bluuebunny/crossref_metadata_2025 huggingface dataset:
Über Orceinfarbstoffe, XXV. Bildungsmechanismus und Synthese von Orceinfarbstoffen
Authors: Musso Hans , Ingomar Záhorszky Uwe , Beecken Hermann , Gottschalk Ellen‐Marie , Krämer Horst
Published: June 2007

Der Mechanismus für die Orceinfarbstoffbildung wird im Sinne der Formelschemata 2 und 3 geklärt. Hydroxy‐hydrochinone reagieren mit Ammoniak über 4‐Amino‐resorcine zu Tetrahydroxy‐diphenylaminen, die von Luft sehr leicht zu Indophenolen oxydiert werden. Diese addieren in alkalischer Lösung Resorcinderivate und spalten Wasser zu 7‐Hydroxy‐phenoxazon‐(2)‐Derivaten ab. Diesem Schema entsprechend werden β‐ und γ‐Hydroxy‐orcein und am Chromophor sowie an den seitenständigen Ringen methylsubstituierte Hydroxy‐resorceine dargestellt.
Metallkomplexe der Dialkyldithiophosphinsäuren, II. Synthese und Dipolmomente einiger Diäthyldithiophosphinato‐Komplexe
Authors: Kuchen Wilhelm , Judat Artur , Metten Josef
Published: June 2007

Bei der Umsetzung von Natriumdiäthyldithiophosphinat (C2H5)2P(S)SNa mit R2SnCl2 entstehen Chelatkomplexe des Typs C6H5, n‐C4H9), deren Dipolmomente auf eine cis‐Konfiguration von R in diesen höchstwahrscheinlich oktaedrischen Komplexen des hexakoordinierten SnIV schließen lassen. — Die für einige Diäthyldithiophosphinato‐Verbindungen gefundenen Dipolmomente sind möglicherweise lediglich Folge einer hohen Atompolarisation.
Eine neue Synthese des (±)‐Eleutherols
Authors: Sieglitz Adolf , Böhme Peter , Jordanides Christos
Published: June 2007

Ausgehend von 2‐Chlor‐5‐methoxy‐toluol erhält man über fünf Stufen 1‐Hydroxy‐8‐methoxy‐2‐[α‐hydroxy‐äthyl]‐naphthalin‐carbonsäure‐(3)‐ lacton. Dieses Produkt zeigt das gleiche IR‐Spektrum wie das aus den Knollen von Eleutherine bulbosa gewonnene (+)‐Eleutherol und ist mit synthetischem (±)‐Eleutherol identisch.
Umlagerung von Bicyclo[n.1.0]alkyl‐carbenen
Authors: Kirmse Wolfgang , Pook Karl‐Heinz
Published: June 2007

Bicyclo[n.1.0]alkyl‐carbene (n = 3−5), erzeugt aus den Tosylhydrazonen der entsprechenden Aldehyde, reagieren zu ca. 70% unter Umlagerung zu Bicyclo‐[n.2.0]alkenen und zu ca. 30% unter Zerfall in Cycloalkene und Acetylen.
Grid portal solutions: a comparison of GridPortlets and OGCE
Authors: Zhang Chongjie , Kelley Ian , Allen Gabrielle
Published: June 2007

In this paper we discuss two of the major Grid portal solutions, the Open Grid Computing Environments Collaboratory (OGCE) and GridPortlets, both of which provide basic tools that portal developers can use to interact with Grid middleware when designing their own custom or application‐specific Grid portals. We investigate and compare what each of these packages provides, discuss their advantages and disadvantages, and identify missing features vital for Grid portal development. The main purpose of this paper is to identify what current toolkits provide, reveal some of their limitations, and provide motivation for the evolution of Grid portal solutions. Application groups should find this paper useful in helping to choose an appropriate Grid portal toolkit for building their Grid portals rapidly in a flexible and modular way. Copyright © 2007 John Wiley & Sons, Ltd.
GEONGrid portal: design and implementations
Authors: Youn Choonhan , Baru Chaitan , Bhatia Karan , Chandra Sandeep , Lin Kai , Memon Ashraf , Memon Ghulam , Seber Dogan
Published: June 2007

We have developed the GEONGrid system for coordinating and managing naturally distributed computing, data, and cluster resources on the cyberinfrastructure. Recently, since the use of Grid technology is still very complex for researchers and scientists, the area of Grid Portals has made excellent progress. The Grid portal system is an emerging open Grid computing environment that promises to provide users with uniform seamless access to remote computing and data resources by providing an easy to use interface to cover over the complexity of more sophisticated Grid technologies. In this paper, we present our initial efforts in the design and implementation of service components in the GEONGrid portal. These service components may be implemented as Web services that follow the conventions of service‐oriented architecture design. In this approach, service components are self‐contained, have a well‐defined programming interface defined in WSDL, and communicate using SOAP messaging. In building a GEONGrid portal, we also use a component‐based user interface design. Portlets provide the desired component model for user interfaces in the same way as Web services. Using this approach, which allows Grid portals to be built out of reusable components, has the obvious advantages of reusability and modularity. Copyright © 2007 John Wiley & Sons, Ltd.
A workflow portal supporting multi‐language interoperation and optimization
Authors: Huang Lican , Akram Asif , Allan Rob , Walker David W. , Rana Omer F. , Huang Yan
Published: June 2007

In this paper we present a workflow portal for Grid applications, which supports different workflow languages and workflow optimization. We present an XSLT converter that converts from one workflow language to another and enables the interoperation between different workflow languages. We discuss strategies for choosing the optimal service from several semantically equivalent Web services in a Grid application. The dynamic selection of Web services involves discovering a set of semantically equivalent services by filtering the available services based on metadata, and selecting an optimal service based on real‐time data and/or historical data recorded during prior executions. Finally, we describe the framework and implementation of the workflow portal which aggregates different components of the project using Java portlets. Copyright © 2007 John Wiley & Sons, Ltd.
Amniote somite derivatives
Authors: Christ Bodo , Huang Ruijin , Scaal Martin
Published: June 2007

