bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design of Brønsted Neutral Organic Bases and Superbases by Computational DFT Methods: Cyclic and Polycyclic Quinones and [3]Carbonylradialenes
Authors: Despotović Ines , Maksić Zvonimir B. , Vianello Robert 
Published: May 2007

AbstractThe gas‐phase proton affinities and basicities of a large number of extended polycyclic π systems possessing a carbonyl oxygen head serving as a basic proton scavenger are explored by using DFT at the B3LYP/6‐311+G(d,p)//B3LYP/6‐31+G(d) level of theory. Some of these neutral organicsuperbases exhibit proton affinities in the range of 264–284 kcal mol–1. In constructing these systems it turned out that a =C(NMe2)2fragment attached to a quinoid six‐membered ring enhanced the basicity to a considerable extent. There is abundant and convincing evidence that protonation triggers strong aromatization of the quinoid rings. Moreover, sequential quinoid rings undergo the aromatic domino effect upon protonation if linearly aligned. Triadic analysis has revealed that highly pronounced basicity in some studied systems is a result of the synergistic action of Koopmans' frozen neutral base ionization energy contribution and subsequent relaxation of the radical cation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Synthesis of the Tetraketide Lactones from the Pikromycin Biosynthetic Pathway
Authors: Oh Hong‐Se , Yun Ji‐Suk , Nah Ki‐Hyun , Kang Han‐Young , Sherman David H. 
Published: May 2007

AbstractSynthesis of tetraketide lactones 2 and 3, which are likely to be produced by a model pikromycin polyketide synthase (PKS), has been investigated. The tetraketide lactones with six‐membered rings, 2a and 2b, were synthesized successfully by the asymmetric aldol reaction, allylation, and the Reformatsky reaction. The attempted synthesis of tetraketide lactones with eight‐membered rings, 3a and 3b, led to the formation of the compounds 2a and 2b. The synthesis of another tetraketide lactone compounds 35 was attempted with the hope that introducing an additional methyl group would lead to a change in thermodynamic stability. However, it produced the corresponding tetraketide lactone 34 with a six‐membered ring. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Multiobjective heuristic approaches to seismic design of steel frames with standard sections
Authors: Ohsaki M. , Kinoshita T. , Pan P. 
Published: May 2007

AbstractSeismic design problem of a steel moment‐resisting frame is formulated as a multiobjective programming problem. The total structural (material) volume and the plastic dissipated energy at the collapse state against severe seismic motions are considered as performance measures. Geometrically nonlinear inelastic time‐history analysis is carried out against recorded ground motions that are incrementally scaled to reach the predefined collapse state. The frame members are chosen from the lists of the available standard sections. Simulated annealing (SA) and tabu search (TS), which are categorized as single‐point‐search heuristics, are applied to the multiobjective optimization problem. It is shown in the numerical examples that the frames that collapse with uniform interstorey drift ratios against various levels of ground motions can be obtained as a set of Pareto optimal solutions. Copyright © 2007 John Wiley & Sons, Ltd.
Stability and accuracy analysis of outer loop dynamics in real‐time pseudodynamic testing of SDOF systems
Authors: Mercan Oya , Ricles James M. 
Published: May 2007

AbstractReal‐time pseudodynamic (PSD) testing is an experimental technique for evaluating the dynamic behaviour of a complex structure. During the test, when the targeted command displacements are not achieved by the test structure, or a delay in the measured restoring forces from the test structure exists, the reliability of the testing method is impaired. The stability and accuracy of real‐time PSD testing in the presence of amplitude error and a time delay in the restoring force is presented. Systems consisting of an elastic single degree of freedom (SDOF) structure with load‐rate independent and dependent restoring forces are considered. Bode plots are used to assess the effects of amplitude error and a time delay on the steady‐state accuracy of the system. A method called the pseudodelay technique is used to derive the exact solution to the delay differential equation for the critical time delay that causes instability of the system. The solution is expressed in terms of the test structure parameters (mass, damping, stiffness). An error in the restoring force amplitude is shown to degrade the accuracy of a real‐time PSD test but not destabilize the system, while a time delay can lead to instability. Example calculations are performed for determining the critical time delay, and numerical simulations with both a constant delay and variable delay in the restoring force are shown to agree well with the stability limit for the system based on the critical time delay solution. The simulation models are also used to investigate the effects of a time delay in the PSD test of an inelastic SDOF system. The effect of energy dissipation in an inelastic structure increases the limit for the critical time delay, due to the energy removed from the system by the energy dissipation. Copyright © 2007 John Wiley & Sons, Ltd.
Footpath morphology and terrain sensitivity on high plateaux: the Mamore Mountains, Western Highlands of Scotland
Authors: Morrocco Stefan M. , Ballantyne Colin K. 
Published: May 2007

