Some results on contractive mappings as related to pattern recognition

Several of the techniques used in pattern recognition are reformulated as the problem of determining fixed points of a function. If x sub 0 is a fixed point of f and if f is contractive at x sub 0, then, for any y belonging to a sufficiently small neighborhood of x sub 0 the orbit of y will converge to x sub 0. Several general results regarding contractive mappings are developed with emphasis on functions

The macroeconomic impacts of foreign direct investment: the Scottish case

A two sector multi-equation macro-econometric model of Scottish manufacturing industry was constructed and distinctive characteristics of the home and foreign sectors explored. In addition dynamic simulations were carried out to elucidate the policy implications of alternative scenarios

Micro-geographic risk factors for malarial infection.

BACKGROUND: Knowledge of geography is integral to the study of insect-borne infectious disease such as malaria. This study was designed to evaluate whether geographic parameters are associated with malarial infection in the East Sepik province of Papua New Guinea (PNG), a remote area where malaria is a major cause of morbidity and mortality. METHODS: A global positioning system (GPS) unit was used at each village to collect elevation, latitude and longitude data. Concurrently, a sketch map of each village was generated and the villages were sub-divided into regions of roughly equal populations. Blood samples were taken from subjects in each region using filter paper collection. The samples were later processed using nested PCR for qualitative determination of malarial infection. The area was mapped using the GPS-information and overlaid with prevalence data. Data tables were examined using traditional chi square statistical techniques. A logistic regression analysis was then used to determine the significance of geographic risk factors including, elevation, distance from administrative centre and village of residence. RESULTS: Three hundred and thirty-two samples were included (24% of the total estimated population). Ninety-six were positive, yielding a prevalence of 29%. Chi square testing within each village found a non-random distribution of cases across sub-regions (p < 0.05). Multivariate logistic regression techniques suggested malarial infection changed with elevation (OR = 0.64 per 10 m, p < 0.05) and distance from administrative centre (OR = 1.3 per 100 m, p < 0.05). CONCLUSION: These results suggest that malarial infection is significantly and independently associated with lower elevation and greater distance from administrative centre in a rural area in PNG. This type of analysis can provide information that may be used to target specific areas in developing countries for malaria prevention and treatment

Rural Child Care in Missouri: How to Improve it

Includes bibliographical references.During 1997 and 1998, a large study called Project REACH (Rural EArly CHildhood Professional Development Initiative), was conducted in a series of interventions over a 16 month period in rural Missouri. The training and follow up was intensive, continuous and individualized. An overview of the results are provided

Tax smoothing in a business cycle model with capital-skill complementarity

This paper undertakes a normative investigation of the quantitative properties of optimal tax smoothing in a business cycle model with state contingent debt, capital-skill complementarity and endogenous skill acquisition under technology and public expenditure shocks. We find that skilled and unskilled labour tax smoothing maintain quantitatively under externalities and exogenous shocks in skill acquisition, as well as when the relative skill supply is exogenously determined. We further find that the government finds it optimal to reduce both the size of the wedge between the marginal rates of substitution and transformation in skill attainment in the long-run and the standard deviation of this wedge over the business cycle. This is achieved by subsidising skill creation and taxing both types of labour income

Developing and Researching PhET simulations for Teaching Quantum Mechanics

Quantum mechanics is difficult to learn because it is counterintuitive, hard to visualize, mathematically challenging, and abstract. The Physics Education Technology (PhET) Project, known for its interactive computer simulations for teaching and learning physics, now includes 18 simulations on quantum mechanics designed to improve learning of this difficult subject. Our simulations include several key features to help students build mental models and intuitions about quantum mechanics: visual representations of abstract concepts and microscopic processes that cannot be directly observed, interactive environments that directly couple students' actions to animations, connections to everyday life, and efficient calculations so students can focus on the concepts rather than the math. Like all PhET simulations, these are developed using the results of education research and feedback from educators, and are tested in student interviews and classroom studies. This article provides an overview of the PhET quantum simulations and their development. We also describe research demonstrating their effectiveness and share some insights about student thinking that we have gained from our research on quantum simulations.Comment: accepted by American Journal of Physics; v2 includes an additional study, more explanation of research behind claims, clearer wording, and more reference

