bluuebunny/crossref_metadata_2025 huggingface dataset:
Sharing knowledge, saving time: an online toolbox to aid junior doctors
Authors: Houston James , Barker William , Clarke Jonathan , Mew Ed
Published: February 2014

Junior doctors are too often frustrated by not being able to quickly find information for how to make referrals, book investigations and contact other professionals at hospital. To make matters worse, much of the knowledge gained by doctors throughout the year is lost during the August rotation. There is an unmet need for retaining such knowledge, in order to facilitate a smoother and safer handover.

We set up the “Doctors Directory” at our trust; a website run by junior doctors, providing specific, up-to-date information relevant to other junior doctors within the trust. Whilst providing day-to-day information, it also contains a "survival guide" for each hospital firm.

We surveyed junior doctors before and after the implementation of this site. 81% of FY1s surveyed have used the site. Of the doctors that had used the site, 94% found it helpful with a mean self reported time saving of 39 minutes a day. Whilst still in its infancy, the site now has mobile access, and has an average of 60 hits a day. Quality improvement projects such as this are readily scalable to other hospitals and have enabled junior doctors to waste less time finding how to do jobs and more time actually getting them done.
Improving the management of Acute Kidney Injury in a District General Hospital: Introduction of the DONUT bundle
Authors: Bhagwanani Anisha , Carpenter Rory , Yusuf Aqeelah
Published: February 2014

The NCEPOD report (2009) on Acute Kidney Injury (AKI) found 20% of post-admission AKIs were avoidable and only 50% of AKI care was considered 'good'. The DONUT bundle comprises of six interventions aimed at improving the management of AKI.

Baseline data was collected prospectively using the biochemistry eAlert system, identifying 50 patients with Stage 1 AKI over a two week period. Management was assessed 24 hours after the eAlert using a standardised proforma. After data analysis, a DONUT sticker was introduced within the Emergency Admissions Unit, providing an efficient method of recording interventions in the notes. Education sessions outlining the DONUT bundle and stickers were delivered via Foundation Program teaching, along with summary flash cards. A re-audit assessed these interventions.

Of the initial cohort (n=50), only 8% of cases had all components of the care bundle completed. Following introduction of the education programme and AKI sticker, re-audit showed a rise in full compliance to 17% (n=42). Only 7% of cases used the AKI sticker but where it was used, there was 100% compliance with the bundle.

In conclusion, AKI management is sub-standard. An education program and the use of a simple sticker can improve management. Further education regarding AKI is needed and work is ongoing to improve compliance with sticker use.
Evaluation of transabdominal ultrasound as a tool for predicting the success of abdominocentesis in horses
Authors: Beccati F. , Nannarone S. , Gialletti R. , Lotto E. , Cercone M. , Dante S. , Bazzica C. , Pepe M.
Published: February 2014

The aim of this study was to evaluate the transabdominal ultrasonography as a tool for predicting the success of abdominocentesis in horses. Patients were included in the study if a complete transabdominal ultrasonography examination and abdominocentesis were performed as part of the clinical work‐up. Ultrasonographically, the amount of peritoneal fluid was assessed using a 4‐point grading system, as well as the amount of peritoneal fluid collected. A χ2or Fischer exact test was performed to test for an association between the ultrasonography findings and fluid retrieved, and between the two grading scales. Interobserver and intraobserver agreement values were calculated using k statistics. Values of P<0.05 were considered significant; 109 horses met the inclusion criteria. Peritoneal fluid was identified ultrasonographically in 72 per cent of horses, and it was collected from 93 per cent of these cases. In horses with no peritoneal fluid identified at ultrasonography (28 per cent), fluid was collected in 70 per cent of cases. There is a significant association between transabdominal ultrasonography detection of peritoneal fluid and the likelihood to obtain a diagnostic amount of peritoneal fluid at abdominocentesis; however, even when peritoneal fluid is not detected during abdominal ultrasonography examination, an amount of peritoneal fluid useful for gross, clinicopathological and cytological evaluation can frequently be obtained.
Embryons somatiques de Vitis rupestris et embryons zygotiques de Vitis sp. : morphologie, histologie, histochimie et développement
Authors: Faure Olivier
Published: February 2014

The problem of the development of grapevine somatic embryos into plantlets was examined through a morphological, histological, and histochemical comparison of zygotic and somatic embryos. Only 3% of somatic embryos were capable of developing into plantlets. However, 27% of these embryos had shoot and root apices showing a histological pattern similar to that observed in zygotic embryos; other embryos had root apex but no shoot apex. In comparison with zygotic embryos, somatic embryos showed the following characteristics: acquisition of giant, and often teratologic, organs, retention of a high proliferative capacity among superficial cells, starch and tannin accumulation, important suberization and slight lignification of superficial cells, differentiation of tracheids in the vascular system, and preservation of a high embryogenic potential in the absence of exogenous growth regulators. The water-saturated atmosphere to which grapevine somatic embryos were submitted during in vitro culture could be unfavourable to germination. Under these conditions, embryos built impermeable suberized superficial layers. Key words: somatic embryos, zygotic embryos, Vitis sp., histochemistry, development.
Hybrid performance and species crossability relationships in willows (Salix)
Authors: Mosseler A.
Published: February 2014

