bluuebunny/crossref_metadata_2025 huggingface dataset:
A web‐based interactive developmental table for the ascidian Ciona intestinalis, including 3D real‐image embryo reconstructions: I. From fertilized egg to hatching larva
Authors: Hotta Kohji , Mitsuhara Kenta , Takahashi Hiroki , Inaba Kazuo , Oka Kotaro , Gojobori Takashi , Ikeo Kazuho
Published: June 2007

The ascidian chordate Ciona intestinalis is an established model organism frequently exploited to examine cellular development and a rapidly emerging model organism with a strong potential for developmental systems biology studies. However, there is no standardized developmental table for this organism. In this study, we made the standard web‐based image resource called FABA: Four‐dimensional Ascidian Body Atlas including ascidian's three‐dimensional (3D) and cross‐sectional images through the developmental time course. These images were reconstructed from more than 3,000 high‐resolution real images collected by confocal laser scanning microscopy (CLSM) at newly defined 26 distinct developmental stages (stages 1–26) from fertilized egg to hatching larva, which were grouped into six periods named the zygote, cleavage, gastrula, neurula, tailbud, and larva periods. Our data set will be helpful in standardizing developmental stages for morphology comparison as well as for providing the guideline for several functional studies of a body plan in chordate. Developmental Dynamics 236:1790–1805, 2007. © 2007 Wiley‐Liss, Inc.
Deciphering the signaling events that promote melanoma tumor cell vasculogenic mimicry and their link to embryonic vasculogenesis: Role of the Eph receptors
Authors: Hess Angela R. , Margaryan Naira V. , Seftor Elisabeth A. , Hendrix Mary J.C.
Published: June 2007

During embryogenesis, the primordial microcirculation is formed through a process known as vasculogenesis. The term “vasculogenic mimicry” has been used to describe the manner in which highly aggressive, but not poorly aggressive melanoma tumor cells express endothelial and epithelial markers and form vasculogenic‐like networks similar to embryonic vasculogenesis. Vasculogenic mimicry is one example of the remarkable plasticity demonstrated by aggressive melanoma cells and suggests that these cells have acquired an embryonic‐like phenotype. Since the initial discovery of tumor cell vasculogenic mimicry by our laboratory, we have been focusing on understanding the molecular mechanisms that regulate this process. This review will highlight recent findings identifying key signal transduction events that regulate melanoma vasculogenic mimicry and their similarity to the signal transduction events responsible for promoting embryonic vasculogenesis and angiogenesis. Specifically, this review will focus on the role of the Eph receptors and ligands in embryonic vasculogenesis, angiogenesis, and vasculogenic mimicry. Developmental Dynamics 236:3283–3296, 2007. © 2007 Wiley‐Liss, Inc.
When is sexual abuse relevant to bulimic disorders? The validity of clinical judgements
Authors: Waller Glenn , Ruddock Angela , Pitts Christopher
Published: June 2007

At a general level, reported sexual abuse appears to be associated with bulimic eating disorders. Clinicians need to judge whether such a history is relevant to individual cases. However, there are few guidelines for making such a decision. This study examines the symptoms and psychological functions associated with clinicians' judgements of relevance in a case series of bulimic women. Where abuse was reported and was judged to be relevant, subsequent measures showed that the women vomited more frequently and had a higher level of specific self‐denigratory beliefs consequent upon the abuse. These findings provide concurrent validation of clinicians' judgements, and offer some promise of standardizing clinical practice in deciding whether to attend to the consequences of reported sexual abuse.
Predictors of eating psychopathology in adolescent girls
Authors: Wood Alison , Waller Glen , Gowers Simon
Published: June 2007

As part of a prospective study of the development of eating symptomatology, adolescent girls completed measures of eating attitudes and self‐esteem. At two‐year follow‐up, the predictive validity of those measures was tested. Abnormal eating attitudes at baseline predicted both unhealthy eating attitudes and partial syndrome eating disorder (PSED) at follow‐up. Poor self‐esteem at baseline predicted unhealthy eating attitudes, but was not significantly associated with PSED. The results suggest that measures of both eating attitudes and self‐esteem have potential value as screening instruments for subsequent eating problems, assisting in targeting intervention at an early stage.
Continuity and discontinuity in the history of self‐starvation
Authors: van Deth Ron , Vandereycken Walter
Published: June 2007

Overviewing the history of self‐starvation, extreme fasting may be found in three different forms: a miracle, a spectacle, an illness. Referring to different contexts of interpretation, the transition from sainthood to patienthood suggests a discontinuous pattern in the history of self‐starvation. On the other hand, several similarities in the behaviours of fasting women over the centuries rather point to transhistorical continuity. The discussion usually centres around the question of whether one may apply a ‘modern’ diagnosis such as anorexia nervosa, together with its actual sociocultural meanings, onto the phenomenon of food abstinence in previous centuries.
Comments on the proposed criteria for eating disorders in DSM IV
Authors: Beumont Pierre J. V. , Garner David , Touyz Stephen W.
Published: June 2007

The American Psychiatric Association (APA) soon will publish a new system for the classification of psychiatric illnesses, DSM IV. It is likely to become the accepted scheme throughout the world for at least the next decade, exerting a strong influence on clinical work and research (Kendell, 1991). With admirable openness, the APA has promulgated widely the deliberations of the committees charged with designing the new classificatory system, actively seeking comments from American and overseas experts. Proposals were set out in an Options book, and a series of Draft Criteria have now been published (American Psychiatric Association, 1993) from which a fair idea can be gained of how the final version will look. There is an extensive accompanying text, sections of which have also been circulated to consultants with a special interest in the various areas of classification. Field trial results have been assessed and the proposed criteria discussed at the APA's Annual Meeting in May, with a view to publication of the final form of DSM IV early in 1994.

