bluuebunny/crossref_metadata_2025_split huggingface dataset:
Correlations between deciduous and permanent tooth morphology in a European American sample
Authors: Edgar H.J.H. , Lease L.R. 
Published: February 2007

AbstractThe expression of dental morphological characteristics is partially genetically controlled, and is assumed to be similar in deciduous and permanent dentitions. However, there are few published data comparing normal morphological variation between the two dentitions in the same individual. For the current study, data were collected from European Americans (N = 54) whose teeth were cast both as children and adults. We observed 19 trait expressions in deciduous and permanent dentitions. Deciduous traits were scored based on Hanihara's and Sciulli's descriptions, while permanent teeth were scored using the ASU dental anthropology system. The two dentitions' scores were compared using Goodman–Kruskal's Gamma (γ) in the original, commonly used systems as well as in a new, shared scale to which the scores were converted. Observations were also dichotomized in both formats and compared using tetrachoric correlation. We expected high correlations between the two dentitions and for both statistics to yield similar results. For the original scores, γ correlations vary from −1.0 to 0.68; tetrachoric correlations vary from 0.04 to 0.67. For the shared scale scores, γ correlations range from −1.0 to 1.0 and tetrachoric correlations range between −0.47 and 0.8. Several traits showed no correlation in either test. Overall, categorical data analysis returned more positive moderate to high correlations than tetrachoric correlation analysis, and shared scale tests resulted in more correlations than did tests of data in the original scoring systems. These results reflect differences in commonly used scoring systems, variation in rarely occurring traits, different strengths of trait expression, and complex genetic/environmental interactions. Am J Phys Anthropol, 2007. © 2007 Wiley‐Liss, Inc.
Experience‐dependent recapture rates and reproductive success in male grey mouse lemurs (Microcebus murinus)
Authors: Schmelting Barthel , Zimmermann Elke , Berke Olaf , Bruford Michael W. , Radespiel Ute 
Published: February 2007

AbstractMale mating tactics can vary according to the potential for scramble or contest competition but also as a consequence of individual characteristics, such as body condition and previous experience. The influence of experience, i.e., residency, on male recapture rates and reproductive success was studied in a population of free‐living grey mouse lemurs. Long‐term capture data from 320 individuals revealed that both sexes had very low recapture probabilities within their first year in the study population, but recapture rates declined less sharply during the following years. Capture results and telemetric analyses on 12 focal males revealed that resident males had larger body mass and larger home ranges than new males. Home range size correlated with the number of accessible females, indicating that resident males had higher probabilities to meet mates than new males. The reproductive success of 132 candidate fathers, representing both resident and new males, was determined by means of molecular genotyping. Paternity determination was successful in 38 cases (success rate: 19%). Sixteen resident males and seventeen new males sired offspring. However, in relation to the number of candidate fathers being present in the mating season, resident males were twice as likely to reproduce successfully as new males. These findings suggest experience‐dependent reproductive tactics that most likely correspond to a differential spatial knowledge of resources, mates and potential threats. The results generally agree with the predictions made for a scramble competition regime and demonstrate substantial behavioral plasticity in a nocturnal primate species with a dispersed multi‐male/multi‐female mating system. Am J Phys Anthropol, 2007. © 2007 Wiley‐Liss, Inc.
Regional variation in the postcranial robusticity of late upper paleolithic humans
Authors: Shackelford Laura L. 
Published: February 2007