Interspecific hybridization between Salix amygdaloides Anderss., S. bebbiana Sarg., S. discolor Muhl., S. eriocephala Michx., S. exigua Nutt., S. lucida Muhl., S. pellita Anderss., and S. petiolaris Smith revealed several forms of postzygotic inviability including seed incompatibility, seedling inviability, inferior growth performance, and reduced fertility in the F1 hybrid progeny. The proportion of inviable and inferior progeny varied with the species combination and the specific combining ability of genotypes within each species combination. Family mean growth performance was lower in most interspecific hybrids, but several hybrid combinations produced progeny superior to the average performance of intraspecific crosses involving the same parent species. Interspecific hybrid families were also characterized by high proportions of nonflowering individuals. Viable F1 interspecific hybrids generally suffered reduced male and female fertility, but most female F1 hybrids produced viable open pollinated seed. The relatively high fertility and viability demonstrated by some interspecific hybrids indicates that natural interspecific gene flow between several species of subgenus Vetrix is possible. Crossability relationships based on F1 hybrid viability suggest that Salix exigua is more closely related to species of subgenus Vetrix than to those of subgenus Salix.
Environmental controls of carbon uptake in two woody species with contrasting distributions at the edge of cliffs
Authors: Matthes-Sears U. , Larson D. W.
Published: February 2014

Thuja occidentalis L. and Acer saccharum Marsh, show mutually exclusive distribution patterns along forested cliff edges of the Niagara Escarpment; T. occidentalis occurs at the cliff edge and on the cliff face, whereas A. saccharum occurs with increasing frequency away from the cliff edge. To reveal the controls of such patterns, seasonal and diurnal courses of net photosynthesis (Pn), stomatal conductance (gs), and xylem water potential were measured in situ and related to fluctuations in light, temperature, and moisture. For each species, saplings growing in the cedar zone near the cliff edge were compared with saplings growing in the deciduous forest zone farther from the cliff edge on the plateau. The carbon uptake of both species was most often limited by light; limitation by temperature, atmospheric, or soil moisture was rare. Acer saccharum was slightly better adapted than T. occidentalis to growth at the low light levels in both zones because of a greater light-use efficiency. During severe drought, both species showed reductions in Pn and gs when growing near the cliff edge. In the deciduous forest, in contrast, Pn of T. occidentalis, but not A. saccharum, was significantly reduced, suggesting that A. saccharum may outcompete T. occidentalis for water. In the spring and fall, T. occidentalis had higher Pn and gs in the deciduous forest than at the cliff edge. However, all differences in gas exchange rates between trees in the deciduous forest and at the cliff edge were small and relatively rare. During most of the growing season, Pn and gs differed little between saplings in the two zones. This suggests that the pattern of abundance is not controlled to a substantial degree by carbon gain at the sapling stage. Key words: photosynthesis, water potential, Acer saccharum, Thuja occidentalis, plant zonation, cliff–forest ecotone.
On Dicarpella, Sphaerognomonia, and Apiosporopsis
Authors: Reid James , Dowsett James A.
Published: February 2014

Apiosporopsis (Trav.) Mariani is proposed as the correct name for Sphaerognomonia Poteb. ex Höhn. (type species S. carpinea (Fr.) Poteb. ex Höhn.) and is considered to be a monotypic genus of uncertain affinities. It is demonstrated that Dicarpella H. Syd. & P. Syd. consists of only three species (D. bina, D. liquidambaris-styracifluae, and D. orientalis) whose affinities do not lie with the Diaporthaceae. A new genus, Wuestniopsis, is proposed to accommodate the two remaining species of Dicarpella, D. georgiana and D. quercifolia. Key words: Dicarpella, Sphaerognomonia, Apiosporopsis, taxonomy, nomenclature.
Iterative ranking and clustering analysis of a kettle bog data set
Authors: Wu Q. , Jancey R. C. , Graham R.
Published: February 2014

A multivariate pattern analysis was performed on a data set from a kettle bog in southwestern Ontario. The procedure used involved an iterative ranking and clustering of quadrats. The rationale for this approach was based on the principle of locality of descriptor importance. Twenty-two descriptors and 90 quadrats were used. Of the 22 descriptors used, 19 were plant species and 3 were environmental variables. Four major vegetation groupings were recognized in the study area. Key words: bog, multivariate, pattern, ranking.
Development of wheat (Triticum aestivum) pollen wall before and after effect of a gametocide
Authors: El-Ghazaly Gamal A. , Jensen William A.
Published: February 2014

Light and electron microscopy studies show that pollen wall development in plants treated with the gametocide RH0007 and untreated plants was similar until the stage at which sporopollenin is normally deposited on the wall. At this stage, the pollen wall of treated plants is 80% thinner than that of the control. Shortly after this stage, the pollen grains in the treated plants collapse and abort. We conclude that the gametocide clearly acts through the inhibition of sporopollenin formation, which results in pollen death. As sporopollenin is found only in the pollen wall of seed plants and the spores of nonseed plants, harm to other parts of the plant is not expected to occur. Key words: pollen wall development, Triticum aestivum, gametocide.
Isolation and ultrastructural localization of a soluble protein from Ophiostoma ulmi
Authors: Jeng R. S. , Svircev A. M.
Published: February 2014

