bluuebunny/crossref_metadata_2025 huggingface dataset:
At return to play following hamstring injury the majority of professional football players have residual isokinetic deficits
Authors: Tol Johannes L , Hamilton Bruce , Eirale Cristiano , Muxart Patrice , Jacobsen Philipp , Whiteley Rod
Published: February 2014

Background

There is an ongoing debate regarding the optimal criteria for return to sport after an acute hamstring injury. Less than 10% isokinetic strength deficit is generally recommended but this has never been documented in professional football players after rehabilitation. Our aim was to evaluate isokinetic measurements in MRI-positive hamstring injuries.

Methods

Isokinetic measurements of professional football players were obtained after completing a standardised rehabilitation programme. An isokinetic strength deficit of more than 10% compared with the contralateral site was considered abnormal. Reinjuries within 2 months were recorded.

Results

52 players had a complete set of isokinetic testing before clinical discharge. There were 27 (52%) grade 1 and 25 (48%) grade 2 injuries. 35 of 52 players (67%) had at least one of the three hamstring-related isokinetic parameters that display a deficit of more than 10%. The percentage of players with 10% deficit for hamstring concentric 60°/s, 300°/s and hamstring eccentric was respectively 39%, 29% and 28%. There was no significant difference of mean isokinetic peak torques and 10% isokinetic deficits in players without reinjury (N=46) compared with players with reinjury (N=6).

Conclusions

When compared with the uninjured leg, 67% of the clinically recovered hamstring injuries showed at least one hamstring isokinetic testing deficit of more than 10%. Normalisation of isokinetic strength seems not to be a necessary result of the successful completion of a football-specific rehabilitation programme. The possible association between isokinetic strength deficit and increased reinjury risk remains unknown.
Lymph node revealing solutions in colorectal cancer: should they be used routinely?
Authors: Horne Joanne , Bateman Adrian C , Carr Norman J , Ryder Isobel
Published: February 2014

The Royal College of Pathologists (RCPath) and College of American Pathologists recommend that at least 12 lymph nodes should be harvested for adequate staging of colorectal carcinoma. Just one nodal tumour deposit upstages the malignancy from pN0 to pN1. This is critically important as node-positive patients (pN1) are considered for adjuvant chemotherapy whereas node-negative patients (pN0) may not be. It is not always easy to harvest the required number, especially in patients with rectal carcinoma who may have received neoadjuvant therapy—an increasingly common treatment. The use of neoadjuvant therapy is known to further decrease the number and size of identifiable lymph nodes within specimens, meaning that the lymph node harvest often fails to reach RCPath guidelines. Lymph node revealing solutions consisting of either single chemicals such as alcohol or acetone or compounds have been investigated to help improve the lymph node harvest in difficult specimens, for example, those received following neoadjuvant therapy. Published research evidence reviewed here suggests that lymph node revealing solutions significantly improve lymph node harvesting, and that glacial acetic acid, ethanol, water and formalin is advantageous in comparison with other revealing solutions in that it is safe, cheap, easy to use and relatively quick. However, the quantity of good evidence is limited and the clinical implications of improving lymph node harvesting require further research.
Integrating molecular diagnostics into histopathology training: the Belfast model
Authors: Flynn C , James J , Maxwell P , McQuaid S , Ervine A , Catherwood M , Loughrey M B , McGibben D , Somerville J , McManus D T , Gray M , Herron B , Salto-Tellez M
Published: February 2014

Molecular medicine is transforming modern clinical practice, from diagnostics to therapeutics. Discoveries in research are being incorporated into the clinical setting with increasing rapidity. This transformation is also deeply changing the way we practise pathology. The great advances in cell and molecular biology which have accelerated our understanding of the pathogenesis of solid tumours have been embraced with variable degrees of enthusiasm by diverse medical professional specialties. While histopathologists have not been prompt to adopt molecular diagnostics to date, the need to incorporate molecular pathology into the training of future histopathologists is imperative. Our goal is to create, within an existing 5-year histopathology training curriculum, the structure for formal substantial teaching of molecular diagnostics. This specialist training has two main goals: (1) to equip future practising histopathologists with basic knowledge of molecular diagnostics and (2) to create the option for those interested in a subspecialty experience in tissue molecular diagnostics to pursue this training. It is our belief that this training will help to maintain in future the role of the pathologist at the centre of patient care as the integrator of clinical, morphological and molecular information.
Treatment of ruptured blood blister-like aneurysms with flow diverter SILK stents
Authors: Aydin Kubilay , Arat Anil , Sencer Serra , Hakyemez Bahattin , Barburoglu Mehmet , Sencer Altay , İzgi Nail
Published: February 2014

Introduction

Blood blister-like aneurysms (BBAs) are fragile and difficult to treat. Routine surgical and endovascular treatment methods, such as clipping, clip wrapping, primary coiling, or stent assisted coiling, have relatively high morbidity and mortality rates. In this study, we report clinical and angiographic results for treatment of ruptured BBAs using flow diverter stents.

Methods

We retrospectively reviewed patients who presented with subarachnoid hemorrhages caused by rupture of BBAs and who were treated using flow diverter stents at three neurointervention centers between January 2009 and January 2013. Clinical and angiographic findings, together with the procedural data and follow-up results, are reported.

Results

11 patients were identified in this study. BBAs were located on the supraclinoid internal carotid artery (nine patients) and basilar arteries (two patients). Eight patients were treated by implantation of a single flow diverter stent. Two flow diverter stents were telescopically deployed in each of three patients. The procedures were successful in all cases. No acute complications developed in any case. One patient who had an initial Hess–Hunt grade 4 died of septicemia 2 weeks after the procedure (9%). Another patient developed a minor stroke caused by parent artery thrombosis (9%). Control angiographies performed 3 and 6 months post stenting revealed complete occlusion of the aneurysms in all of the remaining nine patients (82%). 10 of the 11 patients (92%) had good clinical outcomes (modified Rankin Scale score ≤2).

