bluuebunny/crossref_metadata_2025_split huggingface dataset:
Repaired R/C members under cyclic loading
Authors: Popov Egor P. , Bertero Vitelmo V. 
Published: March 2007

AbstractAs a part of a general programme at the University of California, Berkeley, in the study of the seismic behaviour of reinforced concrete members, several of the severely cracked test specimens were repaired. The repair was made using either epoxy resin or concrete. In this paper a comparison of the performance of the original specimens with their performance after the repair is given. The repaired specimens were found to behave in a very satisfactory manner except where the injected epoxy had to restore a large region of destroyed bond between the concrete and the reinforcing steel. This condition was found to be particularly prevalent at the interior beam‐column joints of moment‐resisting frames. In such joints the bottom reinforcing steel of a beam tends to slip through a column due to the gradual bond degradation under cyclic loading. This is mainly caused by the formation of plastic hinges at the column faces. In order to avoid this condition, special details of reinforcement are suggested for controlling the location of plastic hinge formation.
Stresses in column‐supported hyperboloidal shells subject to seismic loading
Authors: Gould Phillip L. , Suryoutomo Herman , Sen Subir K. 
Published: March 2007

AbstractThe computation of stresses within a finite element displacement method analysis of a shell of revolution is considered. The common procedure of applying the kinematic and constitutive laws to the displacement functions is examined and justified for models where the displacements are represented by high‐order polynomial expansions. Also, two alternative computational formats within this technique are explored.The influence of the column‐supported base condition on a hyperboloidal shell of revolution is studied with respect to the stresses calculated from a response spectrum analysis. These studies emphasize the importance of accurately modelling the base region of a column‐supported shell such as a hyperbolic cooling tower.
Earthquake response of steel‐framed multistorey buildings with set‐backs
Authors: Humar J. L. , Wright E. W. 
Published: March 2007

AbstractA study is made of the dynamic behaviour of multistorey steel rigid‐frame buildings with set‐back towers. The effects of set‐backs upon the building frequencies and mode shapes are examined. Then the effects of set‐backs on seismic response are investigated by analysing the response of a series of set‐back building frame models to the El Centro ground motion. Finally, the computed responses to the El Centro earthquake are compared with some code provisions dealing with the seismic design of set‐back buildings.The conclusions derived from the study include the following:

The higher modes of vibration of a set‐back building can make a very substantial contribution to its total seismic response; this contribution increases with the slenderness of the tower.
Some of the important response parameters for the tower portion of a set‐back building are substantially larger than for a related uniform building.
For very slender towers, the transition region between the tower and the base may be subjected to very large storey shears.
Antiplane dynamic soil‐bridge interaction for incident plane SH‐waves
Authors: Abdel‐Ghaffar A. M. , Trifunac M. D. 
Published: March 2007

AbstractThe analysis of dynamic soil‐bridge interaction has been performed in three steps. These are:

The analysis of input motions.
The force‐displacement relationships for the foundations.
The dynamic analysis of the structure itself, i.e. the bridge.
Based on the exact solution of the first two steps, the dynamic interaction of a simple two‐dimensional bridge model erected on an elastic half‐space has been investigated for a single span case. The two‐dimensional model under study consists of an elastic shear girder bridge supported by two rigid abutments and rigid foundations which have a circular cross‐section and are welded to the half‐space. It has been shown that the dynamic interaction depends on:

The incidence angle of plane SH‐waves.
The ratio of the rigidity of the girder and the soil.
The ratio of the girder mass to the mass of the rigid abutment‐foundation system.
The span of the bridge.
The dynamic response of the girder and the effect of the radiative damping in the half‐space on the interaction of the girder have been studied.
Improved numerical dissipation for time integration algorithms in structural dynamics
Authors: Hilber Hans M. , Hughes Thomas J. R. , Taylor Robert L. 
Published: March 2007

