The maximal length of a k-separator permutation

A permutation σ ∈ S[subscript n] is a k-separator if all of its patterns of length k are distinct. Let F(k) denote the maximal length of a k-separator. Hegarty (2013) showed that k + ⌊√2k − 1⌋ − 1 ≤ F(k) ≤ k + ⌊√2k − 3⌋, and conjectured that F(k) = k + ⌊√2k − 1⌋ − 1. This paper will strengthen the upper bound to prove the conjecture for all sufficiently large k (in particular, for all k ≥ 320801).United States. Dept. of Energy. Division of Materials Sciences and Engineering (Grant 1062709)United States. National Security Agency (Grant H98230-11-1-0224

Scenario-Based Design Theorizing:The Case of a Digital Idea Screening Cockpit

As ever more companies encourage employees to innovate, a surplus of ideas has become reality in many organizations – often exceeding the available resources to execute them. Building on insights from a literature review and a 3-year collaboration with a banking software provider, the paper suggests a Digital Idea Screening Cockpit (DISC) to address this challenge. Following a design science research approach, it suggests a prescriptive design theory that provides practitioner-oriented guidance for implementing a DISC. The study shows that, in order to facilitate the assessment, selection, and tracking of ideas for different stakeholders, such a system needs to play a dual role: It needs to structure decision criteria and at the same be flexible to allow for creative expression. Moreover, the paper makes a case for scenario-based design theorizing by developing design knowledge via scenarios

Climate-sensitive health priorities in Nunatsiavut, Canada

Background: This exploratory study used participatory methods to identify, characterize, and rank climate-sensitive health priorities in Nunatsiavut, Labrador, Canada. Methods: A mixed method study design was used and involved collecting both qualitative and quantitative data at regional, community, and individual levels. In-depth interviews with regional health representatives were conducted throughout Nunatsiavut (n = 11). In addition, three PhotoVoice workshops were held with Rigolet community members (n = 11), where participants took photos of areas, items, or concepts that expressed how climate change is impacting their health. The workshop groups shared their photographs, discussed the stories and messages behind them, and then grouped photos into re-occurring themes. Two community surveys were administered in Rigolet to capture data on observed climatic and environmental changes in the area, and perceived impacts on health, wellbeing, and lifestyles (n = 187). Results: Climate-sensitive health pathways were described in terms of inter-relationships between environmental and social determinants of Inuit health. The climate-sensitive health priorities for the region included food security, water security, mental health and wellbeing, new hazards and safety concerns, and health services and delivery. Conclusions: The results highlight several climate-sensitive health priorities that are specific to the Nunatsiavut region, and suggest approaching health research and adaptation planning from an EcoHealth perspective

Perinatal mortality following assisted reproductive technology treatment in Australia and New Zealand, a public health approach for international reporting of perinatal mortality

