bluuebunny/crossref_metadata_2025 huggingface dataset:
An isozyme-based assessment of the genetic variability within the Daucus carota complex (Apiaceae: Caucalideae)
Authors: St. Pierre Michel D. , Bayer Randall J. , Weis I. Michael
Published: February 2014

Daucus carota sensu lato is a phenotypically variable Eurasian species complex that has been naturalized and cultivated worldwide. One hundred and sixty-eight accessions from 32 countries were surveyed by enzyme electrophoresis to determine the extent of genetic variation present in the species. Eight enzyme systems coded by 16 putative loci were surveyed. They indicate that the recognized subspecies have diverged only slightly from one another with respect to the enzymes surveyed. The samples of wild taxa are more genetically diverse than those of the cultivated taxa, but not significantly different with respect to the mean number of alleles per locus, the proportion of polymorphic loci, the observed and expected heterozygosities, or Nei's genetic diversity statistics (P > 0.05). Members of the aggregate group gingidium have significantly lower total gene diversity within a taxon (P <.05) than do members of the aggregate group carota, as well as lower gene diversity within populations of the taxa (P < 0.01). Thus allozyme divergence is concordant with morphological divergence. Cultivars with carotene-pigmented roots show negligible amounts of genetic divergence. They appear to have evolved in a simple pattern after an initial genetic bottleneck. Key words: Daucus carota, isozyme, electrophoresis, genetic variability.
A new approach to the phylogeny of Euascomycetes with a cladistic outline of Arthoniales focussing on Roccellaceae
Authors: Tehler Anders
Published: February 2014

A phylogenetic working hypothesis of euascomycete relationships is presented. Paraphysoidal ascolocular fungi are monophyletic and ascohymenial fungi are paraphyletic as paraphyses are considered plesiomorphic and paraphysoids apomorphic within euascomycete fungi. As a result it is not necessary to postulate parallel evolution of the bitunicate ascus, and furthermore presence of paraphyses in the prototunicate caliciaceous fungi is no longer in conflict with paraphyses in ascohymenial fungi. A cladistic outline of the order Arthoniales with special focus on the Roccellaceae including 20 taxa and 92 characters is presented. The type species of all genera considered are used as terminal taxa. It is suggested that the type species of Arthothelium should be excluded from the order Arthoniales. The Arthoniaceae are paraphyletic as Arthonia radiata and Arthothelium spectabile form a grade pair. The family Roccellaceae is monophyletic and corroborated in its traditional sense, but some rearrangements within the family are made. Opegrapha vulgata and Lecanactis abietina form a pair, but the family Opegraphaceae is paraphyletic if the pair Chiodecton sphaerale and Schismatomma pericleum are included. The originally described ascoma of the species Darbishirella gracillima, Ingaderia pulcherrima, and Reinkella fragillima are found to be lichenicolous fungi. The mycobiont ascomata of Darbishirella gracillima produce 3- not 2-septate spores. No ascomata of the mycobionts of the two latter species have as yet been found. Key words: Euascomycetes, Arthoniales, Roccellaceae, phylogeny, cladistics, lichenicolous.
Bromus pictus of the B. setifolius complex (section Pnigma): numerical taxonomy and chromosome evidence for species rank
Authors: Naranjo C. A. , Arias F. H. , Gil F. E. , Soriano A.
Published: February 2014

Two biotic sympatric taxa of the Bromus setifolius complex, which are presently considered as varieties, were studied using cytological and numerical taxonomy methods. The numerical taxonomy analysis (cluster and principal components analysis) based on 35 characters showed the existence of two phenetically significant groups. One is formed by individuals that correspond to B. setifolius Presl. and the other by individuals with the characters of Bromus pictus Hook. All plants of B. setifolius had 2n = 4x = 28, and all the B. pictus individuals had 2n = 10x = 70. Other cytological differences between the two taxa were found, e.g., karyotype formulae, type of satellites, basic genome length, asymmetry, C-banding patterns, and meiotic chromosome behavior. Cytological differences, which parallel the constant morphological features exhibited by each taxa, justify specific status. Taking into acount other characters, such as perenniality, breeding system, and reproductive isolation barrier, the relationships and evolution of these taxa are discussed. Key words: Bromus setifolius, Bromus pictus, numerical taxonomy, karyotype, C-banding.
Flower bud and root neoformation in thin cell layers of Nicotiana tabacum var. Samsun: a statistical analysis of spatial and temporal changes in mitotic activity
Authors: Mersch G. , Nassogne C. , Havelange A.
Published: February 2014

Our aim was to analyse comparatively the spatial and temporal changes in mitotic activity in tobacco thin cell layers cultured in vitro during the expression of two organogenetic programs, namely the flower bud and root programs. These biological materials were found to be so complex and heterogeneous that we had to rely on sophisticated statistical models for the planned study. Using these models we could detect differences not only between the two programs, but also within each program between different time intervals and, in the flower bud program, between different longitudinal segments of the thin cell layers. Key words: Nicotiana tabacum, flower bud, root, statistical analysis, mitotic activity.
Relationship between water quality parameters and bacterial indicators in a large prairie reservoir: Lake Diefenbaker, Saskatchewan, Canada
Authors: North R.L. , Khan N.H. , Ahsan M. , Prestie C. , Korber D.R. , Lawrence J.R. , Hudson J.J.
Published: February 2014