While members of the American Association have had ample opportunity to express their views, it is important that other professional groups throughout the world also voice their opinions of the new system as they too will be affected by its implementation. The purpose of the present paper is to present a critical appraisal of the proposed criteria for eating disorders in DSM IV.
Toward the proteomic identification of biomarkers for the prediction of HBV related hepatocellular carcinoma
Authors: He Qing‐Yu , Zhu Rui , Lei Ting , Ng Mandy Y.M. , Luk John M. , Sham Pak , Lau George K.K. , Chiu Jen‐Fu
Published: June 2007

Early detection is a key step for effective intervention of hepatocellular carcinoma (HCC), the lack of sensitive and specific biomarkers is a major reason for the high rate of HCC‐related mortality. This report described an integrated strategy by combining SELDI‐ProteinChip, sophisticated algorithm analysis, acetonitrile (ACN) pre‐treatment and two‐dimensional electrophoresis (2DE)–peptide mass fingerprinting (PMF) techniques to identify serological markers for the prediction of HBV‐related HCC. Proteomic profiling of three groups of serum specimens from HBV‐related HCC (50 cases), HBV infection (45 cases), and normal subjects (30 cases) was conducted by using SELDI‐ProteinChip system and the resulting different protein peaks were subjected to stepwise statistical analyses. Three most discriminatory peaks at 5890, 11615, and 11724 Da, respectively, were screened out from the statistical algorithm and a predictive model based on the three peaks was constructed and tested using the newly enrolled serum samples. 2DE was applied to separate and compare the serum samples that were pre‐treated by ACN precipitation. The protein spots obviously intensified in HCC sera in the 2DE region of 12 kDa were identified by PMF to be serum SAA, which was validated by SELDI‐TOF spectra of HCC sera after immunoprecipitation using anti‐SAA antibody and by Western blot experiments. Given the fact that SAA is not a specific biomarker, further attempt is being made to identify the other two most discriminatory peaks to realize the possibility of using the predictive model for HCC surveillance and prediction. J. Cell. Biochem. 103: 740–752, 2008. © 2007 Wiley‐Liss, Inc.
A novel TEM contrasting technique for extracellular polysaccharides in in vitro biofilms
Authors: Reese Steven , Guggenheim Bernhard
Published: June 2007

In the past, the visualization of the extracellular matrix of biofilms on an ultrastructural level was hampered by shrinkage artifacts. In addition, the reproducible contrasting of extracellular polysaccharides (EPS) has not satisfactorily been solved. Here we describe a method overcoming these difficulties, which produces artifact‐free transmission electron microscopic (TEM) images using multispecies biofilms grown in vitro. Sufficient contrast was achieved by replacing Schiff's reagent with the osmiophilic amino acid methionine. In addition, shrinkage was avoided by replacing the classical dehydration agents with ethylene glycol and 1,2‐pentanediol. Applying this method provided images of biofilms with an intact matrix in which differentially contrasted bacteria were embedded. All six members of the biofilm consortium (Streptococcus sobrinus, Streptococcus oralis, Veillonella dispar, Fusobacterium nucleatum, Actinomyces naeslundii, and Candida albicans) could be distinguished. Within the matrix, structural differences of EPS, probably due to different proportions of α‐1,3 and α‐1,6 linkages, were apparent. Fibrilar polysaccharides were evident around microcolonies of S. sobrinus, and fluffy polysaccharides were detected in the vicinity of S. oralis microcolonies. The ultrastructure of biofilms prepared for TEM using this method allows the imaging of undistorted EPS as well as the differentiated contrasting of the six microbial species of the in vitro biofilm model. This is a major step forward in determining the spatial arrangement of microorganisms in biofilms on an ultrastructural level. Microsc. Res. Tech., 2007. © 2007 Wiley‐Liss, Inc.
Product graph representations
Authors: Feder Tomás
Published: June 2007

We study a hierarchy of canonical representations of grpahs as subgraphs of cartesian products of graphs. This hierarchy starts with the isometric representation, includes the 2‐isometric represnetation, and ends with the cartesian prime factorization. We show that all three representations can be obtained in O(nm) time using O(m) space, for graphs with n vertices and m edges. The algorithms have immediate parallel versions that use n3 processors and run in O(log2 n) time. © 1929 John Wiley & Sons, Inc.
Some upper bounds on the total and list chromatic numbers of multigraphs
Authors: Häggkvist Roland , Chetwynd Amanda
Published: June 2007

In this paper we discuss some estimates for upper bounds on a number of chromatic parameters of a multigraph. In particular, we show that the total chromatic number for an n‐order multigraph exceeds the chromatic index by the smallest t such that t! > n.
An improvement of fraisse's sufficient condition for hamiltonian graphs
Authors: Ainouche A.
Published: June 2007

Let G be a k‐connected graph of order n. For an independent set c, let d(S) be the number of vertices adjacent to at least one vertex of S and > let i(S) be the number of vertices adjacent to at least |S| vertices of S. We prove that if there exists some s, 1 ≤ s ≤ k, such that ΣxiEX d(X\{Xi}) > s(n−1) – k[s/2] – i(X)[(s−1)/2] holds for every independetn set X ={x0, x1 ⃛xs} of s + 1 vertices, then G is hamiltonian. Several known results, including Fraisse's sufficient condition for hamiltonian graphs, are dervied as corollaries.
The domination numbers of the 5 × n and 6 × n grid graphs
Authors: Chang Tony Yu , Clark W. Edwin
Published: June 2007

The k × n grid graph is the product Pk × Pn of a path of length k − 1 and a path of length n − 1. We prove here formulas found by E. O. Hare for the domination numbers of P5 × Pn and P6 × Pn. © 1993 John Wiley & Sons, Inc.
Acyclic graph coloring and the complexity of the star chromatic number
Authors: Guichard David R.
Published: June 2007

