bluuebunny/crossref_metadata_2025_split huggingface dataset:
Individual variation in neural correlates of sadness in children: A twin fMRI study
Authors: Côté Catherine , Beauregard Mario , Girard Alain , Mensour Boualem , Mancini‐Marïe Adham , Pérusse Daniel 
Published: April 2007

AbstractFunctional neuroimaging studies show substantial individual variation in brain activation accompanying the experience of emotion, including sadness. Here we used functional magnetic resonance imaging (fMRI) in 104 pairs of 8‐year‐old twins (47 MZ, 57 DZ) to assess genetic‐environmental contributions to individual differences in neural activation in two prefrontal cortex (PFC) areas previously shown to be involved in sadness. No genetic effects were found for any area, individual environmental factors entirely accounting for individual variation in brain activation related to sadness. Sadness being the prevailing mood in depression, these findings may be of relevance to the etiology of childhood depressive disorders. Hum Brain Mapp 2007. © 2007 Wiley‐Liss, Inc.
Cortical mapping of genotype–phenotype relationships in schizophrenia
Authors: Bearden Carrie E. , van Erp Theo G.M. , Thompson Paul M. , Toga Arthur W. , Cannon Tyrone D. 
Published: April 2007

AbstractAlthough schizophrenia is highly heritable, the search for susceptibility genes has been challenging. The “endophenotype” approach is an alternative method for measuring phenotypic variation that may make it easier to identify susceptibility genes in the context of complexly inherited traits. Neuroimaging methods in particular offer a powerful way to bridge the neurobiology of genes and behavior. Such investigations may be further empowered by complementary strategies involving chromosomal abnormalities associated with schizophrenia, which can help to localize causative genes and better understand the genetic complexity of the illness. Here, we illustrate our use of these convergent approaches, with a focus on neuroimaging studies using novel computational brain mapping algorithms, to investigate genetic influences on brain structure in the development of psychosis. These studies provide compelling evidence that specific genetic loci suspected to predispose to schizophrenia may affect quantitative variation in neural indicators underlying the neurobehavioral phenotype, and illustrate how genetic‐neuroimaging paradigms can improve our understanding of the pathogenesis of this highly disabling mental illness. Hum Brain Mapp, 2007. © 2007 Wiley‐Liss, Inc.
Cervical screening by visual inspection, HPV testing, liquid‐based and conventional cytology in Amazonian Peru
Authors: Almonte Maribel , Ferreccio Catterina , Winkler Jennifer L. , Cuzick Jack , Tsu Vivien , Robles Sylvia , Takahashi Rina , Sasieni Peter 
Published: April 2007

AbstractCervical cancer is an important public health problem in many developing countries, where cytology screening has been ineffective. We compared four tests to identify the most appropriate for screening in countries with limited resources. Nineteen midwives screened 5,435 women with visual inspection (VIA) and collected cervical samples for HPV testing, liquid‐based cytology (LBC) and conventional cytology (CC). If VIA was positive, a doctor performed magnified VIA. CC was read locally, LBC was read in Lima and HPV testing was done in London. Women with a positive screening test were offered colposcopy or cryotherapy (with biopsy). Inadequacy rates were 5% and 11% for LBC and CC respectively, and less than 0.1% for VIA and HPV. One thousand eight hundred eighty‐one women (84% of 2,236) accepted colposcopy/cryotherapy: 79 had carcinoma in situ or cancer (CIS+), 27 had severe‐ and 42 moderate‐dysplasia on histology. We estimated a further 6.5 cases of CIS+ in women without a biopsy. Sensitivity for CIS+ (specificity for less than moderate dysplasia) was 41.2% (76.7%) for VIA, 95.8% (89.3%) for HPV, 80.3% (83.7%) for LBC, and 42.5% (98.7%) for CC. Sensitivities for moderate dysplasia or worse were better for VIA (54.9%) and less favourable for HPV and cytology. In this setting, VIA and CC missed the majority of high‐grade disease. Overall, HPV testing performed best. VIA gives immediate results, but will require investment in regular training and supervision. Further work is needed to determine whether screened‐positive women should all be treated or triaged with a more specific test. © 2007 Wiley‐Liss, Inc.
Dynamic factor extraction of cross‐sectional dependence in panel unit root tests
Authors: Kapetanios George 
Published: April 2007

