bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cyclopentadienyl(diamino)boranes and their Derivatives — a Family of Versatile Ligand Precursors for Constrained Geometry Complexes
Authors: Braunschweig Holger , Breitling Frank M. , Homberger Melanie , von Koblinski Carsten , White Andrew J. P. , Williams David J. 
Published: December 2003

AbstractA wide range of potential ligand precursors for the preparation of boron‐bridged, constrained geometry complexes has been synthesized. These include (i) cyclopentadienyl(diamino)boranes such as (C5H5)B(NiPr2)N(H)Cy (7), (C5H5)B(NiPr2)N(H)Ph (8), and (C5H5)B{N(SiMe3)2}N(H)Ph (9); (ii) the corresponding indenyl derivatives such as (C9H7)B(NiPr2)N(H)Cy (10) and (C9H7)B{N(SiMe3)2}N(H)Cy (11); and (iii) even bulkier derivatives, such as (C5Me4H)B{N(SiMe3)2}N(H)tBu (12), (C5Me4H)B{N(SiMe3)2}N(H)Ph (13), and (C13H9)B(NiPr2)N(H)Ph (C13H9 = fluorenyl) (14). All compounds have been characterised by multinuclear NMR spectroscopy and mass spectrometry, and in the case of 14 by X‐ray diffraction.
Synthesis, Structure and Solution Chemistry of (5, 5′‐Dimethyl‐2, 2′‐bipyridine)(IDA)copper(II) and Structural Comparison With Aqua(IDA)(1, 10‐phenanthroline)copper(II) (IDA = iminodiacetato)
Authors: Craven Emma , Zhang Cungen , Janiak Christoph , Rheinwald Gerd , Lang Heinrich 
Published: December 2003

AbstractThe protolytic equilibria of copper(II), 5, 5′‐dimethyl‐2, 2′‐bipyridine (bpy) and iminodiacetate (IDA) have been investigated by potentiometric titration between pH 2 and 8. Potentiometric titration suggests the presence of [Cu(IDA)(bpy)]0 at a fraction of 28 % of all copper species in solution at pH 8 with a stability constant logβ = 13.9. The crystal structures of [Cu(IDA)(bpy)] · 4H2O (1) and [Cu(IDA)(H2O)(phen)] · 4H2O (2) show the IDA ligand coordinated in the fac‐NO+O mode. The structure of 1 features “dimeric” entities of symmetry‐independent five‐coordinated Cu‐complexes through a long Cu···O contact, hydrogen bonding and π‐stacking, including a “pyridyl—metal‐chelate ring” π‐contact as evidence for metalloaromaticity in aromatic α, α′‐diimine‐copper(II) chelates. The structure of 2 has the tetragonally six‐coordinated molecular Cu‐complexes arranged by hydrogen bonding and π‐stacking. The crystal water in 2 forms infinite corrugated double chains composed of alternating four‐ and six‐membered, edge‐sharing rings of hydrogen‐bonded water molecules.
Gezielte Synthese und Struktur eines oxamid‐verbrückten Nitroxid‐tetraradikal‐dipalladium‐Komplexes
Authors: Sommer Christian , Ponikwar Walter , Ponikwar Werner , Nöth Heinrich , Beck Wolfgang 
Published: December 2003

AbstractDie Reaktion des chloroverbrückten, orthopalladierten Bis(2, 2, 5, 5‐tetramethyl‐4‐phenyl‐2, 5‐dihydroimidazolin‐1‐oxyl) mit dem Oxalsäurediamid‐verbrückten Bis(tetramethylpiperidin‐oxyl) (1) liefert einen Tetranitroxiddipalladium‐Komplex 3 mit einer Oxamid‐Brücke in der trans‐Konformation, der röntgenographisch charakterisiert wurde und einen weitgehend planaren Bau hat. Auch die Struktur des Dinitroxids 1 wurde durch Röntgenbeugung bestimmt: Sie ist durch zwei intramolekulare Wasserstoffbrücken‐Bindungen zwischen den Oxalsäureamid NH und CO Gruppen festgelegt. Das Dinitroxid 1 ergibt mit der chloroverbrückten Verbindung [(Cl)(Et3P)Pd(μ‐Cl)]2 einen diradikalischen Oxamid‐verbrückten Dipalladium Komplex 4.
Synthesen und Strukturen von Perfluororganohalogenomercuraten [Hg(Rf)2X]— (Rf = CF3, C6F5; X = Br, I)
Authors: Schulz Frank , Pantenburg Ingo , Naumann Dieter 
Published: December 2003

