bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modulation of the heteromeric Kir4.1–Kir5.1 channel by multiple neurotransmitters via Gαq‐coupled receptors
Authors: Rojas Asheebo , Su Junda , Yang Liang , Lee Ming , Cui Ningren , Zhang Xiaoli , Fountain Dyanna , Jiang Chun 
Published: June 2007

AbstractThe heteromeric Kir4.1–Kir5.1 channel is a candidate sensing molecule for central CO2chemoreception. Since central CO2chemoreception is subject to neural modulations, we performed studies to test the hypothesis that the Kir4.1–Kir5.1 channel is modulated by the neurotransmitters critical for respiratory control, including serotonin (5‐HT), substance‐P (SP), and thyrotropin releasing hormone (TRH). The heteromeric Kir4.1–Kir5.1 channel was strongly inhibited by SP, TRH, and 5‐HT when expressed inXenopusoocytes, whereas these neurotransmitters had no effect on the homomeric Kir4.1 channel. Such an inhibition was dose‐dependent and relied on specific Gαq‐protein‐coupled receptors and protein kinase C (PKC). No direct interaction of the channel with G‐proteins was found. Channel sensitivity to CO2/pH was not compromised with the inhibition by these neurotransmitters, as the channel remained to be inhibited by acidic pH following an exposure to the neurotransmitters. The firing rate of CO2‐sensitive brainstem neurons cultured in microelectrode arrays was augmented by SP or a 5‐HT2A receptor agonist, which was blocked by PKC inhibitors suggesting that PKC underscores the inhibitory effect of SP and 5‐HT in cultured brainstem neurons as well. Immunostaining showed that both Kir4.1 and Kir5.1 proteins were co‐localized in the cultured brainstem neurons. These results therefore indicate that the heteromeric Kir4.1–Kir5.1 channel is modulated by the neurotransmitters critical for respiratory control, suggesting a novel neuromodulatory mechanism for the chemosensitivity of brainstem neurons to elevated PCO2and acidic pH. J. Cell. Physiol. 214:84–95, 2008. © 2007 Wiley‐Liss, Inc.
Anti‐apoptotic Bcl‐2 enhancing requires FGF‐2/FGF receptor 1 binding in mouse osteoblasts
Authors: Agas Dimitrios , Marchetti Luigi , Menghi Giovanna , Materazzi Stefano , Materazzi Giovanni , Capacchietti Mariolina , Hurley Marja M. , Sabbieti Maria Giovanna 
Published: June 2007

AbstractIn this study, we investigated the role of prostaglandin F2α (PGF2α) in mouse osteoblast survival and the function of fibroblast growth factor 2 (FGF‐2) and fibroblast growth factor receptor 1 (FGFR1) in this process. In particular, for the first time, we demonstrated that PGF2α increased osteoblast survival in a dose‐dependent manner and we showed that the effect is correlated with an increase in Bcl‐2/Bax ratio. Furthermore, we demonstrated that PGF2α caused a decrement of the active caspases 9 and 3. By blocking FGF‐2 with the specific neutralizing antibody and by depletion of FGFR1 gene with a specific siRNA, we showed that FGFR1 and FGF‐2 are critical for the increment of Bcl‐2/Bax ratio and the decrement of the active caspases 9 and 3, induced by PGF2α. Moreover, transmission electron microscopy studies showed that PGF2α increased binding of FGF‐2 and FGFR1 and co‐localization of reactive sites at plasma membrane level. In conclusion, we report a novel mechanism in which PGF2α induces FGF‐2 binding to its specific cell surface receptor 1 leading to a cascade pathway that culminates with increased mouse osteoblast survival. J. Cell. Physiol. 214:145–152, 2008. © 2007 Wiley‐Liss, Inc.
The construction of tutte's 8‐cage and the conder graph
Authors: Lorimer Peter 
Published: June 2007