Two-dimensional polyacrylamide gel electrophoresis was used to identify and isolate a soluble polypeptide, the QP1 protein, which is characteristic of the vegetative hyphae of nonaggressive isolate Q412 of Ophiostoma ulmi. Individual QP1 spots were excised from 16 two-dimensional gels. Polypeptides were eluted from the gel spots by electroelution and lyophilized. The protein was injected into rabbits for the production of polyclonal antibodies. Antiserum specificity was tested by transferring polypeptides from a two-dimensional gel onto nitrocellulose and treating with QP1 serum. The resulting immunoblot contained a single spot that corresponded in shape and location to that of the QP1 polypeptide. Thin sections of fungal mycelia, from nonaggressive isolate Q412 and the aggressive isolate VA of O. ulmi, were treated with QP1 antibodies and protein A – gold. The gold label was localized in thin sections over conidial and hyphal cell walls of the nonaggressive isolate. The aggressive isolate was nonreactive. Mycelia from nonaggressive isolates Q412 and Q311 and aggressive isolates VA and CESS16K of O. ulmi were grown on solid medium, treated with QP1 antibodies, labelled with protein A – gold, and prepared for scanning electron microscopy. The gold-labelled QP1 polypeptide was detected on the leading edge of a small number of hyphae from nonaggressive isolates Q412 and Q311. Key words: immunogold labelling, Ophiostoma ulmi, soluble proteins.
Morphological and foliar terpene characters to distinguish between western and eastern white pine
Authors: Hunt R. S. , Meagher M. D. , Manville J. F.
Published: February 2014

To distinguish between western (Pinus monticola) and eastern (P. strobus) white pines, foliage, buds, and cones were examined and foliar terpenes were extracted and analyzed from representative samples. Needles of P. monticola were heavier, wider (>0.7 mm), and stiffer; buds were larger and usually nonresinous; cone scales, when viewed from the cone bottom, were arranged in five and eight spiralling rows. Needles of P. strobus were lighter, narrower (<0.7 mm), and droopy; buds were small and covered with white resin and bloom; cone scales were arranged in three and five rows. Needles and cones of P. monticola tended to be longer; cones were composed of more scales and contained more scales per centimetre and more scales per spiral row than those of P. strobus, but there was some overlap. Twig pubescence, bud apex shape, phyllotaxy, and seed wing length were not distinctive. Capillary gas-liquid chromatographic analysis of the leaf oils of white pine trees showed that bornyl acetate and β-elemene, present in P. monticola, were essentially absent in P. strobus, while α-humulene, present in P. strobus, was not found in P. monticola. In addition, the amount of β-caryophyllene could be used to differentiate between these species. However, the most obvious discriminating feature was the presence of a substantial and broad peak of unknown and decomposing compound(s) in the chromatograms for P. monticola and its complete absence in the chromatograms for P. strobus. A clone that was highly resistant to blister rust and previously classified as P. monticola is shown by terpene patterns and morphology to be P. strobus. Key words: Pinus monticola, Pinus strobus, terpene, Cronartium, morphology.
First-principles study on the geometry and electronic structures of IIIA atoms doped α-Al2O3:VO
Authors: Ao L. , Nie J.L. , Xiang X. , Zu X.T. , Huang J. , Zhang H.
Published: February 2014

We investigate the geometry and electronic structures of α-Al2O3:VO + AlX systems based on first-principles calculations where VO represents one oxygen vacancy and AlX stands for IIIA atoms (B, Ga, In, and Tl) substituting of one Al atom. It is found that all the aluminates maintain the hexagonal symmetry as the pure α-Al2O3 structure and the lattice parameters a, b, and c are expanded with the increase of the IIIA atoms radius. The electronic property analysis indicates that the band gaps are considerably reduced and the reductions are also related to the radius of doping atoms. But unlike the situation of transition metal doped α-Al2O3 the decreases of the band gap are not due to the spreading of d states, but are mainly owing to the ns states at the bottom of the conduction band.
STOCHASTIC ENERGETICS OF A BROWNIAN MOTOR AND REFRIGERATOR DRIVEN BY NONUNIFORM TEMPERATURE
Authors: BENJAMIN RONALD
Published: February 2014

The energetics of a Brownian heat engine and heat pump driven by position dependent temperature, known as the Büttiker–Landauer heat engine and heat pump, is investigated by numerical simulations of the inertial Langevin equation. We identify parameter values for optimal performance of the heat engine and heat pump. Our results qualitatively differ from approaches based on the overdamped model. The behavior of the heat engine and heat pump, in the linear response regime is examined under finite time conditions and we find that the efficiency is lower than that of an endoreversible engine working under the same condition. Finally, we investigate the role of different potential and temperature profiles to enhance the efficiency of the system. Our simulations show that optimizing the potential and temperature profile leads only to a marginal enhancement of the system performance due to the large entropy production via the Brownian particle's kinetic energy.
MOLECULAR CHARACTERISTICS OF DISSOCIATED WATER WITH MEMORY EFFECT FROM METHANE HYDRATES
Authors: LI QIBIN , LIU CHAO , CHEN XI
Published: February 2014

The properties of sI methane hydrate dissociation at different temperatures are investigated using molecular dynamics (MD) simulations, focusing on the characteristics of structure of melting water that has memory effect. Upon melting, the clathrate structures of hydrate are damaged. The density of dissolved methane decreases as the melting temperature rises. There is a positive correlation between the density of dissociated water molecules and melting temperature. Most oxygen atoms of dissociated water molecules remain tetrahedrally coordinated whereas the hydrate-like torsion angles ( H – O – O – H ) are like that of normal water. Therefore, the tetrahedrally coordinated oxygen atoms are one of the factors contributing to the memory effect.
ARE TIME CONSISTENT VALUATIONS INFORMATION MONOTONE?
Authors: KOVACEVIC RAIMUND M. , PFLUG GEORG CH
Published: February 2014

