bluuebunny/crossref_metadata_2025 huggingface dataset:
Microsphere‐based protease assays and screening application for lethal factor and factor Xa
Authors: Saunders Matthew J. , Kim Heungbok , Woods Travis A. , Nolan John P. , Sklar Larry A. , Edwards Bruce S. , Graves Steven W.
Published: April 2006

Background:

Proteases regulate many biological pathways in humans and are components of several bacterial toxins. Protease studies and development of protease inhibitors do not follow a single established methodology and are mostly protease specific.

Methods:

We have created recombinant fusion proteins consisting of a biotinylated attachment sequence linked to a GFP via a protease cleavage site to develop a multiplexable microsphere‐based protease assay system. Using the proteases lethal factor and factor Xa, we performed kinetic experiments to determine optimal conditions for inhibitor screens and detect known inhibitors using the HyperCyt® flow cytometry system.

Results:

We have demonstrated specific cleavage of lethal factor and factor Xa substrates, optimized screening conditions for these substrates, shown specific inhibition of the proteases, and demonstrated high throughput detection of these inhibitors.

Conclusions:

The assay developed here is adaptable to any site‐specific protease, compatible with high throughput flow cytometry systems, and multiplexable. Coupled with flow cytometry, which provides continuous time resolution and intrinsic resolution of free vs. bound fluorophores, this assay will be useful for high throughput screening of protease inhibitors in general and could simplify assays designed to determine protease mechanism. © 2006 International Society for Analytical Cytology
Does Hurthle cell lesion/neoplasm predict malignancy more than follicular lesion/neoplasm on thyroid fine‐needle aspiration?
Authors: Pu Robert T. , Yang Jack , Wasserman Patricia G. , Bhuiya Tawfiqul , Griffith Kent A. , Michael Claire W.
Published: April 2006

Thyroid fine‐needle aspiration (FNA) is a standard procedure for the clinical triage of thyroid nodules. The diagnosis of an adequately sampled thyroid FNA is generally grouped into three categories: benign, malignant, and indeterminate. The latter group usually includes follicular neoplasm, follicular lesion, and sometimes a more specific diagnosis such as Hurthle cell neoplasm or follicular lesion/neoplasm with Hurthle cell change. Whether a FNA diagnosis of Hurthle cell lesion/neoplasm (HLN) denotes a worse clinical outcome than follicular lesion/neoplasm (FLN) remains controversial. A cohort of 303 thyroid FNA cases with follow‐up thyroidectomy in our institutes was identified, with the follow‐up excision diagnosis compared to the FNA diagnosis in order to address this issue. Of this cohort, 87 cases had an FNA diagnosis of HLN while 216 cases had a diagnosis of FLN. Upon excision, the FNA diagnosis of HLN group had 14 cases of goiter/nodular hyperplasia (16%), 46 cases of adenoma (12 follicular adenoma (14%) and 34 cases of Hurthle cell adenoma (39%)), and 27 cases of carcinoma (31%, 12 papillary carcinoma and 15 Hurthle cell carcinoma). The FLN group had 74 cases of goiter/nodular hyperplasia (34.3%), 8 cases of Hashimoto thyroiditis (3.7%), 73 cases of follicular adenoma (33.8%), one case of granular cell tumor, and 60 cases of carcinoma (27.8%, 46 papillary carcinoma, 12 follicular carcinoma, and 1 Hurthle cell carcinoma and 1 parathyroid carcinoma) upon excision. There is no significant difference in predicting cancer between the two cytology diagnosis groups (HLN versus FLN, 31% versus 27.8%, P = 0.5771). When sorting all the cases by the surgical diagnosis, while comparable for age at diagnosis, the cancer group having the higher proportion of male patients than the non‐cancer group (28.7% versus 16.7%, P = 0.0259). Hurthle cell carcinoma patients are typically older than patients with other cancer diagnoses (59 versus 44, P = 0.0077). Our results suggest that an FNA diagnosis of HLN does not predict more malignancy than FLN. Males and older patients with a HLN FNA diagnosis carry a higher risk of Hurthle cell carcinoma upon thyroidectomy. Diagn. Cytopathol. 2006;34:330–334. © 2006 Wiley‐Liss, Inc.
Infarcted intraductal papilloma of the breast: Cytologic features with stage of infarction
Authors: Ishihara Akinori , Kobayashi Tadao K.
Published: April 2006

Fine‐needle aspiration cytology (FNAC) is being employed with increasing frequency for the pre‐operative diagnostic workup of breast lesions. Although most cases show morphologic features very characteristic of specific entities, rare lesions with infarcted breast can cause problems in interpretation. We present cytologic findings in seven cases of an infarcted intraductal papilloma of the breast (IDPB) that was diagnosed by FNAC, and we also report the correlation of cytological features and stages of infarcted IDPB. In the early stage of infarction, numerous degenerative cells and necrotic debris were demonstrated. Isolated degenerative cells showed columnar, spindle, polygonal and fiber‐like cells, with coagulated and smudged nuclei. Ghost cells were also seen. Extensive necrosis was demonstrated with a few sheets of ductal cells in the mid‐stage of infarction. In the late stage of infarction, clusters of fibroblasts, ductal cells and necrotic debris were found. Knowledge of the characteristic cytologic pattern in different stages of infarcted IDPB may be helpful to suggest the probable pre‐operative diagnosis of those lesions. Familiarity with this entity is important in preventing misdiagnosis of malignancy. Diagn. Cytopathol. 2006;34:373–376. © 2006 Wiley‐Liss, Inc.
Endocervical curetting vs. endocervical brushing as case finding methods
Authors: Maksem John A.
Published: April 2006