AbstractA new family of unconditionally stable one‐step methods for the direct integration of the equations of structural dynamics is introduced and is shown to possess improved algorithmic damping properties which can be continuously controlled. The new methods are compared with members of the Newmark family, and the Houbolt and Wilson methods.
Analysis of the weightiness of site effects on reinforced concrete (RC) building seismic behaviour: The Adra town example (SE Spain)
Authors: Navarro Manuel , Vidal Francisco , Enomoto Takahisa , Alcalá Francisco J. , García‐Jerez Antonio , Sánchez Francisco J. , Abeki Norio 
Published: March 2007

AbstractThe damage distribution in Adra town (south‐eastern Spain) during the 1993 and 1994 Adra earthquakes (5.0 magnitude), that reached a maximum intensity degree of VII (European Macroseismic Scale (EMS scale)), was concentrated mainly in the south‐east zone of the town and the most relevant damage occurred in reinforced concrete (RC) buildings with four or five storeys. In order to evaluate the influence of ground condition on RC building behaviour, geological, geomorphological and geophysical surveys were carried out, and a detailed map of ground surface structure was obtained. Short‐period microtremor observations were performed in 160 sites on a 100m × 100m dimension grid and Nakamura's method was applied in order to determine a distribution map of soil predominant periods. Shorter predominant periods (0.1–0.3 s) were found in mountainous and neighbouring zones and larger periods (greater than 0.5 s) in thicker Holocene alluvial fans. A relationship T = (0.049 ± 0.001)N, where T is the natural period of swaying motion and N is the number of storeys, has been empirically obtained by using microtremor measurements at the top of 38 RC buildings (ranging from 2 to 9 storeys). 1‐D simulation of strong motion on different soil conditions and for several typical RC buildings were computed, using the acceleration record in Adra town of the 1993 earthquake. It is noteworthy that all the aforementioned results show the influence of site effects in the degree and distribution of observed building damage. Copyright © 2007 John Wiley & Sons, Ltd.
Similar development of cued and learned home bases in control and hippocampal‐damaged rats in an open field exploratory task
Authors: Lehmann Hugo , Clark Benjamin J. , Whishaw Ian Q. 
Published: March 2007

AbstractSpatial behavior was examined in control rats and rats with neurotoxic‐induced damage of the hippocampus in an open field “exploratory” task. In Experiment 1, rats were placed on a large circular table for 30 min for four consecutive days with a short wall adjacent to the table and a large black box near the edge of the table diametrically opposite to the wall. On the fifth day, rats were given a probe test during which both cues were removed. Over the training exposures both control and hippocampal‐damaged rats formed “home bases,” operationally defined as places where the rats preferentially stopped and spent time, near the cues. When the cues were removed on the probe day, both groups visited, stopped near, and spent time at places adjacent to the cues' previous location. In Experiment 2, rats were given a similar training protocol, but only a single cue was used, which was a small box placed directly on the table that did not block visibility of the entire room. On the fifth day, the box was moved to the other end of the table. Despite the presence of a cued home base, control and hippocampal‐damaged rats remembered the original location of the home base. The results are discussed in relation to the comparative task demands of formal and informal test procedures and with respect to their relevance to understanding the neural basis of spatial behavior. © 2007 Wiley‐Liss, Inc.
Origin and topography of fibers contributing to the fornix in macaque monkeys
Authors: Saunders Richard C. , Aggleton John P. 
Published: March 2007