Lake Diefenbaker (LD) is a large reservoir on the South Saskatchewan River used for agricultural irrigation, drinking water, and recreation. Our objectives were to determine the distribution and abundance of bacterial indicators in embayments and the main channel of LD and to relate these to environmental factors. Total coliforms (TCs), fecal coliforms (FCs), and fecal indicator bacteria (i.e., Escherichia coli) were measured concurrently with water quality parameters. Although TCs, FCs, and E. coli were present in LD, they rarely exceeded the TC and FC Canadian Council of Ministers of the Environment (CCME) water quality standards for agricultural use (1000 colony-forming units (CFU) per 100 mL and 100 CFU per 100 mL, respectively). The correlation between the bacterial indicators in the sediments and the water column indicates that higher embayment abundances may be related to sediment loading and (or) resuspension events in these frequently mixed embayments. With higher water temperatures and water levels, as well as higher microbial activity, CCME bacterial limits may be exceeded. The greatest contributor to bacterial indicator abundance was water temperature. We predict that water quality standards will be exceeded more frequently with climate warming.
Diosgenin does not express estrogenic activity: a uterotrophic assay
Authors: Medigović Ivana , Ristić Nataša , Živanović Jasmina , Šošić-Jurjević Branka , Filipović Branko , Milošević Verica , Nestorović Nataša
Published: February 2014

This study assessed the effects of diosgenin on estrogenic activity using a uterotrophic assay. Immature female rats received diosgenin orally at doses of 200, 100, or 20 mg/kg body mass; and 17α ethynylestradiol at doses of 1 or 0.3 μg/kg, daily, for 3 consecutive days from day 19 to day 21. Controls were distributed among 2 groups: an intact control group and a vehicle control group. Animals were sacrificed 24 h after the last application of diosgenin, estradiol, or vehicle (22nd day of life). Uterine wet weight, stereological and histomorphometrical changes, immunohistochemical expression of estrogen receptor alpha (ERα), progesterone receptor (PR), and the expression of lactoferrin (LF) were examined. Diosgenin did not affect the uterine wet weight, epithelium height, volume densities of endometrium, endometrial epithelia, number of endometrial glands, or histological appearance of vaginal epithelia. ERα, PR, and LF immunostaining intensity were not altered in the animals that received diosgenin. High-potency reference ER agonist 17α-ethynylestradiol induced a significant increase in all of the measured parameters, and as expected, decreased ERα immunostaining intensity. Based on these data, it can be concluded that diosgenin, at doses of 20–200 mg/kg, did not act as an estrogen agonist in the immature rat uterotrophic assay.
Corrections to gauge theories in effective quantum gravity with a cutoff
Authors: Cynolter G. , Lendvai E.
Published: February 2014

We calculate the lowest order quantum gravity contributions to QED beta function in an effective field theory picture with a momentum cutoff. We use a recently proposed four-dimensional improved momentum cutoff that preserves gauge and Lorentz symmetries. We find that there is nonvanishing quadratic contribution to the photon two-point function but that does not lead to the running of the original coupling after renormalization. We argue that gravity cannot turn gauge theories asymptotically free.
NONRELATIVISTIC HOLOGRAPHY — A GROUP-THEORETICAL PERSPECTIVE
Authors: DOBREV V. K.
Published: February 2014

We give a review of some group-theoretical results related to nonrelativistic holography. Our main playgrounds are the Schrödinger equation and the Schrödinger algebra. We first recall the interpretation of nonrelativistic holography as equivalence between representations of the Schrödinger algebra describing bulk fields and boundary fields. One important result is the explicit construction of the boundary-to-bulk operators in the framework of representation theory, and that these operators and the bulk-to-boundary operators are intertwining operators. Further, we recall the fact that there is a hierarchy of equations on the boundary, invariant with respect to Schrödinger algebra. We also review the explicit construction of an analogous hierarchy of invariant equations in the bulk, and that the two hierarchies are equivalent via the bulk-to-boundary intertwining operators. The derivation of these hierarchies uses a mechanism introduced first for semisimple Lie groups and adapted to the nonsemisimple Schrödinger algebra. These require development of the representation theory of the Schrödinger algebra which is reviewed in some detail. We also recall the q-deformation of the Schrödinger algebra. Finally, the realization of the Schrödinger algebra via difference operators is reviewed.
QUANTUM SYSTEMS BASED UPON GALOIS FIELDS — FROM SUB-QUANTUM TO SUPER-QUANTUM CORRELATIONS
Authors: CHANG L. N. , LEWIS Z. , MINIC D. , TAKEUCHI T.
Published: February 2014

In this paper, we describe our recent work on discrete quantum theory based on Galois fields. In particular, we discuss how discrete quantum theory sheds new light on the foundations of quantum theory and we review an explicit model of super-quantum correlations we have constructed in this context. We also discuss the larger questions of the origins and foundations of quantum theory, as well as the relevance of super-quantum theory for the quantum theory of gravity.
LARGE SU(3) BREAKING EFFECTS AND CP VIOLATION IN B+ DECAYS INTO THREE CHARGED OCTET PSEUDOSCALAR MESONS
Authors: XU DONG , LI GUAN-NAN , HE XIAO-GANG
Published: February 2014

The LHCb collaboration has recently reported evidence for nonzero CP asymmetries in B+ decays into π+K+K-, π+π+π-, K+K+K- and K+π+π-. The branching ratios for these decays have also been measured with different values ranging from 5×10-6 to 51×10-6. If flavor SU(3) symmetry is a good symmetry for B decays, in the case that the dominant amplitude is momentum independent it is expected that branching ratios Br and CP violating rate differences [Formula: see text] satisfy, Br (π+π+π-) = 2 Br (π+K+K-), Br (K+K+K-) = 2 Br (K+π+π-) and Δ CP (π+π+π-) = 2Δ CP (π+K+K-) = -Δ CP (K+K+K-) = -2Δ CP (K+π+π-). The experimental data do not exhibit the expected pattern for the branching ratios. The rate differences for B+→π+π+π- and B+→K+ K+ K- satisfy the relation between ΔS = 0 and ΔS = 1 as well, but the other two do not, with the CP asymmetries having different signs than expected. In this paper, we study how to include momentum dependent and also SU(3) breaking effects on these decays to explain experimental data. We find that by including only the lowest order derivative terms, in the SU(3) limit, the decay patterns cannot be explained. Large SU(3) breaking effects are needed to explain the data.
CHARGED LEPTON MIXING PROCESSES IN 331 MODELS
Authors: CABARCAS J. M. , DUARTE J. , RODRIGUEZ J.-ALEXIS
Published: February 2014