Star chromatic number, introduced by A. Vince, is a natural generalization of chromatic number. We consider the question, “When is χ* < χ?” We show that χ* < χ if and only if a particular digraph is acyclic and that the decisioin problem associated with this question is probably not in NP though it is both NP‐hard and NP‐easy. © 1993 John Wiley & Sons, Inc.
Asymptotic bounds for irredundant and mixed Ramsey numbers
Authors: Chen Guantao , Hattingh Johannes H. , Rousseau Cecil C.
Published: June 2007

The irredundant Ramsey number s(m, n) is the smallest N such that in every red‐blue coloring of the edges of KN, either the blue graph contains an m‐element irredundant set or the red graph contains an n‐element irredundant set. The definition of the mixed Ramsey number t(m, n) differs from s(m, n) in that the n‐element irredundant set is replaced by an n‐element independent set. We prove asymptotic lower bounds for s(n, n) and t(m, n) (with m fixed and n large) and a general upper bound for t(3, n). © 1993 John Wiley & Sons, Inc.
Existence of proportional graphs
Authors: Kärrman Jan
Published: June 2007

The notion of p‐proportional graphs comes from the study of subgraph counts in random graphs, where the p‐proportional graphs occur as exceptional cases in a central limit theorem. In this paper we show that p‐proportional graphs exist for all rational p, 0 < p < 1, and thereby proving a conjecture from [3]. © 1993 John Wiley & Sons, Inc.
On the chordality of a graph
Authors: McKee Terry A. , Scheinerman Edward R.
Published: June 2007

The chordality of a graph G = (V, E) is defined as the minimum k such that we can write E = E1 ∩ … ∩ Ek with each (V, Ei) a chordal graph. We present several results bounding the value of this generalization of boxicity. Our principal result is that the chordality of a graph is at most its tree width. In particular, series‐parallel graphs have chordality at most 2. Potential strengthenings of this statement fail in that there are planar graphs with chordality 3 and series‐parallel graphs with boxicity 3. © 1993 John Wiley & Sons, Inc.
Covering contractible edges in 3‐connected graphs. II. Characterizing those with covers of size three
Authors: Hemminger Robert L. , Yu Xingxing
Published: June 2007

It is shown that if G is a 3‐connected graph with |V(G)| ≥ 10, then, with the exception of one infinite class based on K3,p, it takes at least four vertices to cover the set of contractible edges of G. © 1993 John Wiley & Sons, Inc.
Hamiltonian cycles in 3‐connected claw‐free graphs
Authors: Li MingChu
Published: June 2007

In this paper, we show that every 3‐connected claw‐free graph on n vertices with δ ≥ (n + 5)/5 is hamiltonian. © 1993 John Wiley & Sons, Inc.
Graphs characterized by the second eigenvalue
Authors: Cao Dasong , Yuan Hong
Published: June 2007

In this paper we prove that for a simple graph G without isolated vertices 0 < λ2(G) < 1/3 if and only if G ≅ K̄n‐3 V (K1 ∪ K2), the graph obtained by joining each vertex of K̄n‐3 to each vertex of K1 ∪ K2). © 1993 John Wiley & Sons, Inc.
Representing products of polyhedra by products of edge‐colored graphs
Authors: Gagliardi Carlo , Grasselli Luigi
Published: June 2007

Given an (m + 1)‐colored graph (Γ γ′) and an (n + 1)‐colored graph (, γ″), representing two polyhedra P′, P″ respectively, we present a direct construction of an (m + n+1)‐colored graph (Γ′⊠ Γ″, γ′ ⊠ γ″), which represents the product P′ × P″. Some examples, applications, and conjectures about the genus of manifold products are also presented. © 1993 John Wiley & Sons, Inc.
A note on the line‐distinguishing chromatic number and the chromatic index of a graph
Authors: Salvi N. Zagaglia
Published: June 2007

Let λ(G) be the line‐distinguishing chromatic number and x′(G) the chromatic index of a graph G.

We prove the relation λ(G) ≥ x′(G), conjectured by Harary and Plantholt. © 1993 John Wiley & Sons, Inc.
Unit subduced cycle indices for combinatorial enumeration
Authors: Fujita Shinsaku
Published: June 2007

Combinatorial enumeration by means of unit subduced cycle indices (USCIs) is discussed by using the group I (A5) and the related groups as examples. A modified method for the derivation of USCIs is presented, where a subduced mark table is a key concept. Several properties of USCIs are discussed by clarifying the relationship between double cosets and the subduction of coset representations, which gives an alternative formulation of the USCIs. This treatment provides us with a new prospect concerning the properties of double cosets. The usefulness of subduced cycle indices and cycle indices derived from USCIs is exemplified by enumeration based on an icosahedron.
3‐connected graphs with non‐cut contractible edge covers of size k
Authors: Yu Xingxing
Published: June 2007

In this paper, we show that if a 3‐connected graph G other than K4 has a vertex subset K that covers the set of contractible edges of G and if |K| 3 and |V(G)| 3|K| − 1, then K is a cutset of G. We also give examples to show that this result is best possible. In particular, the result does not hold for K with smaller cardinality.
Dominating sets in n‐cubes
Authors: Weichsel Paul M.
Published: June 2007

A perfectdominatingset S of a graph Γ is a set of vertices of Γ such that every vertex of Γ is either in S or is adjacent to exactly one vertex of S. We show that a perfect dominating set of the n‐cube Qn induces a subgraph of Qn whose components are isomorphic to hypercubes. We conjecture that each of these hypercubes has the same dimension. We then prove that if Qr is a component of the subgraph induced by S, then n − r  1 or 3 (mod 6). A number of examples are given and connections with Steiner Systems and codes are noted.
Independent edges in bipartite graphs obtained from orientations of graphs
Authors: Gimbel J. G. , Reid K. B.
Published: June 2007

Given a digraph D on vertices v1, v2, ⃛, vn, we can associate a bipartite graph B(D) on vertices s1, s2, ⃛, sn, t1, t2, ⃛, tn, where sitj is an edge of B(D) if (vi, vj) is an arc in D. Let OG denote the set of all orientations on the (undirected) graph G. In this paper we will discuss properties of the set S(G) := {β1 (B(D))) | D ≅ OG}, where β1 is the edge independence number.