Somites are segments of paraxial mesoderm that give rise to a multitude of tissues in the vertebrate embryo. Many decades of intensive research have provided a wealth of data on the complex molecular interactions leading to the formation of various somitic derivatives. In this review, we focus on the crucial role of the somites in building the body wall and limbs of amniote embryos. We give an overview on the current knowledge on the specification and differentiation of somitic cell lineages leading to the development of the vertebral column, skeletal muscle, connective tissue, meninges, and vessel endothelium, and highlight the importance of the somites in establishing the metameric pattern of the vertebrate body. Developmental Dynamics 236:2382–2396, 2007. © 2007 Wiley‐Liss, Inc.
Mood, bulimic symptoms and outcome in a community‐based slimming group
Authors: Tata P. , Vigus J. , Bowyer C. , Judd P.
Published: June 2007

The role of psychological and other factors in the treatment of obesity were examined in a community‐based slimming group, where some regular attenders appeared not to be benefiting from the six‐week weight‐loss programme. Forty‐seven women, a significant number of whom were of normal weight, completed psychometric tests assessing variables such as mood, binge eating, and nutritional knowledge. Weight changes were recorded over the course of the programme and at one year follow‐up. Subjects showed statistically significant but limited weightloss over the programme. Most however regained much of the weight over the subsequent year, with high levels of anxiety and binge eating the predominant psychological features of the least successful subjects. The efficacy of conventional dietetic practice, especially for those with mood and/or binge eating problems, is questioned. Identifying and helping this vulnerable sub‐group are stressed and recommendations made regarding psychological interventions for dieters with longterm weight problems.
A study on orientation and absorption spectrum of interfacial molecules by using continuum model
Authors: Ma Jian‐Yi , Wang Jing‐Bo , Li Xiang‐Yuan , Huang Yao , Zhu Quan , Fu Ke‐Xiang
Published: June 2007

In this work, a numerical procedure based on the continuum model is developed and applied to the solvation energy for ground state and the spectral shift against the position and the orientation of the interfacial molecule. The interface is described as a sharp boundary separating two bulk media. The polarizable continuum model (PCM) allows us to account for both electrostatic and nonelectrostatic solute–solvent interactions when we calculate the solvation energy. In this work we extend PCM to the interfacial system and the information about the position and orientation of the interfacial molecule can be obtained. Based on the developed expression of the electrostatic free energy of a nonequilibrium state, the numerical procedure has been implemented and used to deal with a series of test molecules. The time‐dependent density functional theory (TDDFT) associated with PCM is used for the electron structure and the spectroscopy calculations of the test molecules in homogeneous solvents. With the charge distribution of the ground and excited states, the position‐ and orientation‐dependencies of the solvation energy and the spectrum have been investigated for the interfacial systems, taking the electrostatic interaction, the cavitation energy, and the dispersion–repulsion interaction into account. The cavitation energy is paid particular attention, since the interface portion cut off by the occupation of the interfacial molecule contributes an extra part to the stabilization for the interfacial system. The embedding depth, the favorable orientational angle, and the spectral shift for the interfacial molecule have been investigated in detail. From the solvation energy calculations, an explanation has been given on why the interfacial molecule, even if symmetrical in structure, tends to take a tilting manner, rather than perpendicular to the interface. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008
Numerical computations of molecular reactions in associated systems caused by the formation of fractal structures
Authors: Tarasov D. N. , Tiger R. P.
Published: June 2007

The interaction between particles in a system containing fractal clusters has been computationally simulated. The fractal structure of the system has been demonstrated to determine the kinetic characteristics of particle interaction. If a system in an N‐dimensional space (N = 2, 3, 4) contains fractal clusters with the fractal dimension D > N‐1, the rate of interaction of a free particle with particles belonging to clusters depends on their concentration according to the power law. The exponent γ of this power law formally corresponds to the kinetic order of the reaction with respect to the concentration of particles belonging to the clusters. Its value is determined by the free surface of the clusters and depends on its fractal dimension D. The results of simulation qualitatively agree with the data on high, non‐integral orders of many liquid phase molecular reactions characterized by self‐organization of the medium via weak intermolecular interactions, such as hydrogen bonds. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008
An approach to hedetniemi's conjecture
Authors: Sauer N. W. , Zhu X.
Published: June 2007

For a fixed integer n ϵ ω, a graph G of chromatic number greater than n is called persistent if for all n + 1‐chromatic graphs H, the products G × H are n + 1‐chromatic graphs. Wheter all graphs of chromatic number greater than n are persistent is a long‐standing open problem due to Hedetniemi. We call a graph G strongly persistent if G is persistent and the Hajos sum of G with any other persistent graph H is still persistent. This paper extends the class of known persistent graphs by proving the following results: If G is constructed from copies of Kn+1 by Hajos sums, adding vertices and edges and at most one contraction of nonadjacent vertices, then G is strongly persistent. © 1929 John Wiley & Sons, Inc.
A degree condition for spanning eulerian subgraphs
Authors: Chen Zhi‐Hong
Published: June 2007