AbstractThe distribution of neurons contributing to the fornix was mapped by placing the retrograde tracer horseradish peroxidase (HRP) in polyacrylamide gels in different medial to lateral locations within the fornix of three rhesus monkeys (Macaca mulatta). The HRP was placed from 3 to 5 mm caudal to the descending columns of the fornix. Additional information came from a series of rhesus and cynomolgus monkeys (Macaca fasciculata) with anterograde tracer injections in the medial temporal lobe. The hippocampal formation, including the subiculum and presubiculum, together with the entorhinal cortex (EC) and perirhinal cortex (area 35) contribute numerous axons to the fornix in a topographical manner. In contrast, the lateral perirhinal cortex (area 36) and parahippocampal cortical areas TF and TH only contained a handful of cells labeled via the fornix. The medial fornix originates from cells in the caudal half of the subiculum, the lamina principalis interna of the caudal half of the presubiculum, and from the perirhinal cortex (area 35). The intermediate portion of the fornix (i.e., that part midway between the midline and most lateral parts of the fornix) originates from cells in the rostral half of the subiculum and prosubiculum, the anterior presubiculum (only from the lamina principalis externa), the caudal presubiculum (primarily from lamina principalis interna), the rostral half of CA3, the EC (primarily 28I and 28M), and the perirhinal cortex (area 35). The lateral parts of the fornix arise from the rostral EC (28L only) and the most rostral portion of CA3. Subcortically, the medial septum, nucleus of the diagonal band, supramammillary nucleus, lateral hypothalamus, dorsal raphe nucleus, and the thalamic nucleus reuniens all send projections through the fornix, which presumably terminate in the hippocampus and adjacent parahippocampal region. These results not only help to define those regions that project via the fornix, but also reveal those subcortical projections to the hippocampal formation most likely to rely entirely on nonfornical pathways. Published 2007 Wiley‐Liss, Inc.
Flexible use of proximal objects and distal cues by hippocampal place cells
Authors: Renaudineau Sophie , Poucet Bruno , Save Etienne 
Published: March 2007

AbstractThe purpose of the present experiment was to examine how distal cues and proximal objects interact to control firing fields. In a previous study, Shapiro et al. (1997) Hippocampus 7:624–642, suggested that hippocampal place cell firing is controlled by distal cues and proximal floor inserts in a flexible and hierarchical fashion. Control exerted by the combined set of cues prevailed over control by distal cues, which itself prevailed over control by proximal cues. Here, we examined the generality of this hierarchy in the use of cues. Place cells were recorded as rats performed a pellet chasing task on a platform containing three proximal objects, surrounded by a curtain where three visual stimuli were hung. A double rotation of distal and proximal cue sets producing a 180° mismatch revealed noncoherent responses of place cells. Most fields were controlled by the configuration of proximal and distal cues (i.e., remapped). Less often, fields were controlled by specific cues with a majority being controlled by proximal cues, thus suggesting that response hierarchy is modulated by the environment. We finally examined the effect of removing one set of cues after the double rotation session. Half of the fields were controlled by the remaining cues while the other half remapped, thus suggesting a competition between pattern completion and pattern separation processes. Furthermore, cells that were controlled by the remaining cues were mainly those that had remapped in the double rotation session. Our results are compatible with the idea that the flexibility of the place cell system results from an interaction between the sensory properties of individual cell and the attractor networks properties of the whole place cell population. © 2007 Wiley‐Liss, Inc.
A New Synthesis of Pteridines Substituted with Branched and Linear Alkenyl Groups at C(6). The Nitroso‐Ene Reaction of 4‐(Alkenoylamino)‐5‐nitrosopyrimidines
Authors: Zhang Fang‐Li , Schweizer W. Bernd , Xu Ming , Vasella Andrea 
Published: March 2007