AbstractEarly modern humans from the European Upper Paleolithic (UP) demonstrate trends in postcranial biomechanical features that coincide with the last glacial maximum (LGM). These features have been interpreted as evidence that ecological changes of the LGM played a critical role in cultural and biological adaptation in European UP populations. In areas outside of Europe, similar environmental changes occurred with the LGM. This analysis introduces postcranial material from the Late Upper Paleolithic (LUP) of North Africa and Southeast Asia and tests two related hypotheses: 1) LUP samples across the Old World had similar patterns of postcranial robusticity and 2) relative to an available Early Upper Paleolithic (EUP) sample, regional LUP samples demonstrate similar trends in robusticity that may be attributable to climatic effects of the LGM. Cross‐sectional geometric data of the humeri and femora were obtained for 26 EUP and 100 LUP humans from Europe, Africa, and Asia. Despite regional differences, LUP samples are similar relative to the EUP sample. In the humerus, bilateral asymmetry decreases in all LUP samples relative to the EUP sample. In the femur, LUP samples demonstrate increasingly circular femoral midshaft sections, reflecting reduced anteroposterior bending strength relative to the EUP sample. These patterns suggest changes in subsistence behavior and mobility after the LGM across the Old World that are most consistent with reduced mobility and broad‐spectrum resource exploitation. Am J Phys Anthropol, 2007. © 2007 Wiley‐Liss, Inc.
Body size prediction from juvenile skeletal remains
Authors: Ruff Christopher 
Published: February 2007

AbstractThere are currently no methods for predicting body mass from juvenile skeletal remains and only a very limited number for predicting stature. In this study, stature and body mass prediction equations are generated for each year from 1 to 17 years of age using a subset of the Denver Growth Study sample, followed longitudinally (n = 20 individuals, 340 observations). Radiographic measurements of femoral distal metaphyseal and head breadth are used to predict body mass and long bone lengths are used to predict stature. In addition, pelvic bi‐iliac breadth and long bone lengths are used to predict body mass in older adolescents. Relative prediction errors are equal to or smaller than those associated with similar adult estimation formulae. Body proportions change continuously throughout growth, necessitating age‐specific formulae. Adult formulae overestimate stature and body mass in younger juveniles, but work well in 17‐year‐olds from the sample, indicating that in terms of body proportions they are representative of the general population. To illustrate use of the techniques, they are applied to the juvenile Homo erectus (ergaster) KNM‐WT 15000 skeleton. New body mass and stature estimates for this specimen are similar to previous estimates derived using other methods. Body mass estimates range from 50 to 53 kg, and stature was probably slightly under 157 cm, although a precise stature estimate is difficult to determine due to differences in linear body proportions between KNM‐WT 15000 and the Denver reference sample. Am J Phys Anthropol, 2007. © 2007 Wiley‐Liss, Inc.
Population continuity or population change: Formation of the ancient Egyptian state
Authors: Zakrzewski Sonia R. 
Published: February 2007

AbstractThe origins of the ancient Egyptian state and its formation have received much attention through analysis of mortuary contexts, skeletal material, and trade. Genetic diversity was analyzed by studying craniometric variation within a series of six time‐successive Egyptian populations in order to investigate the evidence for migration over the period of the development of social hierarchy and the Egyptian state. Craniometric variation, based upon 16 measurements, was assessed through principal components analysis, discriminant function analysis, and Mahalanobis D2 matrix computation. Spatial and temporal relationships were assessed by Mantel and Partial Mantel tests. The results indicate overall population continuity over the Predynastic and early Dynastic, and high levels of genetic heterogeneity, thereby suggesting that state formation occurred as a mainly indigenous process. Nevertheless, significant differences were found in morphology between both geographically‐pooled and cemetery‐specific temporal groups, indicating that some migration occurred along the Egyptian Nile Valley over the periods studied. Am J Phys Anthropol, 2007. © 2007 Wiley‐Liss, Inc.
When specialized sites are important for synapsis and the distribution of crossovers
Authors: Joyce Eric F. , McKim Kim S. 
Published: February 2007

AbstractIn C. elegans and D. melanogaster, specialized sites have an important role in meiotic recombination. Recent evidence has shown that these sites in C. elegans have a role in synapsis. Here we compare the initiation of synapsis in organisms with specialized sites and those without. We propose that, early in prophase, synapsis requires an initiator to overcome inhibitory factors that function to prevent synaptonemal complex (SC) formation between nonhomologous sequences. These initiators of SC formation can be stimulated by crossover sites, possibly other types of recombination sites and also specialized sites where recombination does not occur. BioEssays 29: 217–226, 2007. © 2007 Wiley Periodicals, Inc.
Regulation of chemotactic networks by ‘atypical’ receptors
Authors: Comerford Iain , Litchfield Wendel , Harata‐Lee Yuka , Nibbs Robert J.B. , McColl Shaun R. 
Published: February 2007

