Biophysical regulation of stem cell behavior within the niche.

Stem cells reside within most tissues throughout the lifetimes of mammalian organisms. To maintain their capacities for division and differentiation and thereby build, maintain, and regenerate organ structure and function, these cells require extensive and precise regulation, and a critical facet of this control is the local environment or niche surrounding the cell. It is well known that soluble biochemical signals play important roles within such niches, and a number of biophysical aspects of the microenvironment, including mechanical cues and spatiotemporally varying biochemical signals, have also been increasingly recognized to contribute to the repertoire of stimuli that regulate various stem cells in various tissues of both vertebrates and invertebrates. For example, biochemical factors immobilized to the extracellular matrix or the surface of neighboring cells can be spatially organized in their placement. Furthermore, the extracellular matrix provides mechanical support and regulatory information, such as its elastic modulus and interfacial topography, which modulate key aspects of stem cell behavior. Numerous examples of each of these modes of regulation indicate that biophysical aspects of the niche must be appreciated and studied in conjunction with its biochemical properties

Strengthening rules-based order in the Asia-Pacific

This paper explores the opportunities for both Australia and Japan jointly to promote their shared interest in strengthening the rule of law in the Asia–Pacific. Overview The rule of law is an essential condition if cooperation and orderly behaviour are to be advanced in the Asia–Pacific. We need norms and rules that guide—and govern—relations among regional states. Australia and Japan share an interest in minimising the role that coercion plays in the Asia–Pacific and maximising cooperation across the region. We’re both liberal democracies, with a strong bilateral security relationship, an alliance with the United States and a genuine commitment to the rule of law. All Asia–Pacific states would profit by following Australia and Japan’s example in promoting and abiding by the rule of law in their external policies. Indeed, our region would be a much safer place if they did. ASPI has this year worked on a project to explore the opportunities for both Australia and Japan jointly to promote our shared interest in strengthening the rule of law in the Asia–Pacific. This report sets out the project’s key findings and outlines policy proposals to enhance Australia–Japan cooperation to bolster the rule of law in the region

Modelling Inflation in Australia

This paper estimates a range of single-equation models of inflation for Australia. We find that traditional models, such as the expectations-augmented standard Phillips curve or mark-up models, outperform the more micro-founded New-Keynesian Phillips curve (NKPC) in explaining trimmed mean inflation, both in terms of in-sample fit and significance of coefficients. This in large part reflects the weak instruments problem in the estimation of the NKPC, and is partly corrected by including a direct measure of inflation expectations, but we still find that the unemployment rate or growth in marginal costs (unit labour cost and import prices) provides a better fit than either the output gap or level of real marginal costs. These traditional models also perform well in out-of-sample tests, relative to alternative models and some common benchmarks, with the standard Phillips curve clearly superior to these benchmarks on this test. As inflation has become better anchored and hence less variable, the magnitude of the errors of the single-equation models has declined, although the explanatory power (in terms of R-squared) has fallen together with this greater stability. We also investigate the empirical importance of some other variables that are commonly cited as determinants of inflation, and find little evidence that either commodity prices or the growth rate of money directly influence Australian underlying inflation.inflation; modelling

Unifying Sparsest Cut, Cluster Deletion, and Modularity Clustering Objectives with Correlation Clustering

Graph clustering, or community detection, is the task of identifying groups of closely related objects in a large network. In this paper we introduce a new community-detection framework called LambdaCC that is based on a specially weighted version of correlation clustering. A key component in our methodology is a clustering resolution parameter, $\lambda$, which implicitly controls the size and structure of clusters formed by our framework. We show that, by increasing this parameter, our objective effectively interpolates between two different strategies in graph clustering: finding a sparse cut and forming dense subgraphs. Our methodology unifies and generalizes a number of other important clustering quality functions including modularity, sparsest cut, and cluster deletion, and places them all within the context of an optimization problem that has been well studied from the perspective of approximation algorithms. Our approach is particularly relevant in the regime of finding dense clusters, as it leads to a 2-approximation for the cluster deletion problem. We use our approach to cluster several graphs, including large collaboration networks and social networks