bluuebunny/crossref_metadata_2025_split huggingface dataset:
An interval method for finding all operating points of non‐linear resistive circuits
Authors: Kolev L. V. , Mladenov V. M. 
Published: July 2007

AbstractA new method for finding the set of all d.c. operating points of non‐linear electronic circuits is suggested. it is applicable in the case where the circuit equations are written in the hybrid‐representation form. In the general case, the non‐linear elements involved may be described by non‐monotone continuous characteristics.The method suggested is based on interval analysis techniques. Unlike other non‐interval methods, this approach guarantees that all operating points will be found within prescribed accuracy in a finite number of steps.The computational efficiency of the present method is illustrated by a numerical example.
Variable dimension algorithms for solving resistive circuits
Authors: Vandenberghe Lieven , Vandewalle Joos 
Published: July 2007

AbstractVariable dimension algorithms are a recent class of globally convergent algorithms for solving sets of non‐linear equations. This paper introduces a simple circuit‐theoretical interpretation of the underlying idea and describes its advantages as compared to the globally convergent methods better known in circuit theory, such as the generalized Katzenelson algorithm. the convergence criterion is also stated in topological terms, and these conditions turn out to coincide with very general sufficient conditions for existence of solutions. the approach taken here can therefore be seen as a constructive way to prove solvability of resistive circuits. the paper also discusses how to implement the algorithm in an efficient and practical way.
Dissipativity as a unified approach to sandberg‐willson‐type properties of non‐linear transistor networks
Authors: Marinov Corneliu A. 
Published: July 2007

AbstractA class of circuits is considered consisting of semiconductor devices (non‐linearly modelled bipolar transistors and junction diodes), non‐linear capacitors and inductors, all connected to a non‐linear resistive multiport. This multiport is described by a global piecewise continuously differentiable operator, while the other non‐linearities are of piecewise linear type. Sufficient conditions for the existence, uniqueness, stability, boundedness and source‐related continuity of the solutions are derived for both direct current and dynamic regimes. All these results are obtained by using the dissipativity property exhibited by the functions appearing in the circuit equations and are extensions of well known results of Sandberg and Willson.
Resistive circuit topologies that admit several solutions
Authors: Fosséprez Marc , Hasler Martin 
Published: July 2007

AbstractNecessary and sufficient conditions are given that a resistive circuit may have several but finitely many solutions. Whether it actually has several solutions depends on the values of the sources and linear resistors as well as on the characteristics of the non‐linear resistors. Such circuits are required for static memory applications of all kinds, including associative memories realized by neural networks. These criteria are given both in terms of linear circuits and circuit topology. In the same way the minimal memory circuits are characterized. They constitute the building blocks for more complicated memory circuits.
Inpatients with eating disorders: Demographic, diagnostic, and service characteristics from a nationwide pediatric sample
Authors: Calderon Rose , Stoep Ann Vander , Collett Brent , Garrison Michelle M. , Toth Karen 
Published: July 2007

AbstractObjective:This study describes the demographic and clinical characteristics of youth hospitalized with an eating disorder, using the Pediatric Health Information System (PHIS) database.Method:Descriptive and inferential statistics were used to examine and compare PHIS inpatients (N = 1,713) with a primary discharge diagnosis of anorexia, bulimia, or eating disorder, not otherwise specified.Results:Of pediatric inpatients with eating disorders, 92% were female and 78% were non‐Hispanic white. Their mean age was 15.3 years; 71% had anorexia; 68% had one or more comorbid psychiatric disorders; 53% stayed on a psychiatric unit; the mean length of stay was 15.7 days. Private insurance paid for 55% of hospital stays. Patients without private insurance were more likely than patients with private insurance to be Black or Hispanic and to have comorbid psychiatric diagnoses.Conclusion:This study provides new information that can be used by hospitals to anticipate developmental and treatment needs of future inpatients with eating disorders. © 2007 by Wiley Periodicals, Inc. Int J Eat Disord 2007
Effects of social comparisons with peers on women's body satisfaction and exercise behavior
Authors: Wasilenko Kari A. , Kulik James A. , Wanic Rebekah A. 
Published: July 2007