In the first section we present some background and related concepts. We show that sets of the form S(G) are convex and that max S(G) ≦ 2 min S(G). Furthermore, this completely characterizes such sets.

In the second section we discuss some bounds on elements of S(G) in terms of more familiar graphical parameters.

The third section deals with extremal problems. We discuss bounds on elements of S(G) if the order and size of G are known, particularly when G is bipartite. In this section we exhibit a relation between max S(G) and the concept of graphical closure.

In the fourth and final section we discuss the computational complexity of computing min S(G) and max S(G). We show that the first problem is NP‐complete and that the latter is polynomial.
The diameter of domination k‐critical graphs
Authors: Favaron Odile , Sumner David P. , Wojcicka Ewa
Published: June 2007

A graph is k‐domination‐critical if γ(G) = k, and for any edge e not in G, γ(G + e) = k − 1. In this paper we show that the diameter of a domination k‐critical graph with k ≧ 2 is at most 2k − 2. We also show that for every k ≧ 2, there is a k‐domination‐critical graph having diameter [(3/2)k − 1]. We also show that the diameter of a 4‐domination‐critical graph is at most 5.
Maximum Bandwidth Under Edge Addition
Authors: Wang Jianfang , West Douglas B. , Yao Bing
Published: June 2007

We determine how much the bandwidth B(G) of a graph G can increase when a single edge is added. Let g(b,n) be the maximum possible value of B(G + e) when G has n vertices and bandwidth b. The problem of studying when B(G + e) ≦ B (G) + 1 was originally possed by Erdos. We determine magnified image © 1996 John Wiley & Sons, Inc.
Hamiltonian weights and unique 3‐edge‐colorings of cubic graphs
Authors: Zhang Cun‐Quan
Published: June 2007

A (1,2)‐eulerian weight w of a grph is hamiltonian if every faithful cover of w is a set of two Hamilton circuits. Let G be a 3‐connected cubic graph containing no subdivition of the Petersen graph. We prove that if G admits a hamiltonian weight then G is uniquely 3‐edge‐colorable. © 1996 John Wiley & Sons, Inc.
A sharp lower bound for the circumference of 1‐tough graphs with large degree sums
Authors: Hoa Vu Dinh
Published: June 2007

We show that every 1‐tough graph G on n ≥ 3 vertices with σ3≧ n has a cycle of length at least min{n, n + (σ3/3 ) − α + 1}, where σ3 denotes the minimum value of the degree sum of any 3 pairwise nonadjacent vertices and α the cardinality of a miximum independent set of vertices in G. Our inequality is sharp and implies some sufficient conditions of hamiltonian cycles. © 1995 John Wiley & Sons, Inc.
An algorithm for the decomposition of graphs into cliques
Authors: Su Xiang‐Ying
Published: June 2007

Chung (F. R. K. Chung, On the decomposition of graphs, SIAM J. Algebraic Discrete Methods 23 (1981), 1–12.) and independently Györi and Kostochka (E. Györi and A. V. Kostochka, On a problem of G. O. H. Katona and T. Tarján, Acta Math. Acad. Sci. Hung. 34 (1979), 321–327.) proved the following theorem: For any graph G with n vertices, the edge set E(G) can be decomposed into cliques such that the sum of the orders of the cliques is at most ⌊n2/2⌋. In this paper, we give a polynomial algorithm for the decomposition of E(G) into cliques which satisfies the condition of the theorem. The time required for this algorithm is at most O(n3). The algorithm may be regarded as a support for Winkler's conjecture posed in P. Winkler (Problem 27, Discrete Math. 101 (1992), 359–360). © 1995, John Wiley & Sons, Inc.
Covering a graph with cycles
Authors: Wang Hong
Published: June 2007

Let k and n be two integers such that k ≥ 0 and n ≥ 3(k + 1). Let G be a graph of order n with minimum degree at least ⌈(n + k)/2⌉. Then G contains k + 1 independent cycles covering all the vertices of G such that k of them are triangles. © 1995, John Wiley & Sons, Inc.
Disproof of a conjecture about independent branchings in k‐connected directed graphs
Authors: Huck Andreas
Published: June 2007

For each k ≥ 3, we construct a finite directed strongly k‐connected graph D containing a vertex t with the following property: For any k spanning t‐branchings, B1, …, Bk in D (i. e., each Bi is a spanning tree in D directed toward t), there exists a vertex x ≠ t of D such that the k, x, t‐paths in B1, …, Bk are not pairwise openly disjoint. This disproves a well‐known conjecture of Frank. © 1995, John Wiley & Sons, Inc.
Digraphs of degree 3 and order close to the moore bound
Authors: Baskoro Edy Tri , Miller Mirka , Plesník Ján , Znám Štefan
Published: June 2007

It is known tht Moore digraphs of degree d > 1 and diameter k > 1 do not exist (see [20] or [5]). Furthermore, for degree 2, it is shown tht for l ≥ 3 there are no digraphs of order “close” to, i.e., one less than Moore bound [18]. In this paper, we shall consider digraphs of diameter k, degree 3 and number of vertices one less than Moore bound. We give a necessary condition for the existence of such digraphs and, using this condition, we deduce that such digraphs do not exist for infinitely many values of the diameter. © 1995 John Wiley & Sons, Inc.
Cores of class II graphs
Authors: Hoffman D. G.
Published: June 2007

