bluuebunny/crossref_metadata_2025_split huggingface dataset:
ERK1/2 map kinase metabolic pathway is responsible for phosphorylation of translation initiation factor eIF4E during in vitro maturation of pig oocytes
Authors: Ellederová Zdenka , Cais Ondřej , Šušor Andrej , Uhlířová Katka , Kovářová Hana , Jelínková Lucie , Tomek Wolfgang , Kubelka Michal 
Published: February 2007

AbstractEukaryotic initiation factor 4E (eIF4E) plays an important role in mRNA translation by binding the 5′‐cap structure of the mRNA and facilitating the recruitment to the mRNA of other translation factors and the 40S ribosomal subunit. eIF4E undergoes regulated phosphorylation on Ser‐209 and this phosphorylation is believed to be important for its binding to mRNA and to other initiation factors. The findings showing that the translation initiation factor eIF4E becomes gradually phosphorylated during in vitro maturation (IVM) of pig oocytes with a maximum in metaphase II (M II) stage oocytes have been documented by us recently (Ellederova et al., 2006). The aim of this work was to study in details the metabolic pathways involved in this process. Using inhibitors of cyclin‐dependent kinases, Butyrolactone I (BL I) and protein phosphatases, okadaic acid (OA) we show that ERK1/2 MAP kinase pathway is involved in this phosphorylation. We also demonstrate that activation and phosphorylation of ERK1/2 MAP kinase and eIF4E is associated with the activating phosphorylation of Mnk1 kinase, one of the two main kinases phosphorylating eIF4E in somatic cells. Mol. Reprod. Dev. 75: 309–317, 2008. © 2007 Wiley‐Liss, Inc.
Effect of oocyte mitochondrial DNA haplotype on bovine somatic cell nuclear transfer efficiency
Authors: Jiao Fei , Yan Jing‐Bin , Yang Xiao‐Yu , Li Hua , Wang Qingxue , Huang Shu‐Zhen , Zeng Fanyi , Zeng Yi‐Tao 
Published: February 2007

AbstractThe development capability of reconstructed bovine embryos via ovum pick‐up (OPU)‐somatic cell nuclear transfer (SCNT) technique has been influenced by the maternal lineage of oocyte cytoplasm, but the underlying mechanism remains unclear. Since mitochondria are the richest maternal‐inherited organelle, in this study, we intended to clarify the effect of mtDNA haplotypes on cloning efficiency. By PCR‐RFLP method, we identified mtDNA haplotypes A and B, differing in six restriction sites. Reconstructed embryos with haplotype A cytoplast achieved better fusion and blastocyst formation rate (64.6% and 39.4%), as compared with haplotype B (53.6% and 26.3%; P < 0.05). To further evaluate the role of mitochondria, the quantity of mtDNA, ATP content, and mRNA level of mtDNA‐encoded COXI, COXIII in both oocytes were measured. Our data indicated that mtDNA copy number in haplotype A oocyte was significantly higher than that in haplotype B oocyte, both at the GV (105.03 ± 0.69 vs. 104.81 ± 0.86 copies/oocyte) and MII stages (105.31 ± 0.71 vs. 105.13 ± 0.63 copies/oocyte; logarithmically transformed values; P < 0.05). ATP content in type A oocyte was also greater at the GV (1.67 ± 0.09 vs. 1.27 ± 0.1 pmol) and MII stages (5.18 ± 0.07 vs. 2.68 ± 0.03 pmol; P < 0.05). Similarly, the mRNA expression level of mtDNA‐encoded COXI and COXIII in haplotype A oocyte was significantly higher comparing to haplotype B oocyte (3.3 ± 2.0 × 103 vs. 0.68 ± 0.45 × 103; 24.9 ± 10.5 × 103 vs. 9.4 ± 3.3 × 103, respectively; P < 0.05). The data suggest that mitochondrial structure, quantity, and function may significantly affect the developmental competence of reconstructed embryos. Mol. Reprod. Dev. 74: 1278–1286, 2007. © 2007 Wiley‐Liss, Inc.
IP micromobility and QoS virtual network testbed
Authors: Nafisi Nima , Wang Lin , Aghvami Hamid , Ferrús Ramon , Revés Xavier 
Published: February 2007