AbstractPteridines substituted with a 1,1‐, 1,2‐, or 1,1,3‐substituted alkenyl group (mostly (E)‐configured) at C(6) were synthesized in high yields by the intramolecular nitroso‐ene reaction of 4‐(alkenoylamino)‐2‐amino‐6‐benzyloxy‐5‐nitroso‐ and 4‐(alkenoylamino)‐2,6‐diamino‐5‐nitrosopyrimidines. Thus, the N‐alkenoyl nitrosopyrimidines 4 and 5 provided the pteridines 6 and 7, respectively, characterized by a 1,2‐disubstituted (E)‐alkenyl substituent, the C(4)‐(E)‐geranoyl amide 13 led regio‐ and stereoselectively to the (E)‐1,1,2‐trisubstituted alkenyl‐pteridine 16, and the C(4)‐(Z) isomer 14 led to 17 possessing a 1,1‐disubstituted alkenyl group. The trifluoromethylated butenoyl amide 15 possessing a less highly nucleophilic alkenoyl group reacted more slowly to give the trifluoromethylated vinylpteridine 18. Also the 4‐(alkenoylamino)‐2,6‐diamino‐5‐nitrosopyrimidine 20 reacted more slowly than 4 and 5, and provided the pteridines 23; introduction of additional N‐acyl groups as in 21 and 22 led to a considerably faster ene reaction.The X‐ray crystal structure analysis of the nitroso amide 15 shows eight symmetrically independent molecules in the unit cell. In the crystalline state, the N,N‐dimethylformamidine derivative 9 of 6 forms a centrosymmetric dimer with the 7,8‐lactam group connected by intermolecular hydrogen bonds.
Model Construction for the A–B–C Ring System of Lysergic Acid via Vilsmeier–Haack‐Type Cyclization of 1H‐Indole‐4‐propanoic Acid Derivatives
Authors: Kurokawa Masayuki , Watanabe Toshiko , Ishikawa Tsutomu 
Published: March 2007

AbstractVilsmeier–Haack‐type cyclization of 1H‐indole‐4‐propanoic acid derivatives was examined as model construction for the A–B–C ring system of lysergic acid (1). Smooth cyclization from the 4 position of 1H‐indole to the 3 position was achieved by Vilsmeier–Haack reaction in the presence of K2CO3 in MeCN, and the best substrate was found to be the N,N‐dimethylcarboxamide 9 (Table 1). The modified method can be successfully applied to an α‐amino acid derivative protected with an N‐acetyl function, i.e., to 27 (Table 2); however, loss of optical purity was observed in the cyclization when a chiral substrate (S)‐27 was used (Scheme 5). On the other hand, the intramolecular Pummerer reaction of the corresponding sulfoxide 20 afforded an S‐containing tricyclic system 22, which was formed by a cyclization to the 5 position (Scheme 3).
New Nitrogenous Bisabolene‐Type Sesquiterpenes from a Hainan Sponge Axinyssa aff. variabilis
Authors: Mao Shui‐Chun , Guo Yue‐Wei , van Soest Rob , Cimino Guido 
Published: March 2007

AbstractTwo new uncommon nitrogenous sesquiterpenes, 11‐ethoxy‐3‐formamidotheonellin (1) and 7‐ethoxy‐3‐formamidobisabolane‐8,10‐diene (2), together with two known related sesquiterpenes, 3‐formamidotheonellin (=theonellin formamide; 3) and theonellin isothiocyanate (4), were isolated from the Hainan sponge Axinyssa aff. variabilis. Their structures were determined on the basis of extensive spectroscopic analysis and by comparison of their NMR data with those of known compounds.
Two New Cholestane Bisdesmosides from Reineckia carnea
Authors: Zhang Zhong‐Quan , Chen Jian‐Chao , Zhou Lin , Qiu Ming‐Hua 
Published: March 2007

AbstractThree cholestane bisdesmosides, together with the corresponding aglycone, were isolated from the whole plant of Reineckia carnea. By detailed analysis of the 1D‐ and 2D‐NMR spectra, chemical methods, and comparison with spectral data of known compounds, the structures were determined to be (1β,3β,16β,22S)‐cholest‐5‐ene‐1,3,16,22‐tetrol (1), (1β,3β,16β,22S)‐cholest‐5‐ene‐1,3,16,22‐tetrol 1,16‐di(β‐D‐glucopyranoside) (2), (1β,3β,16β,22S)‐cholest‐5‐ene‐1,3,16,22‐tetrol 1‐[O‐α‐L‐rhamnopyranosyl‐(1→2)‐β‐D‐glucopyranoside] 16‐(β‐D‐glucopyranoside) (3), (1β,3β,16β,22S)‐cholest‐5‐ene‐1,3,16,22‐tetrol 1‐(β‐D‐glucopyranoside) 16‐(3‐O‐acetyl‐β‐D‐glucopyranoside) (4). Compounds 3 and 4 appeared to be new compounds, while compound 1 was isolated for the first from a natural source. Compound 2 was isolated from the genus Reineckia for the first time.
Enantioselective Oxidation of Secondary Alcohols Catalyzed by Soluble Chiral Polymeric [N′,N′‐Bis(salicylidene)ethane‐1,2‐diaminato(2−)]manganese(III) ([MnIII(salen)]) Type Complexes in a Biphasic System
Authors: Sun Wei , Wu Xiaomei , Xia Chungu 
Published: March 2007

