Fast Entropy Estimation for Natural Sequences

It is well known that to estimate the Shannon entropy for symbolic sequences accurately requires a large number of samples. When some aspects of the data are known it is plausible to attempt to use this to more efficiently compute entropy. A number of methods having various assumptions have been proposed which can be used to calculate entropy for small sample sizes. In this paper, we examine this problem and propose a method for estimating the Shannon entropy for a set of ranked symbolic natural events. Using a modified Zipf-Mandelbrot-Li law and a new rank-based coincidence counting method, we propose an efficient algorithm which enables the entropy to be estimated with surprising accuracy using only a small number of samples. The algorithm is tested on some natural sequences and shown to yield accurate results with very small amounts of data

Determining the Number of Samples Required to Estimate Entropy in Natural Sequences

Calculating the Shannon entropy for symbolic sequences has been widely considered in many fields. For descriptive statistical problems such as estimating the N-gram entropy of English language text, a common approach is to use as much data as possible to obtain progressively more accurate estimates. However in some instances, only short sequences may be available. This gives rise to the question of how many samples are needed to compute entropy. In this paper, we examine this problem and propose a method for estimating the number of samples required to compute Shannon entropy for a set of ranked symbolic natural events. The result is developed using a modified Zipf-Mandelbrot law and the Dvoretzky-Kiefer-Wolfowitz inequality, and we propose an algorithm which yields an estimate for the minimum number of samples required to obtain an estimate of entropy with a given confidence level and degree of accuracy

Thallium isotopic composition of phlogopite in kimberlite-hosted MARID and PIC mantle xenoliths

MARID (Mica-Amphibole-Rutile-Ilmenite-Diopside) and PIC (Phlogopite-Ilmenite-Clinopyroxene) rocks are rare mantle xenoliths entrained by kimberlites. Their high phlogopite modes (15 to ∼100 vol.%) and consequent enrichments in alkali metals and H2O suggest a metasomatic origin. Phlogopite also has high concentrations (>0.2 µg/g) of thallium (Tl) relative to mantle abundances (<3 ng/g). Thallium isotope ratios have proven useful in tracing the input of Tl-rich materials, such as pelagic sediments and altered oceanic crust, to mantle sources because of their distinct isotopic compositions compared to the peridotitic mantle. This study presents the first Tl isotopic compositions of well-characterised phlogopite separates from MARID and PIC samples to further our understanding of their genesis. The PIC rocks in this study were previously interpreted as the products of kimberlite melt metasomatism, whereas the radiogenic and stable N-O isotope systematics of MARID rocks suggest a parental metasomatic agent containing a recycled component. The ε205Tl values of phlogopite in both PIC (–2.7 ± 0.8; 2 s.d., n = 4) and MARID samples (–2.5 ± 1.3; 2 s.d., n = 21) overlap with the estimated mantle composition (–2.0 ± 1.0). PIC phlogopite Tl contents (∼0.4 µg/g) are suggestive of equilibrium with kimberlite melts (0.1–0.6 µg/g Tl), based on partitioning experiments in other silica-undersaturated melts. Kimberlite Tl-ε205Tl systematics suggest their genesis does not require a recycled contribution: however, high temperature-altered oceanic crust cannot be ruled out as a component of the Kimberley kimberlites’ source. Mantle-like ε205Tl values in MARID samples also seem to contradict previous suggestions of a recycled contribution towards their genesis. Recycled components with isotopic compositions close to mantle values (e.g., high temperature-altered oceanic crust) are still permitted. Moreover, mass balance mixing models indicate that incorporation into the primitive mantle of 1–30% of a low temperature-altered oceanic crust + continental crust recycled component or 1–50% of continental crust alone could be accommodated by the Tl–ε205Tl systematics of the MARID parental melt. This scenario is consistent with experimental evidence and existing isotopic data. One PIC phlogopite separate has an extremely light Tl isotopic composition of –9.9, interpreted to result from kinetic isotopic fractionation. Overall, phlogopite is the main host mineral for Tl in metasomatised mantle and shows a very restricted range in Tl isotopic composition, which overlaps with estimates of the mantle composition. These results strongly suggest that negligible high temperature equilibrium Tl isotopic fractionation occurs during metasomatism and reinforces previous estimates of the mantle’s Tl isotopic composition

Columbia River Basin Water Law Institutions and Policies Survey: Report to the Western Water Policy Review Advisory Commission