Conclusions

Implantation of flow diverter stents seems to be a safe and feasible alternative for treatment of ruptured BBAs.
Role of frailty assessment in patients undergoing cardiac interventions
Authors: Rowe Rebecca , Iqbal Javaid , Murali-krishnan Rachel , Sultan Ayyaz , Orme Rachel , Briffa Norman , Denvir Martin , Gunn Julian
Published: February 2014

Average life expectancy is increasing in the western world resulting in a growing number of frail individuals with coronary heart disease, often associated with comorbidities. Decisions to proceed to invasive interventions in elderly frail patients is challenging because they may gain benefit, but are also at risk of procedure-related complications. Current risk scores designed to predict mortality in cardiac procedures are mainly based on clinical and angiographic factors, with limitations in the elderly because they are mainly derived from a middle-aged population, do not account for frailty and do not predict the impact of the procedure on quality of life which often matters more to elderly patients than mortality. Frailty assessment has emerged as a measure of biological age that correlates well with quality of life, hospital admissions and mortality. Potentially, the incorporation of frailty into current risk assessment models will cause a shift towards more appropriate care. The need for a more accurate method of risk stratification incorporating frailty, particularly for elderly patients is pressing. This article reviews the association between frailty and cardiovascular disease, the impact of frailty on outcomes of cardiac interventions and suggests ways in which frailty assessment could be incorporated into cardiology clinical practice.
Effect of compaction water content on the strength of cement-stabilized rammed earth materials
Authors: Beckett Christopher , Ciancio Daniela
Published: February 2014

Current guidelines suggest that stabilized rammed earth materials be compacted at their optimum water content to achieve their maximum strength. Although this is true for traditional rammed earth, there is no evidence that this procedure should also be used for cement-stabilized rammed earth. Furthermore, the water content used at compaction is usually difficult to control on a construction site, so that material might be compacted at water contents other than the optimum. In this paper, a novel experimental programme is presented in which the effect of compaction water content on the unconfined compressive strength of crushed limestone stabilized to 5% Portland cement content is investigated for a range of curing periods. Freeze drying of specimens was used to arrest cement hydration to determine the evolution of hydrated cement content. Scanning electron microscope (SEM) analysis was used to identify differences between the final material microstructures. Results are discussed demonstrating the intimate link between the amount of hydrated cement, material microstructure, and compressive strength.
Carrier heating in quantum dot structures
Authors: Flayyih Ahmed H. , Al-Khursan Amin H.
Published: February 2014

In this paper, the effect of carrier heating (CH) in the four-wave mixing theory in quantum dot (QD) structure has been studied. The influence of parameters such as CH nonlinear gain parameter, wetting layer carrier density, CH time constant, QD ground and excited state energies have been examined. Our model predicts a low CH for QDs which can explain earlier experimental measurements in this field. To the best of our knowledge, this study has not been discussed before.
Finite Groups Which Are the Product of L2 (7) or L2 (8) with a Symmetric Group
Authors: Darafsheh M. R. , Moghaddamfar A. R.
Published: February 2014

In this paper, we find the structure of finite groups G=AB with subgroups A ≅ L2 (7) or L2 (8) and B ≅ Sn (n ≥ 5).
Kasch Modules and pV-Rings
Authors: López-Permouth Sergio R. , Shum K. P. , Sanh Nguyen Van
Published: February 2014

Let R be a ring. A right R-module M is called p-injective if every homomorphism from a principal right ideal of R to M can be given by a left multiplication. A ring R is called a right pV-ring if every simple R-module is p-injective. In this paper, Kasch modules are considered. It is proved that if a Kasch module M is finitely generated and quasi-p-injective, then there is a bijective correspondence between the class of maximal submodules of M and the class of all minimal left ideals of its endomorphism ring. Also, it is proved that if M is a pV-module which is a finitely generated projective self-generator, then its endomorphism ring is a right pV-ring. Finally, it is proved that being a right or left pV-ring is a Morita invariant.
Identities on Maximal Subgroups of GLn(D)
Authors: Kiani D. , Mahdavi-Hezavehi M.
Published: February 2014

Let D be a division ring with centre F. Assume that M is a maximal subgroup of GLn(D) (n≥1) such that Z(M) is algebraic over F. Group identities on M and polynomial identities on the F-linear hull F[M] are investigated. It is shown that if F[M] is a PI-algebra, then [D:F]<∞. When D is non-commutative and F is infinite, it is also proved that if M satisfies a group identity and F[M] is algebraic over F, then we have either M=K* where K is a field and [D:F]<∞, or M is absolutely irreducible. For a finite dimensional division algebra D, assume that N is a subnormal subgroup of GLn(D) and M is a maximal subgroup of N. If M satisfies a group identity, it is shown that M is abelian-by-finite.
On Chains Associated with Elements Algebraic over a Henselian Valued Field
Authors: Aghigh Kamal , Khanduja Sudesh K.
Published: February 2014

