bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimizing the finger tables in Chord‐like DHTs
Authors: Chiola Giovanni , Cordasco Gennaro , Gargano Luisa , Negro Alberto , Scarano Vittorio 
Published: July 2007

AbstractThe Chord protocol is the best known example of implementation of logarithmic complexity routing for structured peer‐to‐peer networks. Its routing algorithm, however, does not provide an optimal trade‐off between resources exploited (the size of the ‘finger table’) and performance (the average or worst‐case number of hops to reach destination). Cordasco et al. showed that a finger table based on Fibonacci distances provides lower number of hops with fewer table entries. In this paper we generalize this result, showing how to construct an improved finger table when the objective is to reduce the number of hops, possibly at the expense of an increased size of the finger table. Our results can also be exploited to guarantee low routing time in case a fraction of nodes fails. Copyright © 2007 John Wiley & Sons, Ltd.
Neighbourhood maps: decentralized ranking in small‐world P2P networks
Authors: Dell'Amico Matteo 
Published: July 2007

AbstractReputation in P2P networks is an important tool to encourage cooperation among peers. It is based on ranking of peers according to their past behaviour. In large‐scale real‐world networks, a global centralized knowledge about all nodes is neither affordable nor practical. For this reason, reputation ranking is often based on local history knowledge available on the evaluating node. This criterion is not optimal, since it ignores useful data about interactions with other peers. In our approach, evaluations of past history create recommendations between nodes, that will be used to form a network called web of trust. Under the assumption that the web of trust has the ubiquitous small‐world property, we propose a simple, scalable and decentralized method, called ‘neighbourhood maps’, which approximates rankings calculated using link‐analysis techniques, exploiting the short‐distance characteristics of small‐world networks. We test our algorithms using data from the OpenPGP web of trust, a real‐world network of trust relationships, and by developing a simple simulation of a file‐sharing network using an evolutive approach. Our results show that it is sufficient to have maps having size $O(\sqrt{n})$, where n is the size of the network, in order to have good results. Copyright © 2007 John Wiley & Sons, Ltd.
The children's DEBQ for assessment of restrained, emotional, and external eating in 7‐ to 12‐year‐old children
Authors: van Strien Tatjana , Oosterveld Paul 
Published: July 2007

AbstractObjective:Construct an age adapted version of the Dutch Eating Behaviour Questionnaire (DEBQ) for measurement of restrained, emotional and external eating in 7‐ to 12‐year‐old children: the DEBQ‐C.Method:The DEBQ‐C was constructed and tested for its reliability, factorial validity, factorial invariance for sex, overweight (BMI‐status), and age, and correlations with measures for unhealthy life style in one sample (382 boys and 387 girls). In a second sample (252 boys and 263 girls) correlations were obtained with measures for body dissatisfaction and parental feeding styles. Single and multigroup confirmatory factor analyses were used.Results:The fit measures for the three factor model and the factorial invariance models with respect to sex, BMI‐status, and age were satisfactory. In the (sub) samples of the 7‐ to 12‐year‐olds Cronbach's alpha's ranged from .73 to .82 and there were satisfactory correlations (p < .01) with other measures.Conclusion:The DEBQ‐C should provide a useful measure for young children's emerging dietary restraint and overeating tendencies. The low prevalence of emotional eating indicates that most young children show the natural reaction to emotional stressors (loss of appetite when feeling lonely, depressed or afraid) and that emotional (over) eating at this age is quite abnormal. © 2007 by Wiley Periodicals, Inc. Int J Eat Disord 2008
Topical TLR9 agonists induce more efficient cross‐presentation of injected protein antigen than parenteral TLR9 agonists do
Authors: Najar Hossain M. , Dutz Jan P. 
Published: July 2007

