Heterogeneity

In humans, genome-wide association studies (GWAS) have been shown to be an effective and thorough approach for identifying polymorphisms associated with disease phenotypes. Here, we describe the first study to perform a genome-wide association study in canine atopic dermatitis (cAD) using the Illumina Canine SNP20 array, containing 22,362 single-nucleotide polymorphisms (SNPs). The aim of the study was to identify SNPs associated with cAD using affected and unaffected Golden Retrievers. Further validation studies were performed for potentially associated SNPs using Sequenom genotyping of larger numbers of cases and controls across eight breeds (Boxer, German Shepherd Dog, Labrador, Golden Retriever, Shiba Inu, Shih Tzu, Pit Bull, and West Highland White Terriers). Using meta-analysis, two SNPs were associated with cAD in all breeds tested. RS22114085 was identified as a susceptibility locus (p?=?0.00014, odds ratio?=?2) and RS23472497 as a protective locus (p?=?0.0015, odds ratio?=?0.6). Both of these SNPs were located in intergenic regions, and their effects have been demonstrated to be independent of each other, highlighting that further fine mapping and resequencing is required of these areas. Further, 12 SNPs were validated by Sequenom genotyping as associated with cAD, but these were not associated with all breeds. This study suggests that GWAS will be a useful approach for identifying genetic risk factors for cAD. Given the clinical heterogeneity within this condition and the likelihood that the relative genetic effect sizes are small, greater sample sizes and further studies will be required.

In an effort to understand the present-day thermal structure of the Jeanne d'Arc Basin, we derive matrix thermal conductivity values, using a geometric mean model, from thermal conductivity values of thirteen lithologic end-members (of which seven are measurements on materials from the Jeanne d'Arc Basin) and lithological data. Temperature corrections to thermal conductivity are made for both matrix and pore water. In-situ thermal conductivities were obtained after correcting for the effect of porosity, which we estimated from both lithological information and digital well logs. Calculated thermal conductivities of the formations range from 1.46 to 2.65 W m -1K -1. The heterogeneity of formation thermal conductivity is caused by at least two factors. The first is lithological variation due to facies change. The second is due to different degrees of compaction. Under-compacted intervals (overpressure zones) are characteristically of lower thermal conductivity. The surface heat flow density calculated with an inverse method in seventeen wells varies from 37.8 to 60.7 mW/m 2. This study indicates that surface heat flow density values estimated without porosity corrections may be 15% higher than those with porosity corrections. We also demonstrate the sensitivity of modelled timing of maturation to thermal conductivity estimations.

In heterogeneous habitats with limiled resources, spacing behaviour will affect individual variation in breeding success and density of populations, and is thus of general interest to ecologists. We investigated how red squirrels Sciurus vulgaris adapl their social organisation to tine-grained heterogeneity in habitat quality, studying spacing behaviour, habitat use and population dynamics in a forest in north Italy, characterised by a mosaic of high-quality (chestnut-pine) and poor-quality patches. We compared the data witfi those ...

We summarize some current trends in embedded systems design and point out some of their characteristics, such as the chasm between analytical and computational models, and the gap between safety-critical and best-effort engineering practices. We call for a coherent scientific foundation for embedded systems design, and we discuss a few key demands on such a foundation: the need for encompassing several manifestations of heterogeneity, and the need for constructivity in design. We believe that the development of a satisfactory Embedded Systems Design Science provides a timely challenge and opportunity for reinvigorating computer science.

This study is part of an ongoing doctoral study that seeks to explore the learning connections of higher education learners. Based on the first principle of Deleuze and Guattari‟s (1987) Rhizome Theory, connection, the study was motivated by what learners connect to and how they connect in the construction of their learning in an ever growing technological environment. Actor Network Theory and the Rhizome Theory formed the theoretical framework that underpinned the study. Two questions that drove this paper were: what the connectors in learners‟ learning network are and how these connectors emerge to support learning. The study was a qualitative one which involved six participants who were by then higher education learners of different levels. Participants were selected using snowball sampling technique. Data collection methods included a focus group interview, observations and artefacts. The study revealed that learners were connected to very complex networks which continually multiplied through three basic rhizonomies that all behave as actors and actants; learners, machine(s) and technology. It was again found that apart from the learner-learner and learner-machine(s) connections; there also existed machine(s)-to-machine(s) and learner-technology connections in the personal learning networks of learners. Learners get connected to learning networks based on need, properties and nature of course studied. The research at this preliminary stage recommended an in-depth study to find out about characteristics of self-directed learners and how they construct meaning in a rhizomatic environment as opposed to existing industrial batch processing system that does not take individual differences into account.