Let p ≥ 2 be a fixed integer. Let G be a simple and 2‐edge‐connected graph on n vertices, and let g be the girth of G. If d(u) + d(v) ≥ (2/(g − 2))((n/p) − 4 + g) holds whenever uv ∉ E(G), and if n is sufficiently large compared to p, then either G has a spanning eulerian subgraph or G can be contracted to a graph G1 of order at most p without a spanning eulerian subgraph. Furthermore, we characterize the graphs that satisfy the conditions above such that G1 has order p and does not have any spanning eulerian subgraph. © 1993 John Wiley & Sons, Inc.
Lower bounds and upper bounds for chromatic polynomials
Authors: Dohmen Klaus
Published: June 2007

In this paper we give lower bounds and upper bounds for chromatic polynomials of simple undirected graphs on n vertices having m edges and girth exceeding g © 1993 John Wiley & Sons, Inc.
On the edge‐toughness of a graph. II
Authors: Peng Y. H. , Tay T. S.
Published: June 2007

The edge‐toughness T1(G) of a graph G is defined as
equation image
where the minimum is taken over every edge‐cutset X that separates G into ω (G ‐ X) components. We determine this quantity for some special classes of graphs that also gives the arboricity of these graphs. We also give a simpler proof to the following result of Peng et al.: For any positive integers r, s satisfying r/2 < s ≤ r, there exists an infinite family of graphs such that for each graph G in the family, λ(G) = r (where λ(G) is the edge‐connectivity of G) T1(G) = s, and G can be factored into s spanning trees. © 1993 John Wiley & Sons, Inc.
N‐extendability of symmetric graphs
Authors: Aldred R. E. L. , Holton D. A. , Lou Dingjun
Published: June 2007

It is proved that a cyclically (k − 1)(2n − 1)‐edge‐connected edge transitive k‐regular graph with even order is n‐extendable, where k ≥ 3 and k − 1 ≥ n ≥ ⌈(k + 1)/2⌉. The bound of cyclic edge connectivity is sharp when k = 3. © 1993 John Wiley & Sons, Inc.
Disjoint circuits in the cartesian product of two directed cycles
Authors: Curran Stephen
Published: June 2007

We show that the Cartesian product of two directed cycles Za X Zb has r disjointly embedded circuits C1, C2, ⃛, Cr with specified knot classes knot(Ci) = (mi, ni), for i = 1, 2, ⃛, r, if and only if there exist relatively prime non‐negative integers m and n such that knot(Ci) = (m, n), for i = 1, 2, ⃛, r, and r(am + bn) ≦ ab. We generalize this result to the Cayley digraph on a finite abelian group with a two‐element generating set.
Toughness, minimum degree, and the existence of 2‐factors
Authors: Bauer D. , Schmeichel E.
Published: June 2007

Degree conditions on the vertices of a t‐tough graph G(1 ≦ t ≦ 2) that ensure the existence of a 2‐factor in G are presented. These conditions are asymptotically best possible for every t ϵ [1, 3/2] and for infinitely many t ϵ [3/2, 2].
On linear vertex‐arboricity of complementary graphs
Authors: Alavi Yousef , Liu Jiuqiang , Wang Jianfang
Published: June 2007

The linear vertex‐arboricity ρ(G) of a graph G is defined to be the minimum number of subsets into which the vertex set of G can be partitioned such that each subset induces a linear forest. In this paper, we give the sharp upper and lower bounds for the sum and product of linear vertex‐arboricities of a graph and its complement. Specifically, we prove that for any graph G of order p.

magnified image and for any graph G of order p = (2n + 1)2, where n ≅ Z+, 2n + 2 ≦ ρ(G) + ρ(G).
A note on minimum graphs with girth pair (4, 2l + 1)
Authors: Hanson Denis , Wang Ping , Macgillivray Gary
Published: June 2007

We show that the size of a smallest connected k‐regular graph with girth pair (4, 2l + 1) is within a constant of (2l + 1) k/2. In so doing we disprove a conjecture of Harary and Kovacs.
Maximum chromatic polynomials of 2‐connected graphs
Authors: Tomescu Ioan
Published: June 2007

In this paper we obtain chromatic polynomials P(G; λ) of 2‐connected graphs of order n that are maximum for positive integer‐valued arguments λ ≧ 3. The extremal graphs are cycles Cn and these graphs are unique for every λ ≧ 3 and n ≠ 5.

We also determine max{P(G; λ): G is 2‐connected of order n and G ≠ Cn} and all extremal graphs relative to this property, with some consequences on the maximum number of 3‐colorings in the class of 2‐connected graphs of order n having X(G) = 2 and X(G) = 3, respectively. For every n ≧ 5 and λ ≧ 4, the first three maximum chromatic polynomials of 2‐connected graphs are determined.
Large k‐preserving sets in infinite graphs
Authors: Huck Andreas , Niedermeyer Frank , Shelah Saharon
Published: June 2007

Let K be a cardinal. If K χ0, define K:= K. Otherwise, let K := K + 1. We prove a conjecture of Mader: Every infinite K‐connected graph G = (V, E) contains a set S ⊆ V with |S| = |V| such that G/S is K‐connected for all S⊆ S.
Uniqueness of maximal dominating cycles in 3‐regular graphs and of hamiltonian cycles in 4‐regular graphs
Authors: Fleischner Herbert
Published: June 2007

We construct 3‐regular (cubic) graphs G that have a dominating cycle C such that no other cycle C1 of G satisfies V(C) ⊆ V(C1). By a similar construction we obtain loopless 4‐regular graphs having precisely one hamiltonian cycle. The basis for these constructions are considerations on the uniqueness of a cycle decomposition compatible with a given eulerian trail in some eulerian graph.
Pancyclic oriented graphs
Authors: Song Zeng Min
Published: June 2007

Let D be an oriented graph of order n ≧ 9 and minimum degree n − 2. This paper proves that D is pancyclic if for any two vertices u and v, either uv ≅ A(D), or dD+(u) + dD−(v) ≧ n − 3.
Hamiltonian graphs with neighborhood intersections
Authors: Chen G. , Schelp R. H.
Published: June 2007