AbstractDirected cell migration is a fundamental component of numerous biological systems and is critical to the pathology of many diseases. Although the importance of secreted chemoattractant factors in providing navigational cues to migrating cells bearing specific chemoattractant receptors is now well‐established, how the function of these factors is regulated is not so well understood and may be of key importance to the design of new therapeutics for numerous human diseases. While regulation of migration clearly takes place on a number of different levels, it is becoming clear that so‐called ‘atypical’ receptors play a role in scavenging, or altering the localisation of, chemoattractant molecules such as chemokines and complement components. These receptors do this through binding and/or internalising their chemoattractant ligands without activating signal transduction cascades leading to cell migration. The atypical chemokine receptor family currently comprises the receptors D6, DARC and CCX‐CKR. In this review, we discuss the evidence from in vitro and in vivo studies that these receptors play a role in regulating cell migration, and speculate that other orphan receptors may also belong to this family. Furthermore, with the advent of gene therapy on the horizon, the therapeutic potential of these receptors in human disease is also considered. BioEssays 29: 237–247, 2007. © 2007 Wiley Periodicals, Inc.
The importance of stress and genetic variation in human aggression
Authors: Craig Ian W. 
Published: February 2007

AbstractBoth genetic and environmental factors have key roles in determining aggressive tendencies. In particular, reaction to stress appears to be an important factor in precipitating aggressive episodes and individuals may vary in their ability to cope with stressful environments depending on their genetic make up. Evidence from humans and primates indicates that adverse rearing conditions may interact with variants in stress and neurotransmitter pathway genes leading to antisocial and/or violent behaviour. Common alleles of some serotonin pathway genes, including those involved in its degradation (monoamine oxidase A, MAOA), or its re‐uptake into pre‐synaptic neurones (serotonin transporter, SERT) have been shown to confer functional variation. Examination of the interaction between the alleles of such polymorphisms (in particular those affecting MAOA) and environmental stressors suggest that they may provide protection against, or increase sensitivity to, abusive upbringing; an observation that may explain part of the variability in developmental outcomes associated with maltreatment. BioEssays 29: 227–236, 2007. © 2007 Wiley Periodicals, Inc.
Probing bacterial nucleoid structure with optical tweezers
Authors: Dorman Charles J. 
Published: February 2007

AbstractThe H‐NS protein is a major component of the nucleoid in Gram‐negative bacterial cells. It is a global regulator of transcription that affects the expression of many genes, including virulence genes in pathogenic species. At a local level, it facilitates the formation of nucleoprotein structures that repress transcriptional promoter function. H‐NS can form bridges between different DNA molecules or between different sections of the same molecule, allowing it to compact and impose structure on the nucleoid. A recent paper by Dame et al.1 reports new insights into H‐NS‐mediated DNA bridging that were obtained using an optical tweezers device. BioEssays 29: 212–216, 2007. © 2007 Wiley Periodicals, Inc.
Stalk‐eyed flies (Diopsidae): Modelling the evolution and development of an exaggerated sexual trait
Authors: Warren Ian , Smith Hazel 
Published: February 2007

AbstractStalk‐eyed flies of the family Diopsidae exhibit a unique form of hypercephaly, which has evolved under both natural and sexual selection. Male hypercephaly is used by female diopsids as an indicator of male quality. By choosing to mate with males expressing the most‐exaggerated hypercephaly, females can benefit both from the enhanced fertility of these males and the transmission of other heritable advantages to their offspring. Stalk‐eyed flies are close relatives of the model organism, Drosophila melanogaster. We have shown that similar genetic and cellular mechanisms regulate the initial development of the head capsule in fruitflies and diopsids. The great diversity of stalk‐eyed fly species, exhibiting varying degrees of hypercephaly and sexual dimorphism, constitutes a major advantage for comparative studies of their development and evolution. BioEssays 29: 300–307, 2007. © 2007 Wiley Periodicals, Inc.
The relationship between non‐protein‐coding DNA and eukaryotic complexity
Authors: Taft Ryan J. , Pheasant Michael , Mattick John S. 
Published: February 2007