Processes τ→lγ, τ→lll with l = e, μ and μ(τ) →e (μ) γ are evaluated in the framework of a model based on the extended symmetry gauge SU(3)c ⊗SU(3)L ⊗U(1)Y with a leptonic sector consisting of five triplets. Lepton flavor violating processes are allowed at tree level in this model through the new Z′ gauge boson. We obtained bounds for the mixing angles in the leptonic sector of the model, considering the experimental measurements of the processes from the BELLE and the BABAR collaborations.
TEST OF IDENTIFIED HADRON MULTIPLICITIES FOR NONEXTENSIVE STATISTICAL MODEL AT LHC ENERGIES
Authors: WIBIG T.
Published: February 2014

We analyzed the identified hadron multiplicity predictions of the generalized thermodynamical model of the multiparticle production processes with nonextensive statistics. The multiplicities measured recently at LHC experiments seem to be consistent with this approach and thermodynamical parameter values are found already by analyzing transverse momentum distributions. The information about the mechanism of the strangeness suppression has been derived to some extent from multistrange hadron abundances.
EXTENSION OF CHERN–SIMONS FORMS AND NEW GAUGE ANOMALIES
Authors: ANTONIADIS IGNATIOS , SAVVIDY GEORGE
Published: February 2014

We present a general analysis of gauge invariant, exact and metric independent forms which can be constructed using higher-rank field-strength tensors. The integrals of these forms over the corresponding space–time coordinates provides new topological Lagrangians. With these Lagrangians one can define gauge field theories which generalize the Chern–Simons quantum field theory. We also present explicit expressions for the potential gauge anomalies associated with the tensor gauge fields and classify all possible anomalies that can appear in lower dimensions.
A METHOD FOR DEFINING INITIAL STRESS IN PROGRESSIVELY DEPOSITED FILM ON A SUBSTRATE
Authors: FU KUNKUN , CHANG LI , ZHENG BAILIN , YIN YONGBAI , YE LIN
Published: February 2014

The initial stress is induced during film formation and is partially counterbalanced through curvature changes. Therefore, it is commonly evaluated by the measured residual stress. Initial stress may directly affect the film formation rather than residual stress in progressively deposited films. In the present work, we introduced a multiple layer model for progressively deposited films to obtain a quantitative solution for estimating the initial stress. The results showed that residual stress in the last layer is equal to the initial stress when layer number approaches infinity. In particular, the initial stress, σi in deposited film could be determined using the equation, σi = σSt/β, in which σSt is the averaged residual stress in films calculated by Stoney formula and β is the correction factor. The value of β varied between 0 and 1, depending on relative modulus and relative thickness of film and substrate. Finally, using element birth and death technique, a finite element model was presented to verify the analytical multiple layer model. Good agreement was obtained between the analytical and FE results.
THE SCROLL CONTROL AND IMPROVING CASCADE SYNCHRONIZATION OF A NOVEL CHAOTIC SYSTEM
Authors: LI YIN , ZHAO YULIN , YAO ZHENG-AN
Published: February 2014

In this paper, on the basis of the Laypunov stability and the cascade synchronization approach, an effectual scroll controller and improving cascade synchronization approach are derived. The chaotic attractor can be displayed to be lopsided, till to be 1-scroll and periodic via the different scroll controller. And the proposed synchronization technique is applied to the new system, which the synchronization controller obtained by improving cascade method and adaptive functions. Numerical results are used to verify the effectiveness of the scheme.
Nonlinear finite element analysis of smart laminated composite sandwich plates
Authors: Sarangi S. K. , Basa B.
Published: February 2014

This paper deals with the nonlinear dynamic analysis of smart laminated composite sandwich plates. A three dimensional energy based finite element (FE) model has been developed for the composite sandwich plates integrated with the patches of active constrained layer damping (ACLD) treatment. Von Kármán type nonlinear strain–displacement relations and the first-order shear deformation theory (FSDT) are adopted individually for each layer of the sandwich plate in developing the FE model. The constraining layer of the ACLD treatment is considered to be made of active fiber composite (AFC) material. The Golla–Hughes–McTavish (GHM) method is used to model the constrained viscoelastic layer of the ACLD treatment in the time domain. Sandwich plates with symmetric and antisymmetric laminated faces separated by HEREX core are considered for evaluation of the numerical results. The numerical results indicate that the ACLD patches significantly improve the damping characteristics of the composite sandwich plates for suppressing their geometrically nonlinear transient vibrations. The effect of variation of piezoelectric fiber orientation angle in the AFC material on the control authority of the ACLD patches is also investigated.
ANALYSIS OF EARDRUM PATHOLOGIES USING THE FINITE ELEMENT METHOD
Authors: GENTIL FERNANDA , GARBE CAROLINA , PARENTE MARCO , MARTINS PEDRO , FERREIRA ANTÓNIO , JORGE RENATO NATAL , SANTOS CARLA , PAÇO JOÃO
Published: February 2014