AbstractVariations in the morphology of a high‐level footpath are characterized using a new approach that relates footpath morphology to six terrain units defined jointly by two contrasting plant communities (U7 grass–heath communities dominated by Nardus stricta and Carex bigelowii, and U10 moss–heath communities dominated by Carex bigelowii and Racomitrium lanuginosum) and by the contrasting textural characteristics of underlying mineral soils developed on schist, granite and quartzite. All six terrain units are characterized by distinct footpath morphologies. The most critical factor affecting footpath morphology is the shear strength of the vegetation mat and underlying root zone. Vegetation mat shear strength was measured using a specially constructed shear rake. On all three lithologies, median shear strengths for U7 communities significantly exceed those for U10 communities, so that pathways on the former are significantly narrower and deeper than those developed on the latter. Adjacent zones of damaged or modified vegetation cover are also wider on U10 communities. The role of mineral soil (regolith) texture and thus underlying lithology in controlling footpath morphology is more complex. For soils with abundant fines, granite soils have lower shearing resistance than schist soils, and are associated with wider footpaths. Footpaths are also wide on clast‐supported quartzite regolith, which has high shearing resistance: pathways are trapezoidal in cross‐section in areas of U7 vegetation cover, but footpaths are very broad and diffuse in areas of U10 cover. Pathway depths are limited by increasing shear and compressive strength with depth. Implications of these findings for further research and management strategies are discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Localization of human intraparietal areas AIP, CIP, and LIP using surface orientation and saccadic eye movement tasks
Authors: Shikata Elisa , McNamara Adam , Sprenger Andreas , Hamzei Farsin , Glauche Volkmar , Büchel Christian , Binkofski Ferdinand 
Published: May 2007

AbstractIn monkeys, areas in the intraparietal sulcus (IPS) play a crucial role in visuospatial information processing. Despite many human neuroimaging studies, the location of the human functional homologs of some IPS areas is still a matter of debate. The aim of the present functional magnetic resonance imaging (fMRI) study was to identify the distinct locations of specific human IPS areas based on their functional properties using stimuli adapted from nonhuman primate experiments, in particular, surface orientation discrimination and memory guided saccadic eye movements (SEM). Intersubject anatomical variability likely accounts for much of the debate. By applying subject by subject analysis, we can demonstrate that sufficient intersubject anatomical and functional commonalities exist. Both the lateral bank of the anterior part of IPS, the putative human homolog of the area AIP, and the caudal part of the IPS (putative CIP) showed activation related to spatial discrimination of surface orientation. Eye tracking conducted during fMRI data acquisition allowed us to show that both areas were separated by an area related to SEM. This area was located in the middle region of the IPS (most probably including LIP), i.e., similar to the location observed in nonhuman primates. In 10 of 11 subjects our putative CIP activation was located in a medial side branch of the posterior part of the IPS, on the opposite side as described in nonhuman primates, making this landmark a useful anatomical marker for the location of CIP. Hum Brain Mapp 2008. © 2007 Wiley‐Liss, Inc.
Reimbursing insurance carriers: The case of ‘muface’ in the spanish health care system
Authors: Pellisé Laura 
Published: May 2007

