. Studies of the relationships between biology and processes, such as modernization, urbanization, and social stratification, are prominent in our journals and meetings. An ongoing study of the interrelationships between toxicant exposure (organochlorines, lead, and mercury), health, and culture among youth of the Mohawk Nation at Akwesasne is located within this context and is used to analyze the strengths and challenges of a partnership approach to biocultural research. To assist in modeling the complex relationships between health, behavior, and culture, we have employed concepts from contemporary social theory, integrated qualitative and quantitative research, and implemented community‐based research principles to develop a partnership approach to research in human biology. The community is directly involved in identifying research goals, developing research protocols appropriate for local cultural sensitivities and complexities, implementing the protocols in the field, and collaborating in the analysis and publication of results. We show the utility of this approach for understanding the relationships of toxicants to behavior and biological outcomes (adolescent growth, sexual maturation, and endocrine system alteration); as well as how it facilitates the agency of participants and communities involved in research, and brings greater social engagement to the development of the new human biology. Am. J. Hum. Biol. 19:511–524, 2007. © 2007 Wiley‐Liss, Inc.
Selected anthropometric measurements of Akwesasne Mohawk youth: Skinfolds, circumferences, and breadths
Authors: Gallo Mia V. , Schell Lawrence M. 
Published: June 2007

AbstractNationally, Native American youth have been shown to be at risk for overweight, and an increased prevalence of obesity among Native American children has been consistently reported. We describe skinfolds, circumferences, and body breadths to assess body size and shape of Akwesasne Mohawk youth (n = 271) between the ages of 10.0 and 16.99. Akwesasne is a sovereign nation with territory in New York state and Canada. Sex‐ and age‐specific comparisons were made to reference values published from the Advance Data from Vital and Health Statistics and from the Third National Health and Examination Survey (NHANES III). Akwesasne youth have thicker skinfolds and larger circumferences than youth in the national surveys. Additionally, these cross‐sectional data indicate that body fat is more centrally distributed in Akwesasne Mohawk boys and girls. Given the numerous studies emphasizing the importance of body fat distribution as a risk factor for chronic, obesity‐related diseases prevalent within Native American communities, and the high level of fatness presented in this study, more concerted efforts need to be applied to help reduce the development of overweight in children from an early age. Am. J. Hum. Biol. 19:525–536, 2007. © 2007 Wiley‐Liss, Inc.
Do children take the same number of steps every day?
Authors: Wickel Eric E. , Eisenmann Joey C. , Pangrazi Robert P. , Graser Susan V. , Raustorp Anders , Tomson L. M. , Cuddihy Thomas F. 
Published: June 2007

AbstractThe purpose of this study was to examine the day‐to‐day variability in pedometer‐assessed physical activity (steps/day). A total of 1,443 children aged 6–12 years from the United States (195 boys, 254 girls), Sweden (257 boys, 252 girls), and Australia (229 boys, 256 girls) wore a pedometer for 4 consecutive weekdays. Repeated measures analysis of variance was used to examine daily differences in steps/day and the coefficient of variation (CV) was calculated for each individual to describe the day‐to‐day variability. Overall, mean steps/day were higher among boys (14,698 ± 3,373 steps/day) than girls (12,086 ± 2,929 steps/day). Significant differences were found between the 4 monitoring days for the entire sample; however, the absolute mean differences were small (55–958 steps) with an overall effect size of 0.01. This trend was apparent regardless of age, gender, and country. Individual CVs ranged from ∼2 to 88% and the overall mean CV approximated 22%. An age‐related increase in the mean CV was observed between 6‐ and 12‐year‐old children. The age × gender × country interaction was not significant (P > 0.05). These findings have implications toward the proper design, analysis, and interpretation of studies regarding physical activity among children. Beyond this aspect, our results lend insight into potential age‐related biological mechanisms that may also influence daily levels and patterns of physical activity. Am. J. Hum. Biol. 19:537–543, 2007. © 2007 Wiley‐Liss, Inc.
Docosahexaenoic acid and shore‐based diets in hominin encephalization: A rebuttal
Authors: Cunnane Stephen C. , Plourde Mélanie , Stewart Kathy , Crawford Michael A. 
Published: June 2007

AbstractCarlson and Kingston ([2007]: Am J Hum Biol 19:132–141) propose that preformed dietary docosahexaenoic acid (an omega‐3 fatty acid in fish) did not have a significant role in hominin encephalization. Their position hinges on claiming that humans are able to make sufficient docosahexaenoic acid from the plant‐based “parent” omega‐3 fatty acid—α‐linolenic acid. They also suggest that hominin fish consumption occurred too late to have materially influenced encephalization. The authors quantify here a summary of the published data showing that humans cannot make sufficient docosahexaenoic acid to maintain normal infant brain development. The authors also provide evidence that the fossil record shows that some of the earliest hominins were regularly consuming fish. Hence, we reject Carlson and Kingston's position and reiterate support for the concept that access to shore‐based diets containing docosahexaenoic acid was necessary for hominin encephalization beyond the level seen in the great apes. Am. J. Hum. Biol. 19:578–581, 2007. © 2007 Wiley‐Liss, Inc.
Conceptualizing information, technology, and people: Comparing information science and information systems literatures
Authors: Sawyer Steve , Huang Haiyan 
Published: June 2007