We find necessary and sufficient conditions for a graph G to be the core of a graph containing an overfull subgraph of the same maximum degree. Thus we enlarge the list of graphs known to be cores of class II graphs. © 1995 John Wiley & Sons, Inc.
Fractional colorings with large denominators
Authors: Fisher David C.
Published: June 2007

The m‐chromatic number χm(G) of a graph G is the fewest colors needed so each node has m colors and no color appears on adjacent nodes. The fractional chromatic number is χ*(G)=limm→∞χm(G)/m. Let m(G) be the least m so that χ* (G) = χm(G)/m. For n node graphs, Chvátal, Garey and Johnson showed m(G) ≦ nn/2 and gave example, where m(G) is asymptotically magnified image. This note gives examples where m(G) is asymptotically λn, where λ ≈︁ 1.346193. © 1995 John Wiley & Sons, Inc.
Some results on tree decomposition of graphs
Authors: Ding Guoli , Oporowski Bogdan
Published: June 2007

We investigate tree decompositions (T,(Xt)tϵV(T)) whose width is “close to optimal” and such that all the subtrees of T induced by the vertices of the graph are “small.” We prove the existence of such decompositions for various interpretations of “close to optimal” and “small.” As a corollary of these results, we prove that the dilation of a graph is bounded by a logarithmic function of the congestion of the graph thereby settling a generalization of a conjecture of Bienstock. © 1995 John Wiley & Sons, Inc.
Synthesis and characterization of succinylcholine‐d18 and succinylmonocholine‐d3 designed for simultaneous use as internal standards in mass spectrometric analyses
Authors: Kuepper Uta , Musshoff Frank , Madea Burkhard
Published: June 2007

Succinylcholine (SUX) is a routinely used yet potentially lethal depolarizing muscle relaxant, the detection of which poses severe problems to the clinical or forensic analyst: within a few minutes after its in vivo administration, SUX is broken down via succinylmonocholine (SMC) to yield the endogenous substances succinic acid and choline. For quantification of SUX and SMC in biological matrices using mass spectrometric detection, appropriate internal standards, i.e. deuterated analogs of the above substances, are indispensable but not commercially available. Internal standards for both substances were hence tailored to fit the analytical needs. The two‐step synthesis and subsequent characterization of SUX‐d18 and SMC‐d3 using a combination of nuclear magnetic resonance (NMR) spectroscopy, fast atom bombardment mass spectroscopy (FAB‐MS) and high‐performance liquid chromatography/tandem mass spectrometry (HPLC‐MS/MS) are described. SUX‐d18 was synthesized by reacting ethanolamine and iodomethane‐d3 in a first quaternization step to choline‐d9, which in turn was esterified with succinyldichloride to yield the final product. SMC‐d3 was produced by esterification of succinic acid anhydride with dimethylaminoethanol, yielding desmethyl‐SMC as intermediate product. The latter was then reacted with iodomethane‐d3 to obtain SMC‐d3. 1H‐ and 13C‐NMR data support the identity and purity as well as the designated deuteration of both preparations, findings which were further confirmed by FAB‐MS as well as HPLC‐MS/MS. Owing to a thoughtful design, the obtained substances SUX‐d18 and SMC‐d3 feature different deuteration patterns at their trimethylamine moieties, and thus finally offer the possibility to simultaneously quantify SUX and SMC in clinical as well as forensic samples using isotope dilution mass spectrometry. Copyright © 2007 John Wiley & Sons, Ltd.
In vitro and in vivo optimization of impaction allografting by demineralization and addition of rh‐OP‐1
Authors: Tsiridis Eleftherios , Ali Zubier , Bhalla Amit , Heliotis Manolis , Gurav Neelam , Deb Sanjukta , DiSilvio Lucy
Published: June 2007

Impaction allografting is a bone tissue engineering technique currently used in lower limb reconstruction orthopedic surgery. Our hypothesis was that biological optimization can be achieved by demineralization and addition of osteogenic protein‐1 (OP‐1) to the allograft. The objective of our in vitro study was to evaluate human mesenchymal stem cell (MSC) proliferation (Alamar Blue assay, titrated thymidine assay, total DNA Hoechst 33258, and scanning electron microscopy) and osteogenic differentiation (alkaline phosphatase assay) in two types of impacted carrier, namely, demineralized bone matrix (DBM) and insoluble collagenous bone matrix (ICBM), with or without OP‐1. The objective in vivo was to compare the osteogenic potential of impacted DBM with or without OP‐1, with that of impacted fresh frozen allograft (FFA), again with or without OP‐1. DBM + OP‐1 optimized osteoinduction and significantly improved (p < 0.05) proliferation and differentiation in comparison to the majority of all other graft preparation in vitro. In addition, DBM + OP‐1 was significantly superior, with regard to osteogenesis, compared to the impacted FFA alone (p < 0.001), FFA + OP‐1 (p = 0.01) and DBM alone (p = 0.02) in vivo. We propose that partial demineralization and addition of OP‐1 provides a good method for improving the osteoinductive properties of fresh allograft currently used in the impaction grafting technique. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1425–1437, 2007
In vivo anterior tibial post contact after posterior stabilizing total knee arthroplasty
Authors: Hanson George R. , Suggs Jeremy F. , Kwon Young‐Min , Freiberg Andrew A. , Li Guoan
Published: June 2007