In this paper, k + 1 real numbers c1, c2, ⃛, ck+1 are found such that the following condition is sufficient for a k‐connected graph of order n to be hamiltonian: for each independent vertex set of k + 1 vertices in G.

magnified image where Si = {v ≅ V:|N(v) ∩ S| = i} for 0 ≦ i ≦ k + 1. Such a set of k + 1 numbers is called an Hk‐sequence. A sufficient condition for the existence of Hk‐sequences is obtained that generalizes many known results involving sum of degrees, neighborhood unions, and/or neighborhood intersections.
A characterization of well‐covered graphs that contain neither 4‐ nor 5‐cycles
Authors: Finbow A. , Hartnell B. , Nowakowski R. J.
Published: June 2007

A graph is well covered if every maximal independent set has the same cardinality. A vertex x, in a well‐covered graph G, is called extendable if G – {x} is well covered and β(G) = β(G – {x}). If G is a connected, well‐covered graph containing no 4‐ nor 5‐cycles as subgraphs and G contains an extendable vertex, then G is the disjoint union of edges and triangles together with a restricted set of edges joining extendable vertices. There are only 3 other connected, well‐covered graphs of this type that do not contain an extendable vertex. Moreover, all these graphs can be recognized in polynomial time.
Self‐dual embeddings of complete multipartite graphs
Authors: Archdeacon Dan
Published: June 2007

In this paper we examine self‐dual embeddings of complete multipartite graphs, focusing primarily on Km(n) having m parts each of size n. If m = 2, then n must be even. If the embedding is on an orientable surface, then an Euler characteristic argument shows that no such embedding exists when n is odd and m  2, 3 (mod 4); there is no such restriction for embeddings on nonorientable surfaces. We show that these embeddings exist with a few small exceptions. As a corollary, every group has a Cayley graph with a self‐dual embedding. Our main technique is an addition construction that combines self‐dual embeddings of two subgraphs into a self‐dual embedding of their union. We also apply this technique to nonregular multipartite graphs and to cubes.
Walks through every edge exactly twice
Authors: Richter R. Bruce
Published: June 2007

In this article, we develop a theory of walks traversing every edge exactly twice. Rosenstiehl and Read proved that if G is a graph with no set of edges that is simultaneously a cycle and a cocycle, then G is planar if and only if there is a closed walk W in G traversing every edge exactly twice such that certain sets of edges derived from W are all cocycles. One consequence of the current work is a simple proof of the Rosenstiehl‐Read theorem. Another is an unusual method for determining the rank (over the integers modulo 2) of a symmetric matrix obtained from a circle graph.
A chvátal–erdős type condition for hamiltonian graphs
Authors: Lu Xiaoyun
Published: June 2007

For a simple graph G of order n ≧ 3, define θ(G) = min{(d(A, A))/|A|; Ø ø A ≠ V}. We shall prove the following Chvátal–Erdős type condition: If α(G) ≦ θ(G)n, then G is Hamiltonian.
Representations of graphs modulo n
Authors: Evans Anthony B. , Fricke Gerd H. , Maneri Carl C. , McKee Terry A. , Perkel Manley
Published: June 2007

A graph is representable modulo n if its vertices can be labeled with distinct integers between 0 and n, the difference of the labels of two vertices being relatively prime to n if and only if the vertices are adjacent. Erdős and Evans recently proved that every graph is representable modulo some positive integer. We derive a combinatorial formulation of representability modulo n and use it to characterize those graphs representable modulo certain types of integers, in particular integers with only two prime divisors. Other facets of representability are also explored. We obtain information about the values of n modulo which paths and cycles are representable.
On the existence of special depth first search trees
Authors: Korach Ephraim , Ostfeld Zvi
Published: June 2007

The Depth First Search (DFS) algorithm is one of the basic techniques that is used in a very large variety of graph algorithms. Most applications of the DFS involve the construction of a depth‐first spanning tree (DFS tree).

In this paper, we give a complete characterization of all the graphs in which every spanning tree is a DFS tree. These graphs are called Total‐DFS‐Graphs. We prove that Total‐DFS‐Graphs are closed under minors. It follows by the work of Robertson and Seymour on graph minors that there is a finite set of forbidden minors of these graphs and that there is a polynomial algorithm for their recognition. We also provide explicit characterizations of these graphs in terms of forbidden minors and forbidden topological minors. The complete characterization implies explicit linear algorithm for their recognition. In some problems the degree of some vertices in the DFS tree obtained in a certain run are crucial and therefore we also consider the following problem: Let G = (V,E) be a connected undirected graph where |V| = n and let d ϵ Nn be a degree sequence upper bound vector. Is there any DFS tree T with degree sequence dT that violates d (i.e., dT ≤ d, which means: E j such that dT(j) > d(j))? We show that this problem is NP‐complete even for the case where we restrict the degree of only on specific vertex to be less than or equal to k for a fixed k ≥ 2 (i.e., d = (n ‐ 1, ⃛, n ‐ 1, k, n ‐ 1, ⃛, n ‐ 1)). 0 1995 John Wiley & Sons, Inc.
Quasi‐transitive digraphs
Authors: Bang‐Jensen Jørgen , Huang Jing
Published: June 2007