Multi-period risk functionals assign a risk value to discrete-time stochastic processes. While convexity and monotonicity extend in straightforward manner from the single-period case, the role of information is more problematic in the multi-period situation. In this paper, we define multi-period functionals in such a way that the development of available information over time (expressed as a filtration) enters explicitly the definition of the functional. This allows to define and study the property of information monotonicity, i.e. monotonicity w.r.t. increasing filtrations. On the other hand, time consistency of valuations is a favorable property and it is well-known that this requirement essentially leads to compositions of conditional mappings. We demonstrate that generally spoken the intersection of time consistent and information monotone valuation functionals is rather sparse, although both classes alone are quite rich. In particular, the paper gives a necessary and sufficient condition for information monotonicity of additive compositions of positively homogeneous risk/acceptability mappings. Within the class of distortion functionals only compositions of expectation or essential infima are information monotone. Furthermore, we give a sufficient condition and examples for compositions of nonhomogeneous mappings exhibiting information monotonicity.
DEPRESSION DIAGNOSIS SUPPORT SYSTEM BASED ON EEG SIGNAL ENTROPIES
Authors: FAUST OLIVER , ANG PENG CHUAN ALVIN , PUTHANKATTIL SUBHA D. , JOSEPH PAUL K.
Published: February 2014

Electroencephalography (EEG) is a measure which represents the functional activity of the brain. We show that a detailed analysis of EEG measurements provides highly discriminant features which indicate the mental state of patients with clinical depression. Our feature extraction method revolves around a novel processing structure that combines wavelet packet decomposition (WPD) and non-linear algorithms. WPD was used to select appropriate EEG frequency bands. The resulting signals were processed with the non-linear measures of approximate entropy (ApEn), sample entropy (SampEn), renyi entropy (REN) and bispectral phase entropy ( P h). The features were selected using t-test and only discriminative features were fed to various classifiers, namely probabilistic neural network (PNN), support vector machine (SVM), decision tree (DT), k-nearest neighbor algorithm (k-NN), naive bayes classification (NBC), Gaussian mixture model (GMM) and Fuzzy Sugeno Classifier (FSC). Our classification results show that, with a classification accuracy of 99.5%, the PNN classifier performed better than the rest of classifiers in discriminating between normal and depression EEG signals. Hence, the proposed decision support system can be used to diagnose, and monitor the treatment of patients suffering from depression.
Symmetric Powers of Symmetric Bilinear Forms
Authors: McGarraghy Seán
Published: February 2014

We study symmetric powers of classes of symmetric bilinear forms in the Witt–Grothendieck ring of a field of characteristic not equal to 2, and derive their basic properties and compute their classical invariants. We relate these to earlier results on exterior powers of such forms.
Weakly and Strongly Regular Near-rings
Authors: Argac N. , Groenewald N. J.
Published: February 2014

In this paper, we prove some basic properties of left weakly regular near-rings. We give an affirmative answer to the question whether a left weakly regular near-ring with left unity and satisfying the IFP is also right weakly regular. In the last section, we use among others left 0-prime and left completely prime ideals to characterize strongly regular near-rings.
Galois Lines for Normal Elliptic Space Curves
Authors: Duyaguit Ma. Cristina Lumakin , Yoshihara Hisao
Published: February 2014

Let C be a curve, and l and 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 obtain a morphism πl|C : C → l0 and an extension of fields (πl|C)* : k(l0) ↪ k(C). If this extension is Galois, then l is said to be a Galois line. We study the defining equations, automorphisms and the Galois lines for quartic curves, and give some applications to the theory of plane quartic curves.
On λ-Finitely Embedded Modules
Authors: Karamzadeh O. A. S. , Rahimpour Sh.
Published: February 2014

In this article, we introduce and study the notion of λ-finitely embedded modules (a 0-finitely embedded module is just a finitely embedded module). We extend some of the basic results of f.e. modules to λ-f.e. modules. We use this concept to give a new proof of a known result which essentially says that a module M has Krull dimension α if and only if each factor module of M is λ-f.e. for some λ ≤ α and α is the least ordinal with this property. It is observed that a semiprime ring R has Krull dimension λ if and only if R is λ-f.e. We improve the theorem of Matlis–Papp and some of its consequences. Finally, some known results in the literature are restated in terms of the above notion.
Rigid Ideals and Radicals of Ore Extensions
Authors: Hong Chan Yong , Kwak Tai Keun , Rizvi S. Tariq
Published: February 2014

For an endomorphism σ of a ring R, Krempa called σ a rigid endomorphism if aσ(a)=0 implies a=0 for a∈R. A ring R is called rigid if there exists a rigid endomorphism of R. In this paper, we extend the σ-rigid property of a ring R to an ideal of R. For a σ-ideal I of a ring R, we call I a σ-rigid ideal if aσ(a)∈I implies a∈I for a∈R. We characterize σ-rigid ideals and study related properties. The connections of the prime radical and the upper nil radical of R with the prime radical and the upper nil radical of the Ore extension R[x;σ,δ], respectively, are also investigated.
Monomial Bases for Little q-Schur Algebras s(2,r)
Authors: Fu Qiang
Published: February 2014

In this paper, we introduce the little q-Schur algebra s(2,r) of type A1. The main purpose of this paper is to construct a monomial base of s(2,r).
The Tor-Groups of Modules of Generalized Power Series
Authors: Liu Zhongkui , Ahsan Javed
Published: February 2014

Let (S,≤) be a strictly ordered monoid, and R a right noetherian ring. Assume that M is a finitely generated right R-module and N a left R-module. Denote by [[MS,≤]] (resp., [[NS,≤]]) the right (resp., left) [[RS,≤]]-module of generalized power series over M (resp., over N). Then we show that there exists an isomorphism of abelian groups [Formula: see text].
An Elementary Classification of Finite Metacyclic p-Groups of Class at Least Three
Authors: Beuerle James R.
Published: February 2014

