bluuebunny/crossref_metadata_2025 huggingface dataset:
Kinetic and mechanism of the homogeneous, unimolecular elimination ofα,β‐unsaturated aldehydes in the gas phase
Authors: Chabán Omar Y. , Domínguez Rosa M. , Herize Armando , Tosta María , Cuenca Angela , Chuchani Gabriel
Published: March 2007

The gas phase thermal decarbonylation ofα,β‐unsaturated aldehydes E‐2‐butenal and E‐3‐phenyl‐2‐methylpropenal was studied in a static system over the temperature range 380.5–490.0 °C and pressure range 55.5–150 Torr. The reactions are homogeneous and unimolecular and obey a first‐order rate law. The rate coefficient is represented by the following Arrhenius equations:

The elimination products of 2‐butenal are propene and CO gas, while 3‐phenyl‐2‐methylpropenal producesα‐methylstyrene,cis‐trans‐β‐methylstyrene, indan, and CO gas. Kinetic and thermodynamic parameters suggest these elimination reactions to proceed through a three‐membered cyclic transition state type of mechanisms. However, a two steps mechanisms for the formation of a carbene type of intermediate through a four‐membered cyclic transition structure can not be overlooked. Copyright © 2007 John Wiley & Sons, Ltd.
Effect of nanoscale diamondoids on the thermomechanical and morphological behaviors of polypropylene and polycarbonate
Authors: Ghosh Arun , Sciamanna Steven F. , Dahl Jeremy E. , Liu Shenggao , Carlson Robert M. K. , Schiraldi David A.
Published: March 2007

Nanoscale MolecularDiamond products (various diamondoid materials), obtained from petrochemical feedstocks, have been investigated as additives for polypropylene and polycarbonate. Three of the homologues of this family (diamantane, triamantane, and the [121]tetramantane isomer) have marginal effects on the thermal and mechanical properties of nonpolar/semicrystalline polypropylene. Mixtures of methylated tetramantane nanofillers also increase the stress–strain behavior of polypropylene composites without significantly impacting their glass transition temperatures. The addition of the selected diamondoids to amorphous/moderately polar polycarbonate increases the polymer tensile modulus significantly with marginal increases in the yield stress. The effects of the selected diamondoids on the thermal stability, crystallinity, and optical properties of polypropylene and polycarbonate are also reported. The results for the mechanical properties show that the selected diamondoids behave as plasticizers in polypropylene, whereas in polycarbonate, they act as antiplasticizers without adversely affecting the optical clarity. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1077–1089, 2007
Practical usage of O'Brien's OLS and GLS statistics in clinical trials
Authors: Dallow Nigel S. , Leonov Sergei L. , Roger James H.
Published: March 2007

Multivariate techniques of O'Brien's OLS and GLS statistics are discussed in the context of their application in clinical trials. We introduce the concept of an operational effect size and illustrate its use to evaluate power. An extension describing how to handle covariates and missing data is developed in the context of Mixed models. This extension allowing adjustment for covariates is easily programmed in any statistical package including SAS. Monte Carlo simulation is used for a number of different sample sizes to compare the actual size and power of the tests based on O'Brien's OLS and GLS statistics. Copyright © 2007 John Wiley & Sons, Ltd.
A Measure of Domain of Applicability for QSAR Modelling Based on Intelligent K‐Means Clustering
Authors: Stanforth Robert W. , Kolossov Evgueni , Mirkin Boris
Published: March 2007

The prediction of a biological activity using a Quantitative Structure–Activity Relationship (QSAR) model is valid only if the compound in question is inside the model's domain of applicability. The existing methods for determining the domain of applicability in descriptor space suffer from problems including poor handling of nonconvex training sets and computational inefficiency. In this paper, we propose a cluster‐based approach to modelling the domain of applicability, which may overcome some of the shortcomings of the existing approaches described. We investigate applying an intelligent version of the K‐means clustering algorithm to this problem, modelling the training set as a collection of clusters in the descriptor space. A test compound is assigned ‘fuzzy membership’ of each individual cluster, from which an overall distance may be calculated. Finally, we experimentally assess how this cluster‐based approach compares with the existing methods.
Three‐Dimensional Quantitative Structure–Activity Relationship of MT3 Melatonin Binding Site Ligands: A Comparative Molecular Field Analysis
Authors: Farce Amaury , Dilly Sébastien , Sabaouni Ahmed , Yous Saïd , Berthelot Pascal , Boutin Jean A. , Delagrange Philippe , Renard Pierre , Chavatte Philippe
Published: March 2007

The Three‐Dimensional Quantitative Structure–Activity Relationship (3D‐QSAR) approach using Comparative Molecular Field Analysis (CoMFA) was applied to a series of 39 compounds evaluated as MT3 binding site ligands. The X‐ray crystal structure of MT3/quinone reductase 2 was used to obtain the putative bioactive conformation of these ligands. Five statistically significant models were obtained from the randomly constituted training sets (30 compounds) and subsequently validated with the corresponding test sets (nine compounds). The best predictive model (n=30, q2=0.608, N=3, r2=0.897, s=0.288, F=75.4) can predict inhibitory activity for a wide range of compounds and offers important structural insight into designing MT3 ligands prior to their synthesis.
Exploration of Physicochemical Properties and Molecular Modeling Studies of Furanylamide Analogs as Antituberculosis Agents
Authors: Gupta Revathi A. , Gupta Arun Kumar , Soni Love Kumar , Kaskhedikar S. G.
Published: March 2007