Anterior polyethylene post failure in posterior stabilizing total knee arthroplasty (TKA) has been reported in recent patient follow‐up studies. However, no data have been reported on the biomechanic interaction between the anterior tibial post and femoral component in posterior stabilizing TKA patients under physiological conditions. The objective of this study was to measure the in vivo anterior tibial post contact area at full knee extension using a dual‐orthogonal fluoroscopic imaging technique. Eleven osteoarthritic patients were investigated after posterior stabilizing TKA to measure the contact between the femoral component box and anterior aspect of the tibial post. Anterior tibial post contact, ranging between 0.5 and 80.9 mm2, was detected in 63% of the healthy patients (seven out of the eleven patients) at weight‐bearing full extension of the knee. The patients with anterior tibial post contact had significantly higher hyperextension angles (−8.4 ± 4.3°) than those without contact (1.4 ± 7.2°). A statistically significant difference was also detected in the femoral component flexion with respect to the femoral shaft between the patients with anterior post contact (2.7 ± 2.7°) and without anterior post contact (−1.3 ± 2.2°). These data indicated that anterior post contact did occur in hyperextension within posterior stabilizing TKA patients. While excessive anterior tibial post contact may cause polyethylene wear and potentially lead to post failure, the tibial post may also act as a substitute for the ACL at low flexion, thus providing stability to the joint after posterior stabilizing TKA. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1447–1453, 2007
Knee instability after acute ACL rupture affects movement patterns during the mid‐stance phase of gait
Authors: Hurd Wendy J. , Snyder‐Mackler Lynn
Published: June 2007

The purpose of this study was to identify gait asymmetries during the mid‐stance phase of gait among subjects with knee instability (“non‐copers”) after acute anterior cruciate ligament (ACL) rupture. Twenty‐one non‐copers with acute, isolated ACL injury ambulated at their intentional walking speed as kinetic, kinematic, and electromyographic (EMG) data were collected bilaterally. Lower extremity movement patterns and muscle activity were analyzed during the mid‐stance and weight acceptance phases of stance. When compared to the uninjured limb, subjects exhibited lower sagittal plane knee excursions and peak knee angles, and higher muscle co‐contraction on the injured limb. There was a lower knee flexion moment at peak knee extension, a trend for the knee contribution to the total support moment to be lower, and a higher ankle contribution to the total support moment on the injured limb. There were differences in the magnitude of muscle activity which included higher hamstring activity and lower soleus activity on the injured limb. Changes in quadriceps, soleus, and hamstring muscle activity on the injured limb were identified during weight acceptance that had not previously been reported, while hip compensation for a lower knee contribution to the total support moment has been described. Non‐copers consistently stabilize their knee with a stiffening strategy involving less knee motion and higher muscle contraction. The variable combination of muscle adaptations that produce joint stiffness, and the ability of both the ankle and the hip to compensate for lower knee control indicate the non‐coper neuromuscular system may be more malleable than previously believed. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1369–1377, 2007
Generation of tendon‐to‐bone interface “enthesis” with use of recombinant BMP‐2 in a rabbit model
Authors: Hashimoto Yusuke , Yoshida Gen , Toyoda Hiromitsu , Takaoka Kunio
Published: June 2007

The anatomical structure at bone‐tendon and bone‐ligament interfaces is called the enthesis. Histologically, the enthesis is characterized by a transitional series of tissue layers from the end of the tendon to bone, including tendon, fibrocartilage, calcified fibrocartilage, and bone. This arrangement yields stronger direct connection of the soft tissues to bone. In surgical repair, the enthesis has proven difficult to reproduce, and the success of ligament‐bone bonding has depended on the fibrous attachment that forms after any ligament reconstructions. In this study, we attempted to generate a direct‐insertion enthesis in two stages. First, recombinant human bone morphogenetic protein‐2 (rhBMP‐2) was injected into the flexor digitorum communis tendon in the rabbit hind limb to induce ectopic ossicle formation. In a second step, the resultant tendon/ossicle complex was then surgically transferred onto the surface of the rabbit tibia to generate a stable tendon‐bone junction. One month following surgery, histomorphological examination confirmed direct insertion of tendon‐bone structures in the proximal tibia of the rabbit. Ultimate failure loads of the BMP‐2‐generated tendon‐bone junction were significantly higher than in the control group (p < 0.01). These findings suggest that it is possible to successfully regenerate a direct tendon‐to‐bone enthesis. Use of this approach may enable successful reconstruction of joints rendered unstable after ligamentous rupture or laxity after anterior cruciate ligament injury. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1415–1424, 2007
Role of fibroblasts and fibroblast‐derived growth factors in periprosthetic angiogenesis
Authors: Tunyogi‐Csapo Miklos , Koreny Tamas , Vermes Csaba , Galante Jorge O. , Jacobs Joshua J. , Glant Tibor T.
Published: June 2007

The periprosthetic granulomatous soft tissue [designated iterfacial membrane (IFM) in this study] exhibits heterogeneous histopathological features, in which highly vascularized areas with dense cellularity alternate with fibrotic and pseudocapsule‐like tissue structures. Although macrophage/monocyte activation is a prominent event in the periprosthetic environment, fibroblasts also phagocytose particulate wear debris both in vivo and in vitro. Particulate wear debris and/or cytokines/growth factors alone or in combination (e.g., in conditioned media of explant cultures of IFMs) stimulated normal synovial and IFM fibroblasts to express inflammatory mediators and growth factors such as interleukin (IL)‐1β, IL‐6, IL‐8, three isoforms of vascular endothelial growth factor (VEGF), monocyte/macrophage chemoattractant protein‐1 (MCP‐1), macrophage‐colony‐stimulating factor (M‐CSF), cycloxygenases (Cox‐1 and Cox‐2), acid‐ and basic‐fibroblast growth factors (FGF‐1 and FGF‐2), leukemia inhibitory factor‐1 (LIF‐1), transforming growth factor β‐1 (TGF‐β1), receptor activator of nuclear factor‐kappa B ligand (RANKL), and osteoprotegerin (OPG). Thus, the fibroblast is capable of expressing a wide array of angiogenic and osteoclastogenic factors which are involved in the detrimental processes of the periprosthetic osteolysis. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1378–1388, 2007
People and large carnivores as biostratinomic agents in Lateglacial cave assemblages
Authors: Lord T. C. , O'Connor T. P. , Siebrandt D. C. , Jacobi R. M.
Published: June 2007