A digraph is quasi‐transitive if there is a complete adjacency between the inset and the outset of each vertex. Quasi‐transitive digraphs are interseting because of their relation to comparability graphs. Specifically, a graph can be oriented as a quasi‐transitive digraph if and only if it is a comparability graph. Quasi‐transitive digraphs are also of interest as they share many nice properties of tournaments. Indeed, we show that every strongly connected quasi‐transitive digraphs D on at least four vertices has two vertices v1 and v2 such that D – vi is strongly connected for i = 1, 2. A result of tournaments on the existence of a pair of arc‐disjoint in‐ and out‐branchings rooted at the same vertex can also be extended to quasi‐transitive digraphs. However, some properties of tournaments, like hamiltonicity, cannot be extended directly to quasi‐transitive digraphs. Therefore we characterize those quasi‐transitive digraphs which have a hamiltonian cycle, respectively a hamiltonian path. We show the existence of highly connected quasi‐transitive digraphs D with a factor (a collection of disjoint cycles covering the vertex set of D), which have a cycle of every length 3 ≦ k ≦ |V(D)| − 1 through every vertex and yet they are not hamiltonian. Finally we characterize pancyclic and vertex pancyclic quasi‐transitive digraphs. © 1995, John Wiley & Sons, Inc.
Relative length of long paths and cycles in graphs with large degree sums
Authors: Enomoto Hikoe , van den Heuvel Jan , Kaneko Atsushi , Saito Akira
Published: June 2007

For a graph G, p(G) denotes the order of a longest path in G and c(G) the order of a longest cycle. We show that if G is a connected graph n ≥ 3 vertices such that d(u) + d(v) + d(w) ≧ n for all triples u, v, w of independent vertices, then G satisfies c(G) ≥ p(G) – 1, or G is in one of six families of exceptional graphs. This generalizes results of Bondy and of Bauer, Morgana, Schmeichel, and Veldman. © 1995, John Wiley & Sons, Inc.
Elementary proof of a counting formula for acyclic bipartite tournaments
Authors: Rousseau C. C.
Published: June 2007

This note gives a simple proof of a formula due to Bollobás, Frank and Karoński for counting acyclic bipartit tournaments. © 1995 John Wiley & Sons, Inc.
2‐connected coverings of bounded degree in 3‐connected graphs
Authors: Gao Zhicheng
Published: June 2007

In a recent paper, Barnette showed that every 3‐connected planar graph has a 2‐connected spanning subgraph of maximum degree at most fifteen, he also constructed a planar triangulation that does not have 2‐connected spanning subgraphs of maximum degree five. In this paper, we show that every 3‐connected graph which is embeddable in the sphere, the projective plane, the torus or the Klein bottle has a 2‐connected spanning subgraph of maximum degree at most six. © 1995 John Wiley & Sons, Inc.
Cross‐leg tibial posterior perforator flap
Authors: Georgescu Alexandru V. , Irina Capota , Ileana Matei
Published: June 2007

Background: In the lower leg posttraumatic pathology, we are frequently confronted with tissue defects that are difficult to cover by local or distance means, because of either the poor tissue quality or the precarious local vessels. One of the still available methods for solving these cases remains the cross‐leg flap. The authors will try to demonstrate the advantages of this method, by using the cross‐leg flap based on perforator vessels. Methods: We are presenting two cases for which we practiced a cross‐leg perforator flap, based on perforator vessels emerging from the posterior tibial artery. Results: The results were favorable, demonstrated by immobilization in a comfortable position, perfect flap integration, pedicle flap's division at 14–21 days, early postsurgery ambulation. Conclusions: The cross‐leg perforator flap diminishes many of the disadvantages created by the classic cross‐leg flap and can be successfully used in cases in which other procedures are prohibited. © 2007 Wiley‐Liss, Inc. Microsurgery, 2007.
Embryology of neural tube defects: information provided by associated malformations
Authors: Cabaret A. S. , Loget P. , Loeuillet L. , Odent S. , Poulain P.
Published: June 2007

Objectives

To get information about embryologic mechanisms of neural tube defects (NTD), by studying the associated malformations.

Methods

Eighty three cases of NTD, seen at the prenatal diagnosis unit of Rennes University Hospital (France) between May 1999 and December 2002, were retrospectively studied. Cases with chromosomal anomalies (5/83), cases without available karyotype or pathologic examination were excluded. 24 spina bifida, and 27 cephalic forms (anencephalies, exencephalies, and encephaloceles) were thus analyzed.

Results

Only 22/51 cases (43%) were strictly isolated NTD. Anomalies of tissues arising from neural crests were noted in 8/51 fetuses (16%), midline or lateralization anomalies in 12/51 (24%), and anomalies of mesoblastic tissues in 17/51 (33%). An already known syndrome was found in 4/51 cases (8%).

Conclusion

NDT are more extensive congenital damages that would suggest the restrictive terminology. That prompts to assess cautiously prenatal diagnosis of NTD, and to get detailed pathological examination after termination of pregnancy. Copyright © 2007 John Wiley & Sons, Ltd.
Cell‐free mRNA concentrations of CRH, PLAC1, and selectin‐P are increased in the plasma of pregnant women with preeclampsia
Authors: Purwosunu Yuditiya , Sekizawa Akihiko , Farina Antonio , Wibowo Noroyono , Okazaki Shiho , Nakamura Masamitsu , Samura Osamu , Fujito Naoya , Okai Takashi
Published: June 2007

Objective

To compare mRNA concentrations of corticotrophin‐releasing hormone (CRH), placenta specific‐1 (PLAC1), and selectin‐P in preeclamptic and normal pregnancies.

Methods

Peripheral blood samples were obtained from 43 pregnant women with preeclampsia and 41 control subjects. Plasma was harvested from samples and RNA extracted. Plasma RNA was analyzed using reverse transcription polymerase chain reaction (PCR) assay. Median concentrations of CRH, PLAC1, and selectin‐P mRNA in plasma were compared, to assess possible differences in distribution. Data were also stratified and compared according to clinical severity of preeclampsia. Finally, CRH, PLAC1, and selectin‐P were plotted against quantitative distributions of blood pressure and proteinuria.