AbstractRecently, considerable emphasis has been placed on the problems arising out of cross‐sectional dependence in panel unit root tests. This paper adopts the factor‐based cross‐sectional dependence paradigm of Bai and Ng (2005) but suggests alternative factor extraction methods. Some theoretical results for these methods are provided. Further, a detailed Monte Carlo study of these methods for multiple and persistent factors is undertaken. It is found that results are radically different from the serially uncorrelated single‐factor case. Tests perform much worse and in some cases it is preferable not to correct at all for cross‐sectional dependence. Copyright © 2007 John Wiley & Sons, Ltd.
Effects of calcium ion‐implantation of titanium on bone cell function in vitro
Authors: Nayab Saima N. , Jones Frances H. , Olsen Irwin 
Published: April 2007

AbstractThe modification of titanium (Ti) surfaces by ion‐implantation has previously been reported to enhance osseointegration in vivo. However, the mechanisms underlying the apparently improved biocompatibility of these novel implant materials are unknown. The aim of this study is, therefore, to determine the precise effects of calcium ion‐implanted Ti on the functional activity of bone cells in vitro. Flow cytometry (FCM) and the reverse transcriptase polymerase chain reaction (RT‐PCR) were used to measure the response of bone‐derived cells to key bone‐associated components, including alkaline phosphatase (ALP), bone morphogenetic protein receptor‐1B (BMPR‐1B), bone sialoprotein (BSP), osteonectin (ON), and osteopontin (OPN). FCM analysis showed that BMPR‐1B, BSP and particularly OPN were significantly up‐regulated in MG‐63 cells cultured on Ca‐implanted Ti compared with control nonimplanted Ti. Moreover, the effects of this novel Ca–Ti surface were found to be mediated, at least partly, via gene activation, since RT‐PCR demonstrated the presence of notably elevated levels of OPN mRNA transcripts in the MG‐63 cells. These findings thus show that Ti surfaces implanted with Ca ions can enhance the expression of certain bone‐associated components in vitro, and suggest that this effect could be the cause of the potential benefit of this material on bone in vivo. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Mechanical stimulation of TMJ condylar chondrocytes encapsulated in PEG hydrogels
Authors: Nicodemus Garret D. , Villanueva Idalis , Bryant Stephanie J. 
Published: April 2007

AbstractTemporomandibular joint (TMJ) disorders are most commonly associated with TMJ disc dislocation and osteoarthritis, which can cause erosion of the articular cartilage on the head of the mandibular condyle. There has been little attention focused on treating the damaged condylar cartilage. Therefore, the overall goal of this research is to create a tissue engineering therapy for resurfacing the damaged cartilage of the condylar process with healthy living tissue. Initially, bovine condylar cartilage explants were studied to understand the tissue structure, composition, and gene expression of the native tissue. The cell response of isolated condylar chondrocytes encapsulated in photopolymerized poly(ethylene glycol) hydrogels as a tissue engineering scaffold was examined in the presence and absence of dynamic loading for up to three days of culture. Condylar chondrocyte viability was maintained within the PEG hydrogel constructs over the culture period and loading conditions. Cell response was examined through real‐time RTPCR for collagen types I and II and aggrecan, nitric oxide production, cell proliferation, proteoglycan (PG) synthesis, and spatial distribution of extracellular matrix through histology. This study demonstrates that PEG hydrogel constructs are suitable for condylar chondrocyte encapsulation in the absence of loading. However, dynamic compressive strains resulted in inhibition of gene expression, cell proliferation, and PG synthesis. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Regulation of the pyrimidine biosynthetic pathway in a pyrD knockout mutant of Pseudomonas aeruginosa
Authors: Ralli Pooja , Srivastava Avinash C. , O'Donovan Gerard 
Published: April 2007

AbstractIn research to date, regulation of the pyrimidine biosynthetic pathway at the level of gene expression has not been shown for wild type Pseudomonas aeruginosa. No repression was observed when uracil was added to the growth medium nor was any derepression seen when Pyr– auxotrophs were limited for pyrimidines. Here we show that the addition of uracil to Pseudomonas minimal medium influenced the synthesis of pyrimidine enzymes, while starvation of a pyrimidine knockout mutant (pyrD) elicited derepression of the pyrimidine enzymes. Moreover, the inclusion of orotate in the growth medium induced the synthesis of dihydroorotase in both wild type and mutant. These results suggest that the pyrimidine pathway in P. aeruginosa is regulated at the level of enzyme synthesis in a manner similar to a number of other Pseudomonas species. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ermittlung von Umformgrenzen beim Freiformschmieden
Authors: Schneider V. , Hirt G. , Brethfeld A. , Lehmann G. , Diener U. 
Published: April 2007