This work investigates the effect of eardrum perforations and myringosclerosis in the mechanical behavior of the tympano-ossicular chain. A 3D model for the tympano-ossicular chain was created and different numerical simulations were made, using the finite element method. For the eardrum perforations, three different calibers of perforated eardrums were simulated. For the micro perforation (0.6 mm of diameter) no differences were observed between the perforated and normal eardrum. For the numerical simulation of the eardrum with the largest perforation caliber, small displacements were obtained in the stapes footplate, when compared with the model representative of normal ossicular-chain, at low frequencies, which is related with major hearing loss in this frequency range. For the numerical simulations of myringosclerosis, the larger differences in the displacement field between the normal and modified model were obtained in the umbo. When observing the results in the stapes footplate, there were no significant differences between the two models, which is in accordance to the clinical data. When simulating an eardrum perforation along with myringosclerosis, there is a decrease in the displacements, both from the umbo and the central part of the stapes footplate, often associated with a pronounced hearing loss. It could be concluded that the reduced displacement of the stapes footplate may be related to a greater hearing loss.
Theorems of Idempotent Commutative Groupoids
Authors: Dudek J. , Gałuszka J.
Published: February 2014

In this paper, among other results, we prove that a clone C with five essentially binary operations is minimal if and only if C is a clone of a non-trivial affine space over GF(7). This result is a product of systematic investigation of varieties of idempotent commutative groupoids. It is probably the most spectacular result of this investigation, but many other results formulated and proved throughout the paper may turn out more useful in further study in this area.
Minimal Presentations and Embedding into Inefficient Semigroups
Authors: Ayık H. , Minisker M. , Vatansever B.
Published: February 2014

In this paper, we show that CLn, the chain with n elements, is efficient and that the direct product CLm× CLnis inefficient. Moreover, we embed any finitely presented semigroup S into an inefficient semigroup, namely, the semigroup S ⋃ SLn, where SLnis the free semilattice of rank n.
Lie Admissible Non-Associative Algebras
Authors: Ahmadi H. Mohammad , Nam Ki-Bong , Pakinathan Jonathan
Published: February 2014

A non-associative ring which contains a well-known associative ring or Lie ring is interesting. In this paper, a method to construct a Lie admissible non-associative ring is given; a class of simple non-associative algebras is obtained; all the derivations of the non-associative simple [Formula: see text] algebra defined in this paper are determined; and finally, a solid algebra is defined.
Finite Groups with a System of Nilpotent Subgroups
Authors: Li Shirong , Dark Rex S.
Published: February 2014

Let G be a finite group and p an odd prime. Let [Formula: see text] be the set of proper subgroups M of G with |G:M| not a prime power and |G:M|p=1. In this paper, we investigate the structure of G if every member of [Formula: see text] is nilpotent. In particular, a new characterization of PSL(2,7) is obtained. The proof of the theorem depends on the classification of finite simple groups.
On a Class of p-Soluble Groups
Authors: Ballester-Bolinches A. , Esteban-Romero R. , Pedraza-Aguilera M. C.
Published: February 2014

Let p be a prime. The class of all p-soluble groups G such that every p-chief factor of G is cyclic and all p-chief factors of G are G-isomorphic is studied in this paper. Some results on T-, PT-, and PST-groups are also obtained.
A Characteristic Subgroup of an $E_{\pi}^n$ Group
Authors: Li Yangming , Wang Yanming
Published: February 2014

Suppose G is a group which is p-stable and p-constrained, where p is an odd prime, and S is a Sylow p-subgroup of G. A classical theorem of Glauberman shows that ZJ(S)Op′(G)◃G, where J(S) is the Thompson subgroup of S. In this paper, we generalize the above result by replacing the odd prime p with a set π of odd primes. More precisely, suppose π is a set of odd primes and G is an [Formula: see text] group which is π-stable and π-constrained. We prove that if H∈ Hallπ(G) then ZJ(H)Oπ′(G)◃G and G=NG(ZJ(H))Oπ′(G). An interesting application is also given.
Auslander–Reiten Orbit Algebras for Self-Injective Nakayama Algebras
Authors: Pogorzały Zygmunt
Published: February 2014

The main result of this paper is the following: Let A be a self-injective Nakayama K-algebra, which is basic and connected. Suppose that A is a right Ae-module of τAe-period 1. (1) If A is an algebra whose Jacobson radical square is zero, then [Formula: see text]. (2) If A is an algebra whose Jacobson radical square is not zero, then [Formula: see text] for some positive integer n.
Groups Satisfying the Maximal Condition on Non-modular Subgroups
Authors: De Falco Maria , Musella Carmela
Published: February 2014

In this paper, (generalized) soluble groups for which the set of non-modular subgroups verifies the maximal condition and groups for which the set of non-permutable subgroups satisfies the same property are classified.
Some Remarks Concerning the Invariants of Rank One Solvable Real Lie Algebras
Authors: Campoamor-Stursberg Rutwig
Published: February 2014

A corrected and completed list of six dimensional real Lie algebras with five dimensional nilradical is presented. Their invariants for the coadjoint representation are computed and some results on the invariants of solvable Lie algebras in arbitrary dimension whose nilradical has codimension one are also given. Specifically, it is shown that any rank one solvable Lie algebra of dimension n without invariants determines a family of (n+2k)-dimensional algebras with the same property.
Green's Relation ℛ on the Monoid of Clone Endomorphisms
Authors: Changphas Thawhat , Denecke Klaus
Published: February 2014