AbstractA unified way is described of constructing two 5‐are‐transitive graphs of valency 3, the Tutte 8‐cage, and the Conder graph. It well illustrates the method of constructing symmetric graphs described in P. Lorimer “Vertex Transitive Graphs: Symmetric Graphs of Prime Valency,” Journal of Graph Theory, 8 (1984, 55–68).
On the chromaticity of certain subgraphs of a q‐tree
Authors: Wanner Thomas 
Published: June 2007

AbstractWe show that a graph G on n ⩾ q + 1 vertices (where q ⩾ 2) has the chromatic polynomial P(G;λ) = λ(λ − 1) … (λ − q + 2) (λ − q + 1)2 (λ − q)n−q−1 if and only if G can be obtained from a q‐tree Ton n vertices by deleting an edge contained in exactly q − 1 triangles of T. Furthermore, we prove that these graphs are triangulated.
A necessary and sufficient condition for connected, locally k‐connected k1,3‐free graphs to be k‐hamiltonian
Authors: Huai‐Lu Zhou 
Published: June 2007

AbstractWe prove the following conjecture of Broersma and Veldman: A connected, locally k‐connected K1,3‐free graph is k‐hamiltonian if and only if it is (k + 2)‐connected (K ⩾ 1).
Maximally connected digraphs
Authors: Fàbrega J. , Fiol M. A. 
Published: June 2007

AbstractThis paper introduces a new parameter I = I(G) for a loopless digraph G, which can be thought of as a generalization of the girth of a graph. Let k, λ, δ, and D denote respectively the connectivity, arc‐connectivity, minimum degree, and diameter of G. Then it is proved that λ = δ if D ⩽ 2I and κ k = δ if D ⩽ 2I ‐ 1. Analogous results involving upper bounds for k and λ are given for the more general class of digraphs with loops. Sufficient conditions for a digraph to be super‐λ and super‐k are also given. As a corollary, maximally connected and superconnected iterated line digraphs and (undirected) graphs are characterized.
Spanning trees with many leaves in cubic graphs
Authors: Griggs Jerrold R. , Kleitman Daniel J. , Shastri Aditya 
Published: June 2007

AbstractFor a connected graph G let L(G) denote the maximum number of leaves in any spanning tree of G. We give a simple construction and a complete proof of a result of Storer that if G is a connected cubic graph on n vertices, then L(G) ⩾ [(n/4) + 2], and this is best possible for all (even) n. The main idea is to count the number of “dead leaves” as the tree is being constructed. This method of amortized analysis is used to prove the new result that if G is also 3‐connected, then L(G) ⩾ [(n/3) + (4/3)], which is best possible for many n. This bound holds more generally for any connected cubic graph that contains no subgraph K4 ‐ e. The proof is rather elaborate since several reducible configurations need to be eliminated before proceeding with the many tricky cases in the construction.
Cycles containing matchings and pairwise compatible euler tours
Authors: Jackson Bill , Wormald Nicholas C. 
Published: June 2007

AbstractLet M be a matching in a graph G such that d(x) + d(y) ≥ |G| for all pairs of independent vertices x and y of G that are incident with M. We determine a necessary and sufficient condition for M to be contained in a cycle of G. This extends results of Häggkvist and Berman, and implies that if M is a 1‐factor of G and |G|  0 (mod 4), then M is contained in a Hamilton cycle of G. We use our results to deduce that an eulerian graph of minimum degree 2k contains k pairwise compatible Euler tours.
Maximal matchings in graphs with large neighborhoods of independent vertices
Authors: Rinsma I. , Little C. H. C. , Woodall D. R. 
Published: June 2007

AbstractWe obtain lower bounds on the size of a maximum matching in a graph satisfying the condition |N(X)| ≥ s for every independent set X of m vertices, thus generalizing results of Faudree, Gould, Jacobson, and Schelp for the case m = 2.
On the parity of planar covers
Authors: Archdeacon Dan , Bruce Richter R. 
Published: June 2007