AbstractThis article aims at contributing to the analysis of financial incentives in managed competition, on the basis of the literature on procurement and regulation under incomplete information. More specifically, we focus on MUFACE, the publicly funded health care system for Spanish civil servants and dependants. MUFACE makes up an internal market, where competing public and private insurers are reimbursed a flat capitation payment.Some of our results are that theoretically, both pre‐contractual (adverse) selection of insurers contracted by MUFACE, and post‐contractual risk selection of enrollees undertaken by insurers, should occur under flat capitation.
Peritoneal cytology for suspected acute appendicitis: An economic evaluation
Authors: Stewart Richard J. , Perry Karl , Bowie Robert D. , O'Dea Desmond J. 
Published: May 2007

AbstractSuspected acute appendicitis is a common reason for surgery. Unfortunately, diagnosis is not always simple and, in recent years, considerable attention has been devoted to developing better diagnostic techniques. Peritoneal cytology is one such technique. It is simple, minimally invasive, and has been established as clinically effective. This paper reports on an economic evaluation of peritoneal cytology, carried out at Wellington Hospital, New Zealand.The analysis is based on two trials totalling 192 patients. The perspective taken initially is that of a hospital financial manager, seeking to minimise costs. In the first trial, there was a marginal increase in overall cost per person presenting with suspected acute appendicitis, from using the test. In the second, there was a reduction. In both trials there were significant health benefits—unnecessary operations were avoided, and necessary operations done more quickly. Also, the practice developed, in the second trial, of sending patients home immediately following a negative test result. This further increased savings.We then discuss the results from a broader perspective. We conclude that the additional personal benefits—less time convalescing, and lower mortality, on average—ensure that the benefits outweigh the costs of the test.
New objective measurement to characterize the porosity of textile implants
Authors: Mühl Thomas , Binnebösel Marcel , Klinge Uwe , Goedderz Thomas 
Published: May 2007

AbstractThe inflammatory and fibrotic intensity of a foreign body reaction largely depends on the porosity of the implanted material. Furthermore, the size of the pore and its geometry define the capability to allow tissue ingrowth. We present an image analysis system, which allows objectifying in two dimensions the pores' structure and geometry of textile fabrics, that are used to reinforce the abdominal wall or pelvic floor. The porosity of the textile is measured at four samples with differences in structure. The porosity decreases markedly if foreign body response is considered, leading to the definition of an “effective porosity”. Because of the high stiffness of the polymer fibers the elasticity of textile implants usually result from a deformation of the pores, leading to a marked reduction of the effective porosity if a mechanical stress is applied. Further in vivo studies have to investigate, whether the preservation of a high effective porosity under stress may help to improve biocompatibility of textile implants. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2008
The angiogenic effects of Angelica sinensis extract on HUVEC in vitro and zebrafish in vivo
Authors: Lam Hio‐Wa , Lin Hui‐Chao , Lao Sin‐Cheng , Gao Jian‐Li , Hong Si‐Jia , Leong Chi‐Weng , Yue Patrick Ying‐Kit , Kwan Yiu‐Wa , Leung Anskar Yu‐Hung , Wang Yi‐Tao , Lee Simon Ming‐Yuen 
Published: May 2007

AbstractAngiogenesis plays an important role in a wide range of physiological processes such as wound healing and fetal development. Many diseases are associated with imbalances in regulation of angiogenesis, in which it is either excessive or there is insufficient blood vessel formation. Angelica sinensis (AS), commonly used in the prescriptions of Chinese medicine, is a potential candidate for curing such diseases. However, biological effects of AS on angiogenesis and underlying mechanisms are yet to be fully elucidated. This investigation describes the angiogenic effects of AS extract on human endothelial cells (HUVEC) in vitro and zebrafish in vivo. The extract was demonstrated, by XTT assay and microscopic cell counting, to stimulate the proliferation of HUVEC; in addition, flow cytometry analysis indicated that the extract increased the percentage of HUVEC in the S phase. The wound healing migration assay illustrated that a dramatic increase in migration could be measured in AS extract‐treated HUVEC. Meanwhile, the number of invaded cells and the mean tube length were significantly increased in AS extract treatment groups. The extract was also demonstrated to promote changes in subintestinal vessels (SIVs) in zebrafish, one feature of angiogenesis. In addition, AS extract was found by real‐time PCR to enhance vascular endothelial growth factor (VEGF) mRNA expression. In a bead‐based immunoassay, higher levels of p38 and JNK 1/2 expression were also observed in effusions compared with control cells. All results suggest that Angelica sinensis extract can promote angiogenesis, and that the angiogenic effects involve p38 and JNK 1/2 phosphorylation. J. Cell. Biochem. 103: 195–211, 2008. © 2007 Wiley‐Liss, Inc.
Macrophage contribution to the response of the rat organ of Corti to amikacin
Authors: Ladrech Sabine , Wang Jing , Simonneau Lionel , Puel Jean‐Luc , Lenoir Marc 
Published: May 2007

AbstractTransdifferentiation of nonsensory supporting cells into sensory hair cells occurs naturally in the damaged avian inner ear. Such transdifferentiation was achieved experimentally in the cochlea of deaf guinea pigs through Atoh 1 gene transfection. Supporting cells may therefore serve as targets for transdifferentiation therapy. Supporting cells rapidly degenerate after hair cell disappearance, however, limiting the therapeutic window for gene transfer. We studied the time course of ultrastructural and phenotypical changes occurring in Deiters cells (hair cell supporting cells) after ototoxic treatment in the rat. The presence of macrophages in the cochlea was also investigated, to study any deleterious effects they may have on pathologic tissues. One week after treatment most hair cells had disappeared. Deiters cells no longer expressed the glial marker vimentin but instead displayed typical hair cell markers, the calcium binding proteins calbindin and parvalbumin. This suggests that a process of transdifferentiation of Deiters cells into hair cells was activated. By 3 weeks post‐treatment, however, the Deiters cells began to degenerate and by 10 weeks post‐treatment the organ of Corti was degraded fully. Interestingly, a marked increase in macrophage density was seen after the end of amikacin treatment to 10 weeks post‐treatment. This suggests chronic inflammation is involved in epithelium degeneration. Consequently, early treatments with anti‐inflammatory factors might promote supporting cell survival, thus improving the efficacy of more specific strategies aimed to regenerate hair cells from nonsensory cells. © 2007 Wiley‐Liss, Inc.
Metabolomic approach to identifying bioactive compounds in berries: Advances toward fruit nutritional enhancement
Authors: Stewart Derek , McDougall Gordon J. , Sungurtas Julie , Verrall Susan , Graham Julie , Martinussen Inger 
Published: May 2007

AbstractPlant polyphenolics continue to be the focus of attention with regard to their putative impact on human health. An increasing and ageing human population means that the focus on nutrition and nutritional enhancement or optimisation of our foodstuffs is paramount. Using the raspberry as a model, we have shown how modern metabolic profiling approaches can be used to identify the changes in the level of beneficial polyphenolics in fruit breeding segregating populations and how the level of these components is determined by genetic and/or environmental control. Interestingly, the vitamin C content appeared to be significantly influenced by environment (growth conditions) whilst the content of the polyphenols such as cyanidin, pelargonidin and quercetin glycosides appeared much more tightly regulated, suggesting a rigorous genetic control. Preliminary metabolic profiling showed that the fruit polyphenolic profiles divided into two gross groups segregating on the basis of relative levels of cyanidin‐3‐sophoroside and cyanidin‐3‐rutinoside, compounds implicated as conferring human health benefits.
Synthesis of modulation insensitive N‐path filters
Authors: Chang S. , Declaris N. , Newcomb R. W. 
Published: May 2007

AbstractThrough the intermediary of state‐variable equations, realization of an N‐path filter from a prescribed transfer function is obtained. An equivalence is found which shows how passive RC circuits incorporating time‐variable gyrators can be used to realize N‐path filters. It is also proved possible to realize any stable transfer function as an N‐path filter structure and that the system is insensitive to the frequency of the multiplying signals or the frequency of the gyration conductance.„Listen again to this. I have seen moonlight Sometimes the statues leaning over like reeds In the middle of living fruit, – the statues”︁[1,p. 95].
The network equilibrium problem in integers
Authors: Rosenthal R. W. 
Published: May 2007

AbstractIn the usual approach to network equilibrium models, the flow variables are modeled as continuous. When the problem under study involves discrete decision makers each controlling an indivisible unit of flow, another approach is called for. We treat the problem as an n‐person noncooperative game with pure strategies corresponding to feasible paths through the network. It is shown that pure‐strategy Nash equilibria exist and that any solution to an integer‐variable analogue of the usual network equilibrium model is such a Nash equilibrium. It is also shown that when individuals can control more than a single unit of flow and want to minimize the sum of their costs, pure‐strategy Nash equilibria do not necessarily exist.
The Capacitated Minimum Spanning Tree
Authors: Chandy K. M. , Lo Tachen 
Published: May 2007

AbstractThe capacitated minimum spanning tree is an offspring of the minimum spanning tree and network flow problems. It has application in the design of multipoint linkages in elementary teleprocessing tree networks. Some theorems are used in conjunction with Little's branch and bound algorithm to obtain optimal solutions. Computational results are provided to show that the problem is tractable.
Network properties of the ARPA computer network
Authors: Frank H. , Chou W. 
Published: May 2007

AbstractThe ARPA Computer Network, which today links over 60 host computers in more than 40 different locations is a significant advance both in computer systems and data communications. The ARPANET uses a communication technique called packet switching to dynamically select message routes through the network. In this paper, we discuss a number of important properties of the network as well as the techniques used to identify these properties. Among the topics discussed are ARPANET growth, performance sensitivity to traffic variations, incremental costs for adding capacity and new sites, peak throughput costs, and network reliability.
Iterative methods for determining the k shortest paths in a network
Authors: Shier D. R. 
Published: May 2007

AbstractThis paper presents and develops an algebraic structure for determining the k shortest paths from a given node to all other nodes of a network. Three new methods for calculating such k shortest path information are examined and compared. These methods are based on a fairly strong analogy which exists between the solution of such network problems and traditional techniques for solving linear equations. On the basis of both theoretical and computational evidence, one of the three methods is seen to offer an extremely effective procedure for finding the k shortest paths from a given node in a network.
Rectilinear steiner trees: Efficient special‐case algorithms
Authors: Aho A. V. , Garey M. R. , Hwang F. K. 
Published: May 2007

AbstractA minimal rectilinear Steiner tree for a set A of points in the plane is a tree which interconnects A using horizontal and vertical lines of shortest possible total length. Such trees have potential application to wire layout for printed circuits. Unfortunately, at present no practical algorithm is known for constructing these trees in general. We present two algorithms, each requiring a number of operations proportional to only a low degree polynomial in the number of points to be interconnected, for the special cases in which all the points of A lie on a small number of parallel lines or on the boundary of a rectangle.
A problem on blocking probabilities in connecting networks
Authors: Chung F. R. K. , Hwang F. K. 
Published: May 2007

AbstractWe begin with a three‐stage linear graph in which the first stage has a single node u and the third stage a single node v. The second stage has k independent nodes, each of which is connected by one link to u and to v. In general, we can form a (2n+1)‐stage linear graph recursively by letting each node in the second stage of a three‐stage linear graph be replaced by a copy of a (2n‐1)‐stage linear graph.A link can either be in the busy state or the idle state. We assume that the states of each link are mutually independent and that any link between stage i and stage i + 1 has the probability I.z of being idle. The nodes u and v are said to be connectable if there exists at least one path from u to v with no busy link. Let P(u, v) denote the probability of such a path existing. Further, let N(2n+1, k) denote the set of (2n+1)‐stage linear graphs whose center stages have k nodes.In this paper, we determine the size of N(2n+1, k). We also give the linear graph in N(2n+1, k) which has the largest P(u, v) and the one which has the smallest. We then show how our results apply to a recent problem in connecting networks.