Group algebras and enveloping algebras with nonmatrix and semigroup identities

Let K be a field of positive characteristic p, let R be either a group algebra K[G] or a restricted enveloping algebra u(L), and let I be the augmentation ideal of R. We first characterize those R for which I satisfies a polynomial identity not satisfied by the algebra of all 2-by-2 matrices over K. Then we examine those R for which I satisfies a semigroup identity (that is, a polynomial identity which can be written as the difference of two monomials).Comment: 11 pages. Written in LaTeX2

Coulomb interaction between a spherical and a deformed nuclei

We present analytic expressions of the Coulomb interaction between a spherical and a deformed nuclei which are valid for all separation distance. We demonstrate their significant deviations from commonly used formulae in the region inside the Coulomb radius, and show that they remove various shortcomings of the conventional formulae.Comment: 7 pages 4 figure

There are no magnetically charged particle-like solutions of the Einstein Yang-Mills equations for Abelian models

We prove that there are no magnetically charged particle-like solutions for Abelian models in Einstein Yang-Mills, but for non-Abelian models the possibility remains open. An analysis of the Lie algebraic structure of the Yang-Mills fields is essential to our results. In one key step of our analysis we use invariant polynomials to determine which orbits of the gauge group contain the possible asymptotic Yang-Mills field configurations. Together with a new horizontal/vertical space decomposition of the Yang-Mills fields this enables us to overcome some obstacles and complete a dynamical system existence theorem for asymptotic solutions with nonzero total magnetic charge. We then prove that these solutions cannot be extended globally for Abelian models and begin an investigation of the details for non-Abelian models.Comment: 48 pages, 1 figur

Ethnophysiography

Ethnophysiography is a new term coined by the authors to refer to an ethnoscience of landforms. Ethnophysiography seeks to document and compare terms used in various languages and cultures to refer to the natural landscape and its parts, and the meanings of those terms. Ethnophysiography is an important part of efforts to construct ontologies of the geographic domain because the categories of landforms, water bodies, etc. are not clearly differentiated in nature the way terms for kinds of plants and animals typically are. Landscape terms and their meanings appear to subdivide reality differently in different cultures; thus clear definitions of meanings in an ontological framework with universal expressive power are needed if semantic interoperability across languages and cultures is to be achieved

Optical limiting properties of (reduced) graphene oxide covalently functionalized by coordination complexes

The nonlinear optical (NLO) and optical limiting (OL) properties of graphene oxide (GO), reduced graphene oxide (RGO), and particularly GO/RGO coordination complex hybrids are reviewed. A brief introduction to mechanisms of OL and a summary of the key measurement techniques for determining NLO/OL merit is provided. A summary of synthetic procedures to GO/RGO coordination complex hybrids is included.We thank the Australian Research Council (ARC) for financial support. D.M.A.S.D. was the recipient of an Australian Postgraduate Award

Law, politics and the governance of English and Scottish joint-stock companies 1600-1850

This article examines the impact of law on corporate governance by means of a case study of joint-stock enterprise in England and Scotland before 1850. Based on a dataset of over 450 company constitutions together with qualitative information on governance practice, it finds little evidence to support the hypothesis that common-law regimes such as England were more supportive of economic growth than civil-law jurisdictions such as Scotland: indeed, levels of shareholder protection were slightly stronger in the civil-law zone. Other factors, such as local political institutions, played a bigger role in shaping organisational forms and business practice

Surgical clipping as the preferred treatment for aneurysms of the middle cerebral artery

In recent years the endovascular treatment of intracranial aneurysms (coiling) has progressively gained recognition, particularly after the publication of the International Subarachnoid Aneurysm Trial (ISAT) in 2002. Despite the fact that in ISAT middle cerebral artery (MCA) aneurysms were clearly underrepresented, the study is often used as an argument to favor coiling above surgery in MCA aneurysms. Taken into account that MCA aneurysms are very well accessible for surgery, a contemporary assessment of the benefits of a preferred surgical strategy for MCA aneurysms was performed in a tertiary neurovascular referral center. A prospectively kept single-center database of 151 consecutive patients with an MCA aneurysm was reviewed over a 6-year period (2001-2006). Long-term follow-up after surgical treatment of a ruptured MCA aneurysm was obtained in 74 out of 77 (96%) patients. The outcome was compared with relevant series in the literature. After a mean follow-up of 4.7 years, 59 out of 74 surgically treated patients (80%) with a ruptured MCA aneurysm had a good outcome (mRankin 0-2). All patients with an unruptured MCA aneurysm also had a good outcome after clipping. This is well-matched with the findings of the literature search, and competitive with the endovascular results. Surgical clipping is recommended as the principal treatment strategy for MCA aneurysms. This is not only ethically defendable in view of the surgical results but also in line with a strategy to maintain surgical experience within centralized neurovascular centers

Comment on: “Peatland carbon stocks and burn history: Blanket bog peat core evidence highlights charcoal impacts on peat physical properties and long-term carbon storage”, by A. Heinemeyer, Q. Asena, W.L. Burn and A.L. Jones (Geo: Geography and Environment. 2018; e00063)

A recent paper by Heinemeyer et al. (2018) in this journal has suggested that the use of prescribed fire may enhance carbon accumulation in UK upland blanket bogs. We challenge this finding based on a number of concerns with the original manuscript including the lack of an unburned control, insufficient replication, unrecognised potential confounding factors, and potentially large inaccuracies in the core dating approach used to calculate carbon accumulation rates. We argue that burn‐management of peatlands is more likely to lead to carbon loss than carbon gain