AbstractThis paper examines issues related to the interaction of QoS and IP micromobility management. More precisely, the inter‐working of a tunnel‐based IP micromobility management with the bandwidth broker QoS control plane is considered. Furthermore, the implementation of the system is detailed and it is tested using a virtual network testbed, based on ‘user‐mode‐Linux’. Finally, as a proof of concept the signalling between the different entities is examined with the protocol analyser ‘ethereal’. Copyright © 2007 John Wiley & Sons, Ltd.
Geometric non‐linear analysis of folded plate structures by the spline strip kernel particle method
Authors: Liew K. M. , Peng L. X. , Kitipornchai S. 
Published: February 2007

AbstractThis paper investigates the geometric non‐linear behaviour of stiffened and un‐stiffened folded plate structures using the spline strip kernel particle method (SSKPM). The first‐order shear deformable plate theory and large deflection theory of von Karman are employed. The folded plate structures are considered as assemblies of individual stiffened and un‐stiffened flat plates that lie on different planes. We regard these stiffened and un‐stiffened plate structures as superelements, and superpose their stiffness matrices to derive the final global stiffness matrices. Several numerical example problems are examined, and comparison studies are carried out with other available results. The effect of the size of the support, the order of the polynomial basis functions, and the spacing of the spline nodes on the convergence of the proposed method is examined. Copyright © 2007 John Wiley & Sons, Ltd.
Vibration analysis of beams with non‐local foundations using the finite element method
Authors: Friswell M. I. , Adhikari S. , Lei Y. 
Published: February 2007

AbstractIn this paper, a non‐local viscoelastic foundation model is proposed and used to analyse the dynamics of beams with different boundary conditions using the finite element method. Unlike local foundation models the reaction of the non‐local model is obtained as a weighted average of state variables over a spatial domain via convolution integrals with spatial kernel functions that depend on a distance measure. In the finite element analysis, the interpolating shape functions of the element displacement field are identical to those of standard two‐node beam elements. However, for non‐local elasticity or damping, nodes remote from the element do have an effect on the energy expressions, and hence the damping and stiffness matrices. The expressions of these direct and cross‐matrices for stiffness and damping may be obtained explicitly for some common spatial kernel functions. Alternatively numerical integration may be applied to obtain solutions. Numerical results for eigenvalues and associated eigenmodes of Euler–Bernoulli beams are presented and compared (where possible) with results in literature using exact solutions and Galerkin approximations. The examples demonstrate that the finite element technique is efficient for the dynamic analysis of beams with non‐local viscoelastic foundations. Copyright © 2007 John Wiley & Sons, Ltd.
Does vaginal bleeding influence first‐trimester markers for Down syndrome?
Authors: Heinig J. , Steinhard J. , Schmitz R. , Nofer J. R. , Witteler R. , Mosel A. , Ahrens A. , Kiesel L. , Klockenbusch W. 
Published: February 2007

AbstractObjectivesTo examine the effect of early vaginal bleeding on first‐trimester screening markers for Down syndrome.MethodsA retrospective study was conducted on 1755 normal singleton fetuses that underwent first‐trimester combined screening for Down syndrome on the basis of ultrasound and maternal serum markers. Fetal δ‐nuchal translucency (NT), maternal serum pregnancy‐associated plasma protein A (PAPP‐A) and free β‐hCG were compared between pregnancies with (n = 252) and without (n = 1503) an episode of vaginal bleeding. Subgroup analysis for the intensity of bleeding (spotting n = 191; light n = 32; heavy n = 29) was performed.ResultsThe median ± SD (log10) for δ‐NT, multiple of medians (MoM) PAPP‐A and MoM free β‐hCG (corrected for maternal weight, smoking and ethnicity) was − 0.17 ± 0.62, 1.10 ± 0.28, 1.1 ± 0.28 and − 0.15 ± 0.51, 0.98 ± 0.26, 0.94 ± 0.3 in pregnancies with and without a history of early vaginal bleeding, which were not significantly different. Exclusion of patients with spotting from the vaginal bleeding group revealed significantly higher maternal serum free β‐hCG MoM values (median ± SD (log10)) compared to patients without bleeding, 1.29 ± 0.27 vs 0.96 ± 0.3(p = 0.011). Screen‐positive (cut off of 1:350) rate after combined first‐trimester screening was 28.1% in patients with light vaginal bleeding and 8.4% in patients without bleeding (p = 0.001).ConclusionsLight vaginal bleeding before first‐trimester combined screening for Down syndrome leads to a higher screen‐positive rate after combined first trimester screening, without a significant difference in serum levels of the screening markers. Copyright © 2007 John Wiley & Sons, Ltd.
Major fetal abnormalities associated with positive screening tests for Smith‐Lemli‐Opitz syndrome (SLOS)
Authors: Craig Wendy Y. , Haddow James E. , Palomaki Glenn E. , Roberson Marie 
Published: February 2007