A hypersubstitution is a map which takes n-ary operation symbols to n-ary terms. Any such map can be uniquely extended to a map defined on the set Wτ(X) of all terms of type τ, and any two such extensions can be composed in a natural way. Thus, the set Hyp (τ) of all hypersubstitutions of type τ forms a monoid. In this paper, we characterize Green's relation ℛ on the monoid Hyp (τ) for the type τ=(n,n). In this case, the monoid of all hypersubstitutions is isomorphic with the monoid of all clone endomorphisms. The results can be applied to mutually derived varieties.
Associative Transitive Loops
Authors: Foguel Tuval
Published: February 2014

In this paper, we investigate the structure of loops in which the associativity relation between pairs of non-trivial elements (i.e., 〈x,y〉 is a group) is transitive. We also look at other properties that come out of the study of this class of loops.
Direct Cancellation of Finite Groups
Authors: Fransman Andrew , Witbooi Peter
Published: February 2014

We prove that if F is a finite group, and G and H are finitely generated groups with finite commutator subgroups for which F × G ≃ F × H, then G ≃ H.
Centralizer Near-rings, Matrix Near-rings and Cyclic p-Groups
Authors: Smith Kirby C. , van Wyk Leon
Published: February 2014

If G is a finite group and [Formula: see text] is a group of automorphisms of G, then it is known that the matrix near-ring [Formula: see text] is a subnear-ring of the centralizer near-ring [Formula: see text] for every m ≥ 2. Conditions are known under which [Formula: see text] is a proper subnear-ring of [Formula: see text], and if [Formula: see text] and G are abelian, then conditions are known which imply the equality [Formula: see text]. In this paper, we characterize the groups [Formula: see text] of automorphisms of a cyclic p-group G for which this equality holds. We also show that for every group [Formula: see text] of automorphisms of a cyclic p-group G, either all the nonzero orbits of G are of unique type or none of the orbits of G is of unique type if p is odd, and there is a third possibility if p=2, namely precisely one of the orbits of G is of unique type.
On the Extended Hecke Group $\overline{H}(\lambda_5)$
Authors: Sahin Recep , Koruoğlu Özden , İkikardes Sebahattin
Published: February 2014

We consider the extended Hecke group [Formula: see text] generated by T(z)=-1/z, [Formula: see text] and [Formula: see text] with [Formula: see text]. In this paper, we study the abstract group structure of the extended Hecke group and its power subgroups [Formula: see text]. Also, we give relations between power subgroups and commutator subgroups of the extended Hecke group [Formula: see text].
A Graph Approach to a Splitting Theorem
Authors: Shi Hongbo
Published: February 2014

By associating a graph to the ring under discussion, we propose a graph approach to extend a well-known ring splitting theorem due to Zaks, and we then describe the global and finitistic dimensions of the ring in the language of the graph.
Dual Quasi-Hopf Algebras and Antipodes
Authors: Li Jinqi
Published: February 2014

Let H be a coalgebra. In this paper, we show that H is a dual quasi-bialgebra if and only if the category [Formula: see text] of comodules is a tensor category; and H is a braided dual quasi-bialgebra if and only if [Formula: see text] is a braided tensor category. If H is a braided dual quasi-Hopf algebra, it is shown that the antipode of H is inner, i.e., s2(h) = ∑ τ (h1)h2τ-1(h3).
On Automorphisms and Derivations of a Lie Algebra
Authors: Varea V. R. , Varea J. J.
Published: February 2014

We study automorphisms and derivations of a Lie algebra L of finite dimension satisfying certain centrality conditions. As a consequence, we obtain that every nilpotent normal subgroup of the automorphism group of L is unipotent for a very large class of Lie algebras. This result extends one of Leger and Luks. We show that the automorphism group of a nilpotent Lie algebra can have trivial center and have yet a unipotent identity component.
On Prime and Semiprime Rings with Derivations
Authors: Argaç Nurcan
Published: February 2014

Let R be a ring and S a nonempty subset of R. A mapping f: R → R is called commuting on S if [f(x),x] = 0 for all x ∈ S. In this paper, firstly, we generalize the well-known result of Posner related to commuting derivations on prime rings. Secondly, we show that if R is a semiprime ring and I is a nonzero ideal of R, then a derivation d of R is commuting on I if one of the following conditions holds: (i) For all x, y ∈ I, either d([x,y]) = [x,y] or d([x,y]) = -[x,y]. (ii) For all x, y ∈ I, either d(x ◦ y) = x ◦ y or d(x ◦ y) = -(x ◦ y). (iii) R is 2-torsion free, and for all x, y ∈ I, either [d(x),d(y)] = d([x,y]) or [d(x),d(y)] = d([y,x]). Furthermore, if d(I) ≠ {0}, then R has a nonzero central ideal. Finally, we introduce the notation of generalized biderivation and prove that every generalized biderivation on a noncommutative prime ring is a biderivation.
Adjoint Mappings and Inverses of Matrices
Authors: Stanimirović Predrag , Bogdanović Stojan , Ćirić Miroslav
Published: February 2014

In this paper, we investigate a general and determinantal representation, and conditions for the existence of a nonzero {2}-inverse X of a given complex matrix A. We introduce a determinantal formula for X, representing its elements in terms of minors of order s = rank (X), 1 ≤ s ≤ r = rank (A), taken from the matrix A and two adequately selected matrices. In accordance with these results, we find restrictions of the adjoint mapping such that the set A{2} is equal to the union of their images. Minors of {2}-inverses are also investigated. Restrictions to the set of {1, 2}-inverses produce the known results from [1–3, 10]. Also, in a partial case, we get known results from [11] relative to the Drazin inverse.
Galois Lines for Space Curves
Authors: Yoshihara Hisao
Published: February 2014