This paper focuses on the performance of endocervical curettage (ECC) and intensive endocervical brushing (ECB) (comprising two or more brushings of the endocervix with liquid‐based cytology and cell‐block examination) in the course of colposcopic examination for abnormal gynecological cytology. To assess their relative effectiveness in disease detection, we reviewed the outcomes of 1,824 colposcopic biopsy collections from women who had an index cytology diagnosis of LSIL or higher. Our intent was to gauge the relative success of ECC and ECB as case‐finding procedures in relation to (1) the original cytological diagnosis and (2) the highest (most abnormal) histological diagnosis of the colposcopy study. Our purpose was to determine whether ECB could effectively replace ECC. One thousand five hundred and seven cases of LSILs or higher cases included an ECC along with two or more colposcopic biopsies and 317 cases included an ECB. ECBs were collected into a liquid fixative and processed as both cytology and cell‐block specimens; whereas, ECCs were processed according to standard histological techniques. We found that intensive ECB recapitulates the highest diagnosis of the colposcopy study about 5–8 times as often as that of ECC. Moreover, when calculating the proportion of positive outcomes, we found that cases examined with biopsy and ECC discovered fewer women with CIN 2 or higher among both LSIL and HSIL index cytologies as compared with those of cases examined with biopsy and ECB (9.2% vs. 16.8% for LSIL and 63.7% vs. 72.2% for HSIL cases); and, more negative outcomes were seen among women evaluated with biopsy plus ECC than those with biopsy plus ECB (11.3% vs. 8.1% for LSIL and 4.7% vs. 1.4% for HSIL cases). Our findings suggest that the colposcopic study is optimized when it is performed in conjunction with ECB as opposed to ECC, and that intensive ECB may be superior to ECC. Diagn. Cytopathol. 2006; 34:313–316. © 2006 Wiley‐Liss, Inc.
Inhibin α‐iCre mice: Cre deleter lines for the gonads, pituitary, and adrenal
Authors: Jorgez Carolina J. , De Mayo Francesco J. , Matzuk Martin M.
Published: April 2006

To expand our knowledge of reproductive function, Cre lines to conditionally knockout essential genes in the mouse gonads were generated. Three transgenic lines of inhibin‐α‐iCre mice were designed by fusing the mouse inhibin‐α promoter with a codon‐improved Cre recombinase (iCre). α‐iCre‐line‐3 expressed high levels of Cre in Sertoli and Leydig cells of the testis and low levels in other tissues, making line 3 an appropriate deleter line for genes expressed in somatic cells of the testis. In contrast, α‐iCre‐line‐1 expressed high levels of Cre in granulosa and theca cells of the ovary and very low levels in other tissues, making line 1 a suitable deleter line for genes expressed in somatic cells of the ovary. A third line, α‐iCre‐line‐2, had low levels of Cre in the gonads but high levels in anterior pituitary and adrenal medulla. These lines could be useful to understand reproduction and other processes by establishing conditional knockout mouse models. genesis 44:183–188, 2006. Published 2006 Wiley‐Liss, Inc.
Silicon‐substituted hydroxyapatite thin films: Effect of annealing temperature on coating stability and bioactivity
Authors: Thian E. S. , Huang J. , Best S. M. , Barber Z. H. , Bonfield W.
Published: April 2006

The effect of annealing temperature on the physicochemical and biological characteristics of magnetron cosputtered silicon‐substituted hydroxyapatite (SiHA) thin coatings was studied. Annealing is required to transform as‐sputtered amorphous films into crystalline coatings. A nanocrystalline, single‐phase apatite structure was achieved for coatings heated to 600 or 700°C and, with increasing annealing temperature, the crystallite size increased. Small crystallites were found to be more soluble in the physiological environment but, at the same time, were able to induce early formation of a new apatite layer. A human osteoblast‐like (HOB) cell model was used to evaluate the performance of these annealed SiHA coatings. HOB cells attached and grew well on coatings and, after 42 days in culture, a mineralization process was observed to be taking place, with evidence of calcium phosphate minerals throughout the extracellular matrix. Our findings indicated that an annealing temperature of 600°C is sufficient to achieve crystalline SiHA coatings and exhibiting good chemical stability and bioactivity. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
C‐type natriuretic peptide for reduction of restenosis: gene transfer is superior over single peptide administration
Authors: Pelisek Jaroslav , Fuchs Alexandra T. , Kuehnl Andreas , Tian Wen , Kuhlmann Michael T. , Rolland Pierre H. , Mekkaoui Choukri , Gaedtke Lars , Nikol Sigrid
Published: April 2006

Background

Restenosis is still a significant clinical problem limiting the long‐term therapeutic success following balloon dilation or stent implantation. New approaches are necessary inhibiting neointima formation and simultaneously promoting re‐endothelialization. Therefore, long‐term therapeutic effects of adventitial liposome‐mediated C‐type natriuretic protein (CNP) gene and CNP peptide applications in a porcine model for restenosis post‐angioplasty were investigated.

Methods

For in vitro applications, primary cultures of porcine vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) were used. Gene transfer was performed with cationic lipid DOCSPER [1,3‐dioleoyloxy‐2‐(N5‐carbamoylspermine)propane]. In vivo treatment of pig femoral arteries was adventitial using a needle injection catheter following balloon angioplasty. Arteries were investigated by angiography, Evan's blue staining, histomorphometry, immunohistochemistry, PCR and RT‐PCR.