Results

All markers were differently distributed between cases and controls. Median values in subgroups correlated with severity of preeclampsia. All markers correlated with both. Selectin‐P was identified as the marker with the highest degree of correlation. No correlation was found between any markers in the control group and proteinuria or blood pressure.

Conclusion

CRH, PLAC1, and selectin‐P are distributed differently in preeclampsia cases compared to controls and correlate with signs of preeclampsia. Copyright © 2007 John Wiley & Sons, Ltd.
Crystal structure of the PIN domain of human telomerase‐associated protein EST1A
Authors: Takeshita Daijiro , Zenno Shuhei , Lee Woo Cheol , Saigo Kaoru , Tanokura Masaru
Published: June 2007

Saccharomyces cerevisiae Est1p is a telomerase‐associated protein essential for telomere length homeostasis. hEST1A is one of the three human Est1p homologues and is considered to be involved not only in regulation of telomere elongation or capping but also in nonsense‐mediated degradation of RNA. hEST1A is composed of two conserved regions, Est1p homology and PIN (PilT N‐terminus) domains. The present study shows the crystal structure of the PIN domain at 1.8 Å resolution. The overall structure is composed of an α/β fold or a core structure similar to the counterpart of 5′ nucleases and an extended structure absent from archaeal PIN‐domain proteins and 5′ nucleases. The structural properties of the PIN domain indicate its putative active center consisting of invariant acidic amino acid residues, which is geometrically similar to the active center of 5′ nucleases and an archaeal PAE2754 PIN‐domain protein associated with exonuclease activity. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Proteochemometric analysis of small cyclic peptides' interaction with wild‐type and chimeric melanocortin receptors
Authors: Kontijevskis Aleksejs , Petrovska Ramona , Mutule Ilze , Uhlen Staffan , Komorowski Jan , Prusis Peteris , Wikberg Jarl E. S.
Published: June 2007

The melanocortin (MC) system confines unique G‐protein coupled receptor pathways, which include the MC1−5 receptors and their endogenous agonists and antagonists, the MCs and the agouti and agouti‐related proteins. The MC4 receptor is an important target for development of drugs for treatment of obesity and cachexia. While natural MC peptides are selective for the MC1 receptor, some cyclic pentapeptides, such as the HS‐129 peptide, show high selectivity for the MC4 receptor. Here we gained insight into the mechanisms for its recognition by MC receptors. To this end we correlated the interaction data of four HS peptide analogues with four wild‐type and 14 multiple chimeric MC receptors to the binary and physicochemical descriptions of the studied entities by use of partial least squares regression, which resulted in highly valid proteochemometric models. Analysis of the models revealed that the recognition sites of the HS peptides are different from the earlier proteochemometrically mapped linear MSH peptides' recognitions sites, although they overlap partially. The analysis also revealed important amino acids that explain the selectivity of the HS‐129 peptide for the MC4 receptor. Proteins 2007. © 2007 Wiley‐Liss, Inc.
A combinatorial testing strategy for concurrent programs
Authors: Lei Yu , Carver Richard H. , Kacker Raghu , Kung David
Published: June 2007

One approach to testing concurrent programs is called reachability testing, which derives test sequences automatically and on‐the‐fly, without constructing a static model. Existing reachability testing algorithms are exhaustive in that they are intended to exercise all possible synchronization sequences of a concurrent program with a given input. In this paper, we present a new testing strategy, calledt‐way reachability testing, that adopts the dynamic framework of reachability testing but selectively exercises a subset of synchronization sequences. The selection of the synchronization sequences is based on a combinatorial testing strategy calledt‐way testing. We present an algorithm that implementst‐way reachability testing, and report the results of several case studies that were conducted to evaluate its effectiveness. The results indicate thatt‐way reachability testing can substantially reduce the number of synchronization sequences exercised during reachability testing while still effectively detecting faults. Copyright © 2007 John Wiley & Sons, Ltd.
Systematic approach for morphological analysis of worn surfaces
Authors: Liskiewicz T. , Mathia T. , Fouvry S. , Neville A.
Published: June 2007

A systematic approach for the analysis of worn surfaces is presented as an analytical tool to deliver information about the current state of the surface. With this approach, not only the quantity but also the quality of the modified surface is revealed, information that is of great importance in cases of surface treatments. The change of bearing ratio is observed with progressive wear, and changes of morphological parameters are related to wear rate. The mechanism of wear particle transfer at the interface is analysed. Prospects for applying this new morphological approach are discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Ähnlichkeitsgesetz des Spektrums von skalaren Schwankungen für den Trägheits‐Konvektionsbereich k ≫ k0 in homogener isotroper Turbulenz
Authors: Szablewski W.
Published: June 2007

Auf der Grundlage der Formel von Corrsin für den Transfer skalarer Schwankungen, die äquivalent ist dem‐5/3‐Gesetz des skalaren Spektrum,s wird für den Trägheits‐Konvektionsbereich k ≫ k0 (k0 Wellenzahl der großen Wirbel) ein Ähnlichkeitsgesetz des skalaren Spektrums hergeleitet, das die Modellkonstante Reλ enthält und in der Asymptote in das–5/3‐Gesetz von Obuchow‐Corrsin übergeht. Für die empirischen Koeffizienten δ bzw. δθ des–5/3‐Gesetzes des Spektrums der Turbulenzenergie bzw. des Spektrums der skalaren Schwankungen nehmen wir die Relation δθ = (2/3) δ an. Mit dem von Shih‐Chun Lin, Shao‐Chi Lin gemessenem eindimensionalen skalaren Spektrum bei Reλ = 150 zeigt sich gute Übereinstimmung.
Zweiphasen‐Kontinuumstheorie einer Suspension starrer, kugelförmiger Teilchen unter Berücksichtigung der Teilchenrotation. Teil II: Gemittelte Bilanzgleichungen, Vergleich mit ähnlichen Theorien
Authors: Immich H.
Published: June 2007