Chemical climatology: a case study for ozone

In 1872 Scottish chemist Robert Angus Smith established the basis of ‘chemical climatology’ explicitly designed to assess the human health impact of the ‘man-made climates’ in cities. Since then usage of chemical climatology has been sporadic. However with large volumes of atmospheric composition datasets available from campaign measurements, monitoring and modelling, as well as pollutant impact studies, an updated framework based on Angus Smith’s principles would be useful as a resource for both scientists and policy makers. Through analogy with the use of the term climate in other areas (e.g. meteorological or political) a modern chemical climatology framework is described, highlighting impact-focused principles. To derive the chemical climatology the impact of atmospheric composition is first identified (e.g. damage to human health) The impact is linked to the state of atmospheric composition in time and space (e.g. ozone concentrations in the UK 1990 -2010). Finally the drivers of the state are assessed (e.g. emissions, chemical background, chemical precursors, meteorology). Two chemical climates are presented: O3-human health and ozone-vegetation. The chemical climates are derived from measurements at the two UK European Monitoring and Evaluation Programme (EMEP) monitoring ‘supersites’: Auchencorth Moss and Harwell. The impacts of O3 on human health and on vegetation are assessed using the SOMO35 and AOT40 metrics respectively. Drivers of significant spatial variation in these impacts across the UK, and temporal changes at Harwell between 1990 and 2011 are discussed, as well as the relative importance of hemispheric, regional and local O3 chemical processing and its precursors. The individual site assessments are placed in regional context through the statistical evaluation of O3 variation across Europe. The chemical climatology framework allows integration of individual scientific studies focussing on specific processes within the impact-state and driver space into a synthesised and more general understanding. This approach provides opportunities for developing understanding of multiple impacts are considered for each chemical component allow identification of common drivers of impacts, and potentially holistically considered mitigation strategies

Protection against Staphylococcus aureus colonization and infection by B-and T-cell-mediated mechanisms

© 2018 Zhang et al. Staphylococcus aureus is a major cause of morbidity and mortality worldwide. S. aureus colonizes 20 to 80% of humans at any one time and causes a variety of illnesses. Strains that are resistant to common antibiotics further complicate management. S. aureus vaccine development has been unsuccessful so far, largely due to the incomplete understanding of the mechanisms of protection against this pathogen. Here, we studied the role of different aspects of adaptive immunity induced by an S. aureus vaccine in protection against S. aureus bacteremia, dermonecrosis, skin abscess, and gastrointestinal (GI) colonization. We show that, depending on the challenge model, the contributions of vaccine-induced S. aureus-specific antibody and Th1 and Th17 responses to protection are different: antibodies play a major role in reducing mortality during S. aureus bacteremia, whereas Th1 or Th17 responses are essential for prevention of S. aureus skin abscesses and the clearance of bacteria from the GI tract. Both antibody-and T-cell-mediated mechanisms contribute to prevention of S. aureus dermonecrosis. Engagement of all three immune pathways results in the most robust protection under each pathological condition. Therefore, our results suggest that eliciting multipronged humoral and cellular responses to S. aureus antigens may be critical to achieve effective and comprehensive immune defense against this pathogen. IMPORTANCE S. aureus is a leading cause of healthcare-and community-associated bacterial infections. S. aureus causes various illnesses, including bacteremia, meningitis, endocarditis, pneumonia, osteomyelitis, sepsis, and skin and soft tissue infections. S. aureus colonizes between 20 and 80% of humans; carriers are at increased risk for infection and transmission to others. The spread of multidrug-resistant strains limits antibiotic treatment options. Vaccine development against S. aureus has been unsuccessful to date, likely due to an inadequate understanding about the mechanisms of immune defense against this pathogen. The significance of our work is in illustrating the necessity of generating multipronged B-cell, Th1-, and Th17-mediated responses to S. aureus antigens in conferring enhanced and broad protection against S. aureus invasive infection, skin and soft tissue infection, and mucosal colonization. Our work thus, provides important insights for future vaccine development against this pathogen

The role of care home fees in the public costs and distributional effects of potential reforms to care home funding for older people in England

In England, Local Authorities (LAs) contribute to the care home fees of two-thirds of care home residents aged 65+ who pass a means test. LAs typically pay fees below those faced by residents excluded from state support. Most proposals for reform of the means test would increase the proportion of residents entitled to state support. If care homes receive the LA fee for more residents, they might increase fees for any remaining self-funders. Alternatively, the LA fee might have to rise. We use two linked simulation models to examine how alternative assumptions on post-reform fees affect projected public costs and financial gains to residents of three potential reforms to the means test. Raising the LA fee rate to maintain income per resident would increase the projected public cost of the reforms by between 22% and 72% in the base year. It would reduce the average gain to care home residents by between 8% and 12%. Raising post-reform fees for remaining self-funders or requiring pre-reform self-funders to meet the difference between the LA and self-funder fees, reduces the gains to residents by 28-37%. For one reform, residents in the highest income quintile would face losses if the self-funder fee rises. © 2012 Cambridge University Press

Detecting Gene-Gene Interactions Using a Permutation-Based Random Forest Method

Identifying gene-gene interactions is essential to understand disease susceptibility and to detect genetic architectures underlying complex diseases. Here, we aimed at developing a permutation-based methodology relying on a machine learning method, random forest (RF), to detect gene-gene interactions. Our approach called permuted random forest (pRF) which identified the top interacting single nucleotide polymorphism (SNP) pairs by estimating how much the power of a random forest classification model is influenced by removing pairwise interactions