AbstractThere are two intriguing paradoxes in molecular biology—the inconsistent relationship between organismal complexity and (1) cellular DNA content and (2) the number of protein‐coding genes—referred to as the C‐value and G‐value paradoxes, respectively. The C‐value paradox may be largely explained by varying ploidy. The G‐value paradox is more problematic, as the extent of protein coding sequence remains relatively static over a wide range of developmental complexity. We show by analysis of sequenced genomes that the relative amount of non‐protein‐coding sequence increases consistently with complexity. We also show that the distribution of introns in complex organisms is non‐random. Genes composed of large amounts of intronic sequence are significantly overrepresented amongst genes that are highly expressed in the nervous system, and amongst genes downregulated in embryonic stem cells and cancers. We suggest that the informational paradox in complex organisms may be explained by the expansion of cis‐acting regulatory elements and genes specifying trans‐acting non‐protein‐coding RNAs. BioEssays 29: 288–299, 2007. © 2007 Wiley Periodicals, Inc.
The origins of polypeptide domains
Authors: Schmidt Edward E. , Davies Christopher J. 
Published: February 2007

AbstractThree decades ago Gilbert posited that novel proteins arise by re‐shuffling genomic sequences encoding polypeptide domains. Today, with numerous genomes and countless genes sequenced, it is well established that recombination of sequences encoding polypeptide domains plays a major role in protein evolution. There is, however, less evidence to suggest how the novel polypeptide domains, themselves, arise. Recent comparisons of genomes from closely related species have revealed numerous species‐specific exons, supporting models of domain origin based on “exonization” of intron sequences. Also, a mechanism for the origin of novel polypeptide domains has been proposed based on analyses of insertion‐based polymorphisms between orthologous genes across broad phylogenetic spectra and between allelic variants of genes within species. This review discusses these processes and how each might participate in the evolutionary emergence of novel polypeptide domains. BioEssays 29: 262–270, 2007. © 2007 Wiley Periodicals, Inc.
DNA methylation with a sting: An active DNA methylation system in the honeybee
Authors: Schaefer Matthias , Lyko Frank 
Published: February 2007

AbstractThe existence of DNA methylation in insects has been a controversial subject over a long period of time. The recently completed genome sequence of the honeybee Apis mellifera has revealed the first insect with a full complement of DNA methyltransferases.1 A parallel study demonstrated that these enzymes are catalytically active and that Apis genes can be methylated in specific patterns.2 These findings establish bees as a model to analyze the function of DNA methylation systems in invertebrate organisms and might also be important to understand evolutionary aspects of DNA methylation in higher eukaryotes. BioEssays 29: 208–211, 2007. © 2007 Wiley Periodicals, Inc.
Stereospecific determination of cis‐ and trans‐resveratrol in rat plasma by HPLC: application to pharmacokinetic studies
Authors: Chen Xijing , He Hui , Wang Guangji , Yang Bing , Ren Weichao , Ma Le , Yu Qiaoling 
Published: February 2007