Results

Using CNP gene transfer in vitro, 29.4 ± 7.2% reduction of cell proliferation in VSMCs was observed. In ECs, the CNP gene did not compromise cellular growth. For the CNP peptide the optimal concentration was 1 mM with 50.7 ± 11.3% reduction of VSMC proliferation and 12.1 ± 5.3% enhancement of growth of ECs. Three weeks following application in vivo complete re‐endothelialization was observed in all treated groups. At 3 months significant reduction of neointima formation was observed using CNP gene vs. CNP peptide (85.9 ± 7.8% vs. 63.3 ± 27.6% reduction, P < 0.05) compared to control treatment.

Conclusion

Periadventitial liposome‐mediated CNP gene transfer in vivo resulted in a significant long‐term reduction of neointima formation without compromising endothelial repair and was superior over single CNP peptide administration. Advantages of CNP are its physiological origin and simultaneous inhibition of VSMC proliferation and promotion of EC growth. Copyright © 2006 John Wiley & Sons, Ltd.
Generation of cell hybrids via a fusogenic cell line
Authors: Cheong Siew Chiat , Blangenois Isabelle , Franssen Jean‐Denis , Servais Charlotte , Phan Vy , Trakatelli Myrto , Bruyns Catherine , Vile Richard , Velu Thierry , Brandenburger Annick
Published: April 2006

Background

Hybrids obtained by fusion between tumour cells (TC) and dendritic cells (DC) have been proposed as anti‐tumour vaccines because of their potential to combine the expression of tumour‐associated antigens with efficient antigen presentation. The classical methods used for fusion, polyethylene glycol (PEG) and electrofusion, are cytotoxic and generate cell debris that can be taken up by DC rendering the identification of true hybrids difficult.

Methods

We have established a stable cell line expressing a viral fusogenic membrane glycoprotein (FMG) that is not itself susceptible to fusion. This cell line has been used to generate hybrids and to evaluate the relevance of tools used for hybrid detection.

Results

This FMG‐expressing cell line promotes fusion between autologous or allogeneic TC and DC in any combination, generating ‘tri‐parental hybrids’. At least 20% of TC are found to be integrated into hybrids.

Conclusions

It is speculated that this tri‐parental hybrid approach offers new possibilities to further modulate the anti‐tumour effect of the DC/TC hybrids since it allows the expression of relevant immunostimulatory molecules by appropriate engineering of the fusogenic cell line. Copyright © 2006 John Wiley & Sons, Ltd.
Mechanical Properties of Blends of Double‐Fullerene End‐Capped Poly(ethylene oxide) and Poly(L‐lactic acid)
Authors: Kai Weihua , Zhao Li , Zhu Bo , Inoue Yoshio
Published: April 2006

Summary: The crystallization behavior and mechanical properties of composites of PLLA and FPEOF were studied using DSC, DMA and tensile strength measurements. For PLLA/FPEOF composites aged at room temperature, when PLLA was amorphous, an astonishing around 100 times increase in the fracture strain with a high modulus was observed. For PLLA/FPEOF composites aged at 90 °C, the mechanical performance of the composites was greatly decreased and the fracture strain did not show much of an increase compared with pure PLLA. A mechanism for the large changes in the mechanical properties of PLLA/FPEOF blends aged at different temperatures was proposed.

Strain‐stress curves of the PLLA/FPEO20F6 composite aged at 90 °C and room temperature.

image

Strain‐stress curves of the PLLA/FPEO20F6 composite aged at 90 °C and room temperature.
Global gene expression profiles associated with retinoic acid‐induced differentiation of embryonal carcinoma cells
Authors: Eifert Cheryl , Sangster‐Guity Niquiche , Yu Li‐Ming , Chittur Sridar V. , Perez Ana V. , Tine John A. , McCormick Paulette J.
Published: April 2006

We have evaluated the effects of retinoic acid (RA) treatment of F9 embryonal carcinoma (EC) cells, which induces differentiation into primitive endoderm, on gene expression patterns. F9 cells were exposed to RA in culture, and global expression patterns were examined with cDNA‐based microarrays at early (8 hr) and later times (24 hr) after exposure. Of the 1,176 known transcripts examined, we identified 57 genes (4.8%) that were responsive to RA at 8 and/or 24 hr: 35 were induced, 20 were repressed, and 2 were differentially regulated at these time points. To determine if our results were dependent on the array technology employed, we also evaluated the response to RA at 24 hr with oligonucleotide‐based arrays. With these more dense arrays (12,488 genes), we identified an additional 353 RA‐regulated genes (2.8%): 173 were upregulated and 180 were downregulated. Thus, a total of 410 genes regulated by RA were identified with roughly equivalent numbers induced or repressed. Although the expression of many genes found on both array platforms was consistent, the results for some genes were disparate. Quantitative PCR studies on a subset of these genes supported the results obtained with the cDNA arrays. Our results confirmed the regulation of several known RA‐responsive genes and we also identified a number of genes not previously known to be RA‐responsive. Those novel genes that were induced presumably contribute to the cellular processes required for a shift from proliferation to differentiation, whereas those new genes that were downregulated may possibly contribute to the maintenance of cell proliferation. Mol. Reprod. Dev. © 2006 Wiley‐Liss, Inc.
Novel multifunctional polymeric materials with predominant cis microstructures derived from α‐norbornenyl macromonomer and stable macroinitiator via ring‐opening metathesis polymerization and atom transfer radical polymerization
Authors: Liaw Der‐Jang , Huang Ching‐Cheng , Ju Jing‐Yang
Published: April 2006