Biostratinomic analysis (processes acting between death and burial) of Lateglacial mammal bone assemblages from three caves in northern England demonstrates the value of re‐examining archived assemblages. With AMS radiocarbon dating of key specimens, these assemblages shed light on the ecology of a region at the northern limit of Lateglacial human activity in Britain. During the Lateglacial Interstadial bears, wolves and humans expanded into the region, bears by around 12 500 14C yr BP, and the earliest evidence for human presence is around 12 300 14C yr BP. At Victoria Cave, wolf activity included predation and scavenging of large ungulates and scavenging bear carcasses apparently resulting from hibernation deaths. The scavenging of bear carcasses is possibly confined to the first part of the Lateglacial Interstadial, whereas evidence for wolf scavenging large ungulates increases later in the Interstadial, after about 11 800 14C yr BP, perhaps reflecting changes in the productivity of the Lateglacial ecosystem, and in human subsistence patterns. The assemblage from Sewell's Cave is wolf den debris from the very end of the Lateglacial Interstadial around 10 800 14C yr BP, whilst that from Kinsey Cave is dominated by large‐bodied carnivores, and is argued to have a quite different taphonomic history. Copyright © 2007 John Wiley & Sons, Ltd.
Reinvestigating hyperpolarized 129Xe longitudinal relaxation time in the rat brain with noise considerations
Authors: Zhou X. , Mazzanti M. L. , Chen J. J. , Tzeng Y.‐S. , Mansour J. K. , Gereige J. D. , Venkatesh A. K. , Sun Y. , Mulkern R. V. , Albert M. S.
Published: June 2007

The longitudinal relaxation time of hyperpolarized (HP) 129Xe in the brain is a critical parameter for developing HP 129Xe brain imaging and spectroscopy and optimizing the pulse sequences, especially in the case of cerebral blood flow measurements. Various studies have produced widely varying estimates of HP 129Xe T1 in the rat brain. To make improved measurements of HP 129Xe T1 in the rat brain and investigate how low signal‐to‐noise ratio (SNR) contributes to these discrepancies, we developed a multi‐pulse protocol during the washout of 129Xe from the brain. Afterwards, we applied an SNR threshold theory to both the multi‐pulse protocol and an existing two‐pulse protocol. The two protocols yielded mean ± SD HP 129Xe T1 values in the rat brain of 15.3 ± 1.2 and 16.2 ± 0.9 s, suggesting that the low SNR might be a key reason for the wide range of T1 values published in the literature, a problem that might be easily alleviated by taking SNR levels into account. Copyright © 2007 John Wiley & Sons, Ltd.
Quantitative measurement of spinal cord blood volume in humans using vascular‐space‐occupancy MRI
Authors: Lu Hanzhang , Law Meng , Ge Yulin , Hesseltine Stephen M. , Rapalino Otto , Jensen Jens H. , Helpern Joseph A.
Published: June 2007

Although perfusion is of major interest for many spinal cord disorders, there is no established, reproducible technique for evaluating blood flow or blood volume of the spinal cord in humans. Here the first report of in vivo measurement of human spinal cord blood volume (scBV) is presented. An FDA‐approved contrast agent, Gd‐DTPA, was used as an intravascular agent for the cord parenchyma, and pre‐/post‐contrast vascular‐space‐occupancy (VASO) MRI experiments were performed to obtain a quantitative estimation of scBV in mL blood/100 mL tissue. VASO MRI was used because it does not rely on knowledge of an arterial input function, it avoids the imaging artifacts of single‐shot echo planar imaging approaches, and it requires only relatively simple and direct calculations for scBV quantification. Preliminary tests at 1.5 T and 3 T gave mean ± SD scBV values of 4.3 ± 0.7 ml/100 mL tissue (n = 6) and 4.4 ± 0.7 ml/100 mL tissue (n = 4), respectively, consistent with the expectation that the scBV values would not be field‐dependent. Copyright © 2007 John Wiley & Sons, Ltd.
Permafrost distribution and active‐layer depths in the McMurdo Dry Valleys, Antarctica
Authors: Bockheim James G. , Campbell Iain B. , McLeod Malcolm
Published: June 2007

The McMurdo Dry Valleys (MDVs) constitute the largest ice‐free area (6700 km2) in Antarctica. Permafrost is ubiquitous in the region and is present as ground ice or buried ice, ice‐cemented permafrost and dry‐frozen permafrost. Using a combined dataset that includes more than 800 shallow (<1.5 m) excavations, we provide a map at a scale of 1:2 million showing the distribution of permafrost in the MDVs. Our data suggest that about 55% of the permafrost is ice cemented, 43% is dry frozen and ground/buried ice comprises at least 2% of the area. Permafrost form is related to climatic zone, age of sediments and local site factors. Ice is present in ice‐cored alpine moraines and coastal tills of Holocene age in hummocky drifts of late Quaternary age (ca. <115 ka); however, it is also present in Miocene‐aged sublimation till in Beacon Valley. Ice‐cemented permafrost is present not only in coastal areas (subxerous climatic zone) and in sediments of late Quaternary age, but also in soils of pre‐Quaternary‐age in ultraxerous regions along the polar plateau. Dry‐frozen permafrost exists along the floors and lower sidewalls of larger ice‐free valleys (xerous climatic zone) in sediments of pre‐late Quaternary age. Dry‐frozen permafrost, which may be unique to Antarctica, appears to form from sublimation of moisture in ice‐cemented permafrost over time. Active‐layer depths are 45 to 70 cm in coastal areas and in the eastern half of Wright and Taylor Valleys, 20 to 45 cm in other ice‐free areas within 60 km of McMurdo Sound, and <20 cm along the polar plateau. Copyright © 2007 John Wiley & Sons, Ltd.
Evaluation of docking programs for predicting binding of Golgi α‐mannosidase II inhibitors: A comparison with crystallography
Authors: Englebienne Pablo , Fiaux Hélène , Kuntz Douglas A. , Corbeil Christopher R. , Gerber‐Lemaire Sandrine , Rose David R. , Moitessier Nicolas
Published: June 2007

Golgi α‐mannosidase II (GMII), a zinc‐dependent glycosyl hydrolase, is a promising target for drug development in anti‐tumor therapies. Using X‐ray crystallography, we have determined the structure of Drosophila melanogaster GMII (dGMII) complexed with three different inhibitors exhibiting IC50's ranging from 80 to 1000 μM. These structures, along with those of seven other available dGMII/inhibitor complexes, were then used as a basis for the evaluation of seven docking programs (GOLD, Glide, FlexX, AutoDock, eHiTS, LigandFit, and FITTED). We found that small inhibitors could be accurately docked by most of the software, while docking of larger compounds (i.e., those with extended aromatic cycles or long aliphatic chains) was more problematic. Overall, Glide provided the best docking results, with the most accurately predicted binding around the active site zinc atom. Further evaluation of Glide's performance revealed its ability to extract active compounds from a benchmark library of decoys. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Distributed basis sets of s‐type Gaussian functions for simple diatomics: Anharmonic‐model distribution
Authors: Glushkov V. N. , Wilson S.
Published: June 2007

An anharmonic model for systematically distributing Gaussian basis sets is presented. Illustrative calculations demonstrate the new approach for the H, HeH2+ and H2 diatomic systems. The total ground state energies for the one‐electron systems and the ground state Hartree‐Fock energy for the H2 molecule supported by distributed basis sets constructed by means of the anharmonic model are compared with the corresponding energies obtained by invoking the variation principle to determine optimal exponents and positions. The use of a series of anharmonic distributions of s‐type Gaussian functions centred on regularly spaced points is also investigated. Calculated energy expectation values supported by our largest distributed basis sets differ from the corresponding exact values by 0.70 μHartree for the H ion and by 0.89 μHartree for the HeH2+ ion. For the ground state Hartree‐Fock energy of the H2 molecule, our distributed basis set yields a value which differs from the finite difference Hartree‐Fock value by 0.67 μHartree. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Andronov‐Hopf‐Bifurkation im Falle stetiger Parameterabhängigkeit
Authors: Schneider K. R.
Published: June 2007

Wir betrachten das Problem der Abzweigung einer periodischen Lösung von einer Gleichgewichtslösung eines zweidimensionalen autonomen Differentialgleichungssystems dx/dt = f(x, λ), falls λ einen kritischen Wert λ0 durchläuft. Unter den Voraussetzungen, daß f bezüglich x dreimal stetig differenzierbar ist, von λ aber nur stetig abhängt und daß beim Durchgang von λ durch λ0 nicht mehr als ein Grenzzyklus von der betrachteten stationären Lösung abzweigt (generischer Fall, der durch ein Koeffizientenkriterium charakterisiert wird), leiten wir ein Kriterium über die Bifurkationsrichtung ab, das diejenigen Kriterien verallgemeinert, die auf der Differenzierbarkeit von f bezüglich λ. basieren. Das Resultat ist auch auf n‐dimensionale Systeme anwendbar, die sich mittels einer Zentrumsmannigfaltigkeit auf zweidimensionale Systeme reduzieren lassen.
Asymptotic Behaviour of Elastoplastic Bodies under Periodic Loading
Authors: Gröger K.
Published: June 2007

In this paper we prove that every quasi‐static deformation process of an elastoplastic body with isotropic and kinematic hardening tends to a periodic process if the loading is periodic in time.
On Non‐Isothermal Rigid Shell Theory
Authors: Epstein M. , Glockner P. G.
Published: June 2007

Using the two fundamental laws of Thermodynamics, results are derived for placing restrictions on constitutive equations of rigid shells. This is achieved by dividing the shell into a number of fictitious layers and accommodating an arbitrary temperature field by use of a continuous piecewise linear coldness function across the thickness. Layer entropy densities are introduced in terms of which the entropy inequality is globally valid for each layer.
Zweiphasen‐Kontinuumstheorie einer Suspension starrer, Kugelförmiger Teilchen unter Berücksichtigung der Teilchenrotation
Authors: Immich H.
Published: June 2007

Für eine Suspension starrer, kugelförmiger Teilchen in einem viskosen Fluid wird eine Zweiphasen‐Kontinuumstheorie (Zwei‐Fluid‐Modell) durch Anwenden einer Volumenmittelung hergeleitet. Es wird gezeigt, daß die volumengemittelten Spannungstensoren der kontinuierlichen und der dispersen Phase nicht symmetrisch sind, wenn man die Rotationsträgheit der starren Teilchen und das Wechselwirkungsmoment zwischen den Phasen berücksichtigt. Außerdem treten als Folge der Mittelung Momentenspannungen in der dispersen Phase auf. Teil I enthält die Ausgangsgleichungen und das Verfahren der Volumenmittelung.
Zur Berechnung von Überschreitenswahrscheinlichkeiten stochastisch beanspruchter mechanischer Systeme
Authors: Friedrich H. , Hennig K.
Published: June 2007

Bei der Untersuchung der Zuverlässigkeit und Sicherheit von stochastisch beanspruchten Konstruktionen besteht eine wesentliche Aufgabe in der Vorausbestimmung der Wahrscheinlichkeit dafür, daß ein solches System versagt, wenn die Beanspruchung oder ein anderer betrachteter stochastischer Prozeß in einem vorgegebenen Zeitintervall mindestens einmal ein bestimmtes Niveau überschreitet. Für diese Überschreitenswahrscheinlichkeit werden Berechnungsformeln abgeleitet.