AbstractA simple, accurate, precise, specific and reproducible high‐performance liquid chromatography (HPLC) method was developed for simultaneous determination of resveratrol isomers in rat plasma. Cis‐resveratrol was made by exposure of a trans‐resveratrol solution to sunlight for 5 days followed by separation by HPLC and identification by mass spectrometry (MS). The assay procedure involved simple liquid–liquid extraction of resveratrol isomers and internal standard (IS, caffeine) from a small plasma volume directly into acetonitrile. The supernatant liquid was added an equal volume of water and injected onto a Hypersil ODS2 C18 column (5 µm, 4.6 × 250 mm). Mobile phase consisting of methanol and distilled water was used at a flow rate of 1.0 mL/min for the effective separation of cis‐, trans‐resveratrol and caffeine (IS). The detection of the analyte peak was achieved by monitoring the eluate using a UV detector set at 303 nm. The ratio of peak area of analyte to IS was used for quantification of plasma samples. Nominal retention times of cis‐, trans‐resveratrol and IS were 3.2, 4.3 and 6.1 min, respectively. The calibration curve was linear ranging from 0.066 to 6.64 and 0.134 to 13.4 µg/mL with correlation coefficients of 0.9998 and 0.9997 for trans and cis isomers, respectively. The absolute recovery of both isomers was more than 85%. The inter‐ and intra‐day precisions in the measurement of quality control (QC) samples, 0.066, 0.664 and 6.64 µg/mL of trans‐resveratrol, were in the range 2.37–6.95% relative standard deviation (RSD) and 0.77–6.97% RSD, respectively. The inter‐ and intra‐day precisions in the measurement of quality control (QC) samples, 0.134, 1.34 and 13.4 µg/mL of cis‐resveratrol, were in the range 1.93–3.72% relative standard deviation (RSD) and 1.13–6.57% RSD, respectively. Both analytes and IS were stable in the battery of stability studies and freeze–thaw cycles. Resveratrol isomers were found to be stable for a period of 30 days on storage at −20°C. The application of the assay to determine the pharmacokinetic disposition after a single oral dose to rats is described. Copyright © 2007 John Wiley & Sons, Ltd.
Analysis of anabolic steroids in hair by GC/MS/MS
Authors: Gambelunghe C. , Sommavilla M. , Ferranti C. , Rossi R. , Aroni K. , Manes N. , Bacci M. 
Published: February 2007

AbstractASTRACT: A simple and sensitive gas chromatography/tandem mass spectrometry (GC/MS/MS) method is described for the detection of anabolic steroids, usually found in keratin matrix at very low concentrations. Hair samples from seven athletes who spontaneously reported their abuse of anabolic steroids, and in a single case cocaine, were analyzed for methyltestosterone, nandrolone, boldenone, fluoxymesterolone, cocaine and its metabolite benzoylecgonine. Anabolic steroids were determinate by digestion of hair samples in 1 m NaOH for 15 min at 95°C. After cooling, samples were purificated by solid‐phase and liquid–liquid extraction, then anabolic steroids were converted to their trimethylsilyl derivative and finally analyzed by GC/MS/MS. For detection of cocaine and benzoylecgonine, hair samples were extracted with methanol in an ultrasonic bath for 2 h at 56°C then overnight in a thermostatic bath at the same temperature. After the incubation, methanol was evaporated to dryness, and benzoylecgonine was converted to its trimethylsilyl derivative prior of GC/MS/MS analysis. Results obtained are in agreement with the athletes' reports, confirming that hair is a valid biological matrix to establish long‐term intake of drugs. Copyright © 2007 John Wiley & Sons, Ltd.
Quantitative LC/MS/MS method and in vivo pharmacokinetic studies of vitexin rhamnoside, a bioactive constituent on cardiovascular system from hawthorn
Authors: Liang Mingjin , Xu Wen , Zhang Weidong , Zhang Chuan , Liu Runhui , Shen Yunheng , Li Huiliang , Wang Xiaolin , Wang Xiangwei , Pan Qiongqun , Chen Chunlin 
Published: February 2007

AbstractA simple and accurate liquid chromatography coupled with tandem mass spectrometry method was developed for determination and in vivo pharmacokinetic studies of vitexin rhamnoside in rat plasma. After protein precipitation using methanol, the analytes were separated by a Luna C18 column with an isocratic elution and analyzed by mass spectrometry in multiple reaction monitoring mode using the respective negative ion at m/z 577.2–293.0 for vitexin rhamnoside and m/z 593.2–413.0 for internal standard (IS) vitexin glucoside. The method was validated systematically within the concentration range 5–5000 µg/L (R > 0.996) and the lower limit of quantitation was 5 µg/L. Acceptable precision and accuracy were acquired for concentrations over the standard curve range. It was further applied to assess pharmacokinetics and bioavailability of vitexin rhamnoside after intravenous and oral administration to rats. The oral bioavailability of vitexin rhamnoside was only 3.57%, which indicated that vitexin rhamnoside had poor absorption or underwent extensive first‐pass metabolism. Practical utility of this new LC/MS/MS method was confirmed in pilot pharmacokinetic studies in rats following both intravenous and oral administration. Copyright © 2007 John Wiley & Sons, Ltd.