BACKGROUND There is a need to have uniformed reporting of perinatal mortality for births following assisted reproductive technology (ART) treatment to enable international comparison and benchmarking of ART practice. METHODS The Australian and New Zealand Assisted Reproduction Database was used in this study. Births of ≥ 20 weeks gestation and/or ≥ 400 grams of birth weight following embryos transfer cycles in Australia and New Zealand during the period 2004 to 2008 were included. Differences in the mortality rates by different perinatal periods from a gestational age cutoff of ≥ 20, ≥ 22, ≥ 24, or ≥ 28 weeks (wks) to a neonatal period cutoff of either < 7 or < 28 days after birth were assessed. Crude and specific (number of embryos transferred and plurality) rates of perinatal mortality were calculated for selected gestational and neonatal periods. RESULTS When the perinatal period is defined as ≥ 20 wks gestation to < 28 days after birth, the perinatal mortality rate (PMR) was 16.1 per 1000 births (n = 630). A progressive contraction of the gestational age groups resulted in marked reductions in the PMR for deaths at < 28 days (22 wks 11.0; 24 wks 7.7; 28 wks 5.6); and similarly for deaths at < 7 days (20 wks 15.6, 22 wks 10.5; 24 wks 7.3; 28 wks 5.3). In contrast, a contraction of the perinatal period from < 28 to < 7 days after birth only marginally reduced the PMR from 16.2 to 15.6 per 1000 births which was consistent across all gestational ages. The PMR for single embryo transfer (SET) births (≥ 20 weeks gestation to < 7 days post-birth) was significantly lower (12.8 per 1000 SET births) compared to double embryo transfer (DET) births (PMR 18.3 per 1000 DET births; p < 0.001, Fisher’s Exact Test). Similarly, the PMR for SET births (≥ 22 weeks gestation to < 7 days post-birth) was significantly lower (8.8 per 1000 SET births, p < 0.001, Fisher’s Exact Test) when compared to DET births (12.2 per 1000 DET births). The highest PMR (50.5 per 1000 SET births, 95% CI 36.5-64.5) was for twins following SET births (≥ 20 weeks gestation to < 7 days post-birth) compared to twins following DET (23.9 per 1000 DET births, 95% CI 20.8-27.1). CONCLUSION Reporting of perinatal mortality of ART births is an essential component of quality ART practice. This should include measures that monitor the impact on perinatal mortality of multiple embryo transfer. We recommend that reporting of perinatal deaths following ART treatment, should be stratified for three gestation-specific perinatal periods of ≥ 20, ≥ 22 and ≥ 28 completed weeks to < 7 days post-birth; and include plurality specific rates by SET and DET. This would provide a valuable international evidence-base of PMR for use in evaluating ART policy, practice and new research.Elizabeth A Sullivan, Yueping A Wang, Robert J Norman, Georgina M Chambers, Abrar Ahmad Chughtai and Cynthia M Farquha

Toxic effects of phenothiazines on the eye

Publications about the retinotoxic action of phenothiazine derivatives led the author to undertake an ophthalmological investigation in two psychiatric hospitals in The Netherlands. The pharmacological actions of phenothiazine preparations are listed and a survey of the phenothiazine derivatives which are at present in use is given. Some retinotoxic substances are discussed and a survey is given of the literature on the ocular complications of phenothiazine therapy. The eyes of 561 patients were examined. of whom 541 are included in this study. 343 of these patients(63.4 %) were found to have retinopathy. The correlation between the retinopathy and the total dose of phenothiazine preparations taken. and between the retinopathy and the duration of treatment. was highly significant. The correlation between the retinopathy and the average daily dose taken was significant. The retinopathy was associated with a reduced standing potential of the eye. as determined by electro-oculography. It was possibly responsible for diminished visual acuity in some cases, and for an abnormally large proportion of protans in the group of patients with colour defects. It was not possible to ascribe a more severe retinotoxic action to one or more specific phenothiazine derivatives than to others. In the author's opinion regular examination of the eyes of patients who are being treated with phenothiazine preparations in high dosage and for for a long period of time is indicated

The "Last Mile" Problem in Personalized Medicine: a Dynamic Interactive Graphical Software Solution

Clinicians and patients typically experience difficulty with the conditional probability reasoning (Bayes Theorem) required to make inferences about health states on the basis of diagnostic test results. This problem will grow in importance as we move into the era of personalized medicine where an increasing supply of imprecise diagnostic tests meets an increasing demand to use such tests on the part of intelligent but statistically innumerate clinicians and patients. We describe a user friendly, interactive, graphical software interface for calculating, visualizing, and communicating accurate inferences about uncertain health states when diagnostic information (test sensitivity and specificity, and health state prevalence) is relatively imprecise and ambiguous in its application to a specific patient. The software is free, open-source, and runs on all popular PC operating systems (Windows, Mac, Linux