AbstractBei den Umsetzungen von Hg(Rf)2 (Rf = CF3, C6F5) mit [(18‐C‐6)K]X (X = Br, I) in CH2Cl2 oder H2O bilden sich die Mercurate [(18‐C‐6)K][Hg(Rf)2X] in guten Ausbeuten. Die Trifluormethylverbindungen [(18‐C‐6)K][Hg(CF3)2X] kristallisieren isotyp in der monoklinen Raumgruppe P21; die azentrische Raumgruppe wird durch Messung des optischen SHG‐Effektes bestätigt. [(18‐C‐6)K][Hg(C6F5)2Br] kristallisiert in der monoklinen Raumgruppe P21/n und [(18‐C‐6)K][Hg(C6F5)2I] in der triklinen Raumgruppe P1¯. In allen vier Kristallen liegen die Anionen monomer mit T‐förmiger Umgebung des Quecksilbers vor. Die Massenspektren sowie die thermische Stabilität der Mercurate werden beschrieben.
[Cu7] Cluster in SrCu7In6 — Synthesis and Structure Refinement of a Twinned Crystal
Authors: Zaremba Vasyl' I. , Muts Ihor R. , Hoffmann Rolf‐Dieter , Pöttgen Rainer 
Published: December 2003

AbstractThe intermetallic compound SrCu7In6 was synthesized by reaction of the elements in a glassy carbon crucible under flowing argon and subsequently homogenized by annealing at 670 K in an evacuated sealed quartz ampoule for one month. It was investigated by X‐ray diffraction on powders and single crystals: Pnnm, a = 1261.7(2) pm, b = 1261.7(2) pm, c = 1271.4(2) pm, wR2 = 0.1046, 2468 F2 values, 145 variables. The refinement was based on a twinned crystal. The structure constitutes a new superstructure of the cubic NaZn13 type. Indium and copper atoms are well ordered on the Zn2 position of NaZn13. They form icosahedra centered by copper atoms (Zn1 position). The copper atoms form a one‐dimensional infinite cluster chain with Cu—Cu distances ranging from 253 to 280 pm while the indium atoms make up a three‐dimensional network enveloping the copper chains. The strontium atoms occupy large cavities built up by 12 indium and 12 copper atoms. The structure‐chemical relation between the structures NaZn13, CeNi8.5Si4.5, LaNi7In6, and SrCu7In6 is discussed on the basis of a group‐subgroup relation.
Neue binäre Stannide A52Sn82 (A = K, Cs) mit Sn‐ und Sn‐Cluster‐Anionen
Authors: Hoch Constantin , Wendorff Marco , Röhr Caroline 
Published: December 2003

AbstractDie Kristallstrukturen der aus den Elementen zugänglichen neuen isotypen binären Stannide A52Sn82 (A = K/Cs; monoklin, Raumgruppe P21/c, a = 2561.8(7)/ 2712.0(7), b = 1479.2(5)/1555.0(4), c = 5565.3(9)/5878.23(8) pm, Z = 4) enthalten ensprechend A52[Sn9]6[Sn4]7 zum weissen Phosphor isoelektronische und isostrukturelle Zintl‐Anionen Sn und elektronisch den Wade‐Regeln folgende Nido‐Cluster Sn. Die Packung der beiden Anionensorten kann entsprechend topologisch der Anordnung der beiden Atomsorten in den μ‐Phasen zugeordnet werden.
Variable permeability effect on vortex instability of a horizontal natural convection flow in a saturated porous medium with variable wall temperature
Authors: Hassanien I.A. , Salama A.A. , Elaiw A.M. 
Published: December 2003

AbstractA linear stability theory is used to analyze the vortex instability of free convection boundary layer flow in a saturated porous medium adjacent to a horizontal surface where the wall temperature is a power function of the distance from the origin. The variation of permeability in the vicinity of the solid boundary is approximated by an exponential function. The variation rate itself depends slowly on the streamwise coordinate, such as to allow the problem to possess a set of solutions, invariant under a group of transformations. Velocity and temperature profiles as well as local Nusselt number for the base flow are presented for the uniform permeability UP and variable permeability VP cases. The critical Rayleigh numbers and the associated wave numbers are obtained for both UP and VP cases. It is found that the variable permeability effect tends to increase the heat transfer rate and destabilize the flow to the vortex mode of disturbance.
Motivation and self‐perception profiles and links with physical activity in adolescent girls
Authors: Biddle Stuart J.H , Wang C.K.John 
Published: December 2003