Let v be a henselian valuation of a field K, and [Formula: see text] be the (unique) extension of v to a fixed algebraic closure [Formula: see text] of K. For an element [Formula: see text], a chain [Formula: see text] of elements of [Formula: see text] such that θi is of minimal degree over K with the property that [Formula: see text] and θm ∈ K, is called a complete distinguished chain for θ with respect to (K, v). In 1995, Popescu and Zaharescu proved the existence of a complete distinguished chain for each [Formula: see text] when (K, v) is a complete discrete rank one valued field (cf. [10]). In this paper, for a henselian valued field (K, v) of arbitrary rank, we characterize those elements [Formula: see text] for which there exists a complete distinguished chain. It is shown that a complete distinguished chain for θ gives rise to several invariants associated to θ which are same for all the K-conjugates of θ.
Complementarity of Subgroups and the Structure of Finite Groups
Authors: Guo Xiuyun , Shum K. P.
Published: February 2014

In this paper, we consider a finite group in which some subgroups are complemented in a special subgroup of a given group. Some new conditions are obtained for a finite group in a formation [Formula: see text] containing the class [Formula: see text] of finite supersolvable groups. Our results generalize the recent results on the complemented subgroups of finite groups.
Characters and Representations of p-Groups of Class 2
Authors: Herzog Marcel , Lev Arieh
Published: February 2014

In this paper, a systematic way is described for the construction of all irreducible characters and irreducible representations of finite p-groups of class 2.
Generalized Enrichments of Categories for Operads
Authors: Ma Zizhu
Published: February 2014

Most enriched categories also have an ordinary category structure which is compatible with the enrichment on them. In this paper, enrichments in a monoidal category are generalized to arbitrary categories. These specialize to the classical enrichments when sets are regraded as discrete categories. We also generalize the definitions of PROs and PROPs as some generalized enrichments of categories. Then an operad in some monoidal category corresponds to a generalized PROP. Algebras of operads induce some special kind of monoidal functors. In the category of small categories, we construct several operads to define lax monoids and lax commutative monoids which are formal descriptions of natural associativity and commutativity. Using this identification, operads and their algebras can be studied by lax commutative monoids and morphisms between them.
A Short Proof to Some Results of Sun and Wang
Authors: Cao Wei
Published: February 2014

We give a short proof to some results of Sun and Wang on counting the number of solutions of a class of equations over finite fields. Our proof is elementary and only based on matrix properties and recursion techniques.
A Note on Clean Rings
Authors: Wang Zhou , Chen Jianlong
Published: February 2014

Let R be a ring and g(x) a polynomial in C[x], where C=C(R) denotes the center of R. Camillo and Simón called the ring g(x)-clean if every element of R can be written as the sum of a unit and a root of g(x). In this paper, we prove that for a, b ∈ C, the ring R is clean and b-a is invertible in R if and only if R is g1(x)-clean, where g1(x)=(x-a)(x-b). This implies that in some sense the notion of g(x)-clean rings in the Nicholson–Zhou Theorem and in the Camillo–Simón Theorem is indeed equivalent to the notion of clean rings.
Recognition by Spectrum of L16(2m)
Authors: Grechkoseeva Maria A. , Shi Wujie , Vasilev Andrey V.
Published: February 2014

In this paper we prove that the simple linear groups L16(2m)(m ≥ 1) over fields of characteristic 2 are recognizable by the sets of their element orders.
On Ideals Generated by Monomials and One Binomial
Authors: Barile Margherita
Published: February 2014

We determine, in a polynomial ring over a field, the arithmetical rank of certain ideals generated by a set of monomials and one binomial.
Leibniz Central Extension on a Block Lie Algebra
Authors: Wang Qing , Tan Shaobin
Published: February 2014

Let [Formula: see text] be the Lie algebra over C with basis {Lm,n | m,n ∈ Z, n ≥ 0} and relations [Lm,n,Lm1,n1] =((n+1)m1-(n1+1)m) Lm+m1,n+n1. In this paper, we determine the second cohomology group and the second Leibniz cohomology group of [Formula: see text].
A Note on Local Cohomology
Authors: Mafi Amir , Zakeri Hossein
Published: February 2014

A certain set of associated primes of the Matlis duality of any top local cohomology module of a complete filter local ring is characterized. Also, it is proved that the set of associated primes of a finitely generated module over a four-dimensional local ring is finite.
Finite p-Groups All of Whose Subgroups of Index p2 Are Abelian
Authors: Zhang Qinhai , Sun Xiujuan , An Lijian , Xu Mingyao
Published: February 2014

In this paper, we give a complete classification of finite p-groups all of whose subgroups of index p2 are abelian.
Cohomological Dimension of Generalized Local Cohomology Modules
Authors: Amjadi Jafar , Naghipour Reza
Published: February 2014

The study of the cohomological dimension of algebraic varieties has produced some interesting results and problems in local algebra. Let 𝔞 be an ideal of a commutative Noetherian ring R. For finitely generated R-modules M and N, the concept of cohomological dimension cd 𝔞(M, N) of M and N with respect to 𝔞 is introduced. If 0 → N' → N → N'' → 0 is an exact sequence of finitely generated R-modules, then it is shown that cd 𝔞(M, N) = max { cd 𝔞(M, N'), cd 𝔞(M, N'')} whenever proj dim M < ∞. Also, if L is a finitely generated R-module with Supp (N/Γ𝔞(N)) ⊆ Supp (L/Γ𝔞(L)), then it is proved that cd 𝔞(M, N) ≤ max { cd 𝔞(M,L), proj dim M}. Finally, as a consequence, a result of Brodmann is improved.
On Hyper (Abelian of Finite Rank) Groups
Authors: Wehrfritz B. A. F.
Published: February 2014