AbstractObjectiveDetermine the relationship between positive screening interpretations for Smith‐Lemli‐Opitz syndrome (SLOS) and other fetal abnormalities, to aid counseling and diagnostic activities.MethodsAn SLOS screening algorithm was incorporated into California's second‐trimester screening program for Down syndrome and open neural tube defects (ONTDs). Between 2002 and 2004, 777 088 pregnant women were given an SLOS risk interpretation, using alpha‐fetoprotein (AFP), unconjugated estriol (uE3), and human chorionic gonadotrophin (hCG) measurements. Outcomes were obtained in 98.8% of screen‐positive pregnancies.ResultsSLOS screen positives, alone or in combination with screen positives for other fetal disorders (Down syndrome, trisomy 18, ONTD), were associated with a high risk for fetal pathology. Type and frequency of chromosomal or anatomic abnormalities (or fetal death) varied according to screen‐positive combination. Among 2018 screen‐positive pregnancies, 644 fetal deaths were identified. Among the 1374 viable pregnancies, 519 were screen positive for SLOS alone; two SLOS cases and 51 other serious abnormalities were identified (14 aneuploidies; 37 anatomic). The remaining 855 were also screen positive for at least one other disorder; two SLOS cases and 327 other abnormalities were identified (180 aneuploidies; 157 anatomic).ConclusionFor screening programs implementing the SLOS algorithm, the present data may be useful for counseling and to guide diagnostic studies. Copyright © 2007 John Wiley & Sons, Ltd.
Reasons for antidepressant prescriptions in Canada
Authors: Patten Scott B. , Esposito Eleonora , Carter Brian 
Published: February 2007

AbstractPurposeTo describe reasons reported by physicians making recommendations for treatment with antidepressant medications.MethodsData collected by IMS Health Canada in a database called the Canadian Disease and Therapeutic Index (CDTI) were used in this analysis. CDTI data are collected from a representative sample of office‐based physicians who complete diaries in their practices during selected sampling periods. A drug recommendation is recorded each time a treatment is recommended. The data are weighted to produce national estimates of the frequency of such recommendations.ResultsThe frequency of recommendations for antidepressant treatment increased between 2000 and 2004. However, there was a slight decrease in 2005. Two types of antidepressant medications, tricyclic antidepressants (TCAs) and trazodone showed distinct patterns of use. TCAs were more commonly used for non‐psychiatric indications than for psychiatric indications, especially for sleep‐ and pain‐related reasons. Trazodone was frequently recommended for sleep problems. The proportion of recommendations for depressive disorders for antidepressants as a group remained stable over the 5‐year study period.ConclusionsAbout one‐third of antidepressant recommendations are for reasons other than depression. It can no longer be assumed that the frequency of antidepressant use is a measure of the frequency of pharmacological depression treatment. However, prescription data may be useful for tracking trends. Copyright © 2007 John Wiley & Sons, Ltd.
Isotactic poly(butene‐1) trigonal crystal growth in the melt
Authors: Yamashita Motoi , Hoshino Akitaka , Kato Minoru 
Published: February 2007

AbstractCrystal growth of the trigonal form of isotactic poly(butene‐1) (it‐PB1) was successfully observed in the melt at atmospheric pressure. The growth rate of trigonal crystals was obtained by in situ optical microscopy. It is one hundredth that of it‐PB1 tetragonal crystals. The growth rate of trigonal crystals, as well as that of tetragonal crystals, shows supercooling dependence derived from the nucleation theory. The value of the kinetic constant K of trigonal crystals is about 3.3 times larger than that of tetragonal crystals. The value of the pre‐exponential factor G0 of trigonal crystals was found to be 41 times as large as that of tetragonal crystals. The difference between these K values can be attributed to the conformational entropy of the ethyl side groups in a nucleating stem. The discrepancy found in the values of G0 could be explained by introducing pinning and nucleation barriers, which originate from the crystal thickness δlc, which does not depend on the crystallization temperature. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 684–697, 2007
Brownian dynamics simulation of polyelectrolyte dilute solutions: Relaxation time and elongational flow
Authors: Pamies R. , Cifre J. G. Hernández , De La Torre J. García 
Published: February 2007