ABSTRACTResearch shows a decline in participation in physical activity across the teenage years. It is important, therefore, to examine factors that might influence adolescent girl's likelihood of being physically active. This study used contemporary theoretical perspectives from psychology to assess a comprehensive profile of motivational and self‐perception variables in 11–16 year old English girls (n=516). A cross‐sectional design was employed. Cluster analysis was conducted to (a) map cluster profiles and (b) test whether clusters differed in physical self‐worth, global self‐esteem, and physical activity. Results revealed a five‐cluster solution depicting 40% of the sample as moderately motivated, 30% lowly motivated in two clusters, and 30% highly motivated, also in two clusters. However, differences between clusters on physical activity were quite small. Results show potential areas for intervention to enhance the motivation of adolescent girls for physical activity.
Trajectories of delinquent behaviour in adolescence and their covariates: relations with initial and time‐averaged factors
Authors: Wiesner Margit , Silbereisen Rainer K 
Published: December 2003

ABSTRACTThis longitudinal study examined individual, family, and peer covariates of distinctive trajectories of juvenile delinquency, using data from a community sample of 318 German adolescents (mean age at the first wave was 11.45 years). Latent growth mixture modelling analysis revealed four trajectory groups: high‐level offenders, medium‐level offenders, low‐level offenders, and rare offenders. The trajectory groups were discriminated better by time‐averaged covariates than by initial status covariates. High peer tolerance of deviance and low parental empathy were consistently linked to varying offending trajectories, whereas gender, low academic achievement, and low parental monitoring appeared to be trajectory‐specific covariates.
Associations among sexual attraction status, school belonging, and alcohol and marijuana use in rural high school students
Authors: Rostosky Sharon Scales , Owens Gina P , Zimmerman Rick S , Riggle Ellen D.B 
Published: December 2003

ABSTRACTAnalysis of data collected from 1725 9th graders from 25 rural high schools revealed that students reporting same‐sex attraction or uncertainty about their attraction status also reported significantly lower GPAs, lower school belonging, and higher marijuana and alcohol use. Regression analyses confirmed that beyond the effects of GPA and biological sex, sexual minority attraction status was negatively associated with school belonging. Further, while higher school belonging significantly decreased the odds of alcohol and marijuana use, sexual attraction status did not significantly contribute to the model. Post‐hoc analyses indicated that sexual minority students systematically reported that they perceived less privacy in completing the survey, lending support to the notion that these adolescents may feel less trusting of their school environments. These findings are discussed in light of the need for interventions to address the developmental challenges of sexual minority students.
Morphological development of microglia in the postnatal rat brain
Authors: Orłowski Dariusz , Sołtys Zbigniew , Janeczko Krzysztof 
Published: December 2003

AbstractMorphological transformation of lectin‐positive microglia/macrophages in the developing rat cerebral hemisphere was analysed using quantitative methods. During the first postnatal month, the cells showed increases in their size and fractal dimension accompanied by a simultaneous decrease in their solidity. Regional variations in dynamics of the process indicated the existence of spatio‐temporal developmental gradients within the cerebral hemisphere wall which might correspond with regional patterns of neuronal differentiation. Results of the present study prove that the quantitative methods can be the source of reliable data replacing subjective cell typologies.
Roger B. Porter, Pierre Sauvé, Arvind Subramanian and Amerito B. Zampetti (eds) (2001) Efficiency, Equity, Legitimacy: The Multilateral Trading System at the Millennium
Authors: Rossini Gianpaolo 
Published: December 2003

Book reviewed in this article:Roger B. Porter, Pierre Sauvé, Arvind Subramanian and Amerito B. Zampetti (eds), Efficiency, Equity, Legitimacy: The Multilateral Trading System at the Millennium
The Term Structure of Interest Differentials in a Target Zone with Time‐varying Devaluation Risk
Authors: Knot Klaas , Dijkstra Theo , Haan Jakob de 
Published: December 2003

We extend Svensson's (1991b) analysis of the term structure of interest rate differentials in a target zone. First, the model includes a time‐varying devaluation risk, and second, we analyse the term structure of interest differentials vis‐a‐vis Germany in five countries: Belgium, Denmark, France, Italy and the Netherlands. In our sample, 1983–1993, we differentiate between stable and unstable periods. The findings for Denmark and the Netherlands, and for Belgium in the relatively stable period are broadly in line with Svensson's theory, whereas the other results are more in accordance with the model that allows for a time‐varying devaluation risk.(J.E.L. E43, F31).
Private and Government Employment in the OECD: Productivities and Wages
Authors: Karras Georgios 
Published: December 2003