In this paper, we classify metacyclic p-groups of nilpotency class at least three up to isomorphism by giving a canonical presentation for each isomorphism class.
Prime Factors of π-Partial Character Degrees and Conjugacy Class Sizes of π-Elements
Authors: Beltrán Antonio , Felipe María José
Published: February 2014

Let G be a finite solvable group. We prove that any prime dividing any irreducible π-partial character degree of G divides the size of some conjugacy class of π-elements of G. Under certain hypothesis, we show that if two distinct primes r and s both divide some irreducible π-partial character degree, then there exists a conjugacy class of π-elements whose size is divisible by rs.
On Conditions for an Endomorphism to be an Automorphism
Authors: Abdollahi Alireza , Endimioni Gérard
Published: February 2014

If K is a set of automorphisms of a group G, an endomorphism θ : G → G is said to be K-pointwise if for each element t ∈ G, there exists an element φ ∈ K such that θ (t) = φ (t). This generalizes the notion of pointwise inner automorphism. We show that in some special cases, a K-pointwise endomorphism is necessarily an automorphism (it is not true in general).
On the Betti Numbers of Shifted Complexes of Stable Simplicial Complexes
Authors: Tang Zhongming , Zhuang Guifen
Published: February 2014

Let Δ be a stable simplicial complex on n vertexes. Over an arbitrary base field K, the symmetric algebraic shifted complex Δs of Δ is defined. It is proved that the Betti numbers of the Stanley-Reisner ideals in the polynomial ring K[x1, x2, …, xn] of the symmetric algebraic shifted complex, exterior algebraic shifted complex and combinatorial shifted complex of Δ are equal.
On the Tubes of Exterior Algebras
Authors: Guo Jinyun , Wu Qiuxian , Wan Qianhong
Published: February 2014

In this paper, we study the Koszul modules of complexity 1 of an exterior algebra of a vector space V over an algebraically closed field. We prove that there are ℙ (V)-orthogonal families of such modules, each of which consists of Koszul modules filtered by the cyclic ones corresponding to the same point in ℙ (V). We also prove that they are invariant under syzygy, so they are all on the homogeneous tubes.
Extending the Property of a Maximal Right Ideal
Authors: Birkenmeier Gary F. , Huynh Dinh Van , Kim Jin Yong , Park Jae Keol
Published: February 2014

We extend various properties from a direct summand X of a module M, whose complement is semisimple, to its trace in M or to M itself. The case when MR = RR and the properties are injectivity or P-injectivity is fully described. As applications, we extend some known results for right HI-rings and give a new characterization of semisimple rings. We conclude this paper by giving some conditions that yield the self-injectivity of von Neumann regular rings.
On p-Separability of Subgroups of Free Metabelian Groups
Authors: Bardakov Valerij G.
Published: February 2014

We prove that every free metabelian non-cyclic group has a finitely generated isolated subgroup which is not separable in the class of nilpotent groups. As a corollary, we prove that for every prime number p, an arbitrary free metabelian non-cyclic group has a finitely generated p′-isolated subgroup which is not p-separable.
On the Structure of a Class of Graded Modules Related to Symmetric Pairs
Authors: Han Gang
Published: February 2014

Let [Formula: see text] be the Cartan decomposition of a real semisimple Lie algebra and [Formula: see text] be its complexification. Let [Formula: see text] be the corresponding isotropy representation, and the exterior algebra [Formula: see text] becomes a graded [Formula: see text]-module by extending ν. We study a graded [Formula: see text]-submodule C of [Formula: see text] and get two important decompositions of the [Formula: see text]-module [Formula: see text]. Let [Formula: see text] be the symmetric algebra over [Formula: see text]. Then [Formula: see text] also has an [Formula: see text]-module structure, which is [Formula: see text]-equivariant, and C is a space of generators for this module. Our results generalize Kostant's results in the special case that ν is the adjoint representation of a semisimple Lie algebra.
On the Torsion Units of Some Integral Group Rings
Authors: Hertweck Martin
Published: February 2014

It is shown that any torsion unit of the integral group ring ℤG of a finite group G is rationally conjugate to a trivial unit if G = P ⋊ A with P a normal Sylow p-subgroup of G and A an abelian p′-group (thus confirming a conjecture of Zassenhaus for this particular class of groups). The proof is an application of a fundamental result of Weiss. It is also shown that the Zassenhaus conjecture holds for PSL(2,7), the finite simple group of order 168.
Symmetric Units in Alternative Loop Rings
Authors: Goodaire Edgar G. , Polcino Milies César
Published: February 2014

Let L be an RA loop, that is, a loop whose loop ring in any characteristic is an alternative, but not associative, ring. For α = ∑ αℓℓ in a loop ring RL, define α♯= ∑ αℓℓ-1and call α symmetric if α♯= α. We find necessary and sufficient conditions under which the symmetric units are closed under multiplication (and hence form a subloop of the loop of units in RL) when R has characteristic two and when R= Z, the ring of rational integers.
Generalized Derivations with Power-Central Values on Multilinear Polynomials
Authors: Wang Yu
Published: February 2014

Let R be a prime algebra over a commutative ring K, Z and C the center and extended centroid of R, respectively, g a generalized derivation of R, and f (X1, …,Xt) a multilinear polynomial over K. If g(f (X1, …,Xt))n ∈ Z for all x1, …, xt ∈ R, then either there exists an element λ ∈ C such that g(x)= λx for all x ∈ R or f(x1, …,xt) is central-valued on R except when R satisfies s4, the standard identity in four variables.
Centroids of Differentiably Simple Color Algebras
Authors: Zhang Xuemei , Zhou Jianhua
Published: February 2014