AbstractThe polymeric [N′,N′‐bis(salicylidene)ethane‐1,2‐diaminato(2−)]manganese(III) ([MnIII(salen)]) type complexes 1 and 2 were successfully applied to the oxidative kinetic resolution of secondary alcohols. The reaction proceeded readily at room temperature with excellent enantioselectivities of up to 99.9% ee. A variety of substrates, including aromatic and aliphatic alcohols, could be tolerated. The polymeric catalysts could easily be recovered and recycled.
Error analysis for the evaluation of model performance: rainfall–runoff event summary variables
Authors: Pebesma Edzer J. , Switzer Paul , Loague Keith 
Published: March 2007

AbstractThis paper provides a procedure for the evaluation of model performance for rainfall–runoff event summary variables, such as total discharge or peak runoff. The procedure is based on the analysis of model errors, defined as the differences between observed values and values predicted by a simulation model. Model errors can (i) indicate whether and where the model can be improved, (ii) be used to measure the performance of a model, and (iii) be used to compare model simulations. In this paper, both statistical and graphical methods are used to characterize model errors. We explore model recalibration by relating model errors to the model predictions, and to external, independent variables. The R‐5 catchment data sets that we used in this study include summary variables for 72 rainfall–runoff events. The simulations used in this study were previously conducted with the quasi‐physically based rainfall–runoff model QPBRRM for 11 different characterizations of the R‐5 catchment, each with increasing information or a refined spatial discretization of the overland flow planes. This paper is about proposing model diagnostics and not about procedures for using diagnostics for model modification. Copyright © 2007 John Wiley & Sons, Ltd.
Improved anti‐cancer effect of interferon gene transfer by sustained expression using CpG‐reduced plasmid DNA
Authors: Kawano Hiroki , Nishikawa Makiya , Mitsui Masaru , Takahashi Yuki , Kako Keiko , Yamaoka Kiyoshi , Watanabe Yoshihiko , Takakura Yoshinobu 
Published: March 2007

AbstractPlasmid DNA (pDNA) expressing mouse interferon (IFN)‐β or IFN‐γ (pCMV‐Muβ and pCMV‐Muγ, respectively) has been shown to be effective in inhibiting the growth of colon carcinoma CT‐26 cells in the liver (Kobayashi et al., Molecular Therapy 2002;6:737–44). The therapeutic effect of such IFN gene transfer could be significantly increased by the sustained expression of IFNs. In the present study, CpG‐reduced pDNA encoding IFN‐β or IFN‐γ (pGZB‐Muβ and pGZB‐Muγ, respectively) was constructed. pCMV‐Muβ and pCMV‐Muγ were used as conventional CpG‐replete pDNAs. Each pDNA was injected into the tail vein of mice by the hydrodynamics‐based procedure. An injection of pGZB‐Muβ resulted in very high IFN‐β activities in the serum for at least 24 hr after injection, whereas the IFN‐β activity after pCMV‐Muβ injection declined quickly. About a 14‐fold greater amount of IFN‐β was produced from pGZB‐Muβ than from pCMV‐Muβ. pGZB‐Muβ markedly inhibited the pulmonary metastasis of CT‐26 cells. Similar, but more marked results were obtained with pGZB‐Muγ: it increased the area under the concentration‐time curve by more than a 60‐fold and the mean residence time of IFN‐γ 4‐fold compared with pCMV‐Muγ. The survival time of the pGZB‐Muγ‐treated mice was significantly (p < 0.05) longer than that of the saline‐ or pCMV‐Muγ‐treated mice. These results indicate that long‐term expression of IFN can be achieved by CpG‐reduced pDNA and sustained IFN gene expression results in enhanced therapeutic effects of IFN gene transfer against tumor metastasis. © 2007 Wiley‐Liss, Inc.
Silencing of tissue factor pathway inhibitor‐2 gene in malignant melanomas
Authors: Nobeyama Yoshimasa , Okochi‐Takada Eriko , Furuta Junichi , Miyagi Yohei , Kikuchi Kanako , Yamamoto Akifumi , Nakanishi Yukihiro , Nakagawa Hidemi , Ushijima Toshikazu 
Published: March 2007