This paper estimates the productivity of private and government employment for a panel of 23 OECD economies over the 1961–1992 period, and investigates their relation to the government/private wage ratio. The paper finds that (i) the elasticities of output with respect to private and government employment are statistically significantly different from each other; (ii) the marginal products of private and government employment are not statistically significantly different, which suggests that government employment is neither over‐ nor under‐provided, and that shifting employment from one sector to the other is not likely to produce substantial output gains; and (iii) in most of the countries examined, government workers are overpaid in the sense that the government/private wage ratio exceeds the corresponding ratio of marginal products.(J.E.L. E24, E62).
Liquidity Creation through Banks and Markets: A Theoretical Perspective on Securitization
Authors: Von Thadden Ernst‐Ludwig 
Published: December 2003

Securitization is a process that transforms some traditional non‐traded banking assets into marketable securities. To evaluate this process, this paper surveys theories of the intertemporal allocation of funds through demand deposits and anonymous markets, first separately and then in an integrated model. It reviews some work on the role of market frictions and asset characteristics, and concludes that the interplay between these two is crucial in explaining the observed co‐existence of demand deposits and anonymous markets. This suggests that securitization is an opportunity, rather than a threat, to banks.(J.E.L.: D50, G21)
Does Correlation Between Stock Returns Really Increase During Turbulent Periods?
Authors: Chesnay Francois , Jondeau Eric 
Published: December 2003

Correlations betwen international equity markets are often claimed to increase during periods of high volatility. Therefore the benefits of international diversification are reduced when they are most needed, i.e. during turbulent periods. This paper investigates the relationship between international correlation and stock‐market turbulence. We estimate a multivariate Markov‐switching model, in which the correlation matrix varies across regimes. Subsequently, we test the null hypothesis that correlations are regime‐independent. Using weekly stock returns for the S&P, the DAX and the FTSE over the period 1988–99, we find that international correlations significantly increased during turbulent periods.(J.E.L.: C53, G15).
Measuring Monetary Policy Shocks in a Small Open Economy
Authors: Arcangelis Giuseppe De , Giorgio Giorgio Di 
Published: December 2003

This paper presents different specifications of a structural VAR model which are useful to identify monetary policy shocks and their macroeconomic effects for the Italian economy in the 1990s. The analysis is based on a detailed institutional description of the functioning of the domestic market for bank reserves. In this setting, we try to establish if monetary policy shocks are better identified using exchange rates or foreign exchange reserves as a conditioning variable for the small open economy framework. Our analysis confirms the view that the Bank of Italy has been targeting the rate on overnight interbank loans in the 1990s. This is coherent with either proposed modelling choices. Therefore, we interpret shocks to the overnight rate as purely exogenous monetary policy shocks and study how they impact the economy.(J.E.L.: E52, F41, F47).
On the Institutional Design of the European Monetary Union: Conservatism, Stability Pact and Economic Shocks
Authors: Gambacorta Leonardo 
Published: December 2003

The aim of this paper is to design the optimal institutional arrangement for a monetary union. Using a two‐country rational expectations model, the study analyses how the conservatism of the area‐wide central bank and the penalty system for fiscal deviation (Stability and Growth Pact) should be designed with respect to different economic shocks. The optimal institutional arrangement is also dependent on who is the ‘leader’ of the policy game. When national governments move first, the independent area‐wide central bank can exercise greater discipline over national fiscal policies, making the Stability Pact unnecessary.(J.E.L.: E58, E63, F42).
Competition Among Banks, Capital Requirements and International Spillovers
Authors: Acharya Viral V. 
Published: December 2003

The design of prudential bank capital requirements interacts with the industrial organization of the banking sector, in particular, with the level of competition among banks. Increased competition leads to excessive risk‐taking by banks which may have to be counteracted by tighter capital requirements. When capital requirements are internationally uniform but the levels of competition among banks in different countries are not, international spillovers arise on financial integration of these countries. This result begs a more careful analysis of the effect of financial liberalization on the stability of banking sectors in emerging countries. It also calls into question the merits of employing uniform capital requirements across countries that diverge in the industrial organization of their banking sectors.(J.E.L.: G21, G28, G38, F36, E58, D62)
Perverse Effects of an External Ratings‐Related Capital Adequacy System
Authors: Honohan Patrick 
Published: December 2003