The chains of ideals of differentiably simple (non-associative) color algebras and those of their centroids are studied. It is proved that for any finite-dimensional differentiably simple (non-associative) color algebra A and any set D of its color derivations, A is D-simple if and only if its centroid 𝙲(A) is D*-simple, where 𝙲(A) is a unitary ∊-commutative associative color algebra, and D* is the set of the color derivations determined by D.
Green's Relations on the Monoid of Regular Hypersubstitutions
Authors: Changphas Th. , Wismath S. L.
Published: February 2014

The theory of hyperidentities and hypervarieties is based on the fact that the set Hyp (τ) of all hypersubstitutions of a fixed type τ forms a monoid, with a Galois connection between submonoids of this monoid and complete sublattices of the lattice of all varieties of type τ. For this reason, there is interest in studying the semigroup or monoid properties of Hyp (τ) and its submonoids. One approach is to study the five relations known as Green's relations definable on any semigroup. In this paper, we consider the type τ = (n) with one n-ary operation symbol for n≥ 1, and the submonoid Reg (n) of regular hypersubstitutions. We characterize Green's relations on every subsemigroup of Reg (n); then using this characterization we describe which subsemigroups of Reg (n) are 𝒢-subsemigroups of Reg (n) defined by Levi.
Remarks on Symmetry Classes of Tensors
Authors: Fan Yun , Zhu Ping
Published: February 2014

This paper discusses symmetry operators of the tensor product of free modules of finite rank over domains, shows two formulas to calculate the rank of their images, and applies them to the modular symmetry classes of tensors.
δ-Lifting and δ-Supplemented Modules
Authors: Koşan Muhammet Tamer
Published: February 2014

In this paper, δ-lifting and δ-supplemented modules are defined as generalizations of lifting and supplemented modules. Several properties of these modules are proved. New characterizations of δ-semiperect and δ-perfect rings studied in [9] are obtained using δ-lifting and δ-supplemented modules.
Pell Numbers, Pell–Lucas Numbers and Modular Group
Authors: Mushtaq Q. , Hayat U.
Published: February 2014

We show that the matrix A(g), representing the element g = ((xy)2(xy2)2)m (m ≥ 1) of the modular group PSL(2,Z) = 〈x,y : x2 = y3 = 1〉, where [Formula: see text] and [Formula: see text], is a 2 × 2 symmetric matrix whose entries are Pell numbers and whose trace is a Pell–Lucas number. If g fixes elements of [Formula: see text], where d is a square-free positive number, on the circuit of the coset diagram, then d = 2 and there are only four pairs of ambiguous numbers on the circuit.
Generalized Inflations of Completely Simple Semigroups
Authors: Wang Qiang , Wismath Shelly L.
Published: February 2014

Clarke and Monzo defined a construction called a generalized inflation of a semigroup, and proved that for unions of groups, all null extensions are generalized inflations. We characterize when a groupoid containing a completely simple semigroup B is an associative generalized inflation of B, and thus provide a way to construct all associative generalized inflations (null extensions) of a given completely simple semigroup. This answers a question posed by Clarke and Monzo.
Representations of Subgroups of Universal Triangle Groups
Authors: Xia Jianguo
Published: February 2014

Let G be a universal triangle group, and H a subgroup of G such that the chamber system ΔHis a tight triangle geometry. Then H, which is canonically isomorphic to the topological fundamental group π1(ΔH) of ΔH, is a finitely presented group. For some H we give their representations.
On the Efficiency of the Direct Products of Monogenic Monoids
Authors: Ayık Hayrullah , Campbell C. M. , O'Connor J. J.
Published: February 2014

We give necessary and sufficient conditions for the efficiency of the direct product of finitely many finite monogenic monoids.
Primitive Near-rings — Some Structure Theorems
Authors: Wendt Gerhard
Published: February 2014

We show that any zero symmetric 1-primitive near-ring with descending chain condition on left ideals can be described as a centralizer near-ring in which the multiplication is not the function composition but sandwich multiplication. This result follows from a more general structure theorem on 1-primitive near-rings with multiplicative right identity, not necessarily having a chain condition on left ideals. We then use our results to investigate more closely the multiplicative semigroup of a 1-primitive near-ring. In particular, we show that the set of regular elements forms a right ideal of the multiplicative semigroup of the near-ring.
Study of Semi-projective Retractable Modules
Authors: Haghany A. , Vedadi M. R.
Published: February 2014

For a semi-projective retractable module MR with endomorphism ring S, we prove u.dim MR= u.dim SS, and find necessary and sufficient conditions on M in order that S be respectively semiprime, right nonsingular, finitely cogenerated, cocyclic, or weakly co-Hopfian. Precise descriptions of the right singular ideal of S and the socle of M are given, and in addition if S is a semiprime ring, it is shown that MR is FI-extending if and only if SS is FI-extending.
Band Congruences of t-Archimedean Ordered Semigroups
Authors: Kehayopulu Niovi , Tsingelis Michael
Published: February 2014

