bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unit subduced cycle indices for combinatorial enumeration
Authors: Fujita Shinsaku 
Published: June 2007

AbstractCombinatorial 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

AbstractIn 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

AbstractA 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

AbstractGiven 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

AbstractA 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

AbstractWe 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

AbstractA (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

AbstractWe 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

AbstractChung (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

AbstractLet 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

AbstractFor 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

AbstractIt 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.
Fractional colorings with large denominators
Authors: Fisher David C. 
Published: June 2007

AbstractThe 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

AbstractWe 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

AbstractSuccinylcholine (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

AbstractImpaction 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

AbstractAnterior 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

AbstractThe 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

AbstractThe 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

AbstractThe 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

AbstractBiostratinomic 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

AbstractThe 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

AbstractAlthough 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.