We study the class of groups G, each of whose non-trivial images contains a non-trivial abelian normal subgroup of finite rank. This is very much wider than the class, studied earlier by Robinson and others, of hyperabelian groups H with finite abelian section rank. Our main results are that these groups G are hypercentral by residually finite and are divisible by hypo(abelian of finite exponent). They need not be divisible by residually finite, unlike the groups H above. In practice, we work with a somewhat wider but less easily described class of groups.
On the Nilpotency and Solubility of the Central Automorphism Group of a Finite Group
Authors: Jafari Mir-Heidar , Jamali Ali-Reza
Published: February 2014

In this paper we completely study the nilpotency and solubility of the group Aut c(G) of central automorphisms of a finite group G.
Higher Class Groups of Locally Triangular Orders over Number Fields
Authors: Guo Xuejun , Kuku Aderemi
Published: February 2014

In this paper, we study the K-theory of triangular rings. As an application, we show that for a locally triangular order Λ, the p-torsion in the higher class group Cl2n(Λ) can only occur for primes p which lie under the prime ideals ℘ of [Formula: see text], at which Λ is not maximal.
A Note on the Artinianness and Vanishing of Local Cohomology and Generalized Local Cohomology Modules
Authors: Khashyarmanesh K. , Khosh-Ahang F.
Published: February 2014

The first part of this paper is concerned with the Artinianness of certain local cohomology modules [Formula: see text] when M is a Matlis reflexive module over a commutative Noetherian complete local ring R and 𝔞 is an ideal of R. Also, we characterize the set of attached prime ideals of [Formula: see text], where n is the dimension of M. The second part is concerned with the vanishing of local cohomology and generalized local cohomology modules. In fact, when R is an arbitrary commutative Noetherian ring, M is an R-module and 𝔞 is an ideal of R, we obtain some lower and upper bounds for the cohomological dimension of M with respect to 𝔞.
Dipolarizations in Kac–Moody Algebras
Authors: Wang Yan , Meng Daoji
Published: February 2014

In this paper, some methods are given to construct dipolarizations in Kac–Moody algebras as well as their some subalgebras, and an illustrative example is provided. The dipolarizations found in this paper include symmetric and non-symmetric ones.
On θ*-Pairs and the Structure of Finite Groups
Authors: Feng Haihui , Guo Xiuyun
Published: February 2014

Let H, C and D be subgroups of a finite group G. The pair (C, D) is called a θ*-pair for H if (1) D = (C ∩ H)G, 〈Cg, H〉 = G for every g ∈ G, and (2) KH < G for every subgroup K of G with K/D ᐊ G/D and K/D < C/D. In this paper, we obtain some results on θ*-pairs which imply G to be solvable, supersolvable or nilpotent.
Non-degenerate Invariant Bilinear Forms on Lie Color Algebras
Authors: Wang Song , Zhu Linsheng
Published: February 2014

In this paper, we study Lie color algebras 𝔤 with a non-degenerate color-symmetric, 𝔤-invariant bilinear form B, such a (𝔤,B) is called a quadratic Lie color algebra. Our first result generalizes the notion of double extensions to quadratic Lie color algebras. This notion was introduced by Medina and Revoy to study quadratic Lie algebras. In the second theorem, we give a sufficient condition for a quadratic Lie color algebra to be a quadratic Lie color algebra by double extension. At last, we generalize the notion of T*-extensions to Lie color algebras.
Local Cohomology with Supports in the Non-free Locus
Authors: Marcelo Agustín , Muñoz Masqué J. , Rodríguez Mielgo C.
Published: February 2014

The groups of local cohomology with supports in the non-free locus of a module are used in order to obtain three classifications and one characterization of four classes of modules.
Some Hyperbolic 3-Manifolds with Totally Geodesic Boundary
Authors: Telloni Agnese Ilaria
Published: February 2014

We construct a family of compact hyperbolic 3-manifolds with totally geodesic boundary, depending on three integer parameters. Then we determine geometric presentations of the fundamental groups of these manifolds and prove that they are cyclic coverings of the 3-ball branched along a specified tangle with two components. Finally, we give a classification of these manifolds up to homeomorphism (resp., isometry), and determine their isometry groups.
Recognition of Finite Simple Linear Groups L4(2k) by Spectrum
Authors: Xu Mingchun
Published: February 2014

A finite group G is said to be recognizable by spectrum, i.e., by the set of element orders, if every finite group H having the same spectrum as G is isomorphic to G. Grechkoseeva, Shi and Vasilev have proved that the simple linear groups Ln(2k) are recognizable by spectrum for n=2m≥ 16. In this paper we establish the recognizability for the case n=4.
Pentavalent One-regular Graphs of Square-free Order
Authors: Li Yantao , Feng Yan-Quan
Published: February 2014

A graph is one-regular if its automorphism group acts regularly on the set of its arcs. Let n be a square-free integer. It is shown in this paper that a pentavalent one-regular graph of order n exists if and only if n = 2 · 5tp1p2 … ps ≥ 62, where t ≤ 1, s ≥ 1, and pi's are distinct primes such that 5|(pi-1). For such an integer n, there are exactly 4s-1 non-isomorphic pentavalent one-regular graphs of order n, which are Cayley graphs on dihedral groups constructed by Kwak et al. This work is a continuation of the classification of cubic one-regular graphs of order twice a square-free integer given by Zhou and Feng.
On the Clique Numbers of Non-commuting Graphs of Certain Groups
Authors: Abdollahi A. , Azad A. , Mohammadi Hassanabadi A. , Zarrin M.
Published: February 2014