AbstractTopical application of adjuvant to the skin promotes the generation of immune responses to co‐administered peptide or protein antigen. We demonstrate that topical administration of CpG adjuvant (a TLR9 agonist) induces the cross‐presentation of, and antigen‐specific CTL induction to, locally injected soluble protein antigen. C57BL/6 mice were immunized by subcutaneous or intramuscular injection with ovalbumin (OVA) protein as model antigen. Application of CpG to the local skin induced more efficient cross‐presentation of the injected antigen than co‐injected adjuvant. Robust antigen‐specific CTL responses were generated, as determined by antigen‐specific CTL enumeration using tetramers, IFN‐γ ELISPOT analysis and cytotoxicity assays. Long‐term memory CTL responses were induced. Topical administration of adjuvant induced Langerhans cell migration, local type 1 IFN‐dependent myxovirus‐resistance protein A expression and bystander dendritic cell (DC) activation. Soluble antigen‐bearing DC within the skin draining lymph nodes were mainly CD11chiCD11bhilangerinloDEC205lo. Topical administration did not result in the splenomegaly or systemic cytokine induction (including TNF‐α, IL‐12, IFN‐γ and MCP‐1) noted with parenteral administration. Topical TLR9 family agonists may be used to modulate the immune response to soluble protein vaccines administered by standard percutaneous route. Topical adjuvant administration increases efficacy of CTL induction and reduces toxicity when compared to parenteral adjuvant administration.
Pyrazole‐Based Ligands for the [Copper–TEMPO]‐Mediated Oxidation of Benzyl Alcohol to Benzaldehyde and Structures of the Cu Coordination Compounds
Authors: Salinas Uber Jorge , Vogels Yorick , van den Helder Dave , Mutikainen Ilpo , Turpeinen Urho , Fu Wen Tian , Roubeau Olivier , Gamez Patrick , Reedijk Jan 
Published: July 2007

AbstractNew pyrazole‐based ligands have been designed, and the catalytic performances of their copper(II) complexes for the [copper/TEMPO]‐mediated oxidation of benzyl alcohol to benzaldehyde have been examined. The pyridine‐pyrazole ligands give efficient catalysts, while the use of naphthol‐pyrazole ligands results in inactive catalytic systems. Single‐crystals of four Cu coordination compounds obtained from pyridine‐pyrazole ligands and a free ligand have been isolated and were characterized by X‐ray diffraction. Thus, the solid‐state structures of three copper(II) complexes are described, together with a copper(I) coordination chain, exhibiting luminescent properties. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Approximate basket option valuation for a simplified jump process
Authors: Flamouris Dimitris , Giamouridis Daniel 
Published: July 2007

AbstractThis study proposes the use of a simplified jump process, namely the Bernoulli jump process, to develop approximate basket option valuation formulas. The proposed model is based on a more realistic stochastic process—relative to the standard geometric Brownian motion—without introducing additional intractability. Typical approximations, necessary for the development of the closed form formulas, are validated on the basis of a Monte Carlo experiment. © 2007 Wiley Periodicals, Inc. Jrl Fut Mark 27:819–837, 2007
Pricing American options on foreign currency with stochastic volatility, jumps, and stochastic interest rates
Authors: Guo Jia‐Hau , Hung Mao‐Wei 
Published: July 2007

AbstractBy applying the Heath–Jarrow–Morton (HJM) framework, an analytical approximation for pricing American options on foreign currency under stochastic volatility and double jump is derived. This approximation is also applied to other existing models for the purpose of comparison. There is evidence that such types of jumps can have a critical impact on earlyexercise premiums that will be significant for deep out‐of‐the‐money options with short maturities. Moreover, the importance of the term structure of interest rates to early‐exercise premiums is demonstrated as is the sensitivity of these premiums to correlation‐related parameters. © 2007 Wiley Periodicals, Inc. Jrl Fut Mark 27:867–891, 2007
Transcriptional oncogenomic hot spots in Barrett's adenocarcinomas: Serial analysis of gene expression
Authors: Razvi Mohammad H. , Peng Dunfa , Dar Altaf A. , Powell Steven M. , Frierson Henry F. , Moskaluk Christopher A. , Washington Kay , El‐Rifai Wael 
Published: July 2007