AbstractA covering is a graph map ϕ: G → H that is an isomorphism when restricted to the star of any vertex of G. If H is connected then |ϕ−1(v)| is constant. This constant is called the fold number. In this paper we prove that if G is a planar graph that covers a nonplanar H, then the fold number must be even.
On the largest tree of given maximum degree in a connected graph
Authors: Caro Y. , Krasikov I. , Roditty Y. 
Published: June 2007

AbstractWe prove that every connected graph G contains a tree T of maximum degree at most k that either spans G or has order at least kδ(G) + 1, where δ(G) is the minimum degree of G. This generalizes and unifies earlier results of Bermond [1] and Win [7]. We also show that the square of a connected graph contains a spanning tree of maximum degree at most three.
Score sequences of oriented graphs
Authors: Avery Peter 
Published: June 2007

AbstractWe extend Landau's concept of the score structure of a tournament to that of the score sequence of an oriented graph, and give a condition for an arbitrary integer sequence to be a score sequence. The proof is by construction of a specific oriented graph Δ(S) with given score sequence S. It is shown that Δ(S) is transitive and has the minimum number of arcs among the oriented graphs with score sequence S.
On path lengths modulo three
Authors: Deng Xiaotie , Papadimitriou Christos H. 
Published: June 2007

AbstractWe show that between any two nodes of a cubic, planar, three‐connected graph there are three paths whose lengths are 0, 1, and 2 modulo 3, respectively. The proof is by a rather extensive case analysis. Counterexamples show that all three hypotheses (i.e., planarity, degree‐three, and three‐connectivity) are necessary.
Tutte polynomials for trees
Authors: Chaudhary Sharad , Gordon Gary 
Published: June 2007

AbstractWe define two two‐variable polynomials for rooted trees and one two‐variable polynomial for unrooted trees, all of which are based on the coranknullity formulation of the Tutte polynomial of a graph or matroid. For the rooted polynomials, we show that the polynomial completely determines the rooted tree, i.e., rooted trees T1 and T2 are isomorphic if and only if f(T1) = f(T2). The corresponding question is open in the unrooted case, although we can reconstruct the degree sequence, number of subtrees of size k for all k, and the number of paths of length k for all k from the (unrooted) polynomial. The key difference between these three polynomials and the standard Tutte polynomial is the rank function used; we use pruning and branching ranks to define the polynomials. We also give a subtree expansion of the polynomials and a deletion‐contraction recursion they satisfy.
A short proof for a generalization of Vizing's theorem
Authors: Berge Claude , Fournier Jean Claude 
Published: June 2007

AbstractFor a simple graph of maximum degree Δ, it is always possible to color the edges with Δ + 1 colors (Vizing); furthermore, if the set of vertices of maximum degree is independent, Δ colors suffice (Fournier). In this article, we give a short constructive proof of an extension of these results to multigraphs. Instead of considering several color interchanges along alternating chains (Vizing, Gupta), using counting arguments (Ehrenfeucht, Faber, Kierstead), or improving nonvalid colorings with Fournier's Lemma, the method of proof consists of using one single easy transformation, called “sequential recoloring”, to augment a partial k‐coloring of the edges.
General results on tolerance intersection graphs
Authors: Jacobson M. S. , McMorris F. R. , Scheinerman E. R. 
Published: June 2007

AbstractIn this paper, general results are presented that are related to ϕ‐tolerance intersection graphs previously defined by Jacobson, McMorris, and Mulder. For example, it is shown that all graphs are ϕ‐tolerance intersection graphs for all ϕ, yet for “nice” ϕ, almost no graphs are ϕ‐tolerance interval graphs. Additional results about representation of trees are given.
Rotation numers for complete bipartite graphs
Authors: Haviland Julie , Thomason Andrew 
Published: June 2007

AbstractA rooted graph is a pair (G, x) where G is a simple undirected graph and x ϵ V(G). If G if rooted at x, then its rotation number h(G, x) is teh minimum number of edges in a graph F, of the same order as G, such that for all v ϵ V(F) we can find a copy of G in F with the root x at v. Rotation numbers for complete bipartite graphs were itroduced in [4] by Cockayne and Lorimer. Several cases were evaluated by Bollobás and Cockayne in [2], and in this paper we give a full solution.
A note on n‐extendable graphs
Authors: Yu Qinglin 
Published: June 2007