Let G be a non-abelian group. The non-commuting graph [Formula: see text] of G is defined as the graph whose vertex set is the non-central elements of G and two vertices are joint if and only if they do not commute. In a finite simple graph Γ, the maximum size of complete subgraphs of Γ is called the clique number of Γ and denoted by ω(Γ). In this paper, we characterize all non-solvable groups G with [Formula: see text], where 57 is the clique number of the non-commuting graph of the projective special linear group PSL (2,7). We also determine [Formula: see text] for all finite minimal simple groups G.
Fully Kasch Modules and Rings
Authors: Baziar M. , Haghany A. , Vedadi M. R.
Published: February 2014

We carry out a study of modules MR satisfying the property that every module in σ[M] is a Kasch module. Such modules are called fully Kasch. Several sufficient conditions for a module to be fully Kasch are given which are also necessary in case the module satisfies a property (∗). We prove that if R is right Artinian, or right FBN, or Morita equivalent to a right duo ring, then every R-module satisfies the condition (∗). When R is Morita equivalent to a right duo ring, an R-module M is fully Kasch if and only if R/ ann R(mR) is a left perfect ring for any non-zero m ∈ M. These considerations tackle a question raised by Albu and Wisbauer.
On Cofinitely Lifting Modules
Authors: Wang Yongduo , Wu Dejun
Published: February 2014

Let R be a ring and M a right R-module. M is called a cofinitely lifting module if for any cofinite submodule N of M, there exists a direct summand K of M such that K ≤ N and N/K ≪ M/K. It is proved that every cofinite direct summand of a cofinitely lifting module is cofinitely lifting. For a cofinitely lifting module M and a fully invariant submodule N of M, we show that M/N is also cofinitely lifting. We prove that a duo module M=M1⊕ M2 is cofinitely lifting if M1 and M2 are both cofinitely lifting. Let M=M1⊕ M2 be an amply supplemented module. It is shown that if M1 and M2 are both cofinitely lifting and relatively cofinitely small projective and M1 is cofinitely pseudo-M2-projective (or M2 is cofinitely pseudo-M1-projective), then M is cofinitely lifting.
Certain One-point Extension of Minimal 2-Fundamental Algebras
Authors: Jaworska Alicja
Published: February 2014

A certain one-point extension of minimal 2-fundamental algebras is examined. The characterization of associated vector space categories is given and the Auslander–Reiten quiver for such an extension is shown.
On Binomial Equations Defining Rational Normal Scrolls
Authors: Barile Margherita
Published: February 2014

We show that a rational normal scroll can in general be set-theoretically defined by a proper subset of the 2-minors of the associated two-row matrix. This allows us to find a class of rational normal scrolls that are almost set-theoretic complete intersections.
Factoring Abelian Groups, Cliques in Graphs and Covering Sets
Authors: Szabó Sándor
Published: February 2014

The paper deals with the following problem: If a finite abelian 2-group is a direct product of its subsets of cardinality 4, does it follow that at least one of the factors is periodic? Two results are presented. In the first one, the structures of the group and the subsets are restricted but the size of the the group is not. In the second one, the group and the factors are general but the order of the group is 26.
Lie Super-bialgebra Structures on the Centerless Twisted N=2 Super-conformal Algebra
Authors: Fa Huanxia , Li Junbo , Xin Bin
Published: February 2014

In this paper, Lie super-bialgebra structures on the centerless twisted N=2 super-conformal algebra [Formula: see text] are considered, which are proved to be coboundary triangular.
Weak Quasi-Armendariz Rings
Authors: Başer Muhittin , Kaynarca Fatma , Kwak Tai Keun , Lee Yang
Published: February 2014

In this paper, we introduce and study weak quasi-Armendariz rings which unify the notions of weak Armendariz rings and quasi-Armendariz rings. It is shown that the weak quasi-Armendarizness is a Morita invariant property. For a semiprime ring R, it is shown that R[x]/〈xn〉 is weak quasi-Armendariz, where R[x] is the polynomial ring over R and 〈xn〉 is the ideal of R[x] generated by xn. Various properties of weak quasi-Armendariz rings are also observed.
Mixed Product Ideals Generated by s-Sequences
Authors: La Barbiera Monica , Restuccia Gaetana
Published: February 2014

We consider monomial ideals of mixed products in the polynomial ring in two sets of variables and we investigate when they are generated by an s-sequence in order to compute invariants of their symmetric algebra.
Note on Primitive Ideals of Enveloping Algebras in Prime Characteristic
Authors: Yao Yufeng
Published: February 2014

Let [Formula: see text] be a restricted Lie algebra over an algebraically closed field F of characteristic p > 0, [Formula: see text] the center of the universal enveloping algebra [Formula: see text] of [Formula: see text]. In this note, we study primitive ideals of [Formula: see text]. The following results are included: (1) The ideal of [Formula: see text] generated by the central character ideal associated with any irreducible [Formula: see text]-module has finite co-dimension in [Formula: see text]. Furthermore, the co-dimension is no less than [Formula: see text], where [Formula: see text] is the maximal dimension of irreducible [Formula: see text]-modules. (2) Each annihilator ideal of irreducible [Formula: see text]-modules of maximal dimension is generated by the corresponding central character ideal in [Formula: see text]. (3) Each G-stable ideal in [Formula: see text] for [Formula: see text] contains nonzero fixed points under the action of G, where G is a connected reductive algebraic group. Additionally, the arguments on ideals help us to give an alternative description of the Azumaya locus in the Zassenhaus variety without using the normality of the Zassenhaus variety.
Attached Primes of Local Cohomology for Modules Finite over a Ring Homomorphism
Authors: Tehranian Abolfazl , Tousi Massoud , Yassemi Siamak
Published: February 2014