AbstractSerial analysis of gene expression (SAGE) provides quantitative and comprehensive expression profiling in a given cell population. In our efforts to define gene expression alterations in Barrett's‐related adenocarcinomas (BA), we produced eight SAGE libraries and obtained a total of 457,894 expressed tags with 32,035 (6.9%) accounting for singleton tags. The tumor samples produced an average of 71,804 tags per library, whereas normal samples produced an average of 42,669 tags per library. Our libraries contained 67,200 unique tags representing 16,040 known gene symbols. Five hundred and sixty‐eight unique tags were differentially expressed between BAs and normal tissue samples (at least twofold; P ≤ 0.05), 395 of these matched to known genes. Interestingly, the distribution of altered genes was not uniform across the human genome. Overexpressed genes tended to cluster in well‐defined hot spots located in certain chromosomes. For example, chromosome 19 had 26 overexpressed genes, of which 18 mapped to 19q13. Using the gene ontology approach for functional classification of genes, we identified several groups that are relevant to carcinogenesis. We validated the SAGE results of five representative genes (ANPEP, ECGF1, PP1201, EIF5A1, and GKN1) using quantitative real‐time reverse‐transcription PCR on 31 BA samples and 26 normal samples. In addition, we performed an immunohistochemistry analysis for ANPEP, which demonstrated overexpression of ANPEP in 6/7 (86%) Barrett's dysplasias and 35/65 (54%) BAs. ANPEP is a secreted protein that may have diagnostic and/or prognostic significance for Barrett's progression. The use of genomic approaches in this study provided useful information about the molecular pathobiology of BAs. © 2007 Wiley‐Liss, Inc.
Brain response to visual sexual stimuli in heterosexual and homosexual males
Authors: Paul Thomas , Schiffer Boris , Zwarg Thomas , Krüger Tillmann H.C. , Karama Sherif , Schedlowski Manfred , Forsting Michael , Gizewski Elke R. 
Published: July 2007

AbstractAlthough heterosexual and homosexual individuals clearly show differences in subjective response to heterosexual and homosexual sexual stimuli, the neurobiological processes underlying sexual orientation are largely unknown. We addressed the question whether the expected differences in subjective response to visual heterosexual and homosexual stimuli may be reflected in differences in brain activation pattern. Twenty‐four healthy male volunteers, 12 heterosexuals and 12 homosexuals, were included in the study. BOLD signal was measured while subjects were viewing erotic videos of heterosexual and homosexual content. SPM02 was used for data analysis. Individual sexual arousal was assessed by subjective rating. As compared to viewing sexually neutral videos, viewing erotic videos led to a brain activation pattern characteristic for sexual arousal in both groups only when subjects were viewing videos of their respective sexual orientation. Particularly, activation in the hypothalamus, a key brain area in sexual function, was correlated with sexual arousal. Conversely, when viewing videos opposite to their sexual orientation both groups showed absent hypothalamic activation. Moreover, the activation pattern found in both groups suggests that stimuli of opposite sexual orientation triggered intense autonomic response and may be perceived, at least to some extent, as aversive. Hum Brain Mapp, 2008. © 2007 Wiley‐Liss, Inc.
Test–retest and between‐site reliability in a multicenter fMRI study
Authors: Friedman Lee , Stern Hal , Brown Gregory G. , Mathalon Daniel H. , Turner Jessica , Glover Gary H. , Gollub Randy L. , Lauriello John , Lim Kelvin O. , Cannon Tyrone , Greve Douglas N. , Bockholt Henry Jeremy , Belger Aysenil , Mueller Bryon , Doty Michael J. , He Jianchun , Wells William , Smyth Padhraic , Pieper Steve , Kim Seyoung , Kubicki Marek , Vangel Mark , Potkin Steven G. 
Published: July 2007

