Particle filter-based parameter estimation in a model of the human circadian rhythm

Recent insights into the effects of light on human health call for a more human-centric approach in automatic lighting control systems. We contribute to the provisioning of lighting settings tailored to the needs of individuals by addressing the challenge of predicting the response of an individual’s circadian rhythm to light exposure. Existing models of the human circadian rhythm are not tailored to individual physiological characteristics such as intrinsic circadian period, light sensitivity and age. We propose to improve model accuracy by using Bayesian statistical inference to estimate the values of model parameters that reflect these physiological characteristics. We illustrate our generic method by applying to a combination of two popular models of the circadian rhythm. By processing individual light exposure- and actigraphy data recoded during a field trial with 20 human subjects with a Particle Filter, we estimate each subject’s intrinsic circadian period. When correlating these to the subjects’ Munich Chronotype Questionnaire Midsleep on Free Days time, a significant relationship was found: r > 0.6 and p < 0.01. This shows the proposed method has good potential for improving model accuracy

Design and application of nanoscale actuators using block-copolymers

Block copolymers are versatile designer macromolecules where a “bottom-up” approach can be used to create tailored materials with unique properties. These simple building blocks allow us to create actuators that convert energy from a variety of sources (such as chemical, electrical and heat) into mechanical energy. In this review we will discuss the advantages and potential pitfalls of using block copolymers to create actuators, putting emphasis on the ways in which these materials can be synthesised and processed. Particular attention will be given to the theoretical background of microphase separation and how the phase diagram can be used during the design process of actuators. Different types of actuation will be discussed throughout

Biased Monte Carlo optimization of protein sequences

We demonstrate the application of a biased Monte Carlo method for the optimization of protein sequences. The concept of configurational-biased Monte Carlo has been used, but applied to sequence/composition rather than coordinates. Sequences of two-dimensional lattice proteins were optimized with the new approach and results compared with conventional Monte Carlo and a self-consistent mean-field (SCMF) method. Biased Monte Carlo(MC) was far more efficient than conventional MC, especially on more complex systems and with faster cooling rates. Biased MC did not converge as quickly as SCMF, but often found better sequences

Energy Efficiency Renovation Financing Models for Homeowners and Net Present Value Analysis: Case Study from India

In India, the lack of financing mechanisms has been identified as a major impediment in achieving energy efficiency (EE) and requires focused research to identify barriers and propose innovative financial models. This paper presents details of selected Government of India initiatives that highlight interlinking strategies of energy efficiency renovations, their financing models, and institutional policies needed for their implementation. These initiatives show that residential buildings have tremendous scope for retrofitting as they successfully attract finances through Energy Service Companies (ESCOs) and Renewable ESCO (RESCO) routes. This research highlights understanding of financial and technical barriers in energy efficiency retrofitting for existing residential buildings. Additionally, it discusses financial models and technical interventions being employed in energy efficiency residential retrofitting projects and demonstrates a retrofitting cost model for an actual case study project for composite climate using various physical and technological interventions. The work includes developing retrofitting scenarios through Government initiatives of technical interventions, then performing energy saving calculations, and finally developing cost model explaining the actual savings and payback periods for the potential intervention’s investments. These steps led to the development of a potential cost model which can assist both homeowners and energy professionals in identifying and implementing energy retrofitting measures in the residential building sector

Crop conceptual model for predicting productivity of bread wheat in semi-arid Kenya

 P. K. Kimurto1, K. Gottschalk2, M. G. Kinyua3, J. B. O. Ogola4, B. K. Towett 1(1. Department of Crops, Horticulture & Soil Sciences, Egerton University, P.O. Box 536, Njoro, Kenya;2. Leibniz-Institut für Agrartechnik Potsdam-Bornim e.V. ATB, Max-Eyth-Allee 100, 14469 Potsdam, Germany;3. Department of Plant Breeding and Biotechnology, Moi University, P.O. Box 39000, Eldoret, Kenya;4. Department of Plant Production, University of Venda, a, Private bag X5050, South Africa) Abstract: Carrying out field trial-research in dryland areas is usually expensive and costly for most national breeding programmes; hence development of simple crop simulation models for predicting crop performance in actual semi-arid and arid lands (ASALS) would reduce the number of field evaluation trials.  This is especially critical in developing countries like Kenya where dry areas is approximately 83% of total land area and annual rainfall in these area is low, unreliable and highly erratic, causing frequent crop failures, food insecurity and famine.  This paper used data generated from the rain shelter by measurement of evapotranspiration together with weather variables in Katumani to predict wheat yields in that site.  Maximum yield of the wheat genotype considered for genotype Chozi under ideal conditions was 5 t/ha.  Total above-ground biomass was obtained and grain yield was to be predicted by the model.  Transpiration was estimated from the relationship between total dry matter production and normalised TE (7.8 Pa).  The results presented are based on the assumption that all agronomic conditions were optimal and drought stress was the major limiting factor.  Predicted grain yield obtained from the conceptual model compares very well with realised yields from actual field experiments with variances of 14% – 43% depending on watering regime.  This study showed that it is possible to develop simple conceptual model to predict productivity in wheat in semi-arid areas of Kenya to supplement complicated and more sophisticated models like CERES-maize and ECHAM models earlier used in Kenya.  The presence of uncontrolled factors in the simulation not accounted for in the estimation and could have contributed to decrease in observed yield need to be included in the model, hence modulation of the equations by introducing these factors may be necessary to reduce variances; thus need to be quantified.  To improve the accuracy of prediction and increase wheat production in these areas measures that conserve water and/or make more water available to the crop such as prevention or minimisation of run-off, and rain water harvesting for supplemental irrigation are necessary.Keywords: wheat, conceptual model, drought, evapotranspiration, yield response Citation: Kimurto P. K., K. Gottschalk, M. G. Kinyua, J. B. O. Ogola, and B. K. Towett.  Crop conceptual model for predicting productivity of bread wheat in semi-arid Kenya.  Agric Eng Int: CIGR Journal, 2010, 12(3): 25-37.&nbsp