AbstractIm Rahmen des von der Arbeitsgemeinschaft industrieller Forschungsvereinigungen (AiF) geförderten Vorhabens „Vermeidung von Oberflächenfehlern beim Freiformschmieden”︁ wurden die umformtechnischen Einflüsse auf die Rissentstehung beim Freiformschmieden untersucht. Dafür standen Gussblöcke zweier hochlegierter Stähle (1.2367 und 1.6957) aus der industriellen Produktion zur Verfügung.Das Umformverhalten beider Stähle wurde durch Stauch‐, Zug‐ und Torsionsversuche für den gesamten Warmumformbereich der Industrieschmiedeprozesse charakterisiert. Dabei zeigte sich, dass der Ort der Probenentnahme bei den vorliegenden Blockabmessungen einen geringen Einfluss auf das Umformverhalten der Werkstoffe hat. Des Weiteren sind Untersuchungen zum Umwandlungs‐ und Ausscheidungsverhalten beider Stähle sowie metallografische Untersuchungen durchgeführt worden. Damit sollte die Ursache für Streuungen von Messwerten im unteren Temperaturbereich der Warmumformung ermittelt werden.Anhand von Stauchversuchen mit Schallemissionsanalyse und deren nummerischer Simulation wurden Rissgrenzschaubilder für den in den Industrieschmiedungen ermittelten risskritischen Umformbereich erstellt. Mit deren Hilfe konnten Umformgrenzen für Laborschmiedeversuche bestimmt werden. Bei den Stauchversuchen mit beiden Werkstoffen streuten die durch Schallemissionsanalyse ermittelten Zeitpunkte, bei denen es zum Rissauftritt an den Proben kam, sehr stark. Daher konnte keine eindeutige Umformgrenze in Form einer zulässigen Höhenabnahme bestimmt werden. Stattdessen wurden für die risskritischen Temperaturen beider Stähle die jeweilige maximal zulässige Höhenabnahme bestimmt, die in Laborschmiedeversuchen unter industrienahen Bedingungen überprüft wurde. Es zeigte sich, dass die ermittelten Grenzen sehr sicher sind, da es zu keinem Rissauftritt während der Schmiedungen beider Werkstoffe kam.
Modeling of Transient Thermal Contact Resistance out of Conjugate Gradient Method
Authors: El‐Sabbagh A.M. , Fieberg C. , El‐Magd E. , Kneer R. 
Published: April 2007

AbstractTemperature profile at contacting pairs of any material combination is crucial in many engineering applications. A new experimental approach is suggested to estimate the contact heat transfer coefficient as well as the thermal contact resistance. This method is based on temperature infrared measurements of contact bodies and then solve the inverse problem with conjugate gradient method. Different affecting parameters are studied namely; surface roughness, presence of interlayer, applied pressure and bodies temperature difference. The time dependant heat transfer coefficients resulting from the proposed method need to be validated by a computer model. Close results are shown with slight deviation by the increase of the applied pressure and the temperature difference.
Die Werkstoffbeanspruchung im Wälzkontakt bei hoher Flächenpressung, ermittelt nach Hertz und nach der EHD‐Strömungshypothese
Authors: Schlicht H. , Broszeit E. 
Published: April 2007

AbstractZur Berechnung der Werkstoffbeanspruchung im Wälzkontakt werden üblicherweise eine Hertz`sche Verteilung der Normalspannungen sowie Tangentialspannungen in der Kontaktfläche angenommen, die den Normalspannungen proportional sind. Diese numerische Beschreibung liegt der Lebensdauerberechnung von Wälzlagern zugrunde.Geht man von den wirklichen Kräfteverteilungen im EHD‐Kontakt aus, so lässt sich mittels der EHD‐Strömungshypothese darlegen, dass in manchen Beanspruchungsfällen die tatsächliche Werkstoffbeanspruchung höher ist.
Multiplicity editing including quaternary carbons: improved performance for the 13C‐DEPTQ pulse sequence
Authors: Bigler Peter , Kümmerle Rainer , Bermel Wolfgang 
Published: April 2007