AbstractObjective:Although exposure to thin‐ideal females in the media has been shown to increase women's body dissatisfaction, only a few studies have examined the effects of comparisons with peers, and no prior work has studied the effects of peer comparisons in a naturalistic setting or on objective behavior.Method:Female undergraduates (n = 45) in a campus gym who exercised on a target apparatus were assigned to have a fit‐peer, unfit‐peer, or no‐peer (control) exercise within their view on a nearby apparatus. Objective time spent exercising and body satisfaction reports were collected.Results:Exposure to a fit peer had undermining effects on women's body satisfaction and exercise duration, whereas an unfit peer produced no compensating greater body satisfaction but did elicit longer exercise duration relative to controls.Conclusion:Incidental comparisons with fit versus unfit peers can affect women's body satisfaction and fitness‐related behavior in a naturalistic setting. © 2007 by Wiley Periodicals, Inc. Int J Eat Disord 2007
Structurally Characterized Erbium Alkoxides for Use as an Amphoteric Dopant in PErZT Ceramic Thin Film and Nanoparticles
Authors: Boyle Timothy J. , Ottley Leigh Anna M. , Brewer Luke N. , Sigman Jennifer , Clem Paul G. , Richardson Jacob J. 
Published: July 2007

AbstractA family of erbium alkoxides [Er(OR)3] was prepared from the reaction of Er[N(SiMe3)2]3 with a series of alcohols (HOR) in selected solvents and crystallographically characterized as: [Er(μ‐Onep)2(Onep)]4, (1), [Er4(μ4‐O)(μ3‐Onep)(μ‐Onep)5(Onep)4(py)3] (3), Er3(μ3‐OtBu)2(μ‐OtBu)3(OtBu)4(HOtBu)2 (4), Er3(μ3‐O)(μ‐OtBu)4(OtBu)3(py)3 (7), Er(dmp)3(solv)3 [solv = thf (9), py (10)], [Er(η‐dip)(dip)2]2 (11), Er(dip)3(thf)2 (12), [Er(μ‐OH)(dbp)2(thf)]2 (15), Er(dbp)3(py)2 (16), [Er(μ‐tps)(tps)2]2 (17), Er(tps)3(solv)3 [solv = thf (18) and (py) (19)] where Onep = neopentoxide (OCH2CMe3), OtBu = tert‐butoxide (OCMe3), dmp = 2,6‐dimethylphenoxide [OC6H3(Me)2‐2,6], dip = 2,6‐diisopropylphenoxide [OC6H3(CHMe2)2‐2,6], dbp = 2,6‐di‐tert‐butylphenoxide [OC6H3(CMe3)2‐2,6], tps = triphenylsiloxide [OSi(C6H5)3], tol = toluene, thf = tetrahydrofuran, and py = pyridine. The structures observed and data collected for the Er family of compounds are, in general, consistent with those reported previously for the Dy congeners over the range of solvated mono‐, di‐, tri‐, and tetranuclear species. Representative members of the Er(OR)3 precursors were used for the production of a PErZT precursor solution, which was subsequently used to generate thin films and nanoparticles. Further, these select Er precursors were used to generate Er2O3 nanoparticles. The full characterization of this family of compounds is reported along with the results of the materials investigations.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Pyrrolidino DNA with Bases Corresponding to the 2‐Oxo Deletion Mutants of Thymine and Cytosine: Synthesis and Triplex‐Forming Properties
Authors: Mayer Alain , Leumann Christian J. 
Published: July 2007

AbstractThe dual recognition properties of pyrrolidino DNA species as parallel triplex‐forming oligonucleotides were previously found to be strongly dependent upon the nature of the pyrimidine bases. In the structure–activity study presented here we were able to exclude this differential binding being due to their 2‐oxo function. We had previously reported on the incorporation of pyrrolidino C‐nucleosides into triplex‐forming 2′‐deoxyoligonucleotides (TFOs). The basic nitrogen atom that replaces the 4′‐oxygen atom of the 2′‐deoxysugar in such modified units introduces a positive charge in the third strand, and this is able to produce favourable electrostatic interaction with the negatively charged DNA target duplex. A first series of pyrrolidino pseudonucleosides with the bases isocytosine and uracil proved successful for GC base‐pair recognition, but was unsuccessful for AT base‐pair recognition within the parallel triplex binding motif. Here we report on the synthesis of the two novel 2′‐deoxypyrrolidino nucleosides carrying the bases pyridin‐2‐one and 2‐aminopyridine, their phosphoramidite building blocks and theirincorporation into TFOs. Pyrrolidinylpyridin‐2‐one (dp2P) and ‐2‐aminopyridine (dp2AP), prepared as part of a structure–activity profiling of pyrrolidino DNA in triplex binding, are deletion mutants of T and C, respectively. We found by Tm measurements that neither modification increased triplex binding efficiency relative to the iso‐C‐ and ‐U‐containing pyrrolidino TFOs. These experiments clearly show that the C4 carbonyl function, although important for triplex binding through indirect contributions in general, is not responsible for the differential binding of the latter two aminonucleosides and suggest that TFO conformation is more important. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
The Use of Lithium Amides in the Palladium‐Mediated Synthesis of [Carbonyl‐11C]Amides
Authors: Itsenko Oleksiy , Blom Elisabeth , Långström Bengt , Kihlberg Tor 
Published: July 2007