Twistor theory on a finite graph

We show how the description of a shear-free ray congruence in Minkowski space as an evolving family of semi-conformal mappings can naturally be formulated on a finite graph. For this, we introduce the notion of holomorphic function on a graph. On a regular coloured graph of degree three, we recover the space-time picture. In the spirit of twistor theory, where a light ray is the more fundamental object from which space-time points should be derived, the line graph, whose points are the edges of the original graph, should be considered as the basic object. The Penrose twistor correspondence is discussed in this context

Engineering geological models: an introduction: IAEG commission 25

The generation and use of engineering geological models should be a fundamental activity for any geotechnical project. Such models are an essential tool for engineering quality control and provide a transparent way of identifying project-specific critical engineering geological issues and parameters. Models should also form the basis for designing the scope, the method and assessing the effectiveness of site investigations. However, whilst the idea of models in engineering geology has existed for several decades, there has been little published that systematically distinguishes the different model types and how and when they might be used. This paper presents the views of the International Association for Engineering Geology and the Environment Commission C25 on the ‘Use of Engineering Geological Models

Identification of potential targets and Screening for common signature in novel anticancer inhibitors in human

Cancer remains a basic burden to public health despite substantial efforts aimed at developing effective chemotherapeutics. The goal of the project is to screen for common signature in novel drug targets and identification of potential lead molecules by analysis and prediction of its ADMET properties with high specificity. In the present study we have screened all 11,000 entries for Human Cancer Proteins available in PDB and retrieved 12 hits classified according to space group, accessible/buried surface area, and free energy of dissociation and further considered for the analysis of cation-pi interactions study results showed that high exposed percentage for Lys and Arg due to their hydrophilic properties and having high accessible surface area. Phe was having low percentage of exposed compared to other residues due to its hydrophobic nature. Ligands were screened through HitsGen by Inventus software, which is a standalone software that performs ADMET screening for ligands through six assays namely CACO, efflux, BBB, FDP,VDSS and finally 8 ligands that are being satisfied through all the screening results which are further analysed by docking studies using NOVODOCKER. We have observed that Tyr,Thr,Asp residues have significantly involved in donor /acceptor interaction, Though there is no significant PPI is observed among all the targets. After screening 216 hits and performing protein -ligand interaction studies revealed that Leucovorin and Morphine are potential ligands among 216 hits which can be further analysed for In vivo studies

Chaotic Inflationary Universe on Brane

The chaotic inflationary model of the early universe, proposed by Linde is explored in the brane world considering matter described by a minimally coupled self interacting scalar field. We obtain cosmological solutions which admit evolution of a universe either from a singularity or without a singularity. It is found that a very weakly coupled self-interacting scalar field is necessary for a quartic type potential in the brane world model compared to that necessary in general relativity. In the brane world sufficient inflation may be obtained even with an initial scalar field having value less than the Planck scale. It is found that if the universe is kinetic energy dominated to begin with, it transits to an inflationary stage subsequently.Comment: 13 pages, no fig., accepted in Physical Review

On the evolution of cosmic-superstring networks

We model the behaviour of a network of interacting (p,q) strings from IIB string theory by considering a field theory containing multiple species of string, allowing us to study the effect of non-intercommuting events due to two different species crossing each other. This then has the potential for a string dominated Universe with the network becoming so tangled that it freezes. We give numerical evidence, explained by a one-scale model, that such freezing does not take place, with the network reaching a scaling limit where its density relative to the background increases with N, the number of string types.Comment: Extra references added showing constraints on cosmic superstrings, 7 pages, 7 figure