Let 𝜑 : R → S be a ring homomorphism of Noetherian rings and let 𝔞 be an ideal of R. Let M be a finitely generated S-module with dim R(M)=d. In this paper, we prove that the R-module [Formula: see text] has a secondary representation and we exhibit its set of attached primes (under some technical conditions).
The Graph Expansion of an Ordered Groupoid
Authors: Gilbert N. D. , Miller E. C.
Published: February 2014

We generalise the Margolis-Meakin graph expansion of a group to a construction for ordered groupoids, and show that the graph expansion of an ordered groupoid enjoys structural properties analogous to those for graph expansions of groups. We also use the Cayley graph of an ordered groupoid to prove a version of McAlister's P-theorem for incompressible ordered groupoids.
Construction of Lee Weight Codes Detecting CT-Burst Errors and Correcting Random Errors
Authors: Jain Sapna , Shum K. P.
Published: February 2014

We obtain a construction upper bound over the number of parity check digits for Lee weight codes correcting random errors and simultaneously detecting CT-burst errors.
On the k-Nacci Sequences in Finite Binary Polyhedral Groups
Authors: Deveci Ömür , Karaduman Erdal , Campbell Colin M.
Published: February 2014

A k-nacci sequence in a finite group is a sequence of group elements x0,x1,…,xn,… for which, given an initial (seed) set x0,x1,…,xj-1, each element is defined by [Formula: see text] It is important to note that the Fibonacci length depends on the chosen generating n-tuple for a group. The binary polyhedral groups have been studied recently by C.M. Campbell and P.P. Campbell for their Fibonacci lengths. In this paper, we obtain the period of k-nacci sequences in the binary polyhedral groups 〈2,2,2〉, 〈n,2,2〉, 〈2,n,2〉 and 〈2,2,n〉 for any n > 2.
Locally Finite Conditions on Maximal Subgroups of GLn(D)
Authors: Fallah-Moghaddam R. , Mahdavi-Hezavehi M.
Published: February 2014

Given a division ring D with center F, the structure of maximal subgroups M of GLn(D) is investigated. Suppose D ≠ F or n > 1. It is shown that if M/(M ∩ F*) is locally finite, then char F=p > 0 and either n=1, [D:F]=p2 and M ∪ {0} is a maximal subfield of D, or D=F, n=p, and M ∪ {0} is a maximal subfield of Mp(F), or D=F and F is locally finite. It is also proved that the same conclusion holds if M/(M ∩ F*) is torsion and D is of finite dimension over F. Furthermore, it is shown that if the r-th derived group M(r) of M is locally finite, then either M(r) is abelian or F is algebraic over its prime subfield.
The Solution Set to the Quaternion Matrix Equation $AX-\overline{X}B=0$
Authors: Feng Lianggui , Cheng Wei
Published: February 2014

We give a clear description of the solution set to the quaternion matrix equation [Formula: see text], where A, B are known, X is unknown and [Formula: see text] denotes the usual conjugate of X.
On Generalized Schur's Lemma and Its Applications
Authors: Wang Lizhong
Published: February 2014

In this paper, we generalize Schur's lemma on the basis of endomorphism rings for permutation modules. Let H be a subgroup of G and let M be a module of H. Set N = NG(H). Then there is a natural embedding of End N(MN) into End G(MG). By taking H to be a p-subgroup of G, we can reformulate Green's theory on modular representation. A defect theory is defined on the endomorphism ring of any induced module and it is used to prove Green's correspondence and related results. This defect theory can unify some well known results in modular representation theory. By using generalized Schur's lemma, we can also give a method to determine the multiplicity of simple modules in any permutation module of symmetric groups. This makes it possible to prove various versions of Foulkes' conjecture in a uniform way.
A Note on the p-Deficiency Class of a Finite Group
Authors: Li Tianze , Xu Weigang , Zhang Jiping
Published: February 2014

In this note, we explore the relationship between finite groups of characteristic p type and those of p-deficiency class 1. We study the structure of finite groups of characteristic p type. Besides, we show that the p-rank (resp., p-length) of a p-solvable group which is of exact p-deficiency class r(> 0) is bounded by r (resp., a function of r).
A Note on the Adjacency Criterion for the Prime Graph and the Characterization of Cp(3)
Authors: He Huaiyu , Shi Wujie
Published: February 2014

In this paper, we remedy some errors in the paper [17]; in particular, for any non-abelian finite simple group G other than Alt n such that n-2, n-1 and n are not primes, we prove that for each r ∈ π(G), there always exists s ∈ π(G) which is non-adjacent to r in the Gruenberg-Kegel graph of G. Applications of these results to the recognition problem of some finite simple groups by spectrum are also considered.
Some Characterizations about the Structure of Finite Groups
Authors: Wang Lili , Chen Guiyun
Published: February 2014

A subgroup H of a finite group G is called an ℋ-subgroup of G if NG(H) ∩ Hg ≤ H for all g ∈ G. The set of all ℋ-subgroups of a finite group G is denoted by ℋ(G). In this paper, a sufficient condition about p-nilpotency is given and some new results for a finite group G to be p-nilpotent or supersolvable are obtained based on the assumption that some subgroups belong to ℋ(G).
Galois Lines for Normal Elliptic Space Curves, II
Authors: Yoshihara Hisao
Published: February 2014

For each linearly normal elliptic curve C ⊂ ℙ3, we determine Galois lines and their arrangement. We prove that the curve C has exactly six V4-lines. In case j(C) = 1, it has eight Z4-lines in addition. The V4-lines form the edges of a tetrahedron. In case j(C) = 1, for each vertex of the tetrahedron, there exist exactly two Z4-lines passing through it. As a corollary we obtain that each plane quartic curve of genus 1 does not have more than one Galois point.
Symmetric Self-adjunctions and Matrices
Authors: Došen Kosta , Petrić Zoran
Published: February 2014