Report to the Western Water Policy Review Advisory Commissio

Moving beyond the front line: a 20-year retrospective cohort study of career trajectories from the Indigenous Health Program at the University of Queensland

This report examines critical success factors for enabling Aboriginal and Torres Strait Islander leadership across the health system as demonstrated by alumni of the University of Queensland (UQ) Indigenous Health Program (IHP) (1994–2005) who today work in various leadership roles throughout the country.\ua0It determines the enablers of professional success of these health leaders in various facets of the health system and investigates the impact of active participation in the community of Aboriginal and Torres Strait Islander health professionals over the course of a career. Through this analysis, the report further theorises the confluence of community, subjectivity, self-determination and health

SNEV is an evolutionarily conserved splicing factor whose oligomerization is necessary for spliceosome assembly

We have isolated the human protein SNEV as downregulated in replicatively senescent cells. Sequence homology to the yeast splicing factor Prp19 suggested that SNEV might be the orthologue of Prp19 and therefore might also be involved in pre-mRNA splicing. We have used various approaches including gene complementation studies in yeast using a temperature sensitive mutant with a pleiotropic phenotype and SNEV immunodepletion from human HeLa nuclear extracts to determine its function. A human–yeast chimera was indeed capable of restoring the wild-type phenotype of the yeast mutant strain. In addition, immunodepletion of SNEV from human nuclear extracts resulted in a decrease of in vitro pre-mRNA splicing efficiency. Furthermore, as part of our analysis of protein–protein interactions within the CDC5L complex, we found that SNEV interacts with itself. The self-interaction domain was mapped to amino acids 56–74 in the protein's sequence and synthetic peptides derived from this region inhibit in vitro splicing by surprisingly interfering with spliceosome formation and stability. These results indicate that SNEV is the human orthologue of yeast PRP19, functions in splicing and that homo-oligomerization of SNEV in HeLa nuclear extract is essential for spliceosome assembly and that it might also be important for spliceosome stability

Visualising Conversation Structure across Time: Insights into Effective Doctor-Patient Consultations

Effective communication between healthcare professionals and patients is critical to patients’ health outcomes. The doctor/patient dialogue has been extensively researched from different perspectives, with findings emphasising a range of behaviours that lead to effective communication. Much research involves self-reports, however, so that behavioural engagement cannot be disentangled from patients’ ratings of effectiveness. In this study we used a highly efficient and time economic automated computer visualisation measurement technique called Discursis to analyse conversational behaviour in consultations. Discursis automatically builds an internal language model from a transcript, mines the transcript for its conceptual content, and generates an interactive visual account of the discourse. The resultant visual account of the whole consultation can be analysed for patterns of engagement between interactants. The findings from this study show that Discursis is effective at highlighting a range of consultation techniques, including communication accommodation, engagement and repetition

Curating Complex, Dynamic and Distributed Data: Telehealth as a Laboratory for Strategy

Telehealth monitoring data is now being collected across large populations of patients with chronic diseases such as stroke, hypertension, COPD and dementia. These large, complex and heterogeneous datasets, including distributed sensor and mobile datasets, present real opportunities for knowledge discovery and re-use, however they also generate new challenges for curation. This paper uses qualitative research with stakeholders in two nationally-funded telehealth projects to outline the perceptions, practices and preferences of different stakeholders with regard to data curation. Telehealth provides a living laboratory for the very different challenges implicit in designing and managing data infrastructure for embedded and ubiquitous computing. Here, technical and human agents are distributed, and interaction and state change is a central component of design, rather than an inconvenient challenge to it. The authors argue that there are lessons to be learned from other domains where data infrastructure has been radically rethought to address these challenge

The Third wave in globalization theory

This essay examines a proposition made in the literature that there are three waves in globalization theory—the globalist, skeptical, and postskeptical or transformational waves—and argues that this division requires a new look. The essay is a critique of the third of these waves and its relationship with the second wave. Contributors to the third wave not only defend the idea of globalization from criticism by the skeptics but also try to construct a more complex and qualified theory of globalization than provided by first-wave accounts. The argument made here is that third-wave authors come to conclusions that try to defend globalization yet include qualifications that in practice reaffirm skeptical claims. This feature of the literature has been overlooked in debates and the aim of this essay is to revisit the literature and identify as well as discuss this problem. Such a presentation has political implications. Third wavers propose globalist cosmopolitan democracy when the substance of their arguments does more in practice to bolster the skeptical view of politics based on inequality and conflict, nation-states and regional blocs, and alliances of common interest or ideology rather than cosmopolitan global structures