AbstractAn improved version of the DEPTQ experiment yielding the signal and multiplicity information for all carbon types including the signals of quaternary carbons is proposed. It encompasses all the known advantages of the basic DEPT experiment. In comparison to the original version, signals of the sensitivity‐limiting quaternary carbons are markedly increased: the initial 13C pulse may be adjusted to the Ernst angle, the NOE build‐up period is prolonged by the split relaxation delay and a partial recovery of signal losses due to instrumental imperfections is achieved by the incorporation of composite adiabatic 13C refocussing pulses. Furthermore, pure absorption lineshapes for all carbon types are obtained with only one single scan. These attributes make this experiment attractive for 13C analysis of small molecules (including spectral editing), particularly in high‐throughput analysis laboratories. Copyright © 2007 John Wiley & Sons, Ltd.
The role of multiple drug resistance proteins in fetal and/or placental protection against teratogen‐induced orofacial clefting
Authors: Rawles Lesli Ann , Acuna Diana , Erickson Robert P. 
Published: April 2007

AbstractPrevious studies have shown a role for multiple drug resistance proteins in protecting the fetus from a limited number of teratogens. We have expanded the number of proteins and teratogens examined by comparing the influence of the mdr1a and mdr2 proteins on teratogen‐induced orofacial clefting using their respective knockouts in crosses with the A/J, high susceptibility strain. Western blots identified the presence of mdr1a and possibly mdr2 in the placenta and fetus. Themdr1aknockout, on its unique genetic background showed lower, similar, and higher incidences of clefting compared to A/J for Dilantin, hydrocortisone (HC), and 6‐aminonicotinamide (6‐AN), respectively. Themdr2knockout did not affect 6‐AN clefting when compared to A/J. In reciprocal crosses, when corrected for increased spontaneous clefting, maternally inherited A/J susceptibility genes predominated over the effects of the maternal absence of mdr1a (with 6‐AN). Unlike mdr1a, which had a direct effect in the fetus as shown by genotyping of affected versus unaffected fetuses, an effect of mdr2 in the fetus was not found. Themdr1aknockout was backcrossed to the A/J inbred strain for 11 generations (congenics) to eliminate genetic background effects. Reciprocal crosses showed no maternal effect from the lack ofmdr1a, confirming that mdr1a expression in the fetus, rather than the placenta, protects the fetus from teratogens. Mdr2 seems not to be involved in the protection of the fetus from teratogens. Mol. Reprod. Dev. 74: 1483–1489, 2007. © 2007 Wiley‐Liss, Inc.
Inapproximability results for the inverse shortest paths problem with integer lengths and unique shortest paths
Authors: Bley Andreas 
Published: April 2007

AbstractWe study the complexity of two inverse shortest paths (ISP) problems with integer arc lengths and the requirement for uniquely determined shortest paths. Given a collection of paths in a directed graph D = (V, A), the task is to find positive integer arc lengths such that the given paths are uniquely determined shortest paths between their respective terminals. In the first problem we seek for arc lengths that minimize the length of the longest of the prescribed paths. In the second problem, the length of the longest arc is to be minimized. We show that it is 𝒩𝒫‐hard to approximate the minimal longest path length within a factor less than 8/7 or the minimal longest arc length within a factor less than 9/8. This answers the (previously) open question whether these problems are 𝒩𝒫‐hard or not. We also present a simple algorithm that achieves an 𝒪(∣V∣)‐approximation guarantee for both variants. Both ISP problems arise in the planning of telecommunication networks with shortest path routing protocols. Our results imply that it is 𝒩𝒫‐hard to decide whether a given path set can be realized with a real shortest path routing protocol such as OSPF, IS‐IS, or RIP. © 2007 Wiley Periodicals, Inc. NETWORKS, Vol. 50(1), 29–36 2007
Hardness of robust network design
Authors: Chekuri C. , Shepherd F.B. , Oriolo G. , Scutellá M.G. 
Published: April 2007

AbstractThe authors settle the complexity status of the robust network design problem in undirected graphs. The fact that the flow‐cut gap in general graphs can be large, poses some difficulty in establishing a hardness result. Instead, the authors introduce a single‐source version of the problem where the flow‐cut gap is known to be one. They then show that this restricted problem is coNP‐Hard. This version also captures, as special cases, the fractional relaxations of several problems including the spanning tree problem, the Steiner tree problem, and the shortest path problem. © 2007 Wiley Periodicals, Inc. NETWORKS, Vol. 50(1), 50–54 2007
A cut‐cell non‐conforming Cartesian mesh method for compressible and incompressible flow
Authors: Pattinson J. , Malan A. G. , Meyer J. P. 
Published: April 2007