AbstractThe authors used the bead‐and‐spring model and the Brownian dynamics simulation technique including hydrodynamic interaction to study the behavior of dilute polyelectrolyte solutions under elongational flow. First they carried out simulations to determine the longest relaxation time of a polyelectrolyte, finding that the relaxation time depends on the ionic strength of the solution. Then, they studied the coil‐stretch transition of polyelectrolyte molecules in elongational flow and determined the critical value of the elongational rate necessary in order this transition to occur. In this way, they could compute the value of the Deborah number at which coil‐stretch transition sets in for polyelectrolyte dilute solutions. Finally, they studied the power law relationship that relates the critical elongational rate with the molecular weight of the polyelectrolyte. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 714–722, 2007
Improved lower bounds on the randomized complexity of graph properties
Authors: Chakrabarti Amit , Khot Subhash 
Published: February 2007

AbstractWe prove a lower bound of Ω(n4/3 log 1/3n) on the randomized decision tree complexity of any nontrivial monotone n‐vertex graph property, and of any nontrivial monotone bipartite graph property with bipartitions of size n. This improves the previous best bound of Ω(n4/3) due to Hajnal (Combinatorica 11 (1991) 131–143). Our proof works by improving a graph packing lemma used in earlier work, and this improvement in turn stems from a novel probabilistic analysis. Graph packing being a well‐studied subject in its own right, our improved packing lemma and the probabilistic technique used to prove it may be of independent interest. © 2007 Wiley Periodicals, Inc. Random Struct. Alg., 2007
Understanding engagement: Science demonstrations and emotional energy
Authors: Milne Catherine , Otieno Tracey 
Published: February 2007

AbstractAlthough beloved of some chemists and physicists, science demonstrations have been criticized for stifling inquiry and assisting teachers to maintain a power differential between themselves and students in the classroom. This interpretive study reports the unexpected positive learning outcomes for urban science students in two chemistry classes that resulted from the use of science demonstrations during a unit on gas laws. Beginning with an examination of science demonstrations as sites of interactions, researchers observed greater student engagement and positive emotional energy, more sophisticated use by students of symbol systems associated with chemistry, and a greater willingness of students to move between description of the phenomena and submicroscopic explanations. Applying sociology of emotions to analysis of classroom conversations and actions, we examine the nature of engagement and propose explanations for the positive effect of science demonstrations on the engagement, emotional energy, and learning of students. © 2007 Wiley Periodicals, Inc. Sci Ed 91:523–553, 2007
The effects of the physical environment on job performance: towards a theoretical model of workspace stress
Authors: Vischer Jacqueline C. 
Published: February 2007

AbstractStudies of stress in the work environment pay little attention to features of the physical environment in which work is performed. Yet evidence is accumulating that the physical environment of work affects both job performance and job satisfaction. Contemporary research on stress in the work environment typically focuses on psychosocial factors that affect job performance, strain and employee health, and does not address the growing body of work on the environmental psychology of workspace. This paper reviews theory and research bearing on stress in the workplace and explores how current theory might be applied to the relationship between worker behaviour and physical features of the work environment. The paper proposes a theoretical model of the worker–workspace relationship in which stress and comfort play a critical part, and suggests a methodological approach on which to base future empirical studies. Copyright © 2007 John Wiley & Sons, Ltd.
Three‐dimensional sonography of prenatal skull base development
Authors: Roelfsema N. M. , Grijseels E. W. M. , Hop W. C. J. , Wladimiroff J. W. 
Published: February 2007

AbstractObjectiveTo explore longitudinally the development of the fetal skull base using three‐dimensional (3D) sonography.MethodsSerial 3D sonographic measurements of anterior skull base length, posterior cranial fossa length and skull base angle were made in 126 normal singleton pregnancies at 18–34 weeks of gestation. In a sub‐study of 22 pregnancies, intraobserver variability was determined. Regression analysis for repeated measurements was performed by means of the random coefficients model. Results from an earlier publication on brain volume were extended to the total patient cohort.ResultsMeasurements were technically successful in 69–94% of cases. The coefficient of variation for differences between repeated tests within women was 3.5–7.6% and between repeated analyses of the same recorded volume it was 3.0–5.1%. A statistically significant gestational age‐related increase was established for both the anterior skull base length and the posterior cranial fossa length and the skull base angle showed a small but significant flexion of about 6°. A higher increment in posterior cranial fossa length relative to anterior skull base angle was established. A significant quadratic relationship could be established for both anterior skull base length (P < 0.0001) and posterior cranial fossa length (P < 0.0001) but not for skull base angle, relative to brain volume.ConclusionThe reproducibility was acceptable for all fetal skull base measurements. The more pronounced growth in posterior cranial fossa length relative to anterior skull base length is influenced by brain growth. The small flexion of the skull base angle, however, may be caused by other factors. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Gestational‐age‐adjusted reference values for the modified myocardial performance index for evaluation of fetal left cardiac function
Authors: Hernandez‐Andrade E. , Figueroa‐Diesel H. , Kottman C. , Illanes S. , Arraztoa J. , Acosta‐Rojas R. , Gratacós E. 
Published: February 2007

