Local well-posedness for membranes in the light cone gauge

In this paper we consider the classical initial value problem for the bosonic membrane in light cone gauge. A Hamiltonian reduction gives a system with one constraint, the area preserving constraint. The Hamiltonian evolution equations corresponding to this system, however, fail to be hyperbolic. Making use of the area preserving constraint, an equivalent system of evolution equations is found, which is hyperbolic and has a well-posed initial value problem. We are thus able to solve the initial value problem for the Hamiltonian evolution equations by means of this equivalent system. We furthermore obtain a blowup criterion for the membrane evolution equations, and show, making use of the constraint, that one may achieve improved regularity estimates.Comment: 29 page

Determinant Factors of Dividend Payments in Brazil

This study identifies factors that shaped cash disbursement distribution policies employed by Brazilian public companies listed on the Brazilian Securities, Commodities and Futures Exchange (BM&FBOVESPA) from 1995 to 2011. Relationships between Dividends/Total Assets and potential determinants discussed in the literature, including firm size, corporate governance, profitability, leverage, market to book, liquidity, investment, risk, profit growth, information asymmetry and agency conflict, are examined. The following econometric methods are employed: (1) Tobit, given the nature of the dividend data, and (2) the Generalized Method of Moments (GMM) to control for endogenous regressors. Significant positive variables found include size, return on assets (ROA), market to book, liquidity and profit growth. It can thus be inferred that larger firm size, profitability, market value, liquidity and profit growth correlate with greater firm pro pensity to distribute money to shareholders, thus supporting the theory of corporate finance. Significant negative variables found include leverage, liquidity squared, capex, beta and tag along 100%. It is thus inferred that more significantly leveraged companies that invest more heavily in fixed assets and that exhibit high liquidity, higher risk and less conflict between controlling and minority shareholders will be less likely to pay dividends to shareholders.</p

Monoclonal IgM cold agglutinins with anti-Pr1d specificity in a patient with peripheral neuropathy

A patient with a demyelinating sensory motor polyneuropathy secondary to IgM paraproteinaemia is reported. The paraprotein binds to the gangliosides GD1b, GT1b, GQ1b and GD3, all of which contain disialosyl groups with the sequence NeuAc &#945; 2-8NeuAc &#945; 2-3Gal. The paraprotein also acts as a cold agglutinin recognising the sialic-acid-dependent Pr&lt;sub&gt;1d&lt;/sub&gt; antigenic determinant of the red cell membrane glycophorins. In this and in similar cases that have been reported, the coexistence of anti-Pr cold agglutinins and peripheral neuropathy suggest that they might be the causative agents of the disease

Conceptions of Work and Learning at Work: Impressions from Older Workers

There is substantial literature on new work practices and the associated skills required of workers in the 'new capitalism' but very few consider workers’ perspectives on the advocacies. The study reported here involved 39 participants aged 40 plus who were interviewed to obtain data in relation to their conceptions of work and learning at work. This was conducted with consideration given to the changing work practices occurring around them. The participants were from a medical service and an engineering organization. The data were analyzed qualitatively and results indicated four and five hierarchical conceptions of work, and learning at work, respectively. It became apparent that a significantly large number of older workers conceived of work and learning at work in quantitative terms and as separate entities. The data were further analysed to ascertain how the conceptions mapped with the participants’ AQF levels. This analysis indicated some dissonance between AQF levels and conceptions. The findings of this study provide baseline data to understand older workers’ behaviours in light of the current changes in work practices

Introducing functional thinking in year 2: a case study of early algebra teaching

Sixty-five Year 2 children with ages ranging from six to seven years participated in a teaching experiment to introduce functional thinking. The results show that young children are capable of generalising, can provide examples of relations and functions, can describe the inverse of such relationships and give valid reasons for how they found the inverse relationships. They also indicate that specific features of instruction assist this process, particularly abstracting underlying mathematical relationships, notably the materials used by the teacher and the children, the types of activities and the questions asked by the teacher. This leads to specific implications for the teaching of arithmetic in the early years

Resolvent Estimates for Non-Selfadjoint Operators via Semigroups

We consider a non-self-adjoint $h$-pseudodifferential operator $P$ in the semi-classical limit ($h\to 0$). If $p$ is the leading symbol, then under suitable assumptions about the behaviour of $p$ at infinity, we know that the resolvent $(z-P)^{-1}$ is uniformly bounded for $z$ in any compact set not intersecting the closure of the range of $p$. Under a subellipticity condition, we show that the resolvent extends locally inside the range up to a distance ${\cal O}(1)((h\ln \frac{1}{h})^{k/(k+1)})$ from certain boundary points, where $k\in \{2,4,...\}$. This is a slight improvement of a result by Dencker, Zworski and the author, and it has recently been obtained by W. Bordeaux Montrieux in a model situation where $k=2$. The method of proof is different from the one of Dencker et al, and is based on estimates of an associated semi-group