AbstractWeakly nucleophilic amines were converted into the corresponding lithium amides and used in either one‐ or two‐pot palladium‐mediated reactions with [11C]carbon monoxide and aryl iodides. It was found that palladium acyl complexes may be prepared in a separate step and have sufficient lifetime to be used in a subsequent reaction with a nucleophile. This two‐pot procedure was used for the labelling synthesis of eleven amides (nine of which are analogues of WAY‐100635, a 5‐HT1A radioligand) from weakly nucleophilic amines. The results were compared to a direct one‐pot procedure using lithium amides. Both approaches extend the scope of palladium‐mediated carbonylation using [11C]carbon monoxide and aryl iodides allowing use of weakly nucleophilic amines. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Stereospecific Side Chain Activation in Cyclobutadiene–Fe(CO)3 Chemistry: A Theoretical and Experimental Study on the Structure and Configurational Stability of Cationic, Radical and Anionic Intermediates
Authors: Pfletschinger Anja , Schneider Ulrich , Lex Johann , Schmalz Hans‐Günther 
Published: July 2007

AbstractThe configurational stability of reactive intermediates (cation, radical and anion) derived from ethylcyclobutadiene–Fe(CO)3 by formal abstraction of a hydride, a hydrogen atom or a proton from the pseudobenzylic position was investigated. Density functional calculations (Becke3lyp) predicted that all these reactive intermediates can be regarded as planar chiral structures having a significant configurational stability. The racemization barriers were calculated to be 38.8 kcal mol–1 for the cationic, 16.9 kcal mol–1 for the radical and 44.8 kcal mol–1 for the anionic intermediate. In an experimental part of the study, derivatives of the 1‐hydroxyethyl‐substituted complex, which was enantioselectively prepared by CBS reduction of the acetyl complex, were subjected to SN1‐type as well as single‐electron‐transfer‐driven umpolung reactions. The observed stereospecificity of these transformations (retention of configuration) is in accordance with the predicted configurational stability of the involved reactive intermediates. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Cover Picture: Unusual Influence of the Structures of Transition Metal Complexes on Catalytic C–S and C–Se Bond Formation Under Homogeneous and Heterogeneous Conditions (Eur. J. Org. Chem. 21/2007)
Authors: Beletskaya Irina P. , Ananikov Valentine P. 
Published: July 2007

AbstractThe cover picture shows that tuning the size of the catalyst particles provides a powerful synthetic tool for controlling not only the selectivity and yield, but also the direction of the chemical transformation. Soluble mononuclear and dinuclear phosphine complexes of palladium are excellent catalysts for stereoselctive E–E (E = S, Se) bond addition to alkynes. However, these complexes are poor catalysts for E–H bond addition to alkynes. Increasing the size of the catalyst particles changes the reactivity: polymeric species of nickel and palladium become efficient catalysts of E–H bond addition under heterogeneous conditions, while they are totally inactive in E?E bond addition. The unique self‐organized catalytic system shown in the background (magnified by scanning electron microscopy) combines the best features on the polynuclear metal complex and supported catalyst. Details are presented in the Microreview by I. P. Beletskaya and V. P. Ananikov on p. 3431 ff.
The influence of stereotypes on decisions to shoot
Authors: Correll Joshua , Park Bernadette , Judd Charles M. , Wittenbrink Bernd 
Published: July 2007