It is shown that the multiplicative monoids of Brauer's centralizer algebras generated out of the basis are isomorphic to monoids of endomorphisms in categories where an endofunctor is adjoint to itself, and where, moreover, a kind of symmetry involving the self-adjoint functor is satisfied. As in a previous paper, of which this is a companion, it is shown that such a symmetric self-adjunction is found in a category whose arrows are matrices, and the functor adjoint to itself is based on the Kronecker product of matrices.
Some Remarks on Dedekind Modules
Authors: Karimzadeh S. , Nekooei R.
Published: February 2014

In this paper, we first obtain equivalent conditions for a module over a Prüfer domain and derive properties of Dedekind modules over such a domain. We then obtain equivalent conditions for a finitely generated Dedekind module over an integrally closed ring. Finally, we characterize multiplication Dedekind modules.
Generalized Local Homology for Artinian Modules
Authors: Nam Tran Tuan
Published: February 2014

We introduce generalized local homology which is in some sense dual to generalized local cohomology, and study some properties of generalized local homology modules for artinian modules, such as the artinianness, noetherianness and the characterization of Width I(M) by generalized local homology. By using duality, we get back some properties of generalized local cohomology.
On s-Semiembedded Subgroups of Finite Groups
Authors: Li Yangming
Published: February 2014

Suppose that G is a finite group and H is a subgroup of G. We say that H is s-semipermutable in G if HGp = GpH for any Sylow p-subgroup Gp of G with (p, |H|) = 1; H is s-semiembedded in G if there is a normal subgroup T of G such that HT is s-semipermutable in G and H ∩ T ≤ HssG, where HssG is the subgroup of H generated by all those subgroups of H which are s-semipermutable in G. We investigate the influence of s-semiembedded subgroups on the structure of finite groups. Some recent results are generalized and unified.
Quantum Cocommutative Coalgebras in $^{H}_{H}\mathcal{YD}$ and the Solutions of the Quasi-Yang-Baxter Equation
Authors: Fang Xiaoli , Li Jinqi
Published: February 2014

In this paper, we construct a quantum cocommutative coalgebra in the category of Yetter-Drinfeld modules over a coquasi-Hopf algebra, and give some solutions of the quasi-Yang-Baxter equation.
Contragredient Modules and Invariant Bilinear Forms on Möbius Nonlocal Vertex Algebras
Authors: Sun Jiancai
Published: February 2014

We study contragredient modules for Möbius nonlocal vertex algebras and characterize the space of all invariant bilinear forms on Möbius nonlocal vertex algebras. Finally, Möbius weak quantum vertex algebras of Zamolodchikov-Faddeev type are studied as examples.
Two-parameter Quantum Affine Algebra $U_{r,s}(\widehat{\frak{sl}}_2)$
Authors: Zhang Honglian , Pang Ruzhi
Published: February 2014

We give two realizations of the two-parameter quantum affine algebra [Formula: see text] and prove that its structure is isomorphic to the one-parameter case. In particular, the evaluation representation of [Formula: see text] is obtained.
Exchange Ideals with All Idempotents Central
Authors: Chen Huanyin
Published: February 2014

In this paper we investigate necessary and sufficient conditions on an ideal under which it is an exchange ideal with all idempotents central. Related examples are constructed by means of ideal-extensions. A kind of uniqueness in such ideals is also studied. These provide a new class of such ideals.
Invariants of FP-Projective Dimensions Under Cleft Extensions
Authors: Chen Xiuli , Zhu Haiyan , Li Fang
Published: February 2014

Let H be a finite dimensional Hopf algebra and A be an algebra over a fixed field k. Firstly, it is proved that the left FP-projective dimension is invariant under cleft extensions when H is semisimple and A is left coherent. Secondly, using (co)induction functors, we study the relations between FP-projective dimensions in A # H-Mod and the counterparts in AH-Mod. Finally, we characterize the FP-projective preenvelopes (resp., precovers) under H*-extensions and cleft extensions, respectively.
The Hecke Algebra of a Frobenius P-Category
Authors: Puig Lluis
Published: February 2014

We introduce a new avatar of a Frobenius P-category [Formula: see text] under the form of a suitable subring [Formula: see text] of the double Burnside ring of P — called the Hecke algebra of [Formula: see text] — where we are able to formulate: (i) the generalization to a Frobenius P-category of the Alperin Fusion Theorem, (ii) the “canonical decomposition” of the morphisms in the exterior quotient of a Frobenius P-category restricted to the selfcentralizing objects as developed in chapter 6 of [4], and (iii) the “basic P × P-sets” in chapter 21 of [4] with its generalization by Kari Ragnarsson and Radu Stancu to the virtual P × P-sets in [6]. We also explain the relationship with the usual Hecke algebra of a finite group.
Generalized Baumslag-Solitar Graphs with Soluble Fundamental Groups
Authors: Delgado Alberto L. , Robinson Derek J. S. , Timm Mathew
Published: February 2014

It is shown that the generalized Baumslag-Solitar graphs which have soluble fundamental groups can be constructed from four simple types of graph by a process of decoration. The method of proof is elementary and employs the operations of pinching and contracting edges of graphs.
The k-Nacci Sequences in Some Special Modular Groups
Authors: Deveci Ömür , Campbell Colin M.
Published: February 2014

