Combinatorics of tight geodesics and stable lengths

We give an algorithm to compute the stable lengths of pseudo-Anosovs on the curve graph, answering a question of Bowditch. We also give a procedure to compute all invariant tight geodesic axes of pseudo-Anosovs. Along the way we show that there are constants $1<a_1<a_2$ such that the minimal upper bound on `slices' of tight geodesics is bounded below and above by $a_1^{\xi(S)}$ and $a_2^{\xi(S)}$, where $\xi(S)$ is the complexity of the surface. As a consequence, we give the first computable bounds on the asymptotic dimension of curve graphs and mapping class groups. Our techniques involve a generalization of Masur--Minsky's tight geodesics and a new class of paths on which their tightening procedure works.Comment: 19 pages, 2 figure

Beyond the IMF

A consensus has developed that the International Monetary Fund (IMF) is not fulfilling its role, prompting multiple proposals for reform. However, this paper argues that the focus on reform should be complemented with an exploration of alternatives outside the IMF which hold the potential to not only give developing countries greater bargaining leverage with the Fund but also, by increasing competition, spurring the institution to better performance. The paper argues that most of the IMF’s functions are being carried out in part through alternative institutional arrangements. It focuses in particular on the insurance role of the Fund and argues that developing countries are developing alternative insurance mechanisms, from a higher level of reserves, to regional co-insurance facilities to remittances as a counter-cyclical source of foreign exchange. The de facto exit of its clientele has been driven by the high political costs associated with Fund borrowing and now poses unprecedented challenges for the Fund, in particular pressures on its income. The paper argues for a rapid restructuring and significant cuts of the Fund’s administrative budget with the budget savings instead directed to lower the interest rates charged to borrowers.IMF, reform, developing countries, insurance, foreign exchange, remittances,

Antidumping mechanisms and safeguards in Peru

Peru's experience in the application of antidumping and safeguard measures is characterized by a radical change in the philosophy and procedures of trade at the beginning of the 1990s, and by an increasing use of these mechanisms. Trade liberalization was accompanied by the liberalization of foreign currency transactions and of financial and labor markets. Also, the internal revenue administration was modernized, institutions for regulation and competition defense were created, and state enterprises were transferred to private owners or concessionaires. New laws and institutions were created to regulate markets, including INDECOPI, a novel government agency charged with antimonopoly regulation and consumer defense, and which houses the Antidumping and Subsidies Commission. This highly autonomous and technical Commission became the central player in the implementation of WTO rules and procedures for fair trade. Since the reform was launched, a total of 81 trade protection cases have been presented, of which 57 were followed by a dumping investigation. The application of antidumping duties was approved for 29 of the cases investigated. Only two cases of safeguard investigations were recorded, one of which (Chinese textile clothing articles) is still in the negotiation phase. This paper reviews that case experience in detail, concluding that Peru has clearly differentiated between unfair competition and dumping on the one hand, and damage and safeguards on the other, and has applied strict technical criteria to the former and broader political considerations to the latter. Despite recent indications of a partial retreat from those principles, the decade-old reform is expected to last.

Measurement of the Difference between the Dynamic NMR and Static Susceptibilites of Superfluid 3He-B Using an rf-Biased Superconducting Quantum-Interference Device

The temperature-dependent susceptiblity of superfluid 3He-B has been measured both statically and via a pulse technique in a field of 309 G using an rf-biased superconducting quantum-interference device (SQUID). In the pressure range 26.5 to 18 bar, the dynamic NMR susceptiblity agrees qualitatively with the theoretical weak-coupling predictions for the Balian-Werthamer state. However, the static susceptiblity, measured using the same rf-biased SQUID and detection system, is significantly smaller thatn the dynamic susceptibility

BREAKFAST AND CLASSROOM BEHAVIOUR: AN OBSERVATIONAL STUDY OF GRADE 3 STUDENTS IN A BILINGUAL DEMONSTRATION SCHOOL, IN THAILAND

This study investigated what students consumed for breakfast and their behaviours within the classroom. It attempted to determine whether there is a relationship with inappropriate, off-task or non-compliant behaviour of students and what they had consumed that morning. Recent literature suggests there is. This was observed using a time sampling, coding system. Breakfast Consumption was recorded by a self-completion questionnaire, using the Australian guide to healthy eating (AGHE) as a dietary guide. Correlational analysis was used to determine the relationship between breakfasts and behaviour, and ANOVA (analysis of variance) was used to determine if any significant relationships existed between each behaviour type and diet. The subjects were 23 Grade 3 students (19 boys, 4 girls) of a university affiliated bilingual school in Thailand. The coding of behaviour was done by trained professional observers using Revised Edition of School Observational Coding System (REDSOCS). The modified dietary recall questionnaire was administered at school over a period of 2 weeks. Upon reanalysis of the data there appeared to be a link between an unhealthy diet and off-task and non-compliant behaviours. However these data were not statistically significant. This study suggests that what is consumed in the morning may not have an important affect on students’ classroom behaviour. It is also possible that culture and socio economic factors may have obscured any effects. It is recommended that further research be done to see if these present findings would hold for more varied populations and other types of Thai schools