Novel star‐like polymeric materials with high cis content could be obtained by using α‐norbornenyl macromonomers and highly stable macroinitiators derived from an active norbornene derivative [5‐(2‐bromo‐2‐methylpropionylaminomethyl)bicyclo[2.2.1]hept‐2‐ene (NBBrMPAM)], which was synthesized by the reaction of norbornene methylene amine and 2‐bromo‐2‐methylpropionyl bromide. The α‐norbornenyl macromonomer (NBPMMA), which is polymethyl methacrylate containing norbornenyl end group, was prepared by atom transfer radical polymerization (ATRP) using NBBrMPAM as an initiator. Star‐like polynorbornene with high cis microstructure (cis/trans = 72/28) was obtained directly by ring‐opening metathesis polymerization of NBPMMA macromonomer having number molecular weight (Mn) as low as 6.39 × 103. Random ring‐opening metathesis copolymerization of NBPMMA and norbornene derivative containing carbazole group (NBCbz) was carried out at 25 °C by using Ru catalyst [(Cy3P)2Cl2Ru = CHPh, Cy = cyclohexyl, Ph = phenyl]. High cis (cis/trans = 63/37) organo‐soluble star‐like random poly(NBPMMA‐co‐NBCbz) was successfully obtained with high number‐average molecular weight (Mn) of 4.76 × 104 and molecular weight distribution polydispersity index of 1.78. Organo‐soluble comb‐shaped copolymers with MMA could be successfully obtained using ATRP macroinitiator [poly(HNBBrMPAM)] in diluted macroinitiator solution with a concentration less than 3.64 × 10−2 mol.L−1. This is the first ever attempt to prepare novel star‐like organo‐soluble polymeric materials with high cis microstructure via the combination of ring‐opening metathesis polymerization and ATRP. Multimodification could be considered to be carried out by using the functional bromo group at the end of side chains. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3382–3392, 2006
Synthesis and properties of flame‐retardant benzoxazines by three approaches
Authors: Lin Ching Hsuan , Cai Sheng Xiong , Leu Tsu Shang , Hwang Ting Yu , Lee Hao Hsin
Published: April 2006

We propose three approaches to obtain flame‐retardant benzoxazines. In the first approach, we synthesize a novel benzoxazine (dopot‐m) from a phosphorus‐containing triphenol (dopotriol), formaldehyde, and methyl amine. Dopot‐m is copolymerized with a commercial benzoxazine [6′,6‐bis(3‐phenyl‐3,4‐dihydro‐2H‐1,3‐benzoxazineyl)methane (F‐a)] or diglycidyl ether of bisphenol A (DGEBA). The thermal properties and flame retardancy of the F‐a/dopot‐m copolymers increase with the content of dopot‐m. As for the dopot‐m/DGEBA curing system, the glass‐transition temperature of the dopot‐m/DGEBA copolymer is 252 °C, which is higher than that of poly(dopot‐m). The 5% decomposition temperature of the dopot‐m/DGEBA copolymer increases from 323 to 351 °C because of the higher crosslinking density caused by the reaction of phenolic OH and epoxy. In the second approach, we incorporate the element phosphorus into benzoxazine via the curing reaction of dopotriol and F‐a. After the curing, the thermal properties of the F‐a/dopotriol copolymers are almost the same as those of neat poly(F‐a), and this implies that we can incorporate the flame‐retardant element phosphorus into the polybenzoxazine without sacrificing any thermal properties. In the third approach, we react dopo with electron‐deficient benzoxazine to incorporate the element phosphorus. After the curing, the glass‐transition temperatures of polybenzoxazines decrease slightly with the content of dopo, mainly because of the smaller crosslinking density of the resultant polybenzoxazines. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3454–3468, 2006
Structure and separation properties of π‐complex membranes comprising poly(hexamethylenevinylene) and silver tetrafluoroborate
Authors: Kim Jong Hak , Min Byoung Ryul , Won Jongok , Kang Yong Soo
Published: April 2006

Polymer/silver‐ion π‐complex membranes consisting of poly(hexamethylenevinylene) (PHMV) and silver tetrafluoroborate exhibit unusually high separation performance for olefin/olefin and olefin/paraffin mixtures. The formation of π complexes between silver ions and unsaturated CC bonds of PHMV has been confirmed with wide‐angle X‐ray scattering, differential scanning calorimetry, and X‐ray photoelectron spectroscopy. Fourier transform infrared and ultraviolet spectroscopy studies have revealed that silver ions make π complexes with olefins such as 1,3‐butadiene, propylene, and ethylene. Of these three olefins, 1,3‐butadiene has the highest binding affinity with silver ions in dissolved in PHMV, and this results in its higher solubility and permeance. Therefore, the π‐complex membranes exhibit unusually high separation performance for olefin/olefin and olefin/paraffin mixtures. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1434–1441, 2006
Schräglaufkräfte großer Containerkrane mit Schwingenfahrwerken
Authors: Krahwinkel Manuel
Published: April 2006

Im vorliegenden Beitrag wird ein Verfahren zur Berechnung der Schräglaufkräfte großer Containerkrane mit Schwingenfahrwerken vorgestellt. Die Berücksichtigung der Nachgiebigkeit der Fahrwerkskonstruktion stellt eine Erweiterung der aktuellen Vorschriften mit Angaben zur Berechnung von Schräglaufkräften schienengebundener Krane dar und ermöglicht eine wirtschaftliche Bemessung von Kranbahnbalken und Gründung. Die Anwendung wird am Beispiel eines neuen Containerkranes für den Hamburger Hafen gezeigt. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Innsbrucker Mischbautechnologie am Büro‐ und Geschäftsgebäude St. Marx der T‐Mobile in Wien
Authors: Taus Manfred
Published: April 2006