AbstractThrough this article, we highlight that there are discernibly different patterns among conceptualizations of information, technology, and people across information systems and information science literatures. We do this to clarify the differences in these two areas of scholarship and to further encourage the substantial overlap possible, but not yet engaged, in the research pursued in these areas. We engage this by analyzing published literature in these areas to frame our discussion of the challenges and opportunities for scholars in information science and information systems disciplines to engage in collaborative work.
One‐Dimensional, Cofacial Porphyrin Polymers Formed by Self‐Assembly of meso‐Tetrakis(ERE Donor) Zinc(II) Porphyrins
Authors: Suijkerbuijk Bart M. J. M. , Tooke Duncan M. , Spek Anthony L. , van Koten Gerard , Klein Gebbink Robertus J. M. 
Published: June 2007

AbstractA series of meso‐tetrakis‐(ERE donor) zinc(II) porphyrins nZn (ERE donor=4‐R‐3,5‐bis[(E)‐methyl]phenyl; 1Zn: E=NMe2, R=Br; 2Zn: E=NMe2, R=H; 3Zn: E=OMe, R=Br; 4Zn: E=OMe, R=H) have been synthesized in excellent yields. As a result of the combination of a Lewis acidic site and eight Lewis basic sites within one molecule, monomeric molecules of nZn self‐assemble to form one‐dimensional porphyrin polymers [nZn]∞ in the solid state, as confirmed for 1Zn and 3Zn by X‐ray crystallography. The coordination environment around the zinc(II) ions in these polymers is octahedral. They are ligated by four equatorial nitrogen atoms of the porphyrin and two apical E atoms (E=N, O) provided by the EBrE donor groups of adjacent nZn molecules. Complexes 2Zn and 4Zn did not form single crystals, but solid‐state UV/Vis analysis points to the formation of similar structures. Solution UV/Vis and 1H NMR spectroscopy indicated that interactions between 1Zn and 2Zn monomers in the polymers are stronger than between 3Zn and 4Zn monomers. Interestingly, they also revealed that the presence of a neighboring bromine atom in the EBrE donor groups has a considerable influence on the coordination properties of the benzylic N or O atoms. The zinc(II) ions of the porphyrins most likely adopt only hexacoordination in the solid state, owing to the unique predisposition of Lewis acidic and basic sites in the nZn molecules. Several parameters of the aggregates, for example, the interplanar separation between porphyrins and the zinc–zinc distances, change as a function of the coordinating E groups. The high degree of modularity in their synthesis makes these zinc(II) porphyrins an interesting new entry in noncovalent multiporphyrin assemblies.
Bemessungsrelevante Kennwerte von Feinbeton für einaxiale Druckbeanspruchung
Authors: Brockmann Tanja , Brameshuber Wolfgang , Hinzen Marcus 
Published: June 2007

AbstractFür die Herstellung textilbewehrter Elemente werden so genannte Feinbetone verwendet. Die mechanischen Kennwerte und die Stoffgesetze unter kurzzeitiger einaxialer (statischer) Druckbeanspruchung für die neuartigen Feinbetone als Einzelkomponente des Verbundwerkstoffes Textilbeton werden in dem Beitrag vorgestellt. Zudem werden die Anwendbarkeit bekannter mathematischer Vereinfachungen der Spannungs‐Dehnungsbeziehungen (z. B. Parabel‐Rechteck‐Diagramm) für die Bemessung sowie Kriechkennwerte zur Vorhersage der Kriechverformungen (z. B. Endkriechzahlen) erläutert.
Textilbewehrter Beton zur Verstärkung eines Hyparschalentragwerks in Schweinfurt
Authors: Curbach Manfred , Hauptenbuchner Barbara , Ortlepp Regine , Weiland Silvio 
Published: June 2007

AbstractErstmals wurde bei der Sanierung der Hyparschale der Fachhochschule in Schweinfurt mit der innovativen Technologie des textilbewehrten Betons ein Stahlbetontragwerk verstärkt und sicherer für die Zukunft gemacht. Da textilbewehrter Beton noch kein genormter Konstruktionswerkstoff ist, wurde für den Einsatz der textilen Bewehrung eine Zustimmung im Einzelfall notwendig. Die Verstärkungsarbeiten wurden im Oktober/November 2006 ausgeführt. Die textilbewehrte Feinbetonverstärkung wurde dabei lagenweise aufgebracht. Durch Auflaminieren wurden abwechselnd Feinbeton und drei Lagen textile Bewehrung aus 800 tex Carbonrovings aufgetragen. Die Gesamtdicke der Verstärkung beträgt nur 15 mm.