Let C be a curve, and l, l0 be lines in the projective three space ℙ3. Consider a projection πl: ℙ3 ⋯ → l0 with center l, where l ∩ l0 = ∅. Restricting πl to C, we get a morphism πl|C: C → l0 and an extension of fields (πl|C)* : k(l0) ↪ k(C). We study the algebraic structure of the extension and the geometric structure of C. In particular, we study the structure of the Galois group and the number of Galois lines for some special cases.
A Class of Finite Groups with Abelian Sylow p-Subgroups
Authors: Zhang Zhikai
Published: February 2014

In this paper, we first determine the structure of the Sylow p-subgroup P of a finite group G containing no elements of order 2p (p > 2), and then show that the Broué Abelian Defect Groups Conjecture is true for the principal p-block of G. The result depends on the classification of finite simple groups.
Classification of Table Algebras with Two Basis Elements Whose Product Is a Linear Combination of Their Conjugates
Authors: Arad Zvi , Cohen Efi
Published: February 2014

Table Algebras (A,B) with distinct non-real basis elements a, b∈ B satisfying [Formula: see text], (m, n∈ ℝ+) are studied in this paper. The two cases where either a is real and b is non-real or a, b are both real were completely classified by Arad and Blau. Here, we study the remaining case where a and b are non-real.
n-Clean Rings
Authors: Xiao Guangshi , Tong Wenting
Published: February 2014

Let n be a positive integer. A ring R is called n-clean if every element of R can be written as a sum of an idempotent and n units in R. The class of n-clean rings contains clean rings and (S,n)-rings (i.e., every element is a sum of no more than n units). In this paper, we investigate some properties on n-clean rings. There exists a clean and (S,3)-ring which is not an (S,2)-ring. If R is a ring satisfying (SI), then the polynomial ring R[x] is not n-clean for any positive integer n. An example shows that for any positive integer n> 1, there exists a non n-clean ring R such that the 2× 2 matrix ring M2(R) over R is n-clean.
The Recognition of the Simple Group S8(2) by Its Spectrum
Authors: Mazurov V. D. , Moghaddamfar A. R.
Published: February 2014

In this paper, we show that the simple group S8(2) is irrecognizable by its spectrum.
Counting Representations of Valued Quivers over Finite Fields
Authors: Wang Yanxin
Published: February 2014

For a symmetrizable Borcherds–Cartan matrix A with integer entries and even diagonal entries, we show that there exists a k-species 𝓢 over the finite field k such that 𝓢 and the Borcherds–Cartan matrix provide the same bilinear form. We also show that the number of isomorphism classes of indecomposable representations of any valued graph with fixed dimension vector is a polynomial, and is independent of the orientation of the valued graph. This extends to the situation of valued graphs with loops.
On the Representation of D.G. Seminear-rings
Authors: Samman Mohammad
Published: February 2014

Some results about the representation of d.g. seminear-rings are given. While not all d.g. seminear-rings are faithful, it seems that there are conditions under which the d.g. seminear-rings are. To every (non-faithful) d.g. seminear-ring (S,T), we associate a faithful d.g. seminear-ring [Formula: see text] and prove the existence of such a d.g. seminear-ring. Finally, we show how adjoining an identity to a given d.g. seminear-ring will give the faithfulness we desire.
Characterizations of Morita-like Equivalences for Right XST-Rings
Authors: Ouyang Baiyu , Zhou Liren , Tong Wenting
Published: February 2014

The notion of xst-rings was introduced by García and Marín in 1999. In this paper, we characterize Morita-like equivalences for right xst-rings, obtain the universal theory of Morita equivalences, and prove that two right xst-rings R and T are Morita-like equivalent if and only if there is a Morita context between R and T. We also prove that Morita-like equivalences can be realized by the covariant functors Hom and ⊗ for these rings.
Representations of the Twisted Heisenberg–Virasoro Algebra and the Full Toroidal Lie Algebras
Authors: Jiang Qifen , Jiang Cuipo
Published: February 2014

An explicit construction of indecomposable modules for the twisted Heisenberg–Virasoro algebra and representations for the full toroidal Lie algebras are given.
The Fischer–Clifford Matrices of a Maximal Subgroup of the Sporadic Simple Group of Held
Authors: Ali Faryad
Published: February 2014

The Held group He discovered by Held [10] is a sporadic simple group of order 4030387200 = 210.33.52.73.17. The group He has 11 conjugacy classes of maximal subgroups as determined by Butler [5] and listed in the 𝔸𝕋𝕃𝔸𝕊. Held himself determined much of the local structure of He as well as the conjugacy classes of its elements. Thompson calculated the character table of He . In the present paper, we determine the Fischer–Clifford matrices and hence compute the character table of the non-split extension 3·S7, which is a maximal subgroups of He of index 226560 using the technique of Fischer–Clifford matrices. Most of the computations were carried out with the aid of the computer algebra system 𝔾𝔸ℙ.
Top Local Cohomology Modules
Authors: Dibaei Mohammad T. , Yassemi Siamak
Published: February 2014

For a finitely generated module M over a commutative Noetherian local ring (R,𝔪), it is shown that there exist only a finite number of non-isomorphic top local cohomology modules [Formula: see text] for all ideals 𝔞 of R. It is also shown that for a given integer r ≥ 0, if [Formula: see text] is zero for all 𝔭 in Supp (M), then [Formula: see text] for all i ≥ r.
Maximal Congruences on Some Semigroups
Authors: Sanwong Jintana , Sullivan R. P.
Published: February 2014