AbstractUsing a videogame to simulate encounters with potentially hostile targets, three studies tested a model in which racial bias in shoot/don't‐shoot decisions reflects accessibility of the stereotype linking Blacks to danger. Study 1 experimentally manipulated the race‐danger association by asking participants to read newspaper stories about Black (vs. White) criminals. As predicted, exposure to stories concerning Black criminals increased bias in the decision to shoot. Studies 2 and 3 manipulated the number of White and Black targets with and without guns in the context of the videogame itself. As predicted, frequent presentation of stereotypic (vs. counterstereotypic) targets exacerbated bias (Study 2) and—consistent with our process account—rendered stereotypes more accessible (Study 3). Copyright © 2007 John Wiley & Sons, Ltd.
State‐space discrimination and clustering of atmospheric time series data based on Kullback information measures
Authors: Bengtsson Thomas , Cavanaugh Joseph E. 
Published: July 2007

AbstractStatistical problems in atmospheric science are frequently characterized by large spatio‐temporal data sets and pose difficult challenges in classification and pattern recognition. Here, we consider the problem of identifying geographically homogeneous regions based on similarities in the temporal dynamics of weather patterns. Two disparity measures are
proposed and applied to cluster time series of observed monthly temperatures from locations across Colorado, U.S.A. The two disparity measures are based on state‐space models, where the monthly temperature anomaly dynamics and seasonal variation are represented by latent processes. Our disparity measures produce clusters consistent with known atmospheric flow structures. In particular, the temporal anomaly pattern is related to the topography of Colorado, where, separated by the Continental Divide, the flow structures in the western and eastern parts of the state have different dynamics. The results further suggest that seasonal variation may be affected by locally changing solar radiation levels primarily associated with elevation variations across the Rocky Mountains. The general methodology is outlined and developed in the Appendix. We conclude with a discussion of extensions to time varying and non‐stationary systems. Copyright © 2007 John Wiley & Sons, Ltd.
Factors influencing retention of coarse particulate organic matter in streams
Authors: Quinn John M. , Phillips Ngaire R. , Parkyn Stephanie M. 
Published: July 2007

AbstractInput of terrestrial coarse particulate organic matter (CPOM: leaves and small wood, >1 mm) adds food resources and habitat to streams. Restoration projects often aim to increase CPOM through riparian planting, but this relies on inputs being retained within the restored reach, and quantitative knowledge of factors influencing retention processes is limited. We investigated retention characteristics under base‐flow conditions in 65 stream reaches in pasture, native forests and pine plantations (with and without recent logging) in five contrasting New Zealand regions, using three CPOM analogues, namely 30 cm dowels, soaked ginkgo leaves and waterproof paper triangles. These differed significantly in geometric mean retention distance (Sp), with greatest retention (smallest Sp) of dowels > ginkgos > triangles. Retention efficiency was greater in riffles and glides than in pools. Objects trapping CPOM differed between land uses and regions in predictable ways. For example, in relatively unshaded pasture streams, instream and encroaching vegetation riparian was more important, and wood less important, than in forest. Catchment‐area‐ and width‐specific Sp values were more informative for comparisons amongst sites than deposition velocities (vdep). Catchment‐area‐specific Sp values varied 10‐fold amongst regions and threefold amongst land uses. Stepwise multiple regression models explained 71–74% of variance in Sp for the different CPOM analogues and showed that flow (+ influence; i.e., Sp increases with flow) was the most important factor, followed by submerged wood (−), with periphyton biomass (−) also significant in all models. A comparison with results from Spain showed similar relationships between Sp of plastic CPOM analogues and discharge under base‐flow conditions. Restoring riparian vegetation is expected to ultimately enhance instream CPOM by increasing input and retention by wood. Our findings indicate that this should prioritize small streams if the aim is to optimize the restoration of CPOM influence on instream processes. Copyright © 2007 John Wiley & Sons, Ltd.
Contribution of dead wood to the carbon flux in forested streams
Authors: Elosegi Arturo , Díez Joserra , Pozo Jesús 
Published: July 2007