In the present study, an attempt has been made to explore physicochemical requirements of furanylamide analogs for binding with Mycobacterium tuberculosis UDP‐galactopyranose mutase. Sequential Multiple Linear Regression (SEQ‐MLR) technique was used for the development of a quantitative structure–activity relationship. The quality of QSAR models obtained from SEQ‐MLR is in acceptable statistical range (explained variance ranging from 77.0 to 91.3%). The statistical qualities of the SEQ‐MLR equations were judged by the parameters like explained variance (r2adj), correlation coefficient (r), Standard Error of Estimate (SEE), and variance ratio (F) at specified Degrees of Freedom (df). The generated equations were internally validated using the leave‐one‐out technique. The selected equations were further validated using a test set considering a predictive squared correlation coefficient (r2pred). The study suggested the indispensable nature of the nitro group on furanylamide scaffold and decisiveness of the van der Waals volume for the activity. The toxicity of the furanylamide analogs might be reduced by limiting the number of hydrogen acceptor groups. The selectivity of the compounds was supported by 3D‐Molecular Representation of Structure based on Electron Diffraction (3D‐MoRSE) code at 24th signal by atomic weight and the presence of nitro group. The binding of furanylamide analogs in M. tuberculosis UDP‐galactopyranose mutase enzyme was explored with the help of docking. The most stable ligand–enzyme complex of compound 2 showed that a ligand binds in the vicinity of the FAD. The nitro group buried in the positive charged pocket, which comprised of Arg‐261 and Lys‐164, depicted the crucial ionic interaction. The phenyl ring of the ligand plays a key role in the hydrophobic interaction by π–π stacking with Tyr‐366 and Tyr‐328.
Amphiphilic Conjugated Block Copolymers: Synthesis and Solvent‐Selective Photoluminescence Quenching
Authors: Tu Guoli , Li Hongbo , Forster Michael , Heiderhoff Ralf , Balk Ludwig J. , Sigel Reinhard , Scherf Ullrich
Published: March 2007

A novel, amphiphilic, conjugated block copolymer is described, which was prepared by a Suzuki‐type cross‐coupling of 2‐bromo‐[9,9‐bis(2‐ethylhexyl)fluorene]‐7‐pinacolato boronate as an AB‐type monomer and monobromo‐substituted poly[3‐(6‐bromohexyl)thiophene] (Br‐P3BrHT) as a polymeric end capper in the key step. PF‐P3PHT (P2; PF=poly(9,9‐dialkylfluorene); P3PHT=poly[3‐(6‐diethylphosphonato‐hexyl)thiophene]) as the amphiphilic target polymer was then generated in a polymer‐analogous conversion of the alkyl bromide side chains of the PF‐P3BrHT (P1) precursor into polar alkyl phosphonate groups by reaction with triethyl phosphite. P2 shows a strong influence of the solvent polarity on the optical spectra (absorption, emission). Treatment of solutions of P2 in tetrahydrofuran (THF), a nonselective solvent, with increasing amounts of solvents that are selective for the polar polythiophene blocks (water) or the nonpolar polyfluorene blocks (hexane), respectively, results in the formation of two different types of core–shell aggregates, which show rather different optical properties (photoluminescence quenching, excitation energy transfer).
160‐m‐Fachwerkturm für eine Windenergieanlage – Die höchste Windenergieanlage der Welt
Authors: Dehm Joachim
Published: March 2007

In Laasow ca. 20 km westlich von Cottbus wurde die höchste Windenergieanlage der Welt aufgestellt. Sie hat eine Nabenhöhe von 160 m und mißt bis zur obere Flügelspitze bis 205 m. Der Stahlgitterturm der Fa. SeeBa trägt eine 2,5‐MW‐Maschine FL2500 der Fa. Fuhrländer (Bilder 1 und 2). Mit einem prognostizierten Ertrag von gut 7 Mio. kWh Strom im Jahr kann diese Anlage den Jahresverbrauch von 1800 Vier‐Personen‐Haushalten abdecken.

Durch den Vorstoß in diese Höhen werden an die Planer, Statiker, Lieferanten und Monteure besondere Ansprüche gestellt. Hier soll ein kurzer Überblick über die besonderen Anforderungen bei der Statik dieses Turmes erfolgen. Auch die Unterschiede des für das Tragwerk gewählten Gittermastes im Vergleich zu den bisher üblichen Rohrmasten werden herausgestellt.
Neuartige Umbaukonzepte für einen 280 m hohen abgespannten Mast
Authors: Hornburg Stefan M. , Schuh Bernhard
Published: March 2007

Im Zuge einer Optimierung des Antennensystems der Langwellen‐Sendeanlage Europe 1 waren umfangreiche Sanierungs‐ und Verstärkungsmaßnahmen an einem 280 m hohen abgespannten Sendemast erforderlich. Durch den geplanten Umbau und die damit verbundene höhere Belastung des Tragwerks mußten die Eckstiele von drei Schüssen ausgetauscht werden. Dazu wurde der Mast mit Hilfe einer hydraulischen Hebeeinrichtung und einer Gerüstkonstruktion angehoben. Die Gerüstkonstruktion wurde ohne eine direkte Schraubverbindung mit Rohrschellen gleitfest an den Mast geklemmt. Im überbrückten Bereich konnten so die betroffenen Eckstiele ausgebaut und durch stärkere Profile ersetzt werden. Zusätzlich wurde ein neues Isolationskonzept nach dem Fail‐Safe‐Prinzip realisiert. Hierzu wurde eine numerische Simulation durchgeführt, um zu zeigen, welche Auswirkung ein Isolatorbruch auf die Seilkräfte hat.
Seilunterstützte Montageverfahren im Stahl‐ und Anlagenbau
Authors: Einhaus Marco
Published: March 2007

In zunehmendem Maße müssen Arbeiter und Monteure aufgrund von komplizierten Gebäudegeometrien schwierigste Montagesituationen unter ständiger Absturzgefahr meistern. Sicherheit hat dabei höchste Priorität! Ob Architekt, Konstrukteur, Fassadenbauer, Anlagenbetreiber, Bauherr oder Bauleiter – wird die Arbeitsaufgabe unter Absturzgefahr zu diffizil, greift man auf seilunterstützte Arbeitsverfahren zurück.