Teil II enthält die volumengemittelten Bilanzgleichungen einer jeden Phase. Die enge Verwandtschaft der volumengemittelten Bilanzgleichungen mit den entsprechenden Beziehungen für polare Flüssigkeiten wird demonstriert.
Zur Stabilität einer ferromagnetischen Flüssigkeit in einem vertikalen Magnetfeld
Authors: Beyer K.
Published: June 2007

Im Rahmen der Variationsrechnung untersuchen wir die Stabilität einer ferromagnetischen Flüssigkeit in einem äußeren Magnetfeld. Für die zweite Variation der Gesamtenergie im ungestörten Ausgangszustand wird eine Ungleichung vom Gårdingschen Typ hergeleitet, die eine gute Einsicht in den Mechanismus des Stabilitätsverlusts bietet. Für unsere Betrachtungen besonders wichtig ist die Tatsache, daß sich die zweite Variation der Gesamtenergie stets in überschaubarer Weise aus dem Systemzustand berechnen läßt.
A Mixture Theory for Heat Conduction in Laminated Composites
Authors: Murakami H. , Maewal A. , Hegemier G. A.
Published: June 2007

An asymptotic method of multiple scales is used to construct a continuum theory with microstructure for heat conduction of a periodically laminated medium. The resulting theory is in the form a homogeneous binary mixture theory with a common microtemperature gradient oriented normal to the interfaces. The model contains three conservation equations which include averaged temperatures of two constituents and microtemperature gradient. Finally, the mixture equations are applied for heat conduction in obliquely laminated half space which is suddenly heated on its free surface, and the effect of lay‐up angle is clarified.
Primitive Variable Finite Element Solutions of Free Convection Flows in Porous Media
Authors: Diersch H.‐J.
Published: June 2007

Zur Simulation zweidimensionaler, stationärer und instationärer, freier Konvektionsströmungen in porösen Medien, hervorgerufen durch Konzentrationsgradienten, wird eine Galerkin‐Finite‐Element‐Methode angewendet. Für das numerische Verfahren dienen Druck, Geschwindigkeiten und Konzentration als abhängige Variable. Eine Beschreibung der iterativen Näherungsmethode wird gegeben. Anhand der Berechnung verschiedener Testbeispiele zeigt sich die Gültigkeit und Genauigkeit des verwendeten Finite‐Element‐Modells.
Eine Runge‐Kutta‐Nyström‐Formel 9‐ter Ordnung mit Schrittweitenkontrolle für Differentialgleichungen x = f(t, x)
Authors: Fehlberg E.
Published: June 2007

Eine Runge‐Kutta‐Nyström‐Formel 9‐ter Ordnung für x = f(t, x) mit Schrittweitenkontrolle in × wird aufgestellt. Die vollständigen Bedingungsgleichungen für solch eine Formel werden angegeben. Die Reduktion der Bedingungsgleichungen wird erörtert. Die Berechnung der Koeffizienten der Formel wird erläutert. Die Fehlerterms der Formel werden diskutiert. Die Koeffizienten einer Formel mit kleinen Fehlerterms werden in Bruchform angegeben. Die Anwendung der Formel auf Quadraturprobleme x = f(tx) wird diskutiert. In zwei numerischen Beispielen wird die Formel bezüglich Genauigkeit und Zeitbedarf mit bekannten Formeln 8‐ter und 10‐ter Ordnung verglichen.
Numerische Stabilität von Plattenelementen auf der Grundlage hybrider Deformationsmodelle
Authors: Knothe K. , Herrmann H. , Müller W.
Published: June 2007

Bei Plattenberechnungen mit Elementen auf der Grundlage der vereinfachten, hybriden Deformationsmethode, wobei auf die Erfüllung von C1‐Stetigkeitsforderungen verzichtet wird, können numerische Instabilitäten auftreten. Die Ursache dieser Instabilitäten wird untersucht und es werden Abhilfemaßnahmen aufgezeigt.
Micropolar Flow Due to a Rotating Disc with Suction and Injection
Authors: Guram G. S. , Anwar M.
Published: June 2007

The steady, laminar, and incompressible flow of a micropolar fluid due to a rotating disc with uniform suction and injection is considered. The equations of motion are reduced to dimensionless forms which include six dimensionless parameters, and integrated numerically by Gauss‐Seidel iterative procedure and Simpson's rule. Some of the results are presented in the tables and diagrams, for different values of the suction and injection parameters, and compared with the known results for a Newtonian fluid.
Copula Functions for Residual Dependency
Authors: Braeken Johan , Tuerlinckx Francis , De Boeck Paul
Published: June 2007

Most item response theory models are not robust to violations of conditional independence. However, several modeling approaches (e.g., conditioning on other responses, additional random effects) exist that try to incorporate local item dependencies, but they have some drawbacks such as the nonreproducibility of marginal probabilities and resulting interpretation problems. In this paper, a new class of models making use of copulas to deal with local item dependencies is introduced. These models belong to the bigger class of marginal models in which margins and association structure are modeled separately. It is shown how this approach overcomes some of the problems associated with other local item dependency models.
The hypoxia‐inducible factor is stabilized in circulating hematopoietic stem cells under normoxic conditions
Authors: Piccoli Claudia , D'Aprile Annamaria , Ripoli Maria , Scrima Rosella , Boffoli Domenico , Tabilio Antonio , Capitanio Nazzareno
Published: June 2007