Comparing Ambiguous Inferences When Probabilities are Imprecise

Submitted to journal. Working paper version of submission to Wolfram Demonstration project MArch 12 2010 The Wolfram Demonstartion project is a vehicle for a new form of academic and quantitative publications that uses modern computational software and the worldwide web as the means of an interactive dynamic publications. In principle it is a much more powerful mode of academic publishing than static written text, especially for quantitative sciences where modellling and dynamic simulation and alternative models and simulations are important for both theory and empirical work. The Wolfram Site http://demonstrations.wolfram.com/FAQ.html answers many questions about the publications it contains. Two important questions for the academic QA process , and their answer, are reproduced here: Is there a review process for Demonstrations? Yes. Each Demonstration's content is rigorously reviewed by experts in relevant fields, and automated software-quality-assurance methods are used to check its operation. Do Demonstrations count as academic publications? Yes. Every Demonstration undergoes a rigorous review process that checks for quality, clarity, and accuracy, so you can count them as academic publications. If those responsible for the QA process are in anyway skeptical about these claims I am more than happy to show them the to and fro process with editors and reviewers that has been characteristic of my (our) publications there.Suppose you are interested in the level of a state variable (e.g. a disease is present or absent or of a pre-specified level of severity, or a failure is recorded or not, etc.) and have a potentially useful but imperfect diagnostic test method, (e.g. a blood test result for this disease, or a quality control check for manufacturing defects, is either definitely positive or not). How do you interpret the result of the diagnostic test for the level of the state variable when some or all of the information underlying the inference is ambiguous (imprecise)? This publication for the Wolfram Demonstration project is designed to facilitate the "what-if" exploration of the effects of ambiguities (imprecision) in sensitivity, specificity, and base rate information, alone or in combination, on posterior inferences through a linked tabular natural frequency and graphical probability format representation of underlying uncertainties. The textual description explains the underlying theory of boundedly rational inference. An appendix contains the full Mathematica code used to implement the interactive software that implements and explains the underlying theory

Determinants of Chinese Government Size: An Extreme Bounds Analysis

From 1982 onwards, the Chinese State Council and the National People’s Congress have had a standing policy of reducing the size of the public sector of the Chinese economy. The aim of this policy is to increase the share of Chinese economic activity that is conducted in the market sector. The reasoning behind this policy is that resources that are controlled by the public sector are used relatively inefficiently, impeding Chinese economic growth. Several attempts have been made to reduce the Chinese public sector since 1982. Most regard these previous efforts as having been unsuccessful. This suggests that general economic and social factors may be determining the size of the Chinese public sector. A better understanding of these factors could enable the Chinese government to implement policies that have a greater chance of success. Accordingly, this paper will study the factors associated with the size of the public sector at the level of Chinese provinces. We will use Leamer’s Extreme Bounds Analysis (Leamer, 1985, 2008) to identify robust correlates with public sector size. Explanatory variables include provincial income, share of the population that is working, urbanisation, and ethnic diversity. Policy variables of particular interest include fiscal decentralisation, the “flypaper effect” (i.e., the importance of central government fiscal transfers to provinces), and the previously unexplored factor of the degree of corruption across provinces. Significance of the latter variable would give added support to the Chinese government for it’s current policy of reducing corruption by government officials

Cashless Economies, Data Analysis, and Research-Based Teaching: The Versatility of the Velocity of Money for Teaching Macroeconomics

Simple concepts such as the velocity of money can be powerful tools to stimulate classroom discussions about complex issues in macroeconomics classes. For example, are cashless societies likely or is monetary policy likely to be effective? Such concepts are also ideal for in-class data analysis and for research-based teaching. The velocity of money for example only requires values from three commonly available variables, a simple calculation, and can be analysed by plotting it on a graph. In this paper we provide a summary of the velocity of money, what affects it, and illustrate these with two fascinating cases. We also provide two assignments, including how to create data sets, along with grading rubrics. Finally, we discuss experiences from an assignment we set our class