AbstractThis paper details a multigrid‐accelerated cut‐cell non‐conforming Cartesian mesh methodology for the modelling of inviscid compressible and incompressible flow. This is done via a single equation set that describes sub‐, trans‐, and supersonic flows. Cut‐cell technology is developed to furnish body‐fitted meshes with an overlapping mesh as starting point, and in a manner which is insensitive to surface definition inconsistencies. Spatial discretization is effected via an edge‐based vertex‐centred finite volume method. An alternative dual‐mesh construction strategy, similar to the cell‐centred method, is developed. Incompressibility is dealt with via an artificial compressibility algorithm, and stabilization achieved with artificial dissipation. In compressible flow, shocks are captured via pressure switch‐activated upwinding. The solution process is accelerated with full approximation storage (FAS) multigrid where coarse meshes are generated automatically via a volume agglomeration methodology. This is the first time that the proposed discretization and solution methods are employed to solve a single compressible–incompressible equation set on cut‐cell Cartesian meshes. The developed technology is validated by numerical experiments. The standard discretization and alternative methods were found equivalent in accuracy and computational cost. The multigrid implementation achieved decreases in CPU time of up to one order of magnitude. Copyright © 2007 John Wiley & Sons, Ltd.
Graft versus leukemia effect against juvenile myelomonocytic leukemia after unrelated cord blood transplantation
Authors: Tanoshima Reo , Goto Hiroaki , Yanagimachi Masakatsu , Kajiwara Ryosuke , Kuroki Fumiko , Yokota Shumpei 
Published: April 2007

AbstractA 13‐month‐old female underwent unrelated cord blood transplantation (CBT) for juvenile myelomonocytic leukemia (JMML). In spite of progression of the disease after a conditioning regimen with high‐dose chemotherapy, a complete remission was induced in concordance with development of acute GVHD after reduction of the immunosupressant. She has been in complete remission for 1 year after transplantation. This case illustrates that CBT can provide a potent graft versus leukemia (GVL) effect against JMML. Pediatr Blood Cancer 2008;50:665–667. © 2007 Wiley‐Liss, Inc.
Depressive symptoms and SSRI use in pediatric oncology patients
Authors: Kersun Leslie S. , Elia Josephine 
Published: April 2007

AbstractThis review of depressive symptoms in pediatric cancer patients describes the challenge of recognizing depression in this group, prevalence, risk factors, and treatment, primarily with the selective serotonin reuptake inhibitors (SSRIs). Pediatric oncologists prescribe SSRIs, but there is limited data regarding their use in this setting. Adverse effects, pharmacokinetics and metabolism of SSRIs are reviewed to provide a reference for physicians and inform choices for SSRI prescription. Ongoing research includes incorporation of routine screening measures for depression and future studies might focus on physician recognition and prospectively evaluating treatment for children with cancer and depressive symptoms. Pediatr Blood Cancer 2007;49:881–887. © 2007 Wiley‐Liss, Inc.
The role of academia and the research community in assisting the food and drug administration to ensure U.S. drug safety
Authors: Re Vincent Lo , Strom Brian L. 
Published: April 2007

AbstractPurposeAcademia can play a prominent role in the drug safety arena, unique from that of industry, and a clearer articulation of how it could positively influence the current system is needed. We sought to examine ways that academia could expand its role in U.S. drug safety.MethodsAn ad hoc meeting of academic experts in drug safety and risk management was convened at the Institute of Medicine (IOM) in Washington, D.C.ResultsAcademia should develop a stronger partnership with the Food and Drug Administration (FDA) to increase research on regulatory issues and public health questions and facilitate the prioritization of critical issues on drug safety. Such a collaboration could also facilitate the development of a network of academic centers of excellence in pharmacoepidemiology to address drug safety and risk management questions from a public health standpoint in a timely fashion. The development and testing of methodologic innovations on drug safety should also be encouraged.ConclusionsGreater partnership between academia and the FDA could facilitate the prioritization of important issues on drug safety, allow more research questions on drug safety to be answered in a timely fashion, promote the development of networks for answering these questions, and help generate additional research ideas, ultimately providing enormous benefit to the public health. Copyright © 2007 John Wiley & Sons, Ltd.