Some semigroups without order are decomposable into t-archimedean semigroups via bands. In this paper, we deal with the decomposition of some ordered semigroups into t-archimedean components. The semilattice congruences play an important role in studying the decomposition of semigroups without order. When we pass from semigroups without order to ordered semigroups, the same role is played by the complete semilattice congruences. The characterization of complete semilattices of ordered semigroups of a given type has been considered by the same authors. The r- and l-band congruences have been proved to be useful in studying the decomposition of some types of ordered semigroups, especially the decomposition of r- and l-archimedean ordered semigroups. Band congruences have been proved to be useful in studying the decomposition of some types of ordered semigroups into t-archimedean (ordered) semigroups. The characterization of the bands of ordered semigroups of a given type [Formula: see text] has been recently considered by the same authors. In this paper, we characterize the bands of t-archimedean ordered semigroups. As a result we get a decomposition of some ordered semigroups into t-archimedean components. The decomposition we obtain is uniquely defined.
On the Graph of a Group Mapping and Its Centralizers
Authors: Cheng Yuwen , Huang Feng-Kuo , Wang Chiou-Shing
Published: February 2014

The aim of this paper is to use the graphical properties of a group mapping to study the algebraic properties of its centralizers. Equivalent conditions for the simplicity of the centralizer nearring of a given group mapping are given. Examples are provided to demonstrate and delimit our results.
On a Question of the Theory of Totally Saturated Formations of Finite Groups
Authors: Safonov Vasily G.
Published: February 2014

It is proved that the lattice of totally saturated formations of finite groups is distributive. Thus, we give an affirmative answer to the problem proposed by Shemetkov, Skiba and Guo.
Schur–Zassenhaus Theorem for X-Permutable Subgroups
Authors: Guo Wenbin , Shum K. P. , Skiba Alexander N.
Published: February 2014

Let A and B be subgroups of a group G, and ∅ ≠ X ⊆ G. Then A is said to be X-permutable with B if there exists an element x ∈ X such that ABx= BxA. In this paper, a new version of Schur–Zassenhaus theorem is obtained for X-permutable subgroups, and hence, Question 5.1 in [6] is answered.
On the Yoneda Ext-Algebras of Semiperfect Algebras
Authors: He Jiwei , Ye Yu
Published: February 2014

It is proved that the Yoneda Ext-algebras of Morita equivalent semiperfect algebras are graded equivalent. The Yoneda Ext-algebras of noetherian semiperfect algebras are studied in detail. Let A be a noetherian semiperfect algebra with Jacobson radical J. We construct a right ideal [Formula: see text] of the Yoneda algebra [Formula: see text], which plays an important role in the discussion of the structure of E(A). An extra grading is introduced to [Formula: see text], by which we give a description of the right ideal of E(A) generated by [Formula: see text], and we give a necessary and sufficient condition for a notherian semiperfect algebra to be higher quasi-Koszul. Finally, it is shown that the quasi-Koszulity of a noetherian semiperfect algebra is a Morita invariant.
On Refined Semilattices of Semigroups
Authors: Wang Zhengpan , Guo Yuqi , Shum K. P.
Published: February 2014

We give a short proof for the associativity of the binary operation defined on a refined system of semigroups indexed by a semilattice. The main result given by Zhang, Shum and Zhang in 2001 on the refined semilattice of semigroups is substantially strengthened.
Top Local Cohomology Modules with Specified Attached Primes
Authors: Dibaei Mohammad T. , Jafari Raheleh
Published: February 2014

Let (R, 𝔪) be a complete Noetherian local ring and let M be a finite R-module of positive Krull dimension n. It is shown that any subset T of Assh R(M) can be expressed as the set of attached primes of the top local cohomology module [Formula: see text] for some ideal 𝔞 of R. Moreover, if 𝔞 is an ideal of R such that the set of attached primes of [Formula: see text] is a non-empty proper subset of Assh R(M), then [Formula: see text] for some ideal 𝔟 of R with dim R(R/𝔟) = 1.
On the Ordinary Irreducible Characters of the Heisenberg Group and a Similar Special Group
Authors: Darafsheh M. R. , Misaghian M.
Published: February 2014

Let Hn(q) denote the Heisenberg group defined over the field with q elements. Using the geometry of the finite symplectic group, we describe all the ordinary irreducible characters of Hn(q). A special group of the same type appears as a subgroup of the finite unitary group whose ordinary irreducible characters are described using the geometry of the unitary group.
Centralizers and Vanishing Derivations on Multi-linear Polynomials in Prime Rings
Authors: De Filippis V.
Published: February 2014

Let R be a prime algebra over a commutative ring K with characteristic not equal to 2. Let d and δ be non-zero derivations of R, f(x1,…, xn) a multi-linear polynomial over K with n non-commuting variables, and m ≥ 1 a fixed integer. We prove that if δ (d(f(r1,…, rn))m) = 0 for any r1,…, rn ∈ R, then either f(x1,…, xn) is central valued on R or R satisfies the standard identity s4.
Power GCD Matrices for a UFD
Authors: Hong Shaofang , Zhou Xingwang , Zhao Jianrong
Published: February 2014

Let S = {x1,…, xn} be a set of n distinct positive integers and e ≥ 1 an integer. Then we call the n × n matrix (Se) = ((xi, xj)e) having the eth power of the greatest common divisor (xi, xj) of xi and xj as its (i, j)-entry the power greatest common divisor (GCD) matrix on S. A well-known formula for det (Se) when S = {1, …, n} was given by H.J.S. Smith in 1875/76. In this paper, we consider the power GCD matrices for a UFD along the direction of their structure, determinant and non-singularity, and consequently, we extend the classical result of Smith as well as the results of Beslin and Kassar on UFD given in 1989.
Epimorphisms in the Category of ℓ-Groups
Authors: Lu Xinmin , Qin Hourong
Published: February 2014