Es wird über die Anwendung der Mischbautechnologie am Büro‐ und Geschäftsgebäude St. Marx in Wien berichtet. Wie schon beim Bau des Millennium Towers und einer Reihe weiterer Hochhausbauten in Österreich und Deutschland wurde nun beim Büro‐ und Geschäftsgebäude der T‐Mobile in Wien die Innsbrucker Mischbautechnologie erfolgreich eingesetzt. Zunächst wird das Projekt allgemein beschrieben und dann die Stahl‐ und Verbundkonstruktion des Bauteiles “Hoher Flügel” näher erläutert. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Schubsteifigkeit zweiseitig gelagerter Stahltrapezbleche
Authors: Dürr Markus , Kathage Karsten , Saal Helmut
Published: April 2006

Die hinsichtlich des vermehrten Fertigungsaufwandes und ihrer Haupttragrichtung in der Regel unterbleibende Lagerung der Längsränder von Trapezprofilen begründet deren zweiseitige Lagerung. Da die technischen Regeln keine Möglichkeit zum Ansatz der Schubsteifigkeit zweiseitig gelagerter Schubfelder geben, die zur Stabilisierung biegedrillknickgefährdeter Träger rechnerisch genutzt werden könnte, wurden Versuche und parametrische Finite‐Element‐Berechnungen durchgeführt, mit denen unter Berücksichtigung der Nachgiebigkeit der Verbindungsmittel an den gelagerten Rändern das Tragverhalten bis zum Versagen untersucht wurde. Die gut mit den Versuchsergebnissen übereinstimmenden Berechnungsergebnisse sind die Grundlage für eine Beziehung, mit der die vom Seitenverhältnis und der Schubsteifigkeit des vierseitig gelagerten Schubfeldes abhängende Abminderung durch den Übergang von einer vierseitigen zu einer zweiseitigen Lagerung auf dem Niveau der Bemessungslasten nach [6] dargestellt wird. Die Versagenslasten betragen ein Vielfaches dieser Bemessungslasten. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ertüchtigung bestehender Stahltragwerke aus der Zeit von 1860 bis 1940
Authors: Lüddecke Falk , Mehdianpour Milad , Graße Wolfgang
Published: April 2006

In Vorbereitung auf das Schweißen alter Baustähle erfolgt eine differenzierte Betrachtung der in der Zeit von 1860 bis 1940 verbauten Stähle hinsichtlich prinzipieller Schweißeignung. Für den Puddelstahl konnte aufgrund der unregelmäßig verteilten lamellaren Schlackeneinschlüsse keine prinzipielle Schweißeignung festgestellt werden. Dagegen weist der Flußstahl in ausgewählten Bereichen des Profilquerschnitts, den Speckschichten, eine prinzipielle Schweißeignung auf. Die Speckschichtdicken sind Streuungen unterworfen. Um trotzdem Aussagen über deren geometrische Ausdehnung treffen zu können, wurden Streuung verursachende Einflußfaktoren – insbesondere die Stahl‐ und die Halbzeugherstellung – untersucht. Anhand von Messungen an Querschnitten wurden Speckschichtdicken und deren Streuungen ermittelt.

Basierend auf den Speckschichtdicken ist eine Anpassung des gewählten Lichtbogenhandschweißverfahrens in Hinblick auf die Einbrandtiefe erforderlich. Hierfür wurden gesonderte Laborversuche durchgeführt, um praxisgerechte Schweißparameter zu entwickeln.

Zur Untersuchung der Eignung einer solchen Schweißverbindung für nicht ruhende Beanspruchungen wurden Ermüdungsversuche an geschweißten Flußstahlproben durchgeführt. Die ermittelten Bruchlastwechselzahlen sind bei gleicher Kerbgrundbeanspruchung und Bauteilform denen heutiger Baustähle ähnlich. Damit wurde gezeigt, daß eine erfolgreiche Schweißung an Flußstählen prinzipiell möglich ist. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Youth leadership and youth development: Connections and questions
Authors: Kress Cathann A.
Published: April 2006

The youth development movement represents a broad trend toward promoting opportunity and resilience over preventing delinquency and failure. While the topic of youth leadership is clearly relevant to this movement, the connection between the two topics remains for the most part unexplored and undefined. With this chapter we examine the ways that youth leadership connects to the much broader context of the youth development movement.
Anytown: NCCJ's youth leadership experience in social justice
Authors: Matsudaira Julia , Jefferson Ashley
Published: April 2006

The National Conference for Community and Justice is a national organization whose mission is fighting bias, bigotry, and racism in the United States. Camp Anytown, a four‐day residential education program for high school students, is one of the organization's primary programs devoted to youth leadership.
Arts‐based leadership: Theatrical tributes
Authors: Soumerai Eve Nussbaum , Mazer Rachel
Published: April 2006

As an independent educator, Eve Nussbaum Soumerai has developed numerous theatrical tributes to inspirational historical figures (Anne Frank, Martin Luther King Jr., and the Dalai Lama, for example). By participating in these productions, young people learn about the lives of these figures and share these stories with large numbers of their peers. Soumerai uses the process of developing and performing these plays as a form of youth leadership education.
Succession of sessile organisms on experimental plates immersed in Nabeta Bay, Izu Peninsula, Japan III. Temporal changes in community structure
Authors: Hirata Tetsu
Published: April 2006