AbstractIn the present report, estimates of test–retest and between‐site reliability of fMRI assessments were produced in the context of a multicenter fMRI reliability study (FBIRN Phase 1, www.nbirn.net). Five subjects were scanned on 10 MRI scanners on two occasions. The fMRI task was a simple block design sensorimotor task. The impulse response functions to the stimulation block were derived using an FIR‐deconvolution analysis with FMRISTAT. Six functionally‐derived ROIs covering the visual, auditory and motor cortices, created from a prior analysis, were used. Two dependent variables were compared: percent signal change and contrast‐to‐noise‐ratio. Reliability was assessed with intraclass correlation coefficients derived from a variance components analysis. Test–retest reliability was high, but initially, between‐site reliability was low, indicating a strong contribution from site and site‐by‐subject variance. However, a number of factors that can markedly improve between‐site reliability were uncovered, including increasing the size of the ROIs, adjusting for smoothness differences, and inclusion of additional runs. By employing multiple steps, between‐site reliability for 3T scanners was increased by 123%. Dropping one site at a time and assessing reliability can be a useful method of assessing the sensitivity of the results to particular sites. These findings should provide guidance toothers on the best practices for future multicenter studies. Hum Brain Mapp, 2008. © 2007 Wiley‐Liss, Inc.
Memory, perception, and the ventral visual‐perirhinal‐hippocampal stream: Thinking outside of the boxes
Authors: Bussey T.J. , Saksida L.M. 
Published: July 2007

AbstractThe prevailing paradigm in cognitive neuroscience assumes that the brain can be best understood as consisting of modules specialised for different psychological functions. Within the field of memory, we assume modules for different kinds of memory. The most influential version of this view posits a module called the “medial temporal lobe memory system” which operates in the service of “declarative memory.” This system can be contrasted with a separate “perceptual representation system” in the ventral visual stream, which is critical for perceptual learning and memory, an example of nondeclarative function. Here we question this modular memory systems view and suggest that a better way to understand the ventral visual‐perirhinal‐hippocampal stream is as a hierarchically organised representational continuum. We suggest that in general, rather than trying to map psychological functions onto brain modules, we could benefit by instead attempting to understand the functions of brain regions in terms of the representations they contain, and the computations they perform. © 2007 Wiley‐Liss, Inc.
Running induces widespread structural alterations in the hippocampus and entorhinal cortex
Authors: Stranahan Alexis M. , Khalil David , Gould Elizabeth 
Published: July 2007

AbstractPhysical activity enhances hippocampal function but its effects on neuronal structure remain relatively unexplored outside of the dentate gyrus. Using Golgi impregnation and the lipophilic tracer DiI, we show that long‐term voluntary running increases the density of dendritic spines in the entorhinal cortex and hippocampus of adult rats. Exercise was associated with increased dendritic spine density not only in granule neurons of the dentate gyrus, but also in CA1 pyramidal neurons, and in layer III pyramidal neurons of the entorhinal cortex. In the CA1 region, changes in dendritic spine density are accompanied by changes in dendritic arborization and alterations in the morphology of individual spines. These findings suggest that physical activity exerts pervasive effects on neuronal morphology in the hippocampus and one of its afferent populations. These structural changes may contribute to running‐induced changes in cognitive function. © 2007 Wiley‐Liss, Inc.
Withdrawal behavior and depression in infancy
Authors: Guedeney Antoine 
Published: July 2007