AbstractObjectiveIt has been shown that the modified myocardial performance index (Mod‐MPI) is associated with higher reproducibility than conventional MPI because it uses mitral and aortic valve ‘clicks’ to calculate each time period. We aimed to construct normal reference values for the Mod‐MPI after 19 weeks' gestation.MethodsThe Mod‐MPI was calculated in the left ventricle of 557 normal fetuses at 19–39 weeks' gestation. The isovolumetric contraction time (ICT), isovolumetric relaxation time (IRT) and ejection time (ET) were measured using the Doppler signals (clicks) of the opening and closing of the mitral and aortic valves as landmarks. Mod‐MPI was calculated as (ICT + IRT)/ET.ResultsThroughout gestation, there was a small increase in the Mod‐MPI (at 19 weeks it was 0.35 ± 0.027 (mean ± SD); at 39 weeks, 0.37 ± 0.029; Mod‐MPI = 0.33 + 0.001× gestational age (GA) (weeks), r2 = 0.017). Of the three components, ICT remained constant, IRT increased (IRT = 0.028 + 2.52 × GA (weeks)), and ET slightly decreased (ET = 0.184 − 3.65 × GA (weeks)). Fetal heart rate (FHR) had no effect on the Mod‐MPI, but the duration of IRT, ICT and ET decreased by 13–15% when FHR increased from 130 to 160 beats per minute.ConclusionThe GA‐adjusted reference values for the Mod‐MPI and the three time periods used for its calculation can be applied to fetal cardiac evaluation in the presence of pregnancy‐associated complications. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Lubrication, single screw extrusion rates, and plasticizer structure in flexible PVC compounds
Authors: Daniels Paul H. 
Published: February 2007

AbstractIt is well‐established that changes in plasticizer structure affect (among other things) the melting temperatures, melt viscosities, and lubrication of flexible PVC compounds. In turn, these properties affect the extrudability of the compounds. The current study looks at the effects of plasticizer structure on lubrication, melt viscosities, extrusion rates, stock temperatures, and shear rates of PVC compounds in a single screw extrusion process. J. VINYL ADDIT. TECHNOL., 13:22–25, 2007. © 2007 Society of Plastics Engineers.
Plasticization effect of lignin in some highly filled vinyl formulations
Authors: Feldman D. , Banu D. , El‐Aghoury A. 
Published: February 2007

AbstractThe present study evaluates the impact of partially replacing (vinyl chloride)‐(vinyl acetate) (VC‐VAc) copolymer with lignin (L) in a vinyl flooring formulation. Lignin is a natural polymer resulting in huge quantities from wood delignification in the pulp and paper industry. An organsolv lignin, Alcell lignin (AL), was utilized. Also examined is the impact of replacing the common diethylhexyl phthalate (DOP) with plasticizers having chemical compositions different from those of DOP, i.e., diethylene glycol dibenzoate (2–45), tricresyl phosphate (Lindol®), and phenol alkylsulphonic ester (Mesamoll®). The reason for using other plasticizers is the suspicion that during the service life of vinyl flooring, the attack of fungi and microorganisms leads to the degradation of DOP and to the release of some volatile organic compounds (VOC). For the same reason, in the new flooring formulations, the VC‐VAc copolymer was partially replaced with L. Besides its other functions in wood, L imparts resistance to the attack of most microorganisms. The efficiency in plasticizing AL was also taken into consideration in choosing the above‐mentioned plasticizers. The influence of the new plasticizers, their concentration, and the influence of the partial replacement of VC‐VAc copolymer with AL on the mechanical and thermal properties of the new formulations are discussed. Laboratory data indicated that at a level of 20 parts VC‐VAc copolymer reduction and 5 parts plasticizer reduction, some of the obtained VC‐VAc‐AL blends compare very favorably with VC‐VAc copolymer control plasticized with 35 phr of DOP, the formulation of choice in vinyl flooring materials. J. VINYL ADDIT. TECHNOL., 13:14–21, 2007. © 2007 Society of Plastics Engineers.