Unter seilunterstützten Arbeitsverfahren versteht man den Einsatz von Arbeitnehmern, die sich mit persönlicher Schutzausrüstung (Auffanggurt, Verbindungsmittel, Bandfalldämpfer) gegen Absturz an geeigneten Anschlagpunkten sichern bis hin zu Höhenarbeitern, die am Seil frei hängend besondere Montagen in großer Höhe ausführen. Die Höhenarbeiter können unter Anwendung von Seiltechnik an vertikalen, hohen oder stark geneigten Fassaden, Bauten und Strukturen für den Unterhalt, Kontrollarbeiten, kleine Renovierungen, Montagen und Installationen eingesetzt werden.

Seilunterstützte Arbeitsverfahren müssen nach der Deutschen Betriebssicherheitsverordnung (BetriebSichV) mit zwei voneinander unabhängigen Seilen durchgeführt werden. Das heißt, man benötigt ein Zugangs‐ und ein Positionierungsseil. Somit entsteht eine redundante Sicherung, die bei sicherheitsgerechter Anwendung ein Abstürzen unmöglich macht.
Untersuchungen zur Ermüdungsfestigkeit von Paßschrauben beim Abscheren
Authors: Wichtowski Bernard
Published: March 2007

Im Beitrag werden Ergebnisse von Ermüdungsversuchen zum Abscheren der Paßschrauben M16×1 der Klasse 5.8 nach PN‐91/M‐82342 vorgestellt. Die Untersuchungen umfaßten 15 zweischnittige Versuchskörper, die in fünf Belastungsschritten einseitig zyklisch zugbelastet wurden. Die Gleichung der Regressionsgerade wurde aufgrund der Untersuchungsergebnisse mit der Methode der kleinsten Quadrate bearbeitet. Der lineare Korrelationsfaktor wurde berechnet und der Vertrauensbereich bestimmt. Aus der Gleichung der Regressionsgerade für 2·106 Lastzyklen ergab sich eine dauerhafte Ermüdungsfestigkeit Ztj von 215 MPa.
Modelluntersuchungen zur Windeinwirkung auf stählerne Doppelmantelbehälter
Authors: Ziółko Jerzy , Perliński Aleksander
Published: March 2007

Der Beitrag stellt Ergebnisse von Windkanalversuchen mit zylinderförmigen vertikalen Doppelmantelbehältern mit festem und schwimmendem Dach vor. Bei den Windkanalversuchen wurde die Druckverteilung auf die beiden Mäntel und die beiden Dächer gemessen. Analysiert wurden der Einfluß des Abstandes zwischen den Behältermänteln, der Art des Daches und der Lage des schwimmenden Daches auf die Druckbelastung und ihre Verteilung. Die Ergebnisse der Messungen wurden in Form von Druckkennzahl (Cp)‐Diagrammen dargestellt.
Interaktionsdiagramme zum vereinfachten Beulsicherheitsnachweis für die Stahlsorten S 275, S 420 und S 460
Authors: Misiek Thomas
Published: March 2007

Der Beulsicherheitsnachweis für vierseitig gelagerte, unversteifte lange Platten kann nach DIN 18800‐3:1990‐11, Element (204) als vereinfachter Nachweis durch Einhaltung von grenz(b/t)‐Werten geführt werden. Für allein durch Randspannungen σx und τ beanspruchte Platten aus den Stahlsorten S 275, S 420 oder S 460 werden für diesen Nachweis Interaktionsdiagrammen aufbereitet.
A block‐on‐ring tribocorrosion setup for combined electrochemical and friction testing
Authors: Jellesen M.S. , Hansen M.Ø. , Hilbert L.R. , Møller P.
Published: March 2007

The combined action of corrosion and wear can cause degradation of equipment, and thereby financial losses related to the renewal or repair of damaged equipment. In the food industry, metal degradation is a major concern since metal release eventually can cause health risks for consumers. This study describes a block‐on‐ring testing facility used to determine sliding wear, and additionally allowing for electrochemical measurements, such as potentiodynamic polarization curves and potentiostatic monitoring of current and potential. To verify the reliability and reproducibility of this block‐on‐ring tribocorrosion setup, the tribological and electrochemical behaviour of stainless steel sliding against a ceramic ring in sulphuric acid has been determined. Furthermore, a case taken from the food industry has been examined. The study shows that results made on the described block‐on‐ring testing facility are reliable and can provide improved information about material properties when the material is exposed to combined chemical and mechanical degradation. Copyright © 2007 John Wiley & Sons, Ltd.
Diffusion‐weighted magnetic resonance imaging of acute hypoxic‐ischemic cerebral lesions in the survivor of a monochorionic twin pregnancy: case report
Authors: Righini A. , Kustermann A. , Parazzini C. , Fogliani R. , Ceriani F. , Triulzi F.
Published: March 2007

Monochorionic twin pregnancies complicated by the death of one twin are associated with substantial morbidity in the survivor, with a high risk of developing hypoxic‐ischemic brain damage. In this report, we demonstrate how prenatal diffusion‐weighted magnetic resonance imaging detected focal ischemic lesions in the survivor of a monochorionic twin pregnancy within 1–2 days of cotwin death. A very early diagnosis of cerebral ischemic lesions might influence the management of the pregnancy. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Vesico‐ureteral reflux in children with prenatally detected hydronephrosis: a systematic review
Authors: van Eerde A. M. , Meutgeert M. H. , de Jong T. P. V. M. , Giltay J. C.
Published: March 2007

Objective

To investigate the value of prenatally detected hydronephrosis (PNH) as a prognostic factor for vesico‐ureteral reflux (VUR).