A k-nacci (k-step Fibonacci) sequence in a finite group is a sequence of group elements x0, x1, x2, …, xn, … for which, given an initial (seed) set x0, x1, x2, …, xj-1, each element is defined by [Formula: see text] From the definition, it is clear that the period of the k-nacci sequence in a group depends on the chosen generating set and the order in which the assignments of x0, x1, x2, …, xj-1 are made. In this paper we examine the periods of the k-nacci sequences in the groups 𝔐2, [Formula: see text] and ℜ2, where each term of the sequence is reduced modulo 2.
On the Strong Nilpotence Problem
Authors: Sun Xiaosong
Published: February 2014

In this paper, we describe the structure of quadratic homogeneous polynomial maps F=X+H with JH3=0. As a consequence we show that in dimension n ≤ 6, JH is strongly nilpotent, or equivalently F=X+H is linearly triangularizable.
Vanishing Properties of Dual Bass Numbers
Authors: Li Lingguang
Published: February 2014

Let R be a Noetherian ring, M an Artinian R-module, and 𝖒 ∈ Cos RM. Then cograde R𝔭 Hom R (R𝔭,M) = inf {i | πi(𝔭,M) > 0} and [Formula: see text] where πi(𝔭,M) is the i-th dual Bass number of M with respect to 𝔭, cograde R𝔭 Hom R (R𝔭,M) is the common length of any maximal Hom R (R𝔭, M)-quasi co-regular sequence contained in 𝔭 R𝔭, and fd R𝔭 Hom R (R𝔭, M) is the flat dimension of the R𝔭-module Hom R (R𝔭, M). We also study the relations among cograde, co-dimension and flat dimension of co-localization modules.
Forward modelling as a method for predicting the distribution of deep-marine sands: an example from the Peïra Cava Sub-basin
Authors: Aas Tor Even , Basani Riccardo , Howell John , Hansen Ernst
Published: February 2014

The aerial extent, thickness and internal distribution of grain-size are key, bed-scale controls on turbidite reservoir performance. Process-based modelling provides a method for predicting both the sandbody thickness and the grain-size distribution within the bed. The goal of the current study is to test such an approach on the Annot Sandstone in the Peïra Cava Sub-basin in SE France, and determine whether the process-based model can reliably recreate the bed characteristics observed in the outcrop. Turbidity currents were modelled using a commercially available software solution called MassFlow3D that is based on computational fluid dynamics. The goal of the current study was to accurately replicate a single bed (termed MU5). To achieve this goal, the base of the basin was structurally restored and then a simplified simulation of the beds below MU5 was generated using four flow events in order to recreate the bathymetry on to which MU5 was simulated. Several versions of MU5 were simulated with different input parameters for the flow, and the results were compared with the observed thickness and grain-size distribution from the outcrop. The study suggests that process-based modelling has the potential to be a useful tool in reservoir modelling.

Supplementary material:

Multi-phase flow modelling of transport, deposition and erosion of sediments is available at
http://www.geolsoc.org.uk/SUP18719
.
Mesh saliency via spectral processing
Authors: Song Ran , Liu Yonghuai , Martin Ralph R. , Rosin Paul L.
Published: February 2014

We propose a novel method for detecting mesh saliency, a perceptually-based measure of the importance of a local region on a 3D surface mesh. Our method incorporates
global
considerations by making use of spectral attributes of the mesh, unlike most existing methods which are typically based on
local
geometric cues. We first consider the properties of the log-Laplacian spectrum of the mesh. Those frequencies which show differences from expected behaviour capture saliency in the frequency domain. Information about these frequencies is considered in the spatial domain at multiple spatial scales to localise the salient features and give the final salient areas. The effectiveness and robustness of our approach are demonstrated by comparisons to previous approaches on a range of test models. The benefits of the proposed method are further evaluated in applications such as mesh simplification, mesh segmentation, and scan integration, where we show how incorporating mesh saliency can provide improved results.
Mining order-preserving submatrices from probabilistic matrices
Authors: Fang Qiong , Ng Wilfred , Feng Jianlin , Li Yuliang
Published: February 2014

Order-preserving submatrices
(OPSMs) capture consensus trends over columns shared by rows in a data matrix. Mining OPSM patterns discovers important and interesting local correlations in many real applications, such as those involving biological data or sensor data. The prevalence of uncertain data in various applications, however, poses new challenges for OPSM mining, since data uncertainty must be incorporated into OPSM modeling and the algorithmic aspects.

In this article, we define new probabilistic matrix representations to model uncertain data with continuous distributions. A novel
probabilistic order-preserving submatrix
(POPSM) model is formalized in order to capture similar local correlations in probabilistic matrices. The POPSM model adopts a new probabilistic support measure that evaluates the extent to which a row belongs to a POPSM pattern. Due to the intrinsic high computational complexity of the POPSM mining problem, we utilize the anti-monotonic property of the probabilistic support measure and propose an efficient Apriori-based mining framework called
ProbApri
to mine POPSM patterns. The framework consists of two mining methods,
UniApri
and
NormApri
, which are developed for mining POPSM patterns, respectively, from two representative types of probabilistic matrices, the
UniDist matrix
(assuming uniform data distributions) and the
NormDist matrix
(assuming normal data distributions). We show that the
NormApri
method is practical enough for mining POPSM patterns from probabilistic matrices that model more general data distributions.

We demonstrate the superiority of our approach by two applications. First, we use two biological datasets to illustrate that the POPSM model better captures the characteristics of the expression levels of biologically correlated genes and greatly promotes the discovery of patterns with high biological significance. Our result is significantly better than the counterpart OPSMRM (OPSM with repeated measurement) model which adopts a set-valued matrix representation to capture data uncertainty. Second, we run the experiments on an RFID trace dataset and show that our POPSM model is effective and efficient in capturing the common visiting subroutes among users.