In 1976 Howie proved that a finite congruence-free semigroup is a simple group if it has at least three elements but no zero element. Infinite congruence-free semigroups are far more complicated to describe, but some have been constructed using semigroups of transformations (for example, by Howie in 1981 and by Marques in 1983). Here, for certain semigroups S of numbers and of transformations, we determine all congruences ρ on S such that S/ρ is congruence-free, that is, we describe all maximal congruences on such semigroups S.
A Family of Some Complexes with Group Presentations
Authors: Wang Moon-Ok
Published: February 2014

On the boundary of a polyhedron, we construct a tessellation consisting of 8n pentagons (n ≥ 3). The tessellation produces a family of 3-dimensional orientable closed manifolds with a spine, which correspond to group presentations. We determine the group presentations and their homology groups.
On Graded Bialgebra Deformations
Authors: Du Yu , Chen Xiaowu , Ye Yu
Published: February 2014

We introduce the graded bialgebra deformations, which explain the lifting method of Andruskiewitsch and Schneider. We also relate these graded bialgebra deformations with the corresponding graded bialgebra cohomology groups, which is the graded version of the one due to Gerstenhaber and Schack.
Relatively Endocoherent Modules
Authors: Mao Lixin
Published: February 2014

Let MR be a right R-module over a ring R with S = End (MR). We study the coherence of the left S-module SM relative to a torsion theory for the category of right R-modules. Various results are developed, many extending known results.
A Comparison of Various Types of Degenerations for Algebras
Authors: Dowbor Piotr , Hajduk Adam
Published: February 2014

Three different notions of geometric degeneration for finite dimensional algebras are compared. It is proved that for algebras A0 and A1 of same dimension, if A0 is a CB-degeneration of A1, then A0 is a degeneration of A1 in the classical sense; moreover, if additionally A0 and A1 are basic, then A0 is a CB-degeneration of A1 if and only if A0 is a rigid degeneration of A1. It is also shown that CB-degenerations along affine lines in the different dimension case do not differ so much from those in the equal dimension case.
Trivializers and 2-Complexes
Authors: Wang Xiaofeng , Xie Wanwen , Bao Xiaomin
Published: February 2014

A fundamental theory on the behavior and properties of trivializers of 2-complexes is set up which can be applied to deal with homotopy problems of group presentations and monoid presentations.
Some Characterizations of Krull Monoids
Authors: Kim Hwankoo , Kim Myeong Og , Park Young Soo
Published: February 2014

In this paper, Kaplansky-type theorems are given to characterize GCD-monoids and valuation monoids. Also, (unique) r-factorable monoids are defined and it is shown that S is a Krull monoid if and only if S is a unique t-factorable (resp., w-factorable) monoid if and only if S is a t-factorable (resp., w-factorable) t-Prüfer monoid.
Asymptotic Behavior of Integral Closures in Modules
Authors: Naghipour R. , Schenzel P.
Published: February 2014

Let R be a commutative Noetherian Nagata ring, let M be a non-zero finitely generated R-module, and let I be an ideal of R such that height MI > 0. In this paper, there is a definition of the integral closure Na for any submodule N of M extending Rees' definition for the case of a domain. As the main results, it is shown that the operation N → Na on the set of submodules N of M is a semi-prime operation, and for any submodule N of M, the sequences Ass R M/(InN)a and Ass R (InM)a/(InN)a(n=1,2,…) of associated prime ideals are increasing and ultimately constant for large n.
On the Centro-symmetric Solution of a System of Matrix Equations over a Regular Ring with Identity
Authors: Wang Qingwen , Chang Haixia , Lin Chunyan
Published: February 2014

In this paper, we find the centro-symmetric solution of a system of matrix equations over an arbitrary regular ring [Formula: see text] with identity. We first derive some necessary and sufficient conditions for the existence and an explicit expression of the general solution of the system of matrix equations A1X1 = C1, A2X1 = C2, A3X2 = C3, A4X2 = C4 and A5X1B5 + A6X2B6 = C5 over [Formula: see text]. By using the above results, we establish two criteria for the existence and the representation of the general centro-symmetric solution of the system of matrix equations AaX = Ca, AbX = Cb and AcXBc = Cc over the ring [Formula: see text].
On the Norm of Finite Groups
Authors: Wang Junxin , Guo Xiuyun
Published: February 2014

The norm N(G) of a group G is the intersection of normalizers of all the subgroups of G. Let G be a finite group, p a prime dividing the order of G, and P a Sylow p-subgroup of G. In this paper, it is proved that G is p-nilpotent if Ω1(P) ≤ N(NG(P)), and when p=2, [Formula: see text]. Some applications of this result are given. Finally, a class of finite p-groups in which the index of the norm is exactly p is described.
On Some Finiteness Properties in Infinite Groups
Authors: Baumslag Gilbert , Bogopolski Oleg , Fine Benjamin , Gaglione Anthony , Rosenberger Gerhard , Spellman Dennis
Published: February 2014

We consider some questions concerning finiteness properties in infinite groups which are related to Marshall Hall's theorem. We call these properties Property S and Property R, and they are trivially true in finite groups. We give several elementary proofs using these properties for results on finitely generated subgroups of free groups as well as a new elementary proof of Hall's basic result. Finally, we consider these properties within surface groups and prove an analog of Hall's theorem in that context.
Numerical Semigroups that Differ from a Symmetric Numerical Semigroup in One Element
Authors: Rosales J. C.
Published: February 2014

Given two numerical semigroups S and S', the distance between S and S' is the cardinality of S\S' plus the cardinality of S'\S. In this paper we study those numerical semigroups S for which there is a symmetric numerical semigroup whose distance to S is one.
On the Semigroup of Square Matrices
Authors: Kudryavtseva Ganna , Mazorchuk Volodymyr
Published: February 2014