Methods

The MEDLINE database was searched for articles on PNH and VUR published between 1980 and 2004. A total of 18 studies were identified and reviewed for various aspects. Results were separated for primary and/or secondary VUR whenever possible, because of the different underlying pathogenic mechanisms.

Results

There was considerable variation between the different studies with respect to methodology and study design. One of the main discrepancies was the way in which postnatal abnormalities were ascertained: by postnatal ultrasound, voiding cystourethrogram (VCUG) alone, or combined or sequential ultrasound and VCUG. Taking these limitations into account, the published data showed there to be a mean prevalence of 15% for postnatal primary VUR after PNH. Of all patients with PNH, 53% had no postnatal anomalies, whereas 29% had other anomalies, such as duplex collecting systems.

Conclusions

Of all infants with PNH, 15% had primary VUR proven postnatally and 53% had no other anomalies detected. We suggest a standardized protocol for future studies, to enable better comparison of follow‐up protocols. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Experimental validation of uterine artery volume blood flow measurement by Doppler ultrasonography in pregnant sheep
Authors: Acharya G. , Sitras V. , Erkinaro T. , Mäkikallio K. , Kavasmaa T. , Päkkilä M. , Huhta J. C. , Räsänen J.
Published: March 2007

Objective

To test the hypothesis that Doppler‐derived (calculated) uterine artery volume blood flow (cQUtA) reflects accurately volume blood flow measured directly (mQUtA) in an experimental setting.

Methods

Five pregnant sheep were instrumented at 122–130 days of gestation under general anesthesia. After a 4‐day recovery period, maternal hemodynamics were varied by administering to the sheep under general anesthesia noradrenaline, beta‐blocker, low oxygen gas mixture, epidural bupivacaine and ephedrine, consecutively. The central venous pressure was obtained with the help of a thermodilution catheter. The mean arterial pressure and acid–base status were monitored using a 16‐gauge polyurethane catheter inserted into the descending aorta via a femoral artery. A 6‐mm transit‐time ultrasonic perivascular flow probe was used to measure the mQUtA. Doppler ultrasonography of the uterine artery was performed and volume blood flow was obtained simultaneously by the transit‐time ultrasonic perivascular flow probe during each phase of the experiment.

Results

A total of 31 observations were made. The mQUtA varied between 90 and 800 (mean ± SD, 419 ± 206) mL/min during the experiments. The corresponding values for the cQUtA were 110 and 900 (mean ± SD, 459 ± 211) mL/min. There was a significant correlation (R = 0.76; P < 0.0001) between mQUtA and cQUtA. The mQUtA correlated positively with Doppler‐derived uterine artery absolute velocities, i.e. peak systolic (R = 0.50; P = 0.004), end‐diastolic (R = 0.53; P = 0.002) and time‐averaged maximum (R = 0.69; P < 0.0001) and time‐averaged intensity weighted mean (R = 0.75; P < 0.0001) velocities.

Conclusion

cQUtA correlates well with volume blood flow measured directly. Doppler‐derived uterine artery absolute blood flow velocities reflect uteroplacental volume blood flow in pregnant sheep. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
False Recognition Of Gross Gynecological Invasive Emergency: the role of three‐dimensional ultrasound imaging
Authors: Pril‐Fuhl A.
Published: March 2007

Addendum

Dr Roberto Romero did not participate in the drafting of the text, nor did he review, approve or endorse this manuscript. This article is not approved or endorsed by Perinatology Research Branch, the National Institute of Child Health and Human Development (NICHD), the National Institutes of Health (NIH), or the Department of Health and Human Services of the USA.
Charge induction in semiconductor detectors with pixellated structure
Authors: Samedov Victor V.
Published: March 2007

Considerable interest is now being attracted to the next generation of compound semiconductor detectors with pixellated structure in application to x‐ray and gamma‐astronomy, nuclear spectroscopy and nuclear medicine. The spatial resolution of this type of detectors is mainly determined by the process of charge induction by carriers on electrodes with pixellated structure. Ramo–Shockley's theorem that uses only the conservation‐of‐energy argument is not applicable to segmented electrodes since it gives only the total charge induced on the electrode, not a fraction that induced on a single pixel. In this work a method for finding the exact analytical solution for the Green function, the electric potential and the induced charge is proposed. This method is applicable to detectors with any real configuration of electrodes. Copyright © 2007 John Wiley & Sons, Ltd.
Mechanism of Alu integration into the human genome
Authors: Chen Jian-Min , Férec Claude , Cooper David N.
Published: March 2007

LINE-1 or L1 has driven the generation of at least 10% of the human genome by mobilising Alu sequences. Although there is no doubt that Alu insertion is initiated by L1-dependent target site-primed reverse transcription, the mechanism by which the newly synthesised 3′ end of a given Alu cDNA attaches to the target genomic DNA is less well understood. Intrigued by observations made on 28 pathological simple Alu insertions, we have sought to ascertain whether microhomologies could have played a role in the integration of shorter Alu sequences into the human genome. A meta-analysis of the 1624 Alu insertion polymorphisms deposited in the Database of Retrotransposon Insertion Polymorphisms in Humans (dbRIP), when considered together with a re-evaluation of the mechanism underlying how the three previously annotated large deletion-associated short pathological Alu inserts were generated, enabled us to present a unifying model for Alu insertion into the human genome. Since Alu elements are comparatively short, L1 RT is usually able to complete nascent Alu cDNA strand synthesis leading to the generation of full-length Alu inserts. However, the synthesis of the nascent Alu cDNA strand may be terminated prematurely if its 3′ end anneals to the 3′ terminal of the top strand’s 5′ overhang by means of microhomology-mediated mispairing, an event which would often lead to the formation of significantly truncated Alu inserts. Furthermore, the nascent Alu cDNA strand may be ‘hijacked’ to patch existing double strand breaks located in the top-strand’s upstream regions, leading to the generation of large genomic deletions.
Validation of Two Methods for Fatty Acids Analysis in Eggs
Authors: Mazalli Mônica R. , Bragagnolo Neura
Published: March 2007

A comparative study between two methods (lipid extraction followed by saponification and methylation, and direct methylation) to determine the fatty acids in egg yolk was evaluated. Direct methylation of the samples resulted in lower fatty acid content and greater variation in the results than the lipid extraction followed by saponification and methylation. The low repeatability observed for the direct HCl methylation method was probably due to a less efficient extraction and conversion of the fatty acids into their methyl esters as compared to the same procedure starting with the lipid extract. As the lipid extraction followed by esterification method was shown to be more precise it was validated using powdered egg certified as reference material (RM 8415, NIST) and applied to samples of egg, egg enriched with polyunsaturated omega‐3 fatty acids (n‐3 PUFA), and commercial spray‐dried whole egg powder.
Insulin‐like growth factor‐I (IGF‐I) inhibits neuronal apoptosis in the developing cerebral cortex in vivo
Authors: Hodge Rebecca D. , D'Ercole A. Joseph , O'Kusky John R.
Published: March 2007

Increased expression of insulin‐like growth factor‐I (IGF‐I) in embryonic neural progenitors in vivo has been shown to accelerate neuron proliferation in the neocortex. In the present study, the in vivo actions of (IGF‐I) on naturally occurring neuron death in the cerebral cortex were investigated during embryonic and early postnatal development in a line of transgenic (Tg) mice that overexpress IGF‐I in the brain, directed by nestin genomic regulatory elements, beginning at least as early as embryonic day (E) 13. The areal density of apoptotic cells (NA, cells/mm2) at E16 in the telencephalic wall of Tg and littermate control embryos was determined by immunostaining with an antibody specific for activated caspase‐3. Stereological analyses were conducted to measure the numerical density (NV, cells/mm3) and total number of immunoreactive apoptotic cells in the cerebral cortex of nestin/IGF‐I Tg and control mice at postnatal days (P) 0 and 5. The volume of cerebral cortex and both the NV and total number of all cortical neurons also were determined in both cerebral hemispheres at P0, P5 and P270. Apoptotic cells were rare in the embryonic telencephalic wall at E16. However, the overall NA of apoptotic cells was found to be significantly less by 46% in Tg embryos. The volume of the cerebral cortex was significantly greater in Tg mice at P0 (30%), P5 (13%) and P270 (26%). The total number of cortical neurons in Tg mice was significantly increased at P0 (29%), P5 (29%) and P270 (31%), although the NV of cortical neurons did not differ significantly between Tg and control mice at any age. Transgenic mice at P0 and P5 exhibited significant decreases in the NV of apoptotic cells in the cerebral cortex (31% and 39%, respectively). The vast majority of these apoptotic cells (>90%) were judged to be neurons by their morphological appearance. Increased expression of IGF‐I inhibits naturally occurring (i.e. apoptotic) neuron death during early postnatal development of the cerebral cortex to a degree that sustains a persistent increase in total neuron number even in the adult animal.
Handedness, eyedness and nasal cycle in children with autism
Authors: Dane Senol , Balci Nese
Published: March 2007

Objective

Autism is referred to as cerebral lateralization abnormality. In this study, the possible relationships among handedness, eyedness and nasal cycle in autism have been investigated.

Materials and methods

Thirty‐seven children with autism and 20 controls were included in the study. The patient group included 27 boys and 10 girls who ranged in age from 5 to 20 years. For hand preference, hand used to write and throw a ball was accepted as dominant hand. For eye preference or dominance, eye used to look through keyhole of a door was accepted as dominant eye. Nasal dominance was assessed by a method of measuring the nasal airflow.

Results

The rates of left‐handedness and left‐eyedness were higher in children with autism compared to normal populations. A majority of children with autism had left nasal dominance.

Conclusion

Autism and early language impairment may be associated with left handedness, eyedness and nasal dominance.
Antepartum transabdominal amnioinfusion
Authors: Chhabra S. , Dargan R. , Nasare M.
Published: March 2007

Objective: To determine the usefulness of antepartum transabdominal amnioinfusion (APTA) in reducing perinatal morbidity and mortality due to oligohydramnios. Methods: In this case‐control study of 100 pregnant women with oligohydramnios, 50 received APTA and 50 were treated conservatively. These controls were matched for age, parity, and pregnancy duration with the case patients. Results: There was a mean 4.02‐cm increase in amniotic fluid index (AFI) after amnioinfusion. Only 18% of case patients required cesarean sections vs. 46% of controls. The perinatal mortality rate was 18% among controls and 4% among case patients, and the difference was significant. Conclusion: Antepartum amnioinfusion is a useful procedure to reduce complications resulting from decreased intra‐amniotic volume. It is especially useful in preterm pregnancies, where the procedure allows for a better perinatal outcome by prolonging the duration of pregnancy.
Uterine electromyogram topography to represent synchronization of uterine contractions
Authors: Jiang Wei , Li Gang , Lin Ling
Published: March 2007

Objective: To image the synchronization of different parts of the uterus in relation to the abdominal surface during uterine contractions using uterine electromyogram topography. Methods: Of the 20 participants, 16 were in active labor at term, 1 was in preterm labor, and 3 were experiencing failed induced labor. The signals simultaneously collected by 16 digitized channels were in the frequency ranges of 0.2 to 0.45 Hz and 0.8 to 3 Hz. Relative energies were calculated for these 2 frequency ranges and imaged by means of interpolation and transformation. Results: Uterine topographic imaging during active labor suggested good synchronization in all participants, except in one of the 3 who were experiencing failed induced labor. Most notably, synchronization was as good in preterm labor as it was in labor at term. Conclusion: Uterine electromyogram topography provided good imaging of the synchronization of uterine contractions, and could be used for further research on uterine contractility during term and preterm labor.
Essure® sterilization associated with endometrial ablation
Authors: Donnadieu A.C. , Deffieux X. , Gervaise A. , Faivre E. , Frydman R. , Fernandez H.
Published: March 2007

Objective: To evaluate the feasibility and the outcome of Essure® sterilization associated with different techniques of endometrial ablation. Method: Retrospective study conducted among 23 women with confirmed menometrorrhagia and with the desire for or the medical need for permanent tubal sterilization. Patients underwent combined hysteroscopic placement of Essure® and hysteroscopic endometrial resection procedures: ThermaChoice® (n = 14), NovaSure® (n = 4), Hydrothermablator® (n = 2) and endometrial resection using monopolar energy (n = 1), or bipolar energy (n = 2). Results: Fallopian tubes were successfully cannulated bilaterally in 87% of the cases (20/23). No adverse event was reported. Adequate bilateral occlusion was confirmed for all patients (20/20) by 3D ultrasound and pelvic X‐ray at a 3‐month follow‐up. Furthermore, 85% of these patients were satisfied with the results of the procedure, all experiencing a significant reduction in menstrual blood loss (Higham blood loss score). Conclusion: Combining EA and hysteroscopic sterilization seems to be feasible and efficient in patients with menometrorrhagia.
Choanal atresia in a Himalayan cat – first reported case and successful treatment
Authors: Khoo Amy ML , Marchevsky Andrew M , Barrs Vanessa R , Beatty Julia A
Published: March 2007

A 2-year-old Himalayan cat was presented for investigation of chronic, persistent, unilateral nasal discharge that was unresponsive to antibiotics. Unilateral choanal atresia was diagnosed on nasopharyngoscopy. Following surgical repair using the transnasal route and temporary stenting all clinical signs resolved. This is the first reported case of choanal atresia in a cat. It serves to alert practitioners to the occurrence of this unusual condition which should be included in the differential diagnoses of upper respiratory tract signs in young cats.
Stirring in three‐dimensional mantle convection models and implications for geochemistry: Passive tracers
Authors: Huang Jinshui , Davies Geoffrey F.
Published: March 2007

Numerical three‐dimensional spherical models of stirring of passive tracers in a convective mantle incorporating plate tectonics, taking account of faster mantle overturning in the past and scaling the model to the Earth, show that the mean ages of MORB and OIB samples obtained from the models are ∼1.7 Ga for a 4.5 Ga Earth, close to the observed apparent lead isotopic age of ∼1.8 Ga. Only ∼3% of the mantle remains unprocessed. The processing time, which is the time for a mass equivalent to Earth's mantle to be processed through melting zones, is equal to the value estimated for the Earth (2.9 Ga). These results are consistent with previous results from two‐dimensional models. A simple physical processing theory reveals that the degree of processing, the residence time of tracers in the mantle, and their age distribution are mainly controlled by the processing time. Comparison with analogous two‐dimensional Cartesian models shows that the geometry, viscosity structure, and vigor of convection have only secondary influence on these results.
Upper mantle structure beneath continents: New constraints from multi‐mode Rayleigh wave data in western North America and southern Africa
Authors: Merrer Sophie , Cara Michel , Rivera Luis , Ritsema Jeroen
Published: March 2007

We estimate the averaged 1‐D shear‐wave velocity of the upper mantle beneath western North America and the Kaapvaal region in southern Africa by inverting dispersion measurements of fundamental and higher Rayleigh modes recorded by ∼2000 km aperture broadband arrays. The overtones at periods exceeding 25 s constrain the averaged 1‐D shear‐wave velocity to 650 km depth across the regional arrays. Our overtone analysis confirms the shear‐wave velocity differences observed in global tomographic models with similar horizontal resolution: the western North American mantle features a prominent low velocity zone at depths 50–200 km, while the shear velocity in the upper 180–200 km of the mantle beneath southern Africa is at least 6% higher than in western North America which we interpret as the expression of a cratonic keel. There is no resolvable difference in shear‐wave velocity between southern Africa and western North America below a depth of about 300 km.
Global statistics of multiple tropopauses from the IGRA database
Authors: Añel Juan A. , Antuña Juan C. , de la Torre Laura , Nieto Raquel , Gimeno Luis
Published: March 2007

We present statistics for the occurrence of multiple tropopauses for the entire globe, derived from the meteorological sounding data contained in the Integrated Global Radiosonde Archive (IGRA). The IGRA is the most comprehensive and largest radiosonde data set compiled to date, with more than 1500 stations and data starting from 1938. Statistics were derived from (a) the IGRA tropopause reports (reported tropopauses) and (b) tropopauses calculated from the sounding profiles reported in the IGRA (calculated tropopauses). This work constitutes a necessary precursor to conducting better research on the phenomena of multiple tropopauses and promotes understanding of the global structure of these events. Among other things, we calculated global counts and the latitudinal distribution of percentages of tropopauses with respect to the number of soundings, percentages of second and third tropopauses with respect to the first tropopause, and mean values of pressure and temperature of multiple tropopauses.
Fault‐related folds above the source fault of the 2004 mid‐Niigata Prefecture earthquake, in a fold‐and‐thrust belt caused by basin inversion along the eastern margin of the Japan Sea
Authors: Okamura Yukinobu , Ishiyama Tatsuya , Yanagisawa Yukio
Published: March 2007

The 2004 mid‐Niigata Prefecture earthquake occurred in a fold‐and‐thrust belt that has been growing since late Pliocene time in a Miocene rift basin along the eastern margin of the Japan Sea. We constructed the trajectory of the subsurface faults responsible for the growth of the folds from the geologic structure and stratigraphy in the source region, assuming that the folds have been growing as fault‐related folds because of inclined antithetic shear with a dip of 85° in the hanging wall above a single reverse fault. The fault trajectory constructed from the fold geometries nearly coincides with the geometries of the source fault of the main shock of the 2004 earthquake revealed by aftershocks, which supports that the rupture was along a geologic fault that has ruptured repeatedly during the last a few million years. A three‐dimensional fault model based on 12 fault trajectories constructed along parallel sections revealed that the main shock occurred on a convex bend in the fault surface and that the southern termination of the aftershock distribution nearly coincides with a concave bend in the fault. The close relation between the source fault and the geologic structure shows that it is possible to construct source fault geometry assuming inclined shear as deformation mechanism of a hanging wall and to infer the rupture areas from geologic data.
Coseismic fault‐related fold model, growth structure, and the historic multisegment blind thrust earthquake on the basement‐involved Yoro thrust, central Japan
Authors: Ishiyama Tatsuya , Mueller Karl , Sato Hiroshi , Togo Masami
Published: March 2007

We use high‐resolution seismic reflection profiles, boring transects, and mapping of fold scarps that deform late Quaternary and Holocene sediments to define the kinematic evolution, subsurface geometry, coseismic behavior, and fault slip rates for an active, basement‐involved blind thrust system in central Japan. Coseismic fold scarps on the Yoro basement‐involved fold are defined by narrow fold limbs and angular hinges on seismic profiles, suggesting that at least 3.9 km of fault slip is consumed by wedge thrust folding in the upper 10 km of the crust. The close coincidence and kinematic link between folded horizons and the underlying thrust geometry indicate that the Yoro basement‐involved fold has accommodated slip at an average rate of 3.2 ± 0.1 mm/yr on a shallowly west dipping thrust fault since early Pleistocene time. Past large‐magnitude earthquakes, including an historic M∼7.7 event in A.D. 1586 that occurred on the Yoro blind thrust, are shown to have produced discrete folding by curved hinge kink band migration above the eastward propagating tip of the wedge thrust. Coseismic fold scarps formed during the A.D. 1586 earthquake can be traced along the en echelon active folds that extend for at least 60 km, in spite of different styles of folding along the apparently hard‐linked Nobi‐Ise blind thrust system. We thus emphasize the importance of this multisegment earthquake rupture across these structures and the potential risk for similar future events in en echelon active fold and thrust belts.
Simulation of a supercellular storm using a three‐dimensional mesoscale model with an explicit lightning flash scheme
Authors: Barthe Christelle , Pinty Jean‐Pierre
Published: March 2007

A complete lightning flash scheme is implemented in the three‐dimensional (3‐D) nonhydrostatic mesoscale model Méso‐NH of the French community. The scheme, which is part of the electrical scheme, follows a new approach with two steps. First, lightning flashes are modeled as bidirectional leaders to mimic the vertical propagation of the initial discharge channels along the electric field. Then, a probabilistic branching algorithm is adapted from the dielectric breakdown concept to reinforce the flash propagation toward distant regions of high charge density but immersed in a weak electric field. This results in a high increase of the total length of the lightning flash channel and also in a better capture of the morphology of intracloud lightning flashes. The electrification and lightning schemes are tested for an ideal case of a supercellular storm. The model succeeds in reproducing the general features of a storm and the electric charge cycle. Sensitivity analyses show that the implementation of a branching stage is necessary and efficient enough to relax the growth of the electric field. The intracloud discharges generated by the model look realistic with a two‐layer horizontal structure extending over tens of kilometers from the triggering area. The lightning flash length and the quantity of charge neutralized are ten times more important when the branching algorithm is taken into account. The main conclusion drawn from this study is the feasibility and the benefit of an advanced treatment of lightning flashes in 3‐D numerical simulations with an electrification scheme.
Observations of 1,1‐difluoroethane (HFC‐152a) at AGAGE and SOGE monitoring stations in 1994–2004 and derived global and regional emission estimates
Authors: Greally B. R. , Manning A. J. , Reimann S. , McCulloch A. , Huang J. , Dunse B. L. , Simmonds P. G. , Prinn R. G. , Fraser P. J. , Cunnold D. M. , O'Doherty S. , Porter L. W. , Stemmler K. , Vollmer M. K. , Lunder C. R. , Schmidbauer N. , Hermansen O. , Arduini J. , Salameh P. K. , Krummel P. B. , Wang R. H. J. , Folini D. , Weiss R. F. , Maione M. , Nickless G. , Stordal F. , Derwent R. G.
Published: March 2007

Ground‐based in situ measurements of 1,1‐difluoroethane (HFC‐152a, CH3CHF2) which is regulated under the Kyoto Protocol are reported under the auspices of the AGAGE (Advanced Global Atmospheric Gases Experiment) and SOGE (System of Observation of halogenated Greenhouse gases in Europe) programs. Observations of HFC‐152a at five locations (four European and one Australian) over a 10 year period were recorded. The annual average growth rate of HFC‐152a in the midlatitude Northern Hemisphere has risen from 0.11 ppt/yr to 0.6 ppt/yr from 1994 to 2004. The Southern Hemisphere annual average growth rate has risen from 0.09 ppt/yr to 0.4 ppt/yr from 1998 to 2004. The 2004 average mixing ratio for HFC‐152a was 5.0 ppt and 1.8 ppt in the Northern and Southern hemispheres, respectively. The annual cycle observed for this species in both hemispheres is approximately consistent with measured annual cycles at the same locations in other gases which are destroyed by OH. Yearly global emissions of HFC‐152a from 1994 to 2004 are derived using the global mean HFC‐152a observations and a 12‐box 2‐D model. The global emission of HFC‐152a has risen from 7 Kt/yr to 28 Kt/yr from 1995 to 2004. On the basis of observations of above‐baseline elevations in the HFC‐152a record and a consumption model, regional emission estimates for Europe and Australia are calculated, indicating accelerating emissions from Europe since 2000. The overall European emission in 2004 ranges from 1.5 to 4.0 Kt/year, 5–15% of global emissions for 1,1‐difluoroethane, while the Australian contribution is negligible at 5–10 tonnes/year, <0.05% of global emissions.
Effect of ducting on radio occultation measurements: An assessment based on high‐resolution radiosonde soundings
Authors: Ao C. O.
Published: March 2007

Recent studies have shown that the presence of elevated ducts in the lower atmosphere has an adverse effect on the inversion of GPS radio occultation data. The problem arises because the microwave refractivity within and below an elevated duct is no longer uniquely determined by the bending angle profile. Applying Abel inversion without a priori knowledge of the duct will introduce a negative bias in the retrieved refractivity profile within and below the duct. In this work, high vertical resolution radiosonde data are used to give a quantitative assessment of the characteristics and effects of ducts, including their frequency of occurrences, heights, and thicknesses at different latitudes and seasons. The negative bias from the Abel‐retrieved refractivity profiles resulting from these ducts is also computed. The results give a strong indication that ducting in the lower troposphere is a frequent phenomenon over the tropics and midlatitudes. The ducts are shown to be predominantly caused by sharp changes in the vertical structure of water vapor. The majority of the ducts are found to be below 2 km, with a median duct layer thickness of about 100 m. The negative refractivity bias is shown to be largest below 2 km, with a median value of about 0.5–1% in the tropics and 0.2–0.5% in midlatitudes. The bias is about a factor of 2–3 smaller between 2 to 3 km and is negligible above 4 km.
Synopsis of the historical development of Schumann resonances
Authors: Besser B. P.
Published: March 2007

The life and work of Winfried Otto Schumann and the historical development of the main ideas leading to the hypothesis of Earth‐ionosphere cavity electromagnetic oscillations are reviewed. The so‐called Schumann resonances are a set of frequencies of electromagnetic waves in the natural cavity formed by a planet's (moon's) surface and its ionosphere, in the extremely low frequency (ELF) range, caused by natural electrical activity of the planet (moon) and/or its atmospheric environment. Additionally, the reception of his work by the contemporary scientific community as well as the experimental evidence for the postulated ELF resonance oscillations is described.
Domain structures in highly (100)-oriented epitaxial Pb(Zr0.35,Ti0.65)O3 thin films
Authors: Kim Yong Kwan , Morioka Hitoshi , Funakubo Hiroshi
Published: March 2007

Epitaxial tetragonal Pb(Zr0.35,Ti0.65)O3 films were grown on SrRuO3(100)∕SrTiO3(100) substrates by metal organic chemical vapor deposition. Their ferroelectric domain structures and microstructure were investigated using synchrotron x-ray diffraction and transmission electron microscopy. Highly a-axis oriented films were obtained by decreasing the compressive thermal strain resulting from the low growth temperature and thick film. The a and c domains were significantly tilted and had fourfold symmetry, and their tilt angles to the substrate normal were ∼0.5° and ∼0.9°, respectively. The film contained three domain structures: an a-c domain structure consisting of a periodic array of twin domains, an a1-a2 domain structure in which the a1 and a2 domains were rotated with respect to each other by 90° about the substrate normal direction, and a bilayer twinning structure coexisting with the a-c domain structure and a1-a2 domain structure. The bottom layer was the a1-a2 domain structure, and the top layer was the a-c domain structure. This bilayer structure may be due to a yet unknown domain evolution mechanism in which the strain of the films is inhomogeneous.
Effects of the permanent dipoles of self-assembled monolayer-treated insulator surfaces on the field-effect mobility of a pentacene thin-film transistor
Authors: Jang Yunseok , Cho Jeong Ho , Kim Do Hwan , Park Yeong Don , Hwang Minkyu , Cho Kilwon
Published: March 2007

In order to investigate the effects of permanent dipoles on insulator surfaces on the electrical properties of organic thin-film transistors, the authors fabricated insulators with various self-assembled monolayers and similar surface energies. Surprisingly, they found that the field-effect mobility of pentacene thin-film transistors increases by a factor of approximately 20 for insulators with an electron-withdrawing group. This remarkable increase in the field-effect mobility is due to the increase in the hole density of the insulator surface that arises from the increased band bending of the insulator/semiconductor interface.
Raman scattering and phase transition in TlGaS2 under pressure
Authors: Pérez F. V. , Cadenas R. , Power C. , González J. , Chervin C. J.
Published: March 2007

Raman scattering measurements under pressure were performed in a single crystal of TlGaS2. The analysis of the Raman spectrum suggests that the symmetry of the compound belongs to the monoclinic system. The obtained spectra were decomposed by using the deconvolution method, and the “mode-Grüneisen parameters” of the external and internal vibrational modes were calculated. A first order phase transition at 7.4GPa and at 10GPa for external and internal modes, respectively, was observed.