The hypoxia‐inducible factor (HIF) transcriptional system enables cell adaptation to limited O2availability, transducing this signal into patho‐physiological responses such as angiogenesis, erythropoiesis, vasomotor control, and altered energy metabolism, as well as cell survival decisions. However, other factors beyond hypoxia are known to activate this pleiotropic transcription factor. The aim of this study was to characterize HIF in human hematopoietic stem cells (HSCs) and evidence is provided that granulocyte colony stimulating factor‐mobilized CD34+‐ and CD133+‐HSCs express a stabilized cytoplasmic form of HIF‐1α under normoxic conditions. It is shown that HIF‐1α stabilization correlates with down‐regulation of the tumour suppressor von Hippel‐Lindau protein (pVHL) and is positively controlled by NADPH‐oxidase‐dependent production of reactive oxygen species, indicating a specific O2‐independent post‐transcriptional control of HIF in mobilized HSCs. This novel finding is discussed in the context of the proposed role of HIF as a mediator of progenitor cell recruitment to injured ischemic tissues and/or in the control of the maintenance of the undifferentiated state.
A medal for the Arctic?
Authors: Woodman Richard
Published: June 2007

Ever since the end of the Second World War men who served on ships, both naval and merchant, which were involved in the transport of war materials to north Russia between 1941 and 1945 have sought recognition for their service with an appropriate campaign medal. They have failed to achieve this through a complicated muddle of government policy, ignorance and cold-heartedness.
Alexander von Middendorff and his expedition to Siberia (1842–1845)
Authors: Tammiksaar Erki , Stone Ian R.
Published: June 2007

Alexander Theodor von Middendorff's name is closely associated with the exploration of Siberia and research on the natural history of the Russian Arctic. Yet it is surprising that, in the extensive literature in Russian and German on the environment of those regions, there are no specific analyses of Middendorff's important contribution to these areas of research. He is barely mentioned in English language studies on the history of exploration and science in Siberia and there are very few accounts of his life and work. The present paper is largely based on a number of newly discovered archival documents and contemporary literary sources and is an attempt to fill this lacuna. In this account, all dates are given according to the new style calendar.
Petroleum discourse in the European Arctic: the Norwegian case
Authors: Jensen Leif Christian
Published: June 2007

The article addresses old ‘west-east discourses’ and how they continue to develop in the high north, and, not least, in the Norwegian petroleum debate. Adopting a discourse analytical perspective the author shows how environmental safety is used as an argument in favour of Norway producing oil in the Barents Sea at the earliest possible moment. This is only feasible if a connection is made in the public mind between Russia and the environment. These views, it is argued, stem from ideas about Russia that gained currency after the demise of the Soviet Union. While they perhaps have less to do with Russia's petroleum industry and environmental performance today, they nevertheless have a strong impact on how challenges in the high north and Arctic region are perceived. And, perhaps even more importantly, they define freedom of action and available options. In this paper all references to government departments refer to those of Norway.
F.G. Schwatka's headstone
Authors: Savitt Ronald
Published: June 2007

The explorer F.G. Schwatka, a participant in the Franklin search is buried in Salem, Oregon. This note sets on record information concerning the headstone of his grave.
Century-old ski found at Mys Triest, Ostrov Champa, Zemlya Frantsa-Iosifa, Russia
Authors: Capelotti P.J.
Published: June 2007

A fragment of a ski dating from the late 19th or early 20th century was found at Mys Triest [Cape Trieste] on Ostrov Champa [Champ Island] in the Zemlya Frantsa-Iosifa [Franz Josef Land] archipelago in August 2006. The age and location of the ski suggest a connection with the American era of exploration of Zemlya Frantsa-Iosifa (1898–1905).
Confirmation of the identity of the wreck of the steamer Chelyuskin
Authors: Barr William
Published: June 2007

The two components recovered from a sunken wreck on the bed of the Chukchi Sea in September 2006 have been identified by experts as having come from the Soviet steamer Chelyuskin. They were displayed at an exhibition that opened on 13 February 2007, and was attended by the two surviving members of the complement of Chelyuskin.
The Dutch ‘Miracle’ Revisited: The Impact of Employment Growth on Poverty
Authors: MARX IVE
Published: June 2007

The past decade has been marked by the coming to prominence of social policy doctrines at the centre of which sits the idea that poverty reduction is best achieved through increased levels of labour market participation. A major reference point in the debate is the Netherlands, where a radical policy shift from passive benefit adequacy towards boosting labour market participation was initiated around the late 1980s and where it has been vigorously pursued since. The Netherlands is routinely praised for achieving a meteoric rise in employment, while maintaining extensive social protection and low levels of poverty and inequality. This article shows that unprecedented employment growth during the 1980s and 1990s went accompanied with comparatively small reductions in absolute poverty and a rise in relative poverty among the working-age population. These developments are linked to the main features of Dutch economic and social policy. The article also draws out some general lessons.
Further tales from New York City: (1) Norbert: reading and re-reading, (2) Total embarrassment
Authors: Blaisdell Bob
Published: June 2007

Life in the classroom.
The Adoption and Implementation of a Service Innovation in a Social Work Setting – a Case Study of Family Group Conferencing in the UK
Authors: Brown Louise
Published: June 2007

The last decade has witnessed a growing interest in the promotion and use of innovation as a means of improving public services. Rafts of central government initiatives exist to promote, support and learn from innovative activity. This paper examines the adoption of a new, innovative service in a social work setting in the UK, namely family group conferencing. It explores the rate and pattern of the adoption of this service innovation by Councils with Social Service Responsibilities (CSSRs). It examines the implementation process and identifies: resources, professional resistance, risk, the role of central government and champions amongst the factors that facilitated and inhibited its use in three case study sites.