Child and teenager oral health and dental visiting: results from the National Dental Telephone Interview Survey 2010

This publication reports on oral health, dental visiting and dental treatment needs of Australian children as reported in the National Dental Telephone Interview Survey (NDTIS) 2010. Time series data across all NDTISs conducted since 1994 are presented to provide a picture of how key measures have changed over time. Finally, comparisons with international data are presented to provide a picture of how Australian children fare among their international counterparts.Oral healthThe majority of Australian children report good oral health. However, 7% reported that they had experienced toothache and 10% reported that they had avoided certain foods during the previous 12 months. Children from low income households were more likely to report having fair or poor oral health and to have experienced toothache than children from high income households. There was no significant change over time in these measures.Dental visitingAlmost 70% of children made a dental visit in the previous 12 months and the majority (84%) visited for a check-up. Less than a third of pre-school-aged children had ever made a dental visit. Children from the lowest income households were less likely than those from higher income households to have both made a dental visit and to have visited for a check-up. Both of these measures of dental visiting have remained fairly stable over time.Barriers to dental care useAround 13% of children avoided or delayed making a dental visit due to cost. Around 6% did not have a recommended treatment due to cost. Overall, almost 30% of children avoided or delayed seeking care, did not have recommended treatment or their household experienced a large financial burden due to the cost of dental care. Children from low income households were 7 times as likely than those from high income households to avoid or delay due to cost and 6 times as likely to have not had recommended treatment due to cost.International comparisonsComparable data are available for children in Canada and New Zealand. Overall, Australian children were less likely to report that they had fair or poor oral health, and less likely to have made a dental visit in the previous 12 months than their counterparts in New Zealand. Australian teenagers were less likely than their Canadian counterparts to report fair or poor oral health and were more likely to have avoided or delayed making a dental visit due to cost

The Method of Comparison Equations for Schwarzschild Black Holes

We employ the method of comparison equations to study the propagation of a massless minimally coupled scalar field on the Schwarzschild background. In particular, we show that this method allows us to obtain explicit approximate expressions for the radial modes with energy below the peak of the effective potential which are fairly accurate over the whole region outside the horizon. This case can be of particular interest, for example, for the problem of black hole evaporation.Comment: 7 pages, added figures. Version to appear in PR

The DMT classification of real and quaternionic lattice codes

In this paper we consider space-time codes where the code-words are restricted to either real or quaternion matrices. We prove two separate diversity-multiplexing gain trade-off (DMT) upper bounds for such codes and provide a criterion for a lattice code to achieve these upper bounds. We also point out that lattice codes based on Q-central division algebras satisfy this optimality criterion. As a corollary this result provides a DMT classification for all Q-central division algebra codes that are based on standard embeddings.Comment: 6 pages, 1 figure. Conference paper submitted to the International Symposium on Information Theory 201

Commercialisation Strategies of Technology based European SMEs: Markets for Technology vs. Markets for Products

This paper focuses on European small-medium "serial innovators" at the beginning of the 1990s and provides an empirical basis to answer the following questions: who are the upstream specialized small-medium technology producers? How are they distributed across countries? Are there technologies in which they show a relative advantage? By focusing on firms? history, activities, and the description of events obtained by different data sources, we also investigates if technology based SMEs choose to implement a strategy based on the commercialisation of their technologies or if they invest in the complementary assets of production, marketing and distribution becoming micro-chandlerian firms. Through this analysis we are able to propose a taxonomy of technology based SMEs? strategies in the market for technology, in the market for embedded technologies and in the market for products.SMEs, Technology Strategies, Licensing.

Decoding by Embedding: Correct Decoding Radius and DMT Optimality

The closest vector problem (CVP) and shortest (nonzero) vector problem (SVP) are the core algorithmic problems on Euclidean lattices. They are central to the applications of lattices in many problems of communications and cryptography. Kannan's \emph{embedding technique} is a powerful technique for solving the approximate CVP, yet its remarkable practical performance is not well understood. In this paper, the embedding technique is analyzed from a \emph{bounded distance decoding} (BDD) viewpoint. We present two complementary analyses of the embedding technique: We establish a reduction from BDD to Hermite SVP (via unique SVP), which can be used along with any Hermite SVP solver (including, among others, the Lenstra, Lenstra and Lov\'asz (LLL) algorithm), and show that, in the special case of LLL, it performs at least as well as Babai's nearest plane algorithm (LLL-aided SIC). The former analysis helps to explain the folklore practical observation that unique SVP is easier than standard approximate SVP. It is proven that when the LLL algorithm is employed, the embedding technique can solve the CVP provided that the noise norm is smaller than a decoding radius $\lambda_1/(2\gamma)$, where $\lambda_1$ is the minimum distance of the lattice, and $\gamma \approx O(2^{n/4})$. This substantially improves the previously best known correct decoding bound $\gamma \approx {O}(2^{n})$. Focusing on the applications of BDD to decoding of multiple-input multiple-output (MIMO) systems, we also prove that BDD of the regularized lattice is optimal in terms of the diversity-multiplexing gain tradeoff (DMT), and propose practical variants of embedding decoding which require no knowledge of the minimum distance of the lattice and/or further improve the error performance.Comment: To appear in IEEE Transactions on Information Theor

Do Liquidity Constraints Matter in Explaining Firm Size and Growth? Some Evidence from the Italian Manufacturing Industry

The paper investigates whether liquidity constraints affect firm size and growth dynamics using a large longitudinal sample of Italian manufacturing firms. We run standard panel-data Gibrat regressions, suitably expanded to take into account liquidity constraints (proxied by cash flow). Moreover, we characterize the statistical properties of firms size, growth, age, and cash flow distributions. Pooled data show that: (i) liquidity constraints engender a negative, statistically significant, effect on growth once one controls for size; (ii) smaller and younger firms grow more (and experience more volatile growth patterns) after controlling for liquidity constraints; (iii) the stronger liquidity constraints, the more size negatively affects firm growth. We find that pooled size distributions depart from log-normality and growth rates are well approximated by fat-tailed, tent-shaped (Laplace) densities. We also study the evolution of growth-size distributions over time. Our exercises suggest that the strong negative impact of liquidity constraints on firm growth which was present in the pooled sample becomes ambiguous when one disaggregates across years. Finally, firms who were young and strongly liquidity-constrained at the beginning of the sample period grew persistently more than those who were old and weakly liquidity-constrained.Firm Size, Liquidity Constraints, Firm Growth, Investment, Gibrat Law