In the category of ℓ-groups, we introduce the concepts of Hopfian and generalized Hopfian ℓ-groups. An ℓ-group G is called Hopfian if every surjective ℓ-homomorphism f : G → G is an ℓ-isomorphism, and G is called generalized Hopfian if every surjective ℓ-homomorphism f : G → G has a small kernel in G. By an example we show that the class of generalized Hopfian ℓ-groups is a proper subclass of Hopfian ℓ-groups. In this paper, we establish some characterizations for them, which generalize some results in [9].
On the Calculation of gl.dim Gℕ(A) and ${\rm gl.dim}\, \widetilde{A}$ by Using Gröbner Bases
Authors: Li Huishi
Published: February 2014

Let [Formula: see text] be a K-algebra defined by a finite Gröbner basis [Formula: see text]. In this paper, it is shown how to use the Ufnarovski graph [Formula: see text] and the graph of n-chains [Formula: see text] to calculate gl.dim Gℕ(A) and [Formula: see text], where Gℕ(A), respectively [Formula: see text], is the associated ℕ-graded algebra of A, respectively the Rees algebra of A with respect to the ℕ-filtration FA of A induced by a weight ℕ-grading filtration of K 〈X1,…, Xn〉.
OD-Characterization of Simple K4-Groups
Authors: Zhang Liangcai , Shi Wujie
Published: February 2014

Let M ≠ A10be a simple K4-group. In this paper, we prove that if G is a finite group with the same order and degree pattern as M, then G ≅ M. Equivalently, all simple K4-groups except A10are OD-characterizable. Moreover, we put forward an example to show that A10and J2× Z3have the same order and degree pattern, but they are not isomorphic.
Maximal and Minimal Ranks of the Common Solution of Some Linear Matrix Equations over an Arbitrary Division Ring with Applications
Authors: Wang Qingwen , Song Guangjing , Liu Xin
Published: February 2014

We establish the formulas of the maximal and minimal ranks of the common solution of certain linear matrix equations A1X = C1, XB2 = C2, A3XB3 = C3 and A4XB4 = C4 over an arbitrary division ring. Corresponding results in some special cases are given. As an application, necessary and sufficient conditions for the invariance of the rank of the common solution mentioned above are presented. Some previously known results can be regarded as special cases of our results.
Fischer Matrices for Projective Representations of Generalized Symmetric Groups
Authors: Almestady Mohammed S. , Morris Alun O.
Published: February 2014

The aim of this work is to calculate the Fischer matrices for the covering groups of the Weyl group of type Bnand the generalized symmetric group. It is shown that the Fischer matrices are the same as those in the ordinary case for the classes of Snwhich correspond to partitions with all parts odd. For the classes of Snwhich correspond to partitions in which no part is repeated more than m times, the Fischer matrices are shown to be different from the ordinary case.
Mapping Extension of an Algebra
Authors: Marczak Adam W. , Płonka Jerzy
Published: February 2014

A new construction of algebras called a mapping extension of an algebra is here introduced. The construction yields a generalization of some classical constructions such as the nilpotent extension of an algebra, inflation of a semigroup but also the square extension construction introduced recently for idempotent groupoids. The mapping extension construction is defined for algebras of any fixed type, however nullary operation symbols are here not admitted. It is based on the notion of a retraction and some system of mappings. A mapping extension of a given algebra is constructed as a counterimage algebra by a specially defined retraction. Varieties of algebras satisfying an identity φ(x) ≈ x for a term φ not being a variable (such as varieties of lattices, Boolean algebras, groups and rings) are especially interesting because for such a variety [Formula: see text], all mapping extensions by φ of algebras from [Formula: see text] form an equational class. In the last section, combinatorial properties of the mapping extension construction are considered.
Poincaré Series of Cosets in Coxeter Groups
Authors: Hart Sarah B. , Rowley Peter J.
Published: February 2014

The Poincaré series of a Coxeter group W measures its growth relative to the generating set R. A well-known formula gives an inductive method of calculating the Poincaré series of W when W is finite. The aim of this paper is to obtain generalizations of this formula.
Finite Groups Whose F-Hypercenter Contains Certain Subgroups of Prime Power Order
Authors: Ezzat Mohamed M.
Published: February 2014

In this paper, we study the structure of finite groups G under the assumption that certain abelian subgroups of largest possible exponent of prime power order lie in the 𝔉-hypercenter of G. We improve and extend some results of Ezzat, Shaalan, Elashiry, Asaad, Ramadan, and Buckley.
Normal Structure of Maximal Parabolic Subgroups in Chevalley Groups over Rings
Authors: Stavrova Anastasia
Published: February 2014

We study the normal structure of maximal parabolic subgroups of a Chevalley group over a commutative ring. More precisely, we describe the subgroups of a maximal parabolic subgroup P normalized by the elementary part of its Levi subgroup. As a corollary, we obtain a description of the subgroups in P normalized by its elementary subgroup EP.
Second Order Dehn Functions for Amalgamated Free Products of Groups
Authors: Wang Xiaofeng , Bao Xiaomin
Published: February 2014

A finite set of generators for a free product of two groups of type F3with a subgroup amalgamated, and an estimation for the upper bound of the second order Dehn functions of the amalgamated free product are carried out.
Vertices of Small Order for Simple Modules of Finite Symmetric Groups
Authors: Danz Susanne , Külshammer Burkhard
Published: February 2014

Let F be a field of characteristic p > 0, let 𝔖n denote the symmetric group of degree n < ∞, and let M be a simple F 𝔖n-module with vertex V belonging to a block B of F 𝔖n with defect group Δ. We prove that |Δ| ≤ |V|!, and we also investigate the embedding of V into 𝔖n.