It has recently been proposed that banks should be allowed to hold less capital against loans to borrowers who have received a favourable rating by an approved external credit assessment institution (ECAI), or rating agency. But a plausible model of rating agency behaviour shows that this strategy could have perverse results, actually increasing the risk of deposit insurance outlays. First, there is an issue of signalling, whereby low‐ability borrowers may alter their behaviour so as to secure a lower capital requirement for their borrowing. Second, the establishment of a regulatory cut‐off may actually reduce the amount of risk information made available by raters. Besides, the credibility of rating agencies may not be damaged by neglect of the risk of unusual systemic shocks, though it is these that cause the major bank failure costs.(J.E.L.:E53, G21, G33)
Enforcing the 1988 Basel Capital Requirements: Did it Curtail Bank Credit in Emerging Economies?
Authors: Chiuri Maria Concetta , Ferri Giovanni , Majnoni Giovanni 
Published: December 2003

We examine whether the enforcement of bank capital asset requirements (CARs) curtailed the supply of credit in emerging economies. Preliminarily, we identify 16 emerging economies that – according to official and impartial reports – enforced the 1988 Basel standard during the 1990s. Then we perform our twofold econometric analysis. In the former part, we use macro data to test whether, controlling for economic fundamental variables, the enforcement brought about a slowdown in aggregate credit in these countries vis‐a‐vis other emerging economies. We find some support for our hypothesis. In the latter part, we employ individual bank data to better identify the ‘capital crunch’ effect of the enforcement. Here, we find that CAR enforcement – according to the 1988 Basel standard – significantly curtailed credit supply, particularly at less well‐capitalized banks. The two empirical parts together suggest that the CAR enforcement did curtail aggregate credit in the examined emerging countries and that this result is rooted in the attempt by under‐capitalized banks to reduce their loans. We argue that among developing countries – where banks are often the only source of financial intermediation – the positive effect of higher capital requirements, represented by the reduction of poor quality lending, may be offset by their negative impact on bank liquidity and on the level of economic activity. Hence, our results suggest that particular care is required to avoid potential negative macroeconomic effects when phasing in new and higher capital requirements in emerging economies.(J.E.L.: G18, G21, G28)
Price Discovery and Risk Transfer in the Crude Oil Futures Market: Some Structural Time Series Evidence
Authors: Moosa Imad A. 
Published: December 2003

This paper re‐examines the Garbade and Silber (1983) model with the objective of finding out if the crude oil futures market performs the functions of price discovery and risk transfer. The model is estimated, using daily data, as a system of two seemingly unrelated time series equations allowing the coefficients to be time‐varying. The empirical results reveal that the futures market performs about 60 per cent of the price discovery function, and that the elasticity of supply of arbitrage services is adequately high for the market to perform the risk transfer function.(J.E.L: G13, C22).
Social Cost and Groves Mechanisms
Authors: Campbell Donald E. 
Published: December 2003

When an individual’s reported preference scheme makes a difference to the selection of a policy, that individual’s report imposes a cost on the rest of society because the selected policy would have been different had the individual’s reported preference been different. In a paper in Economic Notes, Giacomo Bonanno argues that the penalty assessed by the pivotal mechanism is not equal to the cost that the individual’s participation imposes on the rest of society. This note argues to the contrary, by presenting what we believe to be the correct definition of social cost.(J.E.L: D62, D71, H41).
An Extended Analytical Approach to Credit Risk Management
Authors: Kurth Alexandre , Taylor Hadley , Wagner Armin 
Published: December 2003

Among the ‘reduced form models’ for measuring the credit risk of a bank's portfolio is CreditRisk+, which provides a closed–form solution for calculating the portfolio loss distribution based on an actuarial approach. The limitations of this model are well known, but they are often misinterpreted as being deeply embedded within the model. Dismantling the mathematical components of the model allows one to modify and extend it in several ways while remaining within an analytical approach. One of the most unattractive features is the orthogonality of the background factors or sectors as it hinders any resemblance to real–world macroeconomic indexes or industrial sectors and geographical areas. Among other extensions, which we mention briefly, we present in more detail how the original model can be amended to consider correlations among default risk sectors and among severity risk segments. These extensions are applied to real–life data, based on mortality rate data produced by the Italian Central Bank.(J.E.L.: C00, C51).
Interbank Lending, Liquidity and Banking Crises
Authors: Brighi Paola 
Published: December 2003

In this paper, we show that abandoning the Diamond and Dybvig hypothesis of a unique bank representing the entire banking system gives rise to the possibility of endogenizing the interbank exchanges. In a system characterized by uncertainty regarding the moment of withdrawal of deposits, access to interbank liquidity decreases the bank risk of failure and bank runs. The possibility, moreover, to invest excess liquidity in the interbank market at a positive interest rate increases expected bank profits.(J.E.L.: E52, G21).