We study the structure of nilpotent subsemigroups in the semigroup M(n,𝔽) of all n×n matrices over a field 𝔽 with respect to the operation of the usual matrix multiplication. We describe the maximal subsemigroups among the nilpotent subsemigroups of a fixed nilpotency degree and classify them up to isomorphism. We also describe isolated and completely isolated subsemigroups and conjugated elements in M(n,𝔽).
On Nilpotency of Generalized Almost-Jordan Right-Nilalgebras
Authors: Arenas Manuel , Labra Alicia
Published: February 2014

We study the variety of algebras A over a field of characteristic ≠ 2, 3, 5 satisfying the identities xy=yx and β {((xx)y)x-((yx)x)x} + γ {((xx)x)y-((yx)x)x}=0, where β, γ are scalars. We do not assume power-associativity. We prove that if A admits a non-degenerate trace form, then A is a Jordan algebra. We also prove that if A is finite-dimensional and solvable, then it is nilpotent. We find three conditions, any of which implies that a finite-dimensional right-nilalgebra A is nilpotent.
Co-support and Coartinian Modules
Authors: Nam Tran Tuan
Published: February 2014

We show that for a linearly compact module over a local ring (R,𝔪), the concept of co-support of modules provided by Melkersson is equivalent with Yassemi's concept. We also introduce the definition of coartinian modules which is in some sense dual to Hartshorne's definition of cofinite modules and show that [Formula: see text] is I-coartinian in case M is a semi-discrete linearly compact R-module with Ndim M=d> 0.
Wreath Product Structure of Left C-rpp Semigroups
Authors: Guo Xiaojiang , Zhao Ming , Shum K. P.
Published: February 2014

The concept of wreath product of semigroups was first introduced by Neumann in 1960, and later on, this concept was used by Preston to investigate the structure of some inverse semigroups. In this paper, we modify the wreath product given by Neumann and Preston to study the structure of some generalized Clifford semigroups. In particular, we prove that a semigroup is a left C-rpp semigroup if and only if it is the wreath product of a left regular band and a C-rpp semigroup. Our result provides a new insight to the structure of left C-rpp semigroups.
Generalized Stable Exchange Rings
Authors: Chen Huanyin
Published: February 2014

A ring R is said to be a generalized stable ring provided that aR + bR = R with a, b ∈ R implies that there exists y ∈ R such that a + by ∈ K(R), where K(R) = {x ∈ R | ∃s, t ∈ R such that sxt = 1}. Let A be a quasi-projective right R-module, and let E = End R(A). If E is an exchange ring, then E is a generalized stable ring if and only if for any R-morphism f : A → M with Im f ≤⊕M and any R-epimorphism g : A → M, there exist e = e2 ∈ E and h ∈ K(E) such that f = g(eh). Furthermore, we prove that every regular matrix over a generalized stable exchange ring admits a diagonal reduction by quasi-invertible matrices.
Annihilator Conditions on Ore Extensions
Authors: Hashemi E.
Published: February 2014

In this paper, we extend the study of various annihilator conditions on the nearring of polynomials and the nearring of formal power series to skew polynomials and skew formal power series in which addition and substitution are used as operations. A result of Hong et al. on the skew polynomial rings and skew power series of an α-rigid Baer ring is extended to Baer conditions in the nearrings of skew polynomials and skew formal power series. Also, for an injective endomorphism α of a ring R, it is shown that R is α-rigid if and only if the nearring (R[x; α], +, ◦) is reduced, if and only if the nearring (R0[[x; α]], +, ◦) is reduced, if and only if R is a reduced and near Armendariz ring.
Representations of a Class of Non-commutative Associative Algebras Related to the Quantum Torus
Authors: Ye Congfeng
Published: February 2014

In this paper, we study the representations of a class of non-commutative associative algebras AQ related to the quantum torus [Formula: see text], which is introduced by Berman, Gao and Krylyuk to study the extended affine Lie algebras. The representations of AQ are important for the study of the representations of certain “half lattice” vertex algebras.
On Quotients of Groups Having a Series with Finite Factors
Authors: Nicotera Chiara
Published: February 2014

The class of groups having a series with finite factors is not quotient closed. In this note, we prove that if the group G has a series whose factors are finite and H is a locally nilpotent normal subgroup of G, then G/H also has a series whose factors are finite.
A Note on the Fundamental Group of a Triangular Algebra
Authors: Xu Fan
Published: February 2014

Let A be a finite dimensional basic connected algebra over a field k of characteristic zero. We generalize the result of [5], and show that if the quiver of A has no oriented cycles, then the fundamental group of any presentation of A by quiver and relations (as defined in [6]) is the quotient of the fundamental group of a privileged presentation of A. In a more general case, we cite and analyze the example given in [3].
Trivalent Non-symmetric Vertex-Transitive Graphs of Order at Most 150
Authors: Ma Xuesong , Wang Ruji
Published: February 2014

Let X be a simple undirected connected trivalent graph. Then X is said to be a trivalent non-symmetric graph of type (II) if its automorphism group A = Aut (X) acts transitively on the vertices and the vertex-stabilizer Av of any vertex v has two orbits on the neighborhood of v. In this paper, such graphs of order at most 150 with the basic cycles of prime length are investigated, and a classification is given for such graphs which are non-Cayley graphs, whose block graphs induced by the basic cycles are non-bipartite graphs.
Weight Theory for Alternating Groups
Authors: Ruff Oliver
Published: February 2014

We use techniques of Okounkov and Vershik to study the ordinary representation theory of the alternating groups without relying on the classical results for the symmetric groups. We classify and construct the simple modules, and study their branching properties.