From percentage covers of sessile organisms obtained over about 3 yr by suspending concrete plates at depths of 1.0, 2.5, 4.0 and 5.5 m in Nabeta Bay, Shimoda, Pacific coast of Japan, changes of five indices of community structure, i.e. number of species (S), Shannon‐Weaver diversity (H′), evenness (J′), McNaughton's dominance (MD) and Horn's similarity (HS), were investigated throughout succession. Colonization curves became horizontal after reaching a maximum at 6 months after immersion at all depths. The number of species appeared to approach equilibrium during the first year of immersion. In the period from 13 to 37 months after immersion, the five indices indicated that communities at the upper two depths had stabilized structures within a limited range of variation, as represented by low HS values, whereas those at the lower two depths had simplified structures, as indicated by low S or H′ values. Furthermore, the results of cluster analysis of samples at four depths indicated that 13 to 37‐month communities at the upper two depths had advanced, converged structures, whereas those at the lower depths had young, non‐converged structures. The stability of community structure observed at the upper two depths could be due to domination of two long‐lived species, the kelp Eisenia bicyclis and the oyster Crassostrea nippona. On the other hand, the simplification of community structure at the lower two depths seems to be due to reduced domination of these two species as a result of disturbances such as scouring by sand.
Spatial relationship among individuals of the Japanese lacertid Takydromus tachydromoides (Sauria, Lacertidae)
Authors: Takeishi Masayoshi , Ono Yuiti
Published: April 2006

The home range of Takydromus tachydromoides was studied in a grassland area from April 1977 to November 1978. The mean size of home range did not differ markedly between sexes; 136.5 m2 for males and 130.8 m2 for females. Home ranges of adults overlapped greatly in each sex, and the lizard was considered to be non‐territorial. Individuals showed return movement to a definite area (sleeping site) within the home range, and the home range did not shift within a year or between years. Characteristics of the home range of this grassland‐inhabiting lizard were discussed in relation to resource abundance and predation pressure.
The ecological pollination syndromes of insect‐pollinated plants in an alpine meadow
Authors: Yumoto Takakazu
Published: April 2006

The insect pollination of an alpine plant community consisting of herbs and shrubs, was observed on Mt. Kisokoma‐ga‐take, central Honshu, Japan. There were two main groups of pollinators, syrphid flies and bumble bees. Although some shrubs were visited by both types of insects, other shrubs and the herbs were visited by either syrphid flies or bumble bees. Two types of herbs categorized by the difference of flower‐visiting insects, the Syrphid‐type and the Bombus‐type, exhibited some clearly contrasting ecological characteristics such as the flowering behavior of individual plants, spatial distribution of the plant populations and segregation of flowering phenology at the community level. The Syrphid‐type herbs were densely distributed throughout wide areas in the tall herb stand, and all the flowers borne by an individual plant bloomed simultaneously. Each species did not markedly segregate its flowering time from that of other species of the same type. The Bombus‐type herbs were distributed locally and/or at low density, and the individual flowers borne by an individual plant showed staggered flowering times. Each species had a more strictly segregated flowering time. These ecological characteristics of these two flower types seemed to be related to the behavioral characteristics of their pollinators.
Jacob Boehme and Paul Tillich: a reassessment of the mystical philosopher and systematic theologian
Authors: PETERSON DANIEL J.
Published: April 2006

Jacob Boehme, the seventeenth-century mystical philosopher, had a significant influence upon Paul Tillich. In this article I offer a reassessment of the relationship between these two thinkers by arguing for an orthodox interpretation of Boehme's doctrine of God that links him more closely with Tillich than recent commentators have suggested. Specifically, I show how Boehme and Tillich stand united against the heterodox Hegel in their presentation of a dynamic process of divinity's self-differentiation and reconciliation that completes itself apart from history rather than within history. This move, I conclude, keeps Boehme and Tillich squarely within the realm of Christian orthodoxy.
Divine omniscience, timelessness, and the power to do otherwise
Authors: RICE HUGH
Published: April 2006

There is a familiar argument based on the principle that the past is fixed that, if God foreknows what I will do, I do not have the power to act otherwise. So, there is a problem about reconciling divine omniscience with the power to do otherwise. However the problem posed by the argument does not provide a good reason for adopting the view that God is outside time. In particular, arguments for the fixity of the past, if successful, either establish His timelessness independently of the problem, or mean that the problem could not be solved by adopting the view that He is timeless.
Persistence and divine conservation
Authors: LAAN DAVID VANDER
Published: April 2006

Plausibly, if an object persists through time, then its later existence must be caused by its earlier existence. Many theists endorse a theory of continuous creation, according to which God is the sole cause of a creature's existence at a given time. The conjunction of these two theses rather unfortunately implies that no object distinct from God persists at all. What strategies for resolving this difficulty are available?
Diurnal and seasonal variability of rainfall in the sub‐Sahel as seen from observations, satellites and a numerical model
Authors: Pinker R. T. , Zhao Y. , Akoshile C. , Janowiak J. , Arkin P.
Published: April 2006