AbstractTo identify tumor‐suppressor genes inactivated by aberrant methylation of promoter CpG islands (CGIs) in human malignant melanomas, genes upregulated by treatment of cells with a demethylating agent, 5‐aza‐2′‐deoxycytidine (5‐aza‐dC), were searched for using oligonucleotide microarrays in melanoma cell lines, HMV‐I, MeWo and WM‐115. Seventy‐nine known genes with CGIs were identified as being upregulated (≥16‐fold), and 18 of them had methylation of their putative promoter CGIs in 1 or more of 8 melanoma cell lines. Among the 18 genes, TFPI‐2, which is involved in repression of the invasive potential of malignant melanomas, was further analyzed. Its expression was repressed in a melanoma cell line with its complete methylation, and was restored by 5‐aza‐dC treatment. It was unmethylated in cultured neonatal normal epidermal melanocyte, and was induced by ultraviolet B. In surgical melanoma specimens, TFPI‐2 methylation was detected in 5 of 17 metastatic site specimens (29%), while it was not detected in 20 primary site specimens (0%) (p = 0.009). By immunohistochemistry, the 5 specimens with promoter methylation lacked immunoreactivity for TFPI‐2. The results showed that TFPI‐2 is silenced in human malignant melanomas by methylation of its promoter CGI and suggested that its silencing is involved in melanoma metastasis. © 2007 Wiley‐Liss, Inc.
Hypoxia can induce c‐Met expression in glioma cells and enhance SF/HGF‐induced cell migration
Authors: Eckerich Carmen , Zapf Svenja , Fillbrandt Regina , Loges Sonja , Westphal Manfred , Lamszus Katrin 
Published: March 2007

AbstractThe c‐Met receptor and its ligand scatter factor/hepatocyte growth factor (SF/HGF) are strongly overexpressed in malignant gliomas. Signaling through c‐Met as well as exposure to hypoxia can stimulate glioma cell migration and invasion. In several cancer cell types, hypoxia was shown to activate the c‐met promoter, which contains hypoxia inducible factor‐1 (HIF‐1) binding sites. We hypothesized that hypoxia might upregulate c‐Met also in glioma cells. Analyzing 18 different glioblastoma cell lines and 10 glioblastoma primary cultures, we found that in 50% of both the cell lines and the primary cultures c‐Met protein levels were increased following exposure to hypoxia. Upregulation of c‐met in response to hypoxia was also detected at the transcriptional level. In all primary cultures and in 16 of the 18 cell lines (89%), HIF‐1α levels were increased by hypoxia. Transfection of siRNA against HIF‐1α abgrogated the hypoxic induction of c‐Met, suggesting that c‐Met expression is upregulated by a HIF‐1α‐dependent mechanism. Hypoxia sensitized glioblastoma cell lines which showed hypoxic induction of c‐Met to the motogenic effects of SF/HGF. These findings suggest that approximately half of all human glioblastomas respond to hypoxia with an induction of c‐Met, which can enhance the stimulating effect of SF/HGF on tumor cell migration. © 2007 Wiley‐Liss, Inc.