AbstractDead wood has been identified as an important structural component of stream ecosystems, and researchers have stressed its role in retaining sediments and organic matter, increasing habitat diversity and providing refugia for aquatic organisms. Because it is a highly refractory compound, known to take very long periods to break down underwater, it has been considered a slow source of dissolved or fine particulate organic matter. We evaluated the contribution of dead wood to the total carbon flux in two headwater forested streams in northern Spain, one running under mature deciduous forest, the other under eucalyptus plantations. Breakdown rates were measured from branches (10 cm long, 3 cm in diameter) of alder, oak and eucalyptus, the main species present at the streams, applied to the standing crop of fine dead wood following four different models and compared with the breakdown loss of leaf litter calculated in a previous work for the same reaches. Calculations showed breakdown losses of fine wood (FW, diameter 1–5 cm) to range from 6·0 to 12·3 g ash‐free dry mass (AFDM) m−2y−1at the deciduous stream and from 4·6 to 7·1 g AFDM m−2y−1at the eucalyptus stream. Conservative assumptions show that fine wood breakdown losses amount to 21% of the mass lost by leaf breakdown at the deciduous stream and to 9% of leaf breakdown at the eucalyptus stream. So, fine dead wood contributes to a significant fraction of the total breakdown of allochthonous organic matter in the studied streams; other sizes of dead wood (twigs, coarse wood) increase the breakdown by an order of magnitude, and thus can result in a large part of the carbon flux being derived from wood. Copyright © 2007 John Wiley & Sons, Ltd.
Living trees provide stable large wood in streams
Authors: Opperman Jeff J. , Merenlender Adina M. 
Published: July 2007

AbstractLarge wood exerts strong influences on stream channel morphology and aquatic ecosystems. Previously, in‐stream large wood has generally been equated with dead wood. However, in streams in Northern California we found that living wood – trees that entered the channel but remained rooted and living – represented a major portion of the functional in‐stream large wood. We hypothesized that living wood will tend to be more stable, due to an attached root wad, and more persistent, due to lack of decay, than similarly sized dead wood. Living wood may provide important in‐stream structure in streams with riparian corridors that lack large conifers. We surveyed 20 stream reaches in Northern California with riparian corridors dominated by broadleaved trees and found that a high proportion of wood jams had key pieces that were still living. Living wood was capable of serving as a key piece for a wood jam at a smaller size than dead wood and had a greater influence on channel morphology. We found that only 74% of the jams without living wood persisted over 1–2 years while 98% of those with living key pieces remained in place. Due to living wood, the range of tree species and sizes that provide stable and functional in‐stream large wood may be broader than previously described. Copyright © 2007 John Wiley & Sons, Ltd.
Size and position matter: riparian plant establishment from fluvially deposited trees
Authors: Francis Robert A. 
Published: July 2007

AbstractThe sprouting of fluvially deposited trees is an important process for floodplain woodland regeneration along dynamic rivers. This paper investigates how tree size and relative elevation of the location of fluvially deposited trees affects their survival. The survival of newly deposited trees along the River Tagliamento, Italy, was monitored over three field campaigns (2001, 2003 and 2005). A significant negative correlation was found between relative elevation and tree survival, while tree length was significantly positively correlated to survival. Consequently, larger trees deposited at lower elevations have a greater likelihood of regeneration, although the influence of these factors varied according to genera. Copyright © 2007 John Wiley & Sons, Ltd.
Validating multiple‐period density‐forecasting models
Authors: Dowd Kevin 
Published: July 2007

AbstractThis paper examines the problem of how to validate multiple‐period density forecasting models. Such models are more difficult to validate than their single‐period equivalents, because consecutive observations are subject to common shocks that undermine i.i.d. The paper examines various solutions to this problem, and proposes a new solution based on the application of standard tests to a resample that is constructed to be i.i.d. It suggests that this solution is superior to alternatives, and presents results indicating that tests based on the i.i.d. resample approach have good power.  Copyright © 2007 John Wiley & Sons, Ltd.
Forecasting German GDP using alternative factor models based on large datasets
Authors: Schumacher Christian 
Published: July 2007

AbstractThis paper discusses the forecasting performance of alternative factor models based on a large panel of quarterly time series for the German economy. One model extracts factors by static principal components analysis; the second model is based on dynamic principal components obtained using frequency domain methods; the third model is based on subspace algorithms for state‐space models. Out‐of‐sample forecasts show that the forecast errors of the factor models are on average smaller than the errors of a simple autoregressive benchmark model. Among the factor models, the dynamic principal component model and the subspace factor model outperform the static factor model in most cases in terms of mean‐squared forecast error. However, the forecast performance depends crucially on the choice of appropriate information criteria for the auxiliary parameters of the models. In the case of misspecification, rankings of forecast performance can change severely.  Copyright © 2007 John Wiley & Sons, Ltd.