Several climatic parameters are observed at the campus of the University of Ilorin, Ilorin, Nigeria in sub‐Sahel Africa. This climatically important region is in the desert transition zone between the Sahara and the savanna of upper Nigeria and is influenced by the dusty Harmattan wind. It is characterized by persistent conditions with high aerosol loading as well as intense dust outbreaks that affect the local climate. The region is under the influence of the West African Monsoon (WAM) which has exhibited a dramatic change from wet conditions in the 50s and 60s to much drier conditions in the 70s, 80s and 90s. Observations at the Ilorin site were established to provide the Earth Observing System (EOS) Community with high quality climatic data, in particular, related to radiative fluxes and aerosols. The station is located in a region with extreme environmental conditions that are not common at other sites around the globe. For example, at Ilorin observed is the highest aerosol optical depth in the AErosol RObotic NETwork (AERONET) and the site is frequented by biomass burning during the dry season, thus adding new radiative effects to the dust aerosols (Pinker et al., 2001; Pandithurai et al., 2001; Holben et al., 2001, Smirnov et al., 2002). Biomass burning in savanna and forest ecosystems over Africa is believed to contribute about 20% to the global biomass burning. Dynamical models to predict WAM are not accurate in West Africa and tropical Atlantic regions, and are unable to simulate fundamental characteristics of rainfall (diurnal, seasonal and annual cycles). In this study we present an analysis of the diurnal and seasonal variability for several years of rainfall observations. Comparison is made with the output of a numerical model and satellite based estimates. It was found that two observed relative peaks in the annual rainfall distribution are seen in the satellite data but are not detected by the numerical model. It was also shown that the satellite data are able to correctly depict diurnal variability. Both the model predictions and the satellite estimates tend to overestimate the rainfall at this site.
Coupled ocean‐atmosphere response to Indian Ocean warmth
Authors: Li Shuanglin , Hoerling Martin P. , Peng Shiling
Published: April 2006

The coupled ocean‐atmosphere response to Indian Ocean warmth is studied. It is shown with atmospheric models that Indian Ocean warmth forces a positive polarity phase of the North Atlantic Oscillation (NAO), confirming results of previous studies. Coupled model experiments show that this NAO response forces a local air‐sea feedback over the North Atlantic Ocean, which intensifies the NAO response. This enhancement is realized through a positive feedback between the NAO atmospheric circulation anomaly and a tripolar North Atlantic SST pattern, consistent with other studies on North Atlantic air‐sea interactions. It is concluded that the North Atlantic and European climate response to Indian Ocean warming may be considerably greater than hitherto judged from the analyses of atmospheric model experiments alone.
Effects of tidal mixing at the Kuril Straits on North Pacific ventilation: Adjustment of the intermediate layer revealed from numerical experiments
Authors: Nakamura Tomohiro , Toyoda Takahiro , Ishikawa Yoichi , Awaji Toshiyuki
Published: April 2006

The effects of tidal mixing at the Kuril Straits on the North Pacific intermediate layer are investigated using an ocean general circulation model. A comparison of numerical experiments with and without a tidal mixing effect suggests that tidal mixing at the Kuril Straits enhances the ventilation of the North Pacific intermediate layer. The enhanced ventilation results in both freshening and cooling down to ∼27.6 σθ. In particular, the simulated North Pacific Intermediate Water (NPIW) becomes fresher and denser (by 0.3 psu and 0.1 σθ at the maximum) and hence more realistic. The enhanced ventilation is caused both through the supply of the ventilated water from the Kuril Straits, which subsequently spreads along the subarctic and subtropical gyres, and through a modification of the circulation there. The ventilation of the supplied water in turn originates from a combination of tidally enhanced convection in the Okhotsk Sea and downward diffusion at the Kuril Straits as discussed in a previous paper. The former affects the upper part of the NPIW, while the latter is dominant in the denser layers. The circulation is modified through a dynamical adjustment to the mass input into an intermediate layer that is produced by the convergence of diapycnal transport due to the tidally enhanced convection and diffusion. The dynamical adjustment is conducted mainly through Kelvin waves which have the ability to induce intergyre flow along the western boundary and also by eastward moving long Rossby waves. The latter can be present under the influence of the wind‐driven gyres for the second and higher baroclinic modes and act to spread information into the interior directly from the western boundary. As a direct consequence of this adjustment, transport of the ventilated water from the Kuril Straits to the subtropical gyre is enhanced by the intergyre flow along the western boundary, which appears as the southward intrusion of the Oyashio Current. The transported water leaves the coast to encircle the interior, and returns to the western boundary, eventually flowing into the equatorial region. Such equatorward transport associated with mass convergence in the intermediate layer is compensated by transport toward the Kuril Straits in the shallower and deeper layers, thereby enhancing both shallow and deep meridional overturning cells by 2–3 Sv. The above dynamical adjustment is thus central to our understanding of the ventilation of the intermediate layer and provides a basis for the analytical model developed in an accompanying paper.
Satellite chartography of atmospheric methane from SCIAMACHY on board ENVISAT: Analysis of the years 2003 and 2004
Authors: Frankenberg C. , Meirink J. F. , Bergamaschi P. , Goede A. P. H. , Heimann M. , Körner S. , Platt U. , van Weele M. , Wagner T.
Published: April 2006

The UV/Vis/near infrared spectrometer SCIAMACHY on board the European ENVISAT satellite enables total column retrieval of atmospheric methane with high sensitivity to the lower troposphere. The vertical column density of methane is converted to column averaged mixing ratio by using carbon dioxide retrievals as proxy for the probed atmospheric column. For this purpose, we apply concurrent total column measurements of CO2 in combination with modeled column‐averaged CO2 mixing ratios. Possible systematic errors are discussed in detail while the precision error is 1.8% on average. This paper focuses on methane retrievals from January 2003 through December 2004. The measurements with global coverage over continents are compared with model results from the chemistry–transport model TM4. In the retrievals, the north‐south gradient as well as regions with enhanced methane levels can be clearly identified. The highest abundances are found in the Red Basin of China, followed by northern South America, the Gangetic plains of India and central parts of Africa. Especially the abundances in northern South America and the Red Basin are generally higher than modeled. Further, we present the seasonal variations within the investigated time period. Peak values in Asia due to rice emissions are observed from August through October. We expand earlier investigations that suggest underestimated emissions in the tropics. It is shown that these underestimations show a seasonal behavior that peaks from August through December. The global measurements may be used for inverse modeling and are thus an important step towards better quantification of the methane budget.
Glacial abrupt climate changes and Dansgaard‐Oeschger oscillations in a coupled climate model
Authors: Wang Zhaomin , Mysak Lawrence A.
Published: April 2006