AbstractA graph G having a perfect matching is called n‐extendable if every matching of size n of G can be extended to a perfect matching. In this note, we show that if G is an n‐extendable nonbipartite graph, then G + e is (n ‐ 1)‐extendable for any edge e ϵ E(G). © 1992 John Wiley & Sons, Inc.
Influence of polyethylene glycol on the excretion and digestibility of amino acids in casein and tannic acid‐fed broilers
Authors: Mansoori Behzad , Ghazi Shahab 
Published: June 2007

AbstractUsing the precision feeding technique, an experiment was conducted to evaluate the influence of tannic acid (TA) and polyethylene glycol (PEG) on the excretion of amino acids and the apparent and true digestibilities of casein protein in broilers. Seventy‐two 9‐week‐old broiler cockerels grouped in nine treatments of eight replicates were fed warm water (50 mL, control birds), casein alone (12 or 18 g) or casein (12 or 18 g) with TA solution (4.5 g per 10 mL) or/and PEG solution (2 g per 10 mL). Total excreta were collected for 48 h and freeze‐dried. The amino acid content of casein and excreta was determined by reverse phase high‐performance liquid chromatography. In the absence of TA the digestibility of casein was almost complete. TA increased the excretion of amino acids to a varying extent (P < 0.01). Although the digestibility of all essential and non‐essential amino acids was adversely affected by the presence of TA, raising the amount of casein from 12 to 18 g improved significantly (P < 0.05) the apparent and true digestibilities of all amino acids. PEG reduced significantly (P < 0.01) the excretion of amino acids and improved significantly (P < 0.01) the amino acid digestibility of casein in TA‐dosed birds. However, the improvement was greater when the lower level of casein (12 g) was fed. Thus PEG might play an important role in inactivating dietary tannins in the gastrointestinal tract of birds and improving protein digestibility and utilisation, particularly when the diet is low or intermediate in protein. Copyright © 2007 Society of Chemical Industry
Potential use of phenolic antioxidants on peanut to control growth and aflatoxin B1 accumulation by Aspergillus flavus and Aspergillus parasiticus
Authors: Passone María A , Resnik Silvia , Etcheverry Miriam G 
Published: June 2007

AbstractFood‐grade antioxidants: butylated hydroxyanisole (BHA), propyl paraben (PP) and butylated hydroxytoluene (BHT) (10 and 20 mmol g−1) and all the mixtures of these chemicals were tested for inhibitory activity on the growth of and aflatoxin B1 (AFB1) accumulation by Aspergillus parasiticus and A. flavus on irradiated (7 kGy) peanut grains. Also, the influence of these treatments was evaluated in different water conditions (0.982, 0.955, 0.937aw) at 11 and 35 days of incubation at 28 °C. Water activity (aw) affected the fungal growth, no fungal development was observed at the highest stress water condition (0.937aw). Butylated hydroxyanisole at 10 mmol g−1 level and all the mixtures with PP and/or BHT were significantly effective (P = 0.05) in increasing lag phase and reducing growth rate and colony forming units per gram of peanut of both Aspergillus section Flavi strains and AFB1 accumulation. The application of BHA at concentrations of 20 mmol g−1 alone or with PP and/or BHT totally inhibited fungal growth at 11 and 35 days of incubation. The results suggest that the addition of these chemical mixtures on peanut grains at low levels has potential to impact synergically on the control of Aspergillus section Flavi. Copyright © 2007 Society of Chemical Industry
Ashtabula's third “P. R.” election
Authors: Atkinson Raymond C. 
Published: June 2007

AbstractAshtabula, Ohio, was the pioneer city in the adoption of the Hare plan of proportional representation for its municipal elections. This year's test was embarrassed by the presence of ten other old‐style ballots…. The story of Kalamazoo's second election under P. R. is promised for early issue.
Nebraska's reorganized State administration
Authors: Buck A. E. 
Published: June 2007