AbstractThis paper describes the history of the concept of infant depression, which has been at the beginning of the discipline of infant mental health, and reviews classification and diagnosis issues, along with some animal models. Several diagnostic criteria have yielded different prevalence rates, and some being unrealistic, but we still do not know when infant depression begins, what its outcome is, and what are its different aspects. It is suggested that infant depression needs a certain amount of emotional and cognitive development to unfold, and that it might not exist before 18–24 months of age, a crossover during which major autoreflexive, cognitive, and emotional abilities emerge. Depression could be an outcome of attachment disorganization in infancy, as depression and disorganization seem to share the same learned helpnessness psychopathological process. Developmental psychopathology considers trouble more from a dimensional point of view rather than from a categorical one, and more as the result of several factors with a sequential action rather than the effect of a genetic disorder with direct expression. Before the limit of 18–24 months, the concept of relational withdrawal seems more applicable and useful.
Bimolecular Formation of Radicals by Hydrogen Transfer, 11. Transfer Hydrogenation of Conjugated Cyclic Dienes and Trienes
Authors: Morgenthaler Jens , Rüchardt Christoph 
Published: July 2007

Abstract1,3‐Cyclohexadiene, 1,3‐cycloheptadiene and cycloheptatriene are smoothly hydrogenated to cyclohexene and cycloheptene, respectively, when heated to 260–340°C with an excess of 9,10‐dihydroanthracene (DHA) in diphenyl ether or benzonitrile. On the basis of a mechanistic study a nonchain three‐step mechanism is proposed which is initiated by a transfer of a hydrogen atom from DHA to the polyenes (retrodisproportionation).
Titanium(IV) Chloride Induced Reactions of Ketones and C‐Acylimines with Dimethylcyanamide
Authors: Mazik Monika , Sustmann Reiner , Boese Roland 
Published: July 2007

AbstractThe reactions of ketones (benzophenone, 4‐methylbenzophenone, acetophenone, acetone, and 2,2,4,4‐tetramethyl‐3‐pentanone) and C‐acylimines with dimethylcyanamide in the presence of titanium(IV) chloride were investigated, Benzophenone and 4‐methylbenzophenone react with dimethylcyanamide to give 4,4‐disubstituted 2‐dimethylamino‐3‐aza‐1‐oxa‐1,3‐butadienes 5 and 4,4‐disubstituted 2‐dimethylamino‐1‐N,N‐dimethylcarbamoyl‐1,3‐diaza‐1,3‐butadienes 9. Ketones with enolizable hydrogen atoms undergo aldol reactions under these conditions. C‐Acylimines 11b–11e, derived from benzil and substituted anilines, undergo [2 + 2] cycloaddition to dimethylcyanamide with subsequent ring opening to 1‐(N,N‐dimethylcarbamoyl)‐2,3,4‐triaryl‐1,4‐diaza‐1,3‐butadienes 15. 1,2‐Diphenyl‐2‐(isopropylimino)ethanone (11a) reacts with dimethylcyanamide to give 2‐dimethylamino‐1‐isopropyl‐4,4‐diphenyl‐2‐imidazolin‐5‐one (23) in a hitherto unknown multistep reaction. The structure of 23 was confirmed by an X‐ray analysis.
Concave Macrobicycles: Absorption Spectra, Luminescence Properties, and Endocavital Complexation of Neutral Organic Guests
Authors: Vögtle Fritz , Michel Ingo , Berscheid Ralf , Nieger Martin , Rissanen Kari , Kotila Sirpa , Airola Karri , Armaroli Nicola , Maestri Mauro , Balzani Vincenzo 
Published: July 2007

AbstractBy a mild modified Eglinton coupling a series of diynebridged macrobicyclic hosts capable of endocavital complexation were synthesized and their structures and complexation properties investigated by X‐ray analysis. The inclusion of DMSO in 7 suggests a direct correlation between steric fit and orientation of the guest. On the basis of this hypothesis, the orientation of acetone in an endocavital inclusion of 2 was predicted and verified by X‐ray analysis. Comparison of the single‐crystal X‐ray structures of the vacant macrobicycle 3 and of a family of macrobicycles showing endocavital or “pocket” complexation of neutral organic guests suggests that torsion of the cavities upon complexation results from induced fit. Hydrogenation of the triple bonds leads to the more flexible macrobicycles 10–12 with collapsable cavities. The absorption and emission spectra of the diynebridged macrobicyclic hosts 1 and 3, of their hydrogenated analogues 11 and 12, and of a hemicage parent compound of 2 (14) were investigated. The macrobicyclic compounds 3, 11, 12 and 14 exhibit a strong fluorescence in CH2Cl2 solution at room temperature. The lack of fluorescence of 2 under such conditions is attributed to the presence of low‐energy charge‐transfer excited states, as indicated by the charge‐transfer bands in the absorption spectrum. In a rigid CH2Cl2 matrix at 77 K all the examined compounds are fluorescent.
Ethylaluminium Dichloride Induced Reactions of Acetals with Unsaturated Carboxylic Esters: Synthesis of Homoallyl Ethers
Authors: Metzger Jürgen O. , Biermann Ursula 
Published: July 2007

AbstractThe ethylaluminium dichloride induced reactions of methyl 10‐undecenoate (1) with dimethyl acetals of formaldehyde 2a, acetaldehyde 2b, isobutyraldehyde 2c, and pivaldehyde 2d gave the corresponding homoallyl ethers 3a, 3b, 3c, and 3d in yields of 48–70%. The products were obtained as mixtures of the (E) and (Z) stereoisomers. With formaldehyde dimethyl acetal (2a), methyl oleate (6), and methyl petroselinate (11) gave the corresponding regioisomeric (E)‐configured homoallyl ethers 7/8 and 12/13.
Double Asymmetric Dihydroxylation of 1,5‐Hexadiene
Authors: Maier Martin E. , Reuter Sebastian 
Published: July 2007

AbstractDouble asymmetric dihydroxylation of 1,5‐hexadiene gave in one step a mixture of the d,l/meso tetrols 6 in a ratio of 3.4:1. From this ratio a facial selectivity of 6.65:1 for each double bond can be calculated. As a consequence of the double reaction the d/l ratio can be estimated to be 44:1. Compound 6 served then as starting material for the preparation of the bis‐epoxide 12 and the 2,5‐dihydroxyhexane (13). While the separation of the diastereomers was not possible so far, this route for the preparation of 6, 12 and 13 might still be useful because it is very short and products derived from them might allow the crucial separation.
Preparation of 1‐Azacyclododeca‐3,8‐diynes and 1,6‐Diazacyclododeca‐3,8‐diynes
Authors: Ritter Joachim , Gleiter Rolf 
Published: July 2007

AbstractThe preparation of N,N′‐dialkyl‐ and N,N′‐diaryl‐1,6‐diazacyclodeca‐3,8‐diynes was achieved by reaction of alkyl‐ or arylamines with 1,4‐dihalobut‐2‐yne under dilution conditions in yields of 5–15%. The compounds synthesized by this procedure were the N,N′‐dimethyl (2b), N,N′‐diethyl (2c), N,N′‐diisopropyl (2d), N,N′‐di‐tert‐butyl (2e), N,N′‐dicyclohexyl (2f), N,N′‐diphenyl (2g), and N,N′‐di‐p‐tolyl (2h) derivatives. The parent compound 2a was obtained in ca. 40% yield by heating 2d with α‐chloroethylchloroformate (20). Using 1,9‐dibromonona‐2,7‐diyne (10) and methylamine or isopropylamine, respectively, the corresponding N‐alkyl‐1‐azacyclodeca‐3,8‐diynes 4b and 4d were synthesized under dilution conditions. By heating 4d with 20 we obtained 1‐azacyclodeca‐3,8‐diyne (4a). As side products of the cyclization reactions the trimers 18 and tetramers 12 and 19 were isolated and characterized. N‐methyl‐1‐azacycloundeca‐3,9‐diyne (14b) was prepared by reaction of 1,10‐dibromodeca‐3,8‐diyne (13) with methylamine.