There are three fundamental features which characterize large glacial millennial (Dansgaard‐Oeschger) oscillations: (1) the climatic transitions were abrupt and large; (2) the lengths of both interstadials and stadials and the period of Dansgaard‐Oeschger oscillations were not uniform; and (3) there were no large millennial oscillations during an early stage of a glacial period and a peak glacial period. In this modeling study we offer a consistent explanation for these three features by employing an Earth system Model of Intermediate Complexity. We demonstrate that a moderate global cooling forces the Atlantic meridional overturning circulation (MOC) into an unstable state and hence causes the flip‐flop of the Atlantic MOC between a strong mode and a weak mode. The durations of both interstadials and stadials associated with these millennial oscillations are modulated by the changing background climate in qualitative agreement with the observations. In a warm climate the Atlantic MOC is strong and stable, with the deep water formed mainly by intense heat loss to the atmosphere. In a cold climate the Atlantic MOC is weak and stable, and this mode is largely maintained by the process of sea ice brine rejection. Since the Dansgaard‐Oeschger oscillations result from an alternation between these two MOC states during an intermediate phase climate, we conclude that brine rejection plays a necessary role in the oscillations, confirming a hypothesis suggested in some proxy data studies.
Simulation of reactive transport of uranium(VI) in groundwater with variable chemical conditions
Authors: Curtis Gary P. , Davis James A. , Naftz David L.
Published: April 2006

The reactive transport of U(VI) in a shallow alluvial aquifer beneath a former U(VI) mill located near Naturita, CO, was simulated using a surface complexation model (SCM) to describe U(VI) adsorption. The groundwater had variable U(VI) concentrations (0.01–20 μM), variable alkalinity (2.5–18 meq/L), and a nearly constant pH equal to 7.1. U(VI) KD values decreased with increasing U(VI) and alkalinity, and these parameters were more important than sediment variability in controlling KD values. Reactive transport simulations were fit to the observed U(VI) and alkalinity by varying the concentration of U(VI) and alkalinity in recharge at the source area. Simulated KD values varied temporally and spatially because of the differential transport of U(VI) and alkalinity and the nonlinearity of U(VI) adsorption. The model also simulated the observed U(VI) tailing, which would not be expected from a constant KD model. The simulated U(VI) concentrations were sensitive to the recharge flux because of the increased flux of U(VI) to the aquifer. The geochemical behavior of U(VI) was most sensitive to the alkalinity and was relatively insensitive to pH.
Exact three‐dimensional spectral solution to surface‐groundwater interactions with arbitrary surface topography
Authors: Wörman Anders , Packman Aaron I. , Marklund Lars , Harvey Judson W. , Stone Susa H.
Published: April 2006

It has been long known that land surface topography governs both groundwater flow patterns at the regional‐to‐continental scale and on smaller scales such as in the hyporheic zone of streams. Here we show that the surface topography can be separated in a Fourier‐series spectrum that provides an exact solution of the underlying three‐dimensional groundwater flows. The new spectral solution offers a practical tool for fast calculation of subsurface flows in different hydrological applications and provides a theoretical platform for advancing conceptual understanding of the effect of landscape topography on subsurface flows. We also show how the spectrum of surface topography influences the residence time distribution for subsurface flows. The study indicates that the subsurface head variation decays exponentially with depth faster than it would with equivalent two‐dimensional features, resulting in a shallower flow interaction.
Nanoskyscrapers of ferroelectric Bi4Ti3O12
Authors: Takahashi R. , Yonezawa Y. , Nakajima K. , Chikyow T. , Koinuma H. , Matsumoto Y.
Published: April 2006

Self-assembled nanoskyscrapers of ferroelectric Bi4Ti3O12 were fabricated by a bottom-up process: flux-mediated epitaxy using an admixture flux. By combinatorial technique, we have discovered a novel flux, VOx, to assist the unique crystal growth for the in-plane alignment of the long c axis of Bi4Ti3O12 on a SrTiO3(001) substrate. We report on the self-assembly of an isolated epitaxial (110)-oriented Bi4Ti3O12 nanoplate and the direct measurement of the piezoelectric properties by a scanning probe microscope technique. Piezoelectric lattice displacement showed a typical butterfly curve, indicating good ferroelectric property.
Rate constants for the reactions of CO3− and O3− with SO2 from 300to1440K
Authors: Miller Thomas M. , Friedman Jeffrey F. , Williamson John S. , Viggiano A. A.
Published: April 2006

Rate constants for the reactions of CO3− and O3− with SO2 have been measured between 300 and 1440K in a high temperature flowing afterglow apparatus. The CO3− rate constants near to the collision rate at low temperatures and fall by about a factor of 50 with temperature until a broad minimum is reached at 900–1300K. The highest temperature point shows the increasing rate constant. Comparison to drift tube data taken in a helium buffer shows that total energy controls the reactivity, presumably because the reaction goes through a long lived complex even at 1440K. The reaction of O3− with SO2 was studied up to 1400K. The rate constant is collisional until 700K and then decreases with increasing temperature. Rate constants measured at 1300 and 1400K appear to show an increase, but that observation is questionable since O3− could not be made cleanly. The O3− data at 1200K and below show that total energy controls reactivity in that range.