AbstractThe reorganization in 1917 of the Illinois state administration into an orderly group of departments has already been copied by several states, as related in our pamphlet “Administrative Consolidation in STate Governments.” The results in Illinois are dealt with in our pamphlet “Administrative Reorganization in Illinois.” The Nebraska reorganization of 1919 has now reached the point where the results ar demonstrable, as set forth in this article prepared after a visit by the writre to Lincoln.
Effect of tertiary amines on yellowing of UV‐curable epoxide resins
Authors: Chiang Tzu Hsuan , Hsieh Tsung‐Eong 
Published: June 2007

AbstractThe work reported demonstrates that the yellowness of UV‐curable epoxide resins can be improved by adding certain tertiary amines in appropriately determined amounts. According to the results of our experiments, 2.0 wt% benzoyl peroxide added to a resin effectively enhances the crosslinking density, and phenolic free radicals are produced during UV curing, which consequently induce yellowness via the reaction of oxygen and the free radicals. Imidazole (1‐amine) and tertiary amines, including 1,2‐dimethylimidazole (2‐amine), 2,4,6‐tris(dimethylaminomethyl)phenol (3‐amine), 1‐methylimidazole (4‐amine) and 2‐methylimidazole (5‐amine), were chosen to be added to resins, and their effects on UV conversion and yellowness were investigated. According to the experimental results, tertiary amines in the resin can provide a certain degree of improvement in yellowness index (ΔYI) and color parameter (ΔE*ab) of the resin sample. Whatever the type of tertiary amine, it is found that the optimum content of amine in resin is 1.0 wt%. Also, among the studied amines, the 3‐amine exhibits the highest UV reactivity and the best efficiency for yellowness improvement with values of Δa*, Δb*, ΔYI and ΔE*ab as low as − 1.4, 6.23, 11.27 and 6.48, respectively. Copyright © 2007 Society of Chemical Industry
Chemo‐enzymatic synthesis of poly(2,2,2‐trichloroethyl 10‐hydroxydecanate)‐block‐polystyrene combining enzymatic self‐condensation polymerization and ATRP
Authors: Sha Ke , Li Dongshuang , Wang Jingyuan 
Published: June 2007

AbstractEnzymatic polymerization in a non‐natural environment is of interest as an environmentally friendly methodology as an alternative to the use of conventional chemical organometallic catalysts. Chemo‐enzymatic synthesis of the AB‐type diblock copolymer poly(2,2,2‐trichloroethyl 10‐hydroxydecanate)‐block‐polystyrene (PHD‐b‐PSt) was carried out by combining enzymatic self‐condensation polymerization (eSCP) and atom‐transfer radical polymerization (ATRP). Biocatalyst Novozyme 435 was successful in catalyzing the eSCP of a novel ω‐hydroxyester, i.e. 2,2,2‐trichloroethyl 10‐hydroxydecanate. The resulting CCl3‐terminated PHD initiated the ATRP of styrene, a ‘living’/controlled radical polymerization. The analysis of the hydrolysate from the copolymer proved the presence of a block copolymer structure. In addition, the well‐defined diblock copolymer PHD‐b‐PSt self‐assembled into nanoscale micelles in aqueous solution. The chemo‐enzymatic synthesis of diblock copolymer PHD‐b‐PSt was achieved by the combination of eSCP and ATRP. The structures and composition of the block copolymer were characterized by means of NMR, infrared and gel permeation chromatography measurements. Differential scanning calorimetry analysis showed that a microphase‐separation structure was formed in the copolymer, which was caused by the crystallization of the PHD segments. As investigated with atomic force microscopy and dynamic light scattering, these micelles had a mean diameter and a spherical shape. To our knowledge, this is the first example of a chemo‐enzymatic synthesis based on eSCP and ATRP. Copyright © 2007 Society of Chemical Industry
Copolyester nanocomposites based on carbon nanotubes: reinforcement effect of carbon nanotubes on viscoelastic and dielectric properties of nanocomposites
Authors: Kalgaonkar Rajendra A , Jog Jyoti P 
Published: June 2007

AbstractNanocomposites based on an amorphous copolyester, poly(ethylene glycol‐co‐cyclohexane‐1,4‐dimethanol terephthalate) and carbon nanotubes were fabricated using a simple melt processing technique. The reinforcement effect of carbon nanotubes in the copolyester was investigated experimentally using different approaches based on dynamic mechanical analysis, rheology and dielectric analysis. The nanocomposites show a mechanical reinforcement effect with significant increase in the stiffness especially in the rubbery regime with increasing nanotube content. An increase in Tg and a decrease in damping are seen, which are derived from the presence of a percolating superstructure of the filler. Rheological experiments show an increase in storage modulus up to four orders of magnitude. Viscolelastic characterization shows that the percolation threshold is at 3 wt% of nanotubes. Dielectric relaxation spectroscopy confirms the presence of this percolating structure. We conclude that the responses of both rheological and electrical properties are different, although both are related to the formation of a percolating network superstructure of the filler. Copyright © 2007 Society of Chemical Industry
Anticholinergics, not beta‐agonists, reduce exacerbations in COPD
Authors: Burrill Peter 
Published: June 2007

AbstractA randomised controlled trial published in a peer‐reviewed journal is considered to be the ‘gold standard’ of information about the effectiveness of a treatment; however, critical appraisal of trials is required in order to judge the value and implications of the results. Here, the author presents an appraisal of a study comparing the efficacy of beta‐agonists and anticholinergics in COPD.Salpeter SR, Buckley NS, Salpeter EE. Meta‐analysis: anticholinergics, but not beta‐agonists, reduce severe exacerbations and respiratory mortality in COPD. J Gen Intern Med 2006;21(10):1011‐9. Copyright © 2007 Wiley Interface Ltd
Oral antidiabetic drugs: their properties and recommended use
Authors: Campbell Ian 
Published: June 2007

AbstractThere are now five classes of oral anti‐diabetic drugs available, with metformin remaining the cornerstone of drug therapy in type 2 diabetes. Our Drug review considers their mode of action, properties and recommended use, followed by sources of further information, an analysis of prescrip tion data and the Datafile. Copyright © 2007 Wiley Interface Ltd
Identification of three novel peptides isolated from the venom of the neotropical social wasp Polistes major major
Authors: ČeŘovský Václav , Pohl Jan , Yang Zhihua , Alam Naseer , Attygalle Athula B. 
Published: June 2007

AbstractThree novel peptides designated as PMM1, PMM2, and PMM3 were isolated and characterized from the venom of the social wasp Polistes major major, one of the most common wasps in the Dominican Republic. By Edman degradation, and MALDI‐TOF and ESI‐QTOF mass spectrometry, the primary sequences of these peptides were established as follows: PMM1, H‐Lys‐Arg‐Arg‐Pro‐Pro‐Gly‐Phe‐Thr‐Pro‐Phe‐Arg‐OH (1357.77 Da); PMM2, H‐Ile‐Asn‐Trp‐Lys‐Lys‐Ile‐Ala‐Ser‐Ile‐Gly‐Lys‐Glu‐Val‐Leu‐Lys‐Ala‐Leu‐NH2 (1909.19 Da); and PMM3, H‐Phe‐Leu‐Ser‐Ala‐Leu‐Leu‐Gly‐Met‐Leu‐Lys‐Asn‐Leu‐NH2 (1317.78 Da). The suggested sequences were confirmed by MS analysis of peptide fragments obtained by enzymatic digestion. The peptide PMM1 is a lysyl‐arginyl‐Thr6‐bradykinine that belongs to the wasp kinins group. The sequence of the PMM2 peptide is unique; it resembles somewhat the tetradecapeptide amides of the mastoparan group; however, the chain is extended by three additional amino acid residues. The sequence of PMM3 dodecapeptide